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chess | What do these game durations mean? | There are different game duration on chess.com. What do options 1|1, 2|1 etc. mean?
| VQAonline_00006496.png | For example 3|2 means each player starts with 3 minutes and gets 2 seconds added to the clock for making a move (this is called an "increment").
When there is no "|", you do not get any time for making a move, and each player gets the displayed time in minutes at the start of the game.
Another notation you might see uses a "+", for example 3+2.
| https://chess.stackexchange.com/questions/34534 |
chess | What is meant by "Licensed" in FIDE website? | I was browsing the candidates' profiles of the FIDE World cup on the official website and noticed something interesting.
On the profile page of GM Vladislav Kovalev, a Belarusian chess GM, has an interesting declaration, called "Licensed", which I didn't find on the profile of any other players.
Initially, I thought that this is because he is playing under FIDE and not Belarus. So I checked the profile of GM Alireza Firouzja and there was NO such declaration whatsoever. But, I have noticed another disparity in Alireza's profile. He is enlisted under the Federation of France but his national ranking is calculated under FIDE.
Can anyone please help me to understand about what's going on?
| VQAonline_00006505.png |
Can anyone please help me to understand about what's going on?
Yes, it is nice that we can look up our entries on the FIDE rating website but actually there is a business need for this information for arbiters and tournament organizers to avoid fines from FIDE.
Whenever a FIDE rated tournament is rated by FIDE (standard time control only because rapid and blitz, for the moment are free) FIDE charges the federation 1 euro per player for Swiss tournaments and lower rated (average rating < 2230) round robins. The full details are given in Appendix 2 of the FIDE 02. Financial Regulations / Financial Rules (effective from 1 Jan 2021) document.
Each of the players must normally be registered with one of the federations and those federations also pay FIDE an annual membership fee which is detailed in Appendix 1 of the above document. All national, over-the-board players are normally registered with a federation and so are regarded as licensed. In exceptional circumstances, e.g. a player seeks asylum, a player may for a time be without a national federation and be registered with FIDE as their federation until they settle on a new federation.
Additionally FIDE has its Online Arena where players can register directly with FIDE and play online. Online players who aren't already registered OTB with a federation get a FIDE online registration. This licenses them to play in FIDE's Online Arena but does not license them to play rated FIDE OTB tournaments.
Normally players pay a registration fee to their national federation which covers them for playing FIDE rated tournaments. If players could register directly with FIDE for free and still play OTB FIDE rated tournaments then this would deprive the federations of the money they need to operate.
Therefore if your federation is FIDE (for whatever reason) then you need to pay FIDE a registration fee (which ideally is more than you would pay a normal federation) before you can be licensed to play OTB.
These rules regarding licensing are defined in the FIDE document Regulations on Registration & Licensing of Players / Regulations for Registration & Licensing of Players (effective from July 1, 2015).
Here are some useful extracts:
2.5 Players with no Federation are automatically considered to be ‘FIDE flag players’ and their website profile cards indicate FID as their Federation.
2.6 Players registered as FID are provisionally licensed to play over the board rated tournaments after paying the ‘FIDE license fee’ of 60 euros. ‘FIDE flag players’ are encouraged to join a National Federation rather continuing to play as FID.
2.7 The provisional license under FIDE flag expires on 30 June of the following year.
2.8 Before 1 July, the license must be renewed with a payment of 60 euros to FIDE, without further notification from FIDE, failing which the license is annulled.
2.9 ‘FIDE flag players’ with a valid provisional license are referred to as ‘licensed’ on their FIDE website profile cards
If an arbiter or organizer submits a tournament for FIDE rating which includes one or more unlicensed FID players then the federation has to pay the license fees, basically a fine. Hence this information (licensed or not) is vital for arbiters and organizers.
Here is the FIDE profile for one of these unlicensed players, Abbagouni, Raja. You will see that in the top right hand corner it says:
Not Licensed Player.
Extra fees for tournament Organizers are applicable.
Please refer to FIDE Handbook or proceed to get license
| https://chess.stackexchange.com/questions/35591 |
chess | Why is Na5 not played in this line of the French Defense, Advance Variation? | I find Na5 a good resource for black in this line of the french, profiting from the fact that white's b-pawn is binned to the bishop. As far as I can understand this position with my limited chess, I find it a strong move, winning space on queenside with the plan of trying Bd7-Rc8-Nc4 on c-file.
[FEN "r1b1kbnr/pp3ppp/1qn1p3/2ppP3/3P4/2P2N2/PP3PPP/RNBQKB1R w KQkq - 3 6"]
6. a3 Nh6 7. b4 cxd4 8. cxd4 Nf5
9. Bb2 Na5
However, I don't find this move at the database of chesstempo I use to use for my correspondence games.
Stockfish neither considers it. It even don't play 10....Nbd2 (it plays Nc3) to defend on c4 (which I would expect), and doesn't wonder at all about Nc4 (it simply trades his bishop for the knight; apparently it should result an advantage on the center).
What's my misunderstanding here?
| VQAonline_00006437.png | The plan you outlined with ...Bd7, ...Rc8, ...Nc4 is a good strategical plan, but there are a few concrete reasons it doesn't work well:
In the opening you should be focusing on developing all your pieces and castling. Your plan with maneuvering the knight to c4 will move the same piece three times.
At depth 33, Stockfish gives 10.Nc3 Bd7 11.Rb1!, breaking the pin on the b2-bishop and attacking the a5-knight. Now you have to move the knight before your a8-rook manages to reach c8. If you go ahead with 11...Nc4 then 12.Bxc4 dxc4 is poor for you. Your new pawn on c4 is mainly a weakness at the moment, and White may blast open the centre with d5 to attack your uncasted king.
Also, White could always play 10.Qa4+. If you block with 10...Bd7 then 11.Qxa5 wins the knight. So you have to respond with retreating the knight: 10...Nc6.
| https://chess.stackexchange.com/questions/24692 |
chess | The move Bg4 in the Pirc defense | I am having trouble understanding a move studied in an opening book. The move is Bg4 in the Pirc defence in this position.
What is the point of aiming to exchange the bishop on f3? The point d4 does not seem to be the reason.
| VQAonline_00006444.png | Compare that position with other variations where White does not allow ...Bg4 to be played. Black often struggles with the development of the c8 bishop.
Also, the central dark squares are indeed a target, so ...Bg4 is clearly helping there (what else could he possibly do in a different square?) Pawn breaks with ...e5 or ...c5 are a possibility as well
| https://chess.stackexchange.com/questions/25230 |
chess | King or Queen-Which piece is which? | I recently bought a set of wooden chess pieces, which I liked for its simplicity.
I'm not sure, however, which one is supposed to be the king and which one is supposed to be the queen.
I would say that the one with the spike is the queen, and the one more flat is the king. Am I right, or is it the opposite?
| VQAonline_00006438.png | In general, a chess set has the king as the tallest piece, followed by queen, bishop, knight, rook and pawn in that order. Notice in the starting position how the piece height decreases smoothly from the centre to the edge. (Also, when buying a chess set, usually the height of the king is given as a guide to the size of the chessmen.)
Thus I would say the king is the taller of the two pieces, which from your picture looks to be the one with the spike on the left.
This ordering of height may not hold for particularly ornate decorative sets.
However, if you're not going to use the set to play against other people in tournaments (where usually Staunton pieces are mandated anyway), the correct answer would probably be: the king is whichever piece you think it is.
| https://chess.stackexchange.com/questions/24719 |
chinese | What does 早待不住了 mean in 要在往常，我一定早待不住了……? |
要在往常，我一定早待不住了，惦记着某某侦探的案件是不是有了突破，……
Google Translate: As usual, I must have been unable to stay any longer, wondering if there was a breakthrough in the case of Detective XX,...
标准教程HSK6上，87页
I don't understand what the part in bold above means. Maybe it's something along the lines of "As usual, I was definitely prematurely restless, ...". It's not clear at all to me.
Question: What does 早待不住了 mean in 要在往常，我一定早待不住了……?
| VQAonline_00006766.png |
要是 signifies a hypothetical construction. 往常 does not only mean ‘as usual’ (which only corresponds to 常, as in 通常, 正常, 常規); 往 here specifies the past, as in 往日, 往事, 往昔. Together they mean ‘normally in the past’.
早 is an adverb meaning ‘already’. Think of that as saying, something happened well in the past (early in the timeline).
他早(就)離開了。 He left already.
待 is a verb meaning ‘to stay’. 不住 is an add-on to it, literally meaning ‘not to a still’. Figuratively, 待不住 means you can’t contain yourself, or you’ve got itchy feet. Perhaps you're excited or anxious about something.
The whole sentence means ‘I’ in the past would’ve not been able to control myself in coming up with the many racing thoughts in my head (unsolved cases, scientific breakthroughs, lottery etc.). My mind is so irritable that these thoughts would have occurred very easily and very soon (hence the use of 早). But now my mind is completely at peace, so they are nowhere to be found.
| https://chinese.stackexchange.com/questions/43915 |
chinese | What does 乐群 (lèqún) mean? | Among the many banners for new students at Nankai Uni is this one:
It says:
爱国 敬业 创新 乐群
Àiguó jìngyè chuàngxīn lèqún
The first three I can translate:
爱国 (àiguó） = patriotism (literally "love country")
敬业 (jìngyè) = dedication to one's job
创新 (chuàngxīn） = innovation
But the fourth one doesn't appear on dict.cn. (And I think I've managed to identify the hanzi characters here.)
Question: What does 乐群 (lèqún) mean?
If we break it down:
乐 (lè) = happy
群 (qún) = group
So I guess it means something like "happy group", which sounds a bit strange.
| VQAonline_00006642.png | Baidu Baike gives the origin of this expression as from 《礼记·学记》, and explains 乐群 as:
乐群：乐于与好朋友相处
Willing to socialize with friends.
| https://chinese.stackexchange.com/questions/26476 |
chinese | Pronunciation Of 佛 in 四川话 | The 1986 edition of《四川方言词典》has the following entry:
乐山的大佛——老石人
Lo2 san1 ni1 da4 fu3——nao3 si2 ren2
乐山大佛距今已有一千多年历史, 所以是“老石人”。谐“老实人”。 ▷你以为他是～嗦? 他才阴倒不老实。
佛 is given the pronunciation of fu3
The 2014 edition of the same dictionary gives 佛 the pronunciation fu2
/note: this dictionary is riddled with errors(!)/
Logically I would have assumed the pinyin to have been written fo2 - which is pretty much how it is pronounced, as far as I can tell.
《四川方言词典》has fu3 and fu2
Are Either fu3 or fu2 correct pronunciations for 佛 in 四川话?
| VQAonline_00006596.png | I tried the 漢語方言大辭典, and there are many places with the fu pronunciation in the southwest mandarin area, for example 佛豆 (= 蠶豆, fava bean) is pronounced fu tou in 畢節; 佛瓜 (瓠瓜 gourd) is pronounced fu gua in 自貢, etc. Not really surprising; 弗 is fu in Mandarin.
| https://chinese.stackexchange.com/questions/14122 |
chinese | What does this MYSQL image say? (Database Locks) | I am reading a mysql article about different kind of locks and this image appeared:
Unfortunately, I cannot copy paste the words because it's in an image. I also don't know how to reproduce this with my keyboard.
If anyone could kindly translate this for me, would be very kind.
| VQAonline_00006773.png | Databases are not my main domain, but I double checked all terms. Here you go.
Blue central box
锁 = lock
Green box
Box
ZH
EN
main
加锁机制
lock engine
upper leaf
乐观锁
optimistic lock
lower leaf
悲观锁
pessimistic lock
Purple box
Box
ZH
EN
main
兼容性
compatibility
upper leaf
共享锁
shared lock
lower leaf
排他锁
exclusive lock
Orange box
Box
ZH
EN
main
锁粒度
lock granularity
upper leaf
表锁
table lock
middle leaf
页锁
page lock
lower leaf
行锁
row lock
Yellow box
Box
ZH
EN
main
锁模式
lock mode
1
记录锁
record lock
2
gap锁
gap lock
3
next-key锁
next-key lock
4
意向锁
intention lock
5
插入意向锁
insert intention lock
| https://chinese.stackexchange.com/questions/45466 |
chinese | What does 餅乾 mean in Taiwan? | I'm unfamiliar with the variety of Mandarin spoken in Taiwan, so I was surprised to see a chilli-snack 香脆椒 referred to as 餅乾:
http://mall.tw100years.com/goods.php?id=9
真不敢相信這真是美味的餅乾！看起來是紅紅的辣椒，吃起來是香、脆外加點淡淡的鹹，不但能幫您排去宿便，還能養顏美容！
The definition of 餅乾 that I'm familiar with is biscuit or cracker, a baked pastry food. This snack doesn't fit that definition; it is made of fried chilli peppers:
| VQAonline_00006558.png | I am Taiwanese, and I have even had this "餅乾" once.
Generally, we can refer to almost every snack that is made with flour and "cracks" in your mouth as 餅乾. So when you say you want some 餅乾, people will not only give you crackers, but also cookies, potato chips, wafer cookies, wafer rolls, mille feuille, etc. These things have their own specific names, of course!
Even these are 餅乾: Jagabee Fries, and Pocky.
I would also like to clarify that this sentence is not in Taiwanese. It is in Standard Chinese, but we have our own accent and wording. Just like the differences between American English and British English. We normally speak two languages in everyday life, i.e. Chinese and Taiwanese, a Min dialect.
| https://chinese.stackexchange.com/questions/5287 |
chinese | Is this a rare/variant character (combining 米 and 団), or not really a Chinese character? |
This character is on the label of a riceball sold at 7-11 in Taipei. I believe this kind of riceball is originally Japanese.
It seems to be some kind of variant of 糰 / 团 but is actually composed of 米 on the left plus 団 on the right. But I can't find it anywhere on the Internet or in Unicode so far.
Is it a known variant, or is it possibly normally considered a Japanese character? On Wiktionary, 団 is listed only as a Japanese shinjitai character. (Shinjitai is a simplified character made in Japan.)
Or maybe it's some kind of fake character made up by 7-11, like a trademark?
| VQAonline_00006616.png | 糰 is 米 + 團. 團 simplified is 团. 团 has a variant character 団.
Thus 米 + 団 = 糰.
団 itself is a variant chacter of 糰.
On the other hand it could just be a clever way of writing 米團 = 米团 = rice ball.
Edit: It is written 御飯團 in all instances I can find regarding the ad. It is a private/funny simplification that has no formal recognition.
| https://chinese.stackexchange.com/questions/20827 |
chinese | What is the meaning of 原湯化原食？ | In the show 人民的名義 the suspect doesn't want to accompany the protagonist on account of his soup getting cold. The protagonist replies "講究啊"（meticulous！）and then:
原湯化原食
None of my many Pleco dictionaries lists 原湯 or 原食，although 原湯 was my phonetic keyboard's first suggestion!
| VQAonline_00006646.png | 原汤化原食 is a kind of eating habit, especially exists in northern areas; means drinking the soup of the dumplings (or noodles etc) after eating them. e.g. for the case of dumplings, 原汤 refers to the water (or you can think it as soup) which used for boiling dumplings, 原食 means dumplings.
一般来讲，“原食”指的是淀粉类食物，比如饺子、面条、馄饨、汤圆等，“原汤”就是水煮这些食物后得到的汤，而“化”有“消化”的意思。所以“原汤化原食”的意思是，汤能够帮助淀粉类食物消化吸收。
(In general, 原食 refers to starchy foods, like dumplings, noodles, wontons, glue puddings etc, 原汤 refers to the water which used for boiling these foods. 化 means digestion, so 原汤化原食 means the soup could help digesting starchy foods.)
There're several various explanations about why people doing this, someone believe 原汤 could help digestion; someone believe 原汤 is nourishing. I prefer to that it's just a habit; people like drinking something after eating and with 原汤 you don't need to cook the soup separately. And I think this article gave a nice summary:
所以，真要较真的话，“专家”们提供的“原汤化原食”的“科学道理”实在是很牵强附会。当然，面汤本身并没有什么不好，与白开水相比，它其中还有一些淀粉甚至维生素。吃完面后喝点面汤，多少也算是节约粮食的表现。如果真的喜欢喝，“喜欢”就是最好的理由。如果非要堆砌一些科学术语来给它一个“科学解释”，可能就是弄巧成拙。
| https://chinese.stackexchange.com/questions/27088 |
christianity | What is meant by "men have been raised up from the fall to far greater heights?" | In Catholic theology it is said that "men have been raised up from the fall to far greater heights."1
What is meant by this and how are the "heights" of a different degree than our first parents' state in the Garden of Eden?
A fuller answer will also include the Orthodox meaning should they have the same theology.
1. E.g. Francisca Javiera del valle in "ABOUT THE HOLY SPIRIT".
[...] because the mercy of the divine Word decided to raise him up from
his fall to even greater heights.
| VQAonline_00006837.png | From the Catechism of the Catholic Church:
CCC 412 But why did God not prevent the first man from sinning? St. Leo the Great responds, "Christ's inexpressible grace gave us blessings better than those the demon's envy had taken away." and St. Thomas Aquinas wrote, "There is nothing to prevent human nature's being raised up to something greater, even after sin; God permits evil in order to draw forth some greater good. Thus St. Paul says, 'Where sin increased, grace abounded all the more'; and the Exsultet sings, 'O happy fault,. . . which gained for us so great a Redeemer!'".
In brief, in Eden we had no Saviour, the Grace had not been shown to the fullest, and our "greater good" was out of reach.
| https://christianity.stackexchange.com/questions/34480 |
christianity | What does Mary look like in the Fatima Apparitions? |
Beginning in the spring of 1917, the children reported apparitions of
an Angel, and starting in May 1917, apparitions of the Virgin Mary,
whom the children described as "the Lady more brilliant than the Sun".
(quoted in Wikipedia) *.
*Was this report accurate? How did Mary really look like in the Fatima Apparitions according to trusted Catholic sources?
(We are not alone in the Universe, Konrad Kulczyk, Sixth Books 2012)
| VQAonline_00006869.png | What does Mary look like in the Fatima Apparitions?
Your quotation from “We are not alone in the Universe” by Konrad Kulczyk, seems to be at odds with Catholic statements about Our Lady and her apparitions at Fátima in 1917.
Konrad Kulczyk seems to almost make the whole situation the imaginations of three little children. Nothing is further from the truth.
Yes, it may be possibly true that both Lucia and Blessed Jacinta never stated that the Lady never called herself the Mother of Jesus nor the Mother of God however she did describe herself as “the Lady of the Rosary” in her final apparition!
It was Mary's final appearance, on Oct. 13, 1917, that became the most famous. In his book "Looking for a Miracle," Joe Nickell states that "an estimated 70,000 people were in attendance at the site, anticipating the Virgin's final visit and with many fully expecting that she would work a great miracle. As before, the figure appeared, and again only to the children. Identifying herself as 'the Lady of the Rosary,' she urged repentance and the building of a chapel at the site. After predicting an end to [World War I] and giving the children certain undisclosed visions, the lady lifted her hands to the sky. Thereupon Lucia exclaimed, 'The sun!' As everyone gazed upward, and saw that a silvery disc had emerged from behind clouds, they experienced what is known [as] a 'sun miracle'." - The Lady of Fátima & the Miracle of the Sun
Wikipedia’s quotation is very close to how Lucia described Our Lady of the Rosary, who is no other than Mary the Mother of Jesus! Nothing more is known.
On May 13, 1917, ten-year old Lucia Santos and her cousins Jacinta and Francisco Marto were herding sheep at a location known as the Cova da Iria near their home village of Fatima, Portugal. Lucia described seeing a woman “Brighter than the sun, shedding rays of light clearer and stronger than a crystal ball willed with the most sparkling water and pierced by the burning rays of the sun”.
As for Kulczyk, never have I come across any statement comparing Our Lady to the imagery that Mary must have seemed like a 3’8” of 1.1 m tall to the imagination of some 12 or 15 year old child. What nonsense. I have read many, many books on Fátima and have never read about any such conclusions by a Catholic author on this subject. Kulczyk is definitely wet behind the ears.
Sorry Kulczyk: Mary wore a blue dress all the way down to feet and not simply a skirt just to her knees like you mention.
The first Marian apparition occurred on 13 May 1917 as the children were tending to their sheep. They had had their lunch, and, as was their habit, had started to pray the rosary when they heard “lightning in a clear sky.” Fearing a storm was approaching, they decided to head home. As they prepared to leave, a strange light in the sky moved toward them. The children reported that, although astonished, they felt no fear. They claimed a beautiful lady appeared before them, “above the holm oak tree, wearing a pure white mantle, which was edged with gold, which went to her feet. In her hands the beads of a rosary shone like stars, with its crucifix the most radiant gem of all.” During this first visit the apparition told the children not to be afraid, that she came from Heaven. She asked them to pray the rosary and to return to the same spot on the thirteenth of every month. Then the apparition returned the same way it had come. - The Marian Apparitions in Fátima as Political Reality: Religion and Politics in Twentieth-Century Portugal
| https://christianity.stackexchange.com/questions/77865 |
christianity | Wall numbers in German church / during German burial ceremony | I have just came about a 10 years old photo of my aunt's burial ceremony that took place in June 2009 in one of the German churches (in a small city close to Oldenburg).
Unfortunately, relation both with my aunt and her living family was/is very weak, so I can't even say, if she was Christian or Protestant and thus, in which church following photo was taken?
Does anyone know what are these numbers printed on the wall in the right part of the photograph?
My first and only guess was that these are song numbers that will be sing during the ceremony. But then, what are those additional numbers (or actually some kind of value ranges)? And why to print song numbers permanently on the wall, if they keep to changed (depending on ceremony, day of year etc.) and thus should rather be displayed using some non-permanent way. Like a display etc.
| VQAonline_00006868.png | The numbers are on little (wooden) panels that can be pushed in a (wooden) rack. In your case both panels and rack have the same colour a the wall, so they are a bit difficult to see.
The numbers give the songs to sing during the service. The red numbers give the verses to sing.
On the denomination: First I thought it is a Catholic Church (esp. because the seats in the sanctuary), but the numbers given lead to songs in the Catholic song book "Gotteslob" (then used 1975 edition) not fitting on a burial. The songs of the protestant "Evangelisches Gesangbuch" fit better. So probably it was a protestant (near Oldenburg: lutheran) service, but I may be mistaken.
| https://christianity.stackexchange.com/questions/71102 |
christianity | Is there a customary way to go around rosary beads? | The picture below depicts one way to go around the rosary beads when praying the Holy Rosary.
If a child were to ask, as they typical do, as to why Catholics when praying the Holy Rosary customarily go around the rosary beads one way rather than the other - if that's what they do, how would one answer? Is there a customary way to go around rosary beads? If yes, what is the reason for that order?
A question in the "same series" as: Is there a particular order in lighting candles on an advent wreath?
| VQAonline_00006848.png | Either direction is acceptable
This might be semi-authoritative since it comes straight from the only approved Marian apparition site in the United States. Up near Green Bay, Wisconsin there is an outdoor rosary walk with the mysteries visible for people who traverse in a right-hand or left-hand direction.
For instance, when you walk around clockwise, you see 1st glorious mystery, 1st luminous. Etc... On a big banner, but if you look at the backside of the banner, its got 5th glorious, 5th luminous, etc... So no matter whether you walk around clockwise or counter-clockwise, you will see the mysteries in their proper order. Which I remarked to my wife, "that's mighty clever, those Catholics are always thinking..."
| https://christianity.stackexchange.com/questions/46337 |
christianity | Would Mormons accept communion, administered by a representative of another Christian denomination, as valid? | There are considerable differences in some beliefs between Catholic and Protestant churches on one hand, and the Mormon church on another hand.
One of these is the belief in Trinity due to which, according to the answers to this question and this question, Lutheran/Protestant churches do not view Mormons as Christian. Another difference is the symbols used with the communion, being that Mormons use water instead of wine (as is explained in the answers to this question).
Now considering some more exceptional situation, such as when serving in U.S. military during a war, as in the book cover shown below, would Mormons accept communion from military chaplains that may not be Mormons?
Or would a Mormon in this case not participate in the communion, or have the communion on their own (or possibly request a Mormon chaplain)?
| VQAonline_00006862.png | A better answer would come from an actual LDS war veteran, but I would imagine that a Mormon in the military may participate in an available ceremony as a symbol of friendship, unity, and support with the rest his regiment. Although they may participate, Latter-day Saints maintain that ordinances are only authorized when exercised by the Priesthood of God, which is had His Church only (the LDS Church). That's not to say the ceremony by the non-LDS chaplain is not beneficial to the Latter-day Saint—it still provides him a blessed opportunity to worship with other Christians who share the same fundamental beliefs—it just is not binding in heaven. In fact, I think any decent member of the LDS Church would encourage, not disparage, participation in available Christian worship services.
You can find out more about the LDS Church and military relations on its website: https://www.lds.org/callings/military-relations/organization-leader-responsibilites?lang=eng and https://www.lds.org/callings/military-relations/military-chaplains?lang=eng. There's nothing particularly quotable but it should give good background. I think the point is that this is up to the individual member's conscience. Other questions and answers on this site go into detail about the Priesthood authority necessary for ordinances to be valid in heaven.
As an aside (that may or may not be relevant), I have personally met and informally interviewed a Latter-day Saint astronaut who commanded a couple Shuttle missions. I asked about how he worships in space. Even he, a Priesthood holder, needed to obtain authorization from his local Priesthood leader (bishop or stake president) before the mission to be able to administer the Sacrament if the opportunity arose. Of course, this was done privately in the extremely limited personal time allotted. But the point is, the administration of ordinances that are considered officially valid before the Lord is well organized, even... in space.
| https://christianity.stackexchange.com/questions/60888 |
christianity | Crucifixion -- torture stake or cross? | The Jehovah's Witnesses state that Jesus was not nailed on a cross, but on a torture stake. The New World Translation of the Bible is phrased accordingly. For example:
Matthew 10:38 (NWT)
And whoever does not accept his torture stake and follow after me is not worthy of me.
(All the other translations (that I know of) translate cross instead.)
What is significant about the difference between a torture stake and a cross, and on which one was Jesus crucified?
An illustration of what might be a torture stake:
Crux Simplex by Justus Lipsius (1547-1606). Wikimedia Commons.
| VQAonline_00006816.png | There is comparatively little evidence in the NT for the shape of the object. There is not much etymological help from the Greek words σταυρός or ξύλον, which do not clearly indicate either shape.
Some of the textual hints we do have are:
But [Thomas] said to them, “Unless I see the nail marks in his hands and put my finger where the nails were, and put my hand into his side, I will not believe.” (John 20:25, NIV)
This suggests that there was more than one nail placed through the hands, which is more likely on a cross than on a stake - though I could imagine a nail through each hand, with the hands side by side. But the JWs assert that the plural is referring to two nails, one through both hands and the other through both feet. The Greek reads "ἐν ταῖς χερσὶν αὐτοῦ τὸν τύπον τῶν ἥλων", which is "in his hands the imprint of the nails", clearly linking multiple nails to the hands specifically.
Above his head they placed the written charge against him: THIS IS JESUS, THE KING OF THE JEWS. (Matthew 27:37, NIV)
If Jesus were crucified as in the picture, the sign would be obscured by his arms. If it were also placed above his hands, Matthew could have written "Above his hands..." - but he didn't.
Carrying his own cross, he went out to the place of the Skull, which in Aramaic is called Golgotha. (John 19:17, NIV)
Several different crucifixion methods were used by the Romans, including the traditional cross and the simple vertical stake. But the reference to carrying suggests that Jesus carried the crossbeam or patibulum of his cross - contemporary sources indicated that condemned people could be made to carry their own patibulum, but not the entire cross or stake, and of course a stake has no crossbeam at all. (Now-familiar depictions of Jesus carrying the whole cross come along later.)
It is common ground between Jehovah's Witnesses and the rest of us that for most of Christian history, Christ's crucifixion has almost always been regarded as being on a cross. The problem that the JWs have with it is that they think that the cross is a pagan symbol which was mistakenly (or maliciously) adopted early on in Christian history, as Christian belief and practice departed from its original form. As a restorationist group, they believe that in rejecting the cross shape they are returning to Christianity as it was meant to be. Insistence on the 'torture stake' is not particularly important in itself, but it is a prominent reminder of their distinctiveness, and of the error into which they think others have fallen.
| https://christianity.stackexchange.com/questions/2109 |
christianity | Why was Dan removed from the list of 12 Israel tribes in Rev 7? | Here is the list of 12 tribes of Israel from Genesis, Numbers and Revelation.
I sorted them according to the list in Genesis 29-30.
In Numbers, Levi is replaced by Ephraim and Manasseh who replaced Joseph also.
But in Revelation 7 Dan is removed and replaced by Manasseh.
Why are these list different? Why is Dan removed from the list?
| VQAonline_00006830.png | Dan fell into idolatry in Judges 17 and 18, and was thus removed:
Judges 18:30-31:
And the people of Dan set up the carved image for themselves, and
Jonathan the son of Gershom, son of Moses, and his sons were priests
to the tribe of the Danites until the day of the captivity of the
land. So they set up Micah's carved image that he made, as long as the
house of God was at Shiloh.
Also, Ephraim is missing as well. Hosea 4:17 explains why:
Ephraim is joined to idols; leave him alone.
See this link for more details.
| https://christianity.stackexchange.com/questions/14725 |
coffee | What do these large bubbles in my French press indicate? | I've seen these bubbles when pressing coffee that I've home roasted in two different presses with two different water sources. I've seen it with coffee from multiple roasts now. The beans are the same in all cases (Rwandan single origin). I am grinding with a burr grinder. Do these large bubbles in the bloom indicate anything about the bean or the roast?
| VQAonline_00006900.png | The bubbles are the result of "degassing" — carbon dioxide escaping from the coffee. Degassing will be especially dramatic in the first 24 hours after roasting, during which 40% of the CO2 leaves the bean. See this blog post: Understanding Degassing.
| https://coffee.stackexchange.com/questions/2952 |
coffee | What is the purpose of the crimp on a moka funnel? | Spurred by this recent moka question...
The funnel on my moka pot has a "crimp" -- a little ring-shaped indentation -- around the middle, similar to this one from Bialetti:
What is the purpose of this crimp?
It is indented toward the middle of the funnel (i.e., not protruding out of the funnel). It's far too low to indicate recommended "fill line" for quantity of grounds (for my taste anyway!) There's no other attachment that fits into it, nor does it engage with any other part on the pot (e.g., the top lip of the funnel sits on the moka pot base). It's one piece of sheet metal; e.g., this isn't a point where two pieces attach. Some moka pots have funnels that have this crimp, and others are solid/flat around the side.
| VQAonline_00006889.png | The crimp is there to support the reducer! The reducer slots into the funnel, and sits on the ridge. You then put coffee on top of it, allowing you to use less coffee in larger pots.
| https://coffee.stackexchange.com/questions/2025 |
coffee | What is the standardized naming of this type of coffee? | What is the "standard" name for this type of coffee in the various countries (I mean made from these type of machines with the paper filter)?
I have noticed when travelling that in some coffee spots in various countries in Europe, this type of coffee is not available. Unless it has a different naming than I am aware.
Is this called American coffee? Because I know that Americano is a type of espresso so it is not the same
| VQAonline_00006894.png | The drip-type coffee is available in many countries in Europe. A list of names:
Filterkaffee in Germany / Austria / Switzerland
filterkaffe in Denmark and Sweden
filterkoffie in the Netherlands
kawa filtrowana in Poland
café filtre in France / Switzerland / Belgium
café filtro in Spain
caffè preperato con il filtro in Italy / Switzerland
Can you see a pattern here: Always a combination of coffee and filter/filtered. The terms are so closely related that if you order "filtered coffee" an attentive waiter should be able to help you even if you don't know the precise term at your destination.
Note that if you order "coffee" without specifying the preparation, you will be served the local "default". This will actually be filtered coffee in many countries of Northern and Central Europe, in Italy, as counter-example, you will get what you'd call "espresso", likewise in Spain or Portugal: small, strong.
Asking for caffè americano will perhaps get you an espresso diluted with hot water in some places in Italy (sources vary whether it's a remenant from WW II or started with international tourism), sometimes caffè all'americana ("coffee American-style") will get you drip coffee. Likewise in touristy areas of Spain, café americano might get you a diluted coffee.
Further north you won't be understood. They will probably direct you to the nearest Starbucks.
Source:
Living and travelling in Europe for decades plus some research for the precise terms.
| https://coffee.stackexchange.com/questions/2275 |
coffee | Where can I get Koiwai coffee milk delivered to Europe? | Since I went to Japan on holidays I've been craving the coffee milk that I've had over there, but I haven't been able to get it at home.
No local asian stores stock it and I haven't been able to find any online stores (although admittedly I have been looking at only English-speaking sites) that have any available - or deliver to Europe.
I'm not sure what it is about it, but i've been thinking about it ever since. Is there somewhere online where I can order some?
| VQAonline_00006892.png | You can buy them from Rakuten. They ship internationally, with the exception of some countries, due to them not sufficing to the standards.
I don't believe there to be such a limit in Europe though, so you should be fine.
It costs ¥ 3,369 which comes down to roughly $27. And no account is required to order.
| https://coffee.stackexchange.com/questions/2084 |
coffee | Are these white bits mold? | I bought some coffee beans today. When I poured them into a jar, I found some white bits. Are they mold? Thanks
| VQAonline_00006925.png | Based on the picture I believe that these white spots are something form when he beans have been harvested or they have been sugar and sprinkled when the manufacture was selling this product.
| https://coffee.stackexchange.com/questions/5898 |
coffee | What is a FlavorLock™ bag? | What is a FlavorLock™ bag? Why it is important for wrapping coffee product or even pet food? Does it have any effect to the product inside if we use an ordinary bag?
| VQAonline_00006902.png | This question is actually answered on the website of the coffee producer.
To summarize, the roasting process of coffee produces carbon dioxide inside the beans, which takes a while to find its way out. Sealing the coffee in tight containers would be problematic, as the carbon dioxide would stay in the beans in this way (making the coffee sour) or may let the bag burst over time.
However, not sealing coffee bags is not a solution either, as exposure to air lets the coffee get stale after a while. As supermarket coffee is unfortunately often stored for long period of time before sold, this would be problematic.
So the solution is to either (1) use a one-way valve that allows the carbon dioxide to escape from the bag without the air coming into the bag, or (2) to let the beans degas before sealing them airtight in bags. Solution (1) is probably best for fresh coffee, so it is used here. I don't know what problem is solved with such valves in pet food containers.
| https://coffee.stackexchange.com/questions/3081 |
coffee | What type of coffee maker is this? | I got a stove top coffee maker, from my grandfather (not antique, he bought it recently). I am not sure what type it is. I claims to be a percolator, but functions more like a moka pot. They have given the nozzle to pour, in the top chamber. It heats water in bottom chamber, and the water passes through coffee powder, placed in between, and a brown liquid falls in the top, which is what I drink.
This is an Amazon.in link to that piece:
https://www.amazon.in/Pigeon-Xpresso-Stainless-Coffee-Perculator/dp/B072F17LRP/
| VQAonline_00006921.png | This is a typical moka pot.
The confusion may stem from the fact that the principle of a moka pot is somewhat similar to a percolator, just without a back flow (sort of a “one way percolator”), and in some descriptions, including the German Wikipedia article on moka pots, the expression “percolator” is used.
| https://coffee.stackexchange.com/questions/5484 |
cogsci | What is the difference between apparent motion and apparent movement? | A definition for apparent movement is:
The perception of movement produced by stimuli that are stationary but are presented first at one position and then, at an appropriate time interval, presented at a different position.
Example:
And apparent motion is defined as:
Motion can be detected even if there is no real motion
Example:
Flip Books
Now to my actual question: I know that those two forms of perception are very close; so what is the actual difference between the two? Is there a pure definition of the difference?
I feel that both apparent movement and apparent motion are according to Gleitman et al. (2010) pretty much the same, and could be applied to both sorts of examples. So if presented with a stimulus/illusion, how would one approach them to discern which is which?
| VQAonline_00006989.png | There is no difference between the two; illusionary movement and motion are interchangeable terms. For example, a definition of apparent motion is (Oxford Index):
A sensation of movement in the absence of actual movement, [for example] visual illusions [...]
And a definition for apparent movement (Psychology Dictionary) is:
[A]n illusion of motion or change of size that is cued by visual tricks.
In other words, apparent movement and apparent motion are the same thing. The two visual illusions you provide, though, are caused by two different neurophysiological phenomena altogether.
The flip book relies on persistent vision where multiple images are blurred into a coherent perception over time.
The rotating spokes illusion is thought to be caused by asymmetric luminance steps that trigger the motion detectors in the brain.
| https://cogsci.stackexchange.com/questions/16089 |
cogsci | Brain Right hemisphere is random and left hemisphere is linear? really? | For long I've seen uncountable number of blogs, websites, tutorials, booklets about career-guide, self-improvement, meditation, parenting etc. claiming;
"Right hemisphere loves to work random, creative way; in contrast left-hemisphere loves to follow instructions and discipline."
"Right hemisphere takes part in lateral-thinking; in contrast left-hemisphere takes part in vertical thinking."
"Right hemisphere deals with pictures, visions, senses, feelings etc; in contrast, Left hemisphere deals with formula, equation, numbers, names, letters, calculations etc."
"Right hemisphere works in nonlinear, meshy manner; in contrast, Left hemisphere works in linear, rigid, sequential way.
"Right hemisphere see the whole, big-picture. Left hemisphere see one part only".
etc.
Some example here , here, here , here, here, here et cetera.
Thus I developed a concept about behavior of 2 hemisphere.
Now While I was going through following research article (of 2000):
Cerebral specialization and interhemispheric communication by M. Gazzaniga (pdf) ,
I stuck on a diagram telling the exact opposite.
(URL: https://d1gqps90bl2jsp.cloudfront.net/content/brain/123/7/1293/F16.medium.gif)
(I've slightly edited the screenshot to enlarge the text and utilize the whitespace).
The only thing of the paper maches with popular view, is; the right hemisphere is taking important part in understanding pictures, geometric shapes, extrapolating to fill a gap in an image, etc.
But according to this diagram; actually Left hemisphere is site for viewing the 'big-picture' of a subject ('living things'), finding 'similarity' (sings, eats, has a etc). Also From personal experience, the way of thinking shown as relational-map at left hemisphere, is the cause of 'randomness' in me, so that I keep many books and files scattered while working; or was broken line (que) in school to collect a grass or stone. The thing shown at left side forces me to collect various objects and arrange them... not the rightward one. Also I zone-out too-much and day-dream because of the left-one... not the right-one.
In contrast, clearly the right-hemisphere in this diagram, is processing information in much rigid, linear or sequential, disciplined way; and looking a small-part... not the big-picture.
So, please could anyone explain me, why should I still have to consider left hemisphere as a rigid linear servant and right-hemisphere as rulebreaker daydreaming artist?
(P.S. most of these popular-series's tell that Right hemisphere is intuitive and Left hemisphere is logical. But I can't believe this because I can't separate logic and intuition. Logic is the bridge between intuition and reality.)
| VQAonline_00006990.png | You shouldn't. It is one of those stubbornly persistent myths. It is almost entirely false. It is true that in some tasks one half of the brain is more prominent (although even in supposed classic cases like speech both halves are actually involved, just one half more than the other).
But the idea that one half of the brain is logical and the other intuitive or emotional is simply false. At most, one half the brain is slightly more prominent in processing some tasks that may be perceived by us as more logical or more intuitive, but that is really as far as it goes.
| https://cogsci.stackexchange.com/questions/16096 |
cogsci | What challenges the ideasthesia balance theory has to answer? | Ideasthesia "can be defined as a phenomenon in which activation of concepts produces phenomenal experience". The examples vary from the Kiki/Bouba phenomenon applied to (possibly) everyone to actually seeing colors in graphemes like in synesthetic people. According to the theory, "there is a strong similarity between semantics and sensations".
(source: ieet.org)
Figure: Sensation vs. meaning balance shown for hypothetical pieces of entertainment (red), art (yellow) and science (white), as they are broken down into their components. Only an art piece is consistently located in the gray area.
Given that this theory is pretty young (first creation in Wikipedia was in 2012 by presumably one avid contributor on the field, based on their username), I wonder if there are any review or critic on the theory. What challenges does it need to answer? Which theory is it incongruent with?
Source:
• Wikipedia: Ideathesia
• TED-Ed: Ideasthesia: How do ideas feel? - Danko Nikolić
• IEEE: Danko Nikolić, Ideasthesia and Art
| VQAonline_00006993.png | Short answer
Ideaesthesia does not comprise a theory or even a hypothesis. It is merely a term meaning 'sensing concepts' or 'perceiving meaning'.
Background
As Steven Jeuris also comments, ideaesthesia is not a theory, it is simply a term. It is a combination of two Greek words, namely 'concept' or 'idea', and the other is 'sensation', or 'aisthesis'. In translation, ideaesthesia means sensing concepts or perceiving meaning (source: Danko Nikolić).
It it used to denote phenomena as the Kiki/Bouba effect (Milan et al., 2013; Martinez & Milan, 2015) and synesthesia (Jürgens & Nikolić, 2012) as you write. These phenomena are associated with assigning shapes to names, and colors to graphemes (and the likes), respectively. As far as I can see, ideaesthesia does not explain anything, it is not an observation, it is not a hypothesis, let alone a theory. It is a term used to group phenomena where people associate seemingly unrelated concepts.
Further, for what it's worth, a cursory Google Scholar search on 'ideaesthesia' yields few hits (82), and those hits that pop up, in part referenced here, point sometimes to questionable journals or to irrelevant papers. I would hence use the term cautiously as it doesn't seem to be widely used.
References
- Jürgens & Nikolić, Translat Neurosci (2012); 3(1): 22-7
- Martinez & Milan, V Int Conf Synesthesia: Science and Art. Alcalà la Real de Jaén. España. 16–19th May 2015
- Milan et al., J Consciousness Studies, 20(1-2
| https://cogsci.stackexchange.com/questions/17933 |
cogsci | How many times on average do people wake up per night? | It would be best if the answer could be broken down by age and sex, and even by other variables (alcohol-drinker vs teetotaller, etc).
If there's a difference between self-report data and data from studies that observe people sleeping, I'm interested in that too.
This image,
which I took from here, implies that waking up several times is normal, but the article doesn't provide any information on averages.
It may be that the median is more useful than the mean in this context.
| VQAonline_00006986.png | Based on this paragraph from the Wikipedia article on hypnograms
On a hypnogram, a sleep cycle is usually around 90 minutes and there are four to six cycles of REM/NREM stages that occur during a major period of sleep.
Most SWS occurs in the first one or two cycles; this is the deepest period of sleep. The second half of the sleeping period contains most REM sleep and little or no SWS and may contain brief periods of wakefulness which can be recorded but are not usually perceived.
The stage that occurs before waking is normally REM sleep.
And this image (also from wiki):
Sample hypnogram showing one sleep cycle (the first of the night) from NREM through REM
A normal and healthy person usually wakes for a brief time after his/her REM stage was finished in each sleep cycle. So, if we consider A 7–8-hour sleep probably includes four cycles, and each cycle include at least one REM, then each person at least wake four times.
| https://cogsci.stackexchange.com/questions/15926 |
cogsci | Why does "bulk" yellow ink look red? | A transparent blue inkjet cartridge looks deep blue, a red one looks deep red, but a yellow one looks red. Tea also looks yellowish when it's shallow and reddish otherwise. Red is another colour, a different wavelength, so why does deep yellow look red?
| VQAonline_00007009.png | Not all liquid or things that are yellow become red when they exist in large quantity. For example, beer, vegetable oil, and normal urine never look red even in large quantity, like in a vat. It really depends on the optical properties of the liquid and the suspended particles in it.
The optical properties of something depend on both its intrinsic factors such as its reflectance, transmittance, and absorptance of the light and the extrinsic factors such as its thickness, the surface that it’s on, the angle of light incidence, and the polarization of the incident light. (This is not to mention psychological factors like the mood when you look at that thing or the surroundings colors or compositions of that thing, which can make that thing look different.)
That’s why a thin film of water is colorless but a large body of water like the lake looks blue. And that’s why there is a phenomenon called iridescence – the phenomenon that certain surfaces appear to change color as the angle of view or the angle of illumination changes – like changing rainbow colors on a soap bubble or on a colorless CD surface.
In your case, I think the color reflection and transmission properties of the ink are different. The ink probably reflects mainly the yellow color, so it looks yellow when reflection of colors is the major event – as when the ink is painted on a surface. But the ink probably transmits more of the red color than the yellow color, so it looks red when transmission of colors is the major event – as when you look through it.
N.B. I think you’ll probably get better answers than mine by posting the question on the Physics forum.
References.
II.8. Reflection, Transmission, and Absorption Gigahertz-Optik.
Elements that Affect the Appearance of Color Konica Minolta.
Iridescence Wikipedia.
| https://cogsci.stackexchange.com/questions/24942 |
cogsci | Effective sampling rate in human visual system | The [stroboscopic effect][1] is often explained as one of the problems of sampling. If sample rate is too low, you might have the impression of the signal frequency being low or even reverse. There are many animations on the internet describing the process but I find static sinus function graph more comprehensible:
You definitely know this effect from car wheels or plane propeller in movies. That's because the movie captures certain amount of frames. If the event is significantly shorter than capture rate, the output doesn't make any sense anymore.
My question is, how can I observe the stroboscopic effect in full light with my very own eyes? I thought there's no fixed frame-rate for human vision. I thought it's an analogous process (continuous stream), rather than digital (timed sampling).
Q: How can be human vision in non-flashing (such as sun) light be subject to stroboscopic effect? Where does the damage happen?
| VQAonline_00006966.png | Yes, you can experience the stroboscopic effect under continuous illumination. This wikipedia article does a nice job of summarizing relevant findings.
As mentioned in the article, there are two competing theories for how the stroboscopic effect happens under continuous illumination in the human visual system. The first theory is that human visual processing is like a movie camera and it operates on roughly discrete frames. The second theory is that neural adaptation is responsible: the brain adapts to the very regular patterns of motion, which can cause visual after-effects where the opposite pattern is perceived. Overlaying the actual motion with the visual after-effect will 'cancel out' the perceived motion.
Kline and Eaglemen (2008) present evidence against the discrete sampling hypothesis and supporting the adaptation hypothesis. Macdonald et al. (2014) present evidence for the discrete sampling account.
| https://cogsci.stackexchange.com/questions/8716 |
cogsci | How do we know what colors animals perceive? | Humans have three kinds of photoreceptors corresponding to different wavelength-spectra:
If say photons with wavelengths of around 530 nanometers hit the human retina, this would lead to the perception of the color conventionally called "green". The color "green", however, is subjective in the sense that it is bound to a certain cortical physiology.
So my question is: Given that we don't have access to how animals perceive color, as we can't infer such qualitative properties purely from physical stimulus properties, how can we conclude that some animals are, say, perceiving ultra-violet colors given certain items or wavelengths? What if they would perceive entirely different colors than known to us?
| VQAonline_00007006.png | There are some levels of confusion in this in question, but basically we can test
what wavelengths animals perceive (simple behavioral tests, e.g. training & testing them to distinguish a certain wavelength)
inspect their cones to determine what wavelengths they could perceive. The latter doesn't necessarily imply that if an animal has say 4 different cones, it has tetrachromatic vision, because there's some degeneracy in some species, which unlike in humans (which have 3 types of cones and trichromatic vision) don't really use all their cones.
To give you a nearly random example of such a paper (this species doesn't have degeneracy), a (freely available) paper on chicks' vision:
The colour vision of domestic chicks (Gallus gallus) was
investigated by training them to small food containers
decorated with tilings of grey and coloured rectangles.
Chicks learn to recognise the colour quickly and
accurately. Chicks have four types of single-cone
photoreceptor sensitive to ultraviolet, short-, medium- or
long-wavelength light. To establish how these receptors
are used for colour vision, stimuli were designed to be
distinguished only by specific combinations of receptors.
We infer (1) that all four single cones are used, and (2) that
their outputs are encoded by at least three opponency
mechanisms: one comparing the outputs of ultraviolet- and
short-wavelength-sensitive receptors, one comparing the
outputs of medium- and long-wavelength receptors and a
third comparing of the outputs of short- and long- and/or
medium-wavelength receptors. Thus, the chicks have
tetrachromatic colour vision. These experiments do not
exclude a role for the fifth cone type, double cones, but
other evidence suggests that these cones serve luminance-based tasks, such as motion detection, and not colour
recognition.
If you want to get philosophical qualia discussions, akin to whether all humans describe the same color with same language, that's a whole different kettle of fish. I don't know of any studies like that in the absence of language. I'm guessing you might be familiar with the dress.
| https://cogsci.stackexchange.com/questions/21883 |
cooking | Why do I have lumps in my caramel? (NOT crystallized sugar.) | There are a lot of caramel questions. Hopefully I'm not repeating anyone...
I've made caramel sauce several times with the recipe from Sally's Baking Addiction. (But using a different beginning procedure: Dissolve sugar in ~1/2 cup of water, not stirring. Put the lid on for a few minutes to clean the sides. After that it's the same.) For some reason, though, whenever I make it I end up with lots of tiny lumps suspended in my caramel. As I mention in the title, these lumps are not little sugar crystals. I've had my caramel crystallize before, and this is very different. They're soft, for one thing, and so I'm not sure what's happening.
At first I thought the little lumps were just air bubbles. That's what they look like. But they actually have some body to them. It's almost like I have tiny bits of cooked egg or something (which is obviously impossible.) They have a gelatinous quality. So my guess is that the cream is doing something weird? Flavor is good, thickness is good, everything is good except these stupid little lumps.
Does anyone know what's happening, and how I can make it stop...? I'm about to take an immersion blender to the mess and let God sort it out.
EDIT/UPDATE: So... I now have a theory that I tend to get my caramel so dark (more of a crimson/burnt sienna than an amber. Probably around 380F) that some of the dairy solids in the butter (maybe even the cream?) cook/coagulate as soon as I add it, leading to those gelatinous lumps. I haven't had the time (or a good reason) to try cooling my syrup with some water before I add the butter yet, but as I said in the original question, this definitely isn't sugar crystallization, and it's been a persistent problem. When my mom's made the recipe before, she didn't have the problem, but she's also terrified of burning her caramel and tends to add the butter much, much sooner.
I've noticed brown specks when I've made chewy caramels and toffee as well, so I'm wondering if cooked and browned dairy solids are my whole problem here.
| VQAonline_00007379.png | So.... I've finally figured it out.
My cream's been curdling because I get my syrup too hot and too dark.
Most caramel recipes recommend heating the initial sugar syrup to no more than 380 degrees, and for the most part, people will get scared and pull it off the heat and add their cream before it even gets close to 380. I know I did when I first started! But without realizing it, I moved beyond those fears, enjoying progressively darker caramels.
However, one thing I was not aware of (and should have learned sooner) is that as sugar decomposes further, creating darker caramel, it becomes more acidic. Maybe not acidic enough in its own right to curdle heavy cream, but heat accentuates the curdling effect of acidity on casein and it's friends. I currently have a jar of caramel "sauce" in my fridge with a layer of dark caramel liquid on the bottom, and lighter, solid dulce de Leche reminiscent curds on top.
To which I said "the FRIG is going on???" I busted out the thermometer and actually added my cream at a wussy 380. It's wayyyy too sweet for my taste, but only a few shreds of cooked/curdled cream floated to the top. That seems significant.
While I can't find a decent chart that measures the pH of caramel at various stages of decomposition, I found lots of references to increasing acidity, and even to milk curdling as a result. Cream is more stable than milk, but the anecdotal stuff I found is still relatable. I have tiny curds instead of big ones, but that doesn't change their nature.
Easy fixes? Don't cook my sugar so hot is the obvious. One idea I haven't tried yet is to make my caramel with a pinch of baking soda, although I might not like the results as much. (I'd try and see, but two batches of caramel in 24 hours is enough for me)
The reason the answer wasn't obvious to anyone is because the recipe I started with never discusses temperature, so I never checked mine, and that's what made my situation unusual. I was trying to make a caramel sauce with a sugar solution approaching baker's caramel.
The moral of this story: if you're EVER following a recipe that instructs you to eyeball something, and then it comes out wrong, check your eyeballs. That means take precise measurements of what you're currently eyeballing and compare to accepted standards in other recipes.
Eg, I should have measured the temperature of my caramel syrup when I added the cream and took it off the heat, as well as noting my recipe's proportions, then compared to the temperatures and proportions of other accepted recipes to see how mine was different.
I could have saved myself a LOT of curdled caramel if I'd realized that 400 degrees is not caramel sauce standard sooner.
| https://cooking.stackexchange.com/questions/80770 |
cooking | Desperately Seeking Chicken Haddies | A staple of my Gran's kitchen when I was a child, Chicken Haddies (unbelievably I found a graphic of the product she favoured, below) was boneless haddock meat wrapped in wax paper then canned (a process unique in my experience.)
She was raised in Southern Ontario but spent decades of her life in mining camps in Ontario, Québec, and Newfoundland. My question is, is anyone aware if Chicken Haddies are still sold anywhere? An internet search finds references to several canneries in Atlantic Canada but the companies have no internet presence.
Please help, Chicken Haddies made the best chowder EVER!
| VQAonline_00007068.png | Apparently the chicken haddie plant had fire damage and we have not been able to buy it for over a year now in New Brunswick, Canada. I too grew up with it for making the best fish cakes. Anyway, the plant is up and running again as of January 2012 and I've been buying at Sobeys.
| https://cooking.stackexchange.com/questions/16949 |
cooking | What is the white substance floating in my fresh mozzarella brine? | I purchased fresh mozzarella bocconcini from Whole Foods six days ago. The mozzarella is sold in a brine solution. I opened the package when I bought it and have kept it refrigerated since, using the original packaging and brine solution. Today, I opened the package again to see some white substance floating in the brine as shown below. The mozzarella smells fine, and based on eating one bite, also tastes normal.
What is this substance, and is my mozzarella still safe to eat?
| VQAonline_00007512.png | Those are just milk solids.
Quality mozzarella is sold floating in whey, the leftover liquid from making cheese. While most of the milk solids are gone from the whey -- that's what the cheese is made from -- not all of them are. As such, some will coagulate in the fridge, floating on top of the whey.
Now, if the floaters were any color other than white, or if they were fuzzy, that would mean mold. But those are really just cheese bits.
| https://cooking.stackexchange.com/questions/100302 |
cooking | Bumps on carbon steel seasoning, can I repair it | I've just got a new De Buyer carbon steel pan and I'm 3 seasons in (oven method) and I'm noticing quite an uneven surface (especially little bubbles). I've tried as best as possible to keep the layers of oil used very thin. I'm wondering if I should strip it down and start over or just forge ahead?
| VQAonline_00007360.png | I think you are fine. I personally feel the best way to continue to season a pan is to actually just to cook in it. The first things I like after the oven or range top seasoning is to use onions, green onions and other inexpensive ingredients. Perhaps also to deep fry some onion rings or french fries as well. This will have the correct heat and also plenty of oil to seep into the pan. Hope this helps.
| https://cooking.stackexchange.com/questions/77250 |
cooking | Old-Fashioned Candy/Deep-Fry Thermometer - How Shallow Can I Go? | I have a thermometer like this:
Today I'm making tostadas. I don't need or want deep oil for that, just over a centimeter would be plenty. In order to submerge the bulb of this thermometer in oil that shallow, the bulb would almost be touching the bottom of the pan. Would I get even close to an accurate reading that way? Is there an accepted minimum depth for using a thermometer of this type?
| VQAonline_00007237.png | That is probably not deep enough to get an accurate reading. It varies with the thermometer, but usually you need at least a couple of centimetres to be submerged to get an accurate reading. Also, unless you are super careful, it will be nearly impossible to stop the thermometer touching the bottom of the pan. In my experience the clips on these doohickies are terrible for adjusting the angle of the thermometer.
When shallow frying in this manner I usually just go by rules of thumb. One that has never let me down is to use a wooden chopstick. When you think the oil is getting hot enough, place the tip of the chopstick in the oil. If bubbles rapidly appear around the chopstick, you're hot to trot.
| https://cooking.stackexchange.com/questions/49654 |
cooking | Is this a bad apple? | I cut my apple open this morning and found that it had an unexpected consistency emanating from the core. I couldn't find much about what's going on here other than maybe this is some kind of mold (seems unlikely).
What's going on with this apple?
This particular apple was part of an Amazon Fresh delivery. I've had about 10 of them up to this point, all of which were good apples.
I took a bite before throwing it out. It tasted fine and the texture is the same as far as I can tell (dense, fibrous). Ultimately I decided to toss it erring on the side of caution.
| VQAonline_00007410.png | This appears to be watercore, specifically radial watercore, from the image you have posted. It should be safe to eat, according to this site and this site.
According to an article from Washington State University, watercore is a disorder of some apple variants, which can cause the internal flesh to appear glassy [shiny and translucent] later into the growing season. In some studies, low levels of calcium have been shown alongside the condition. As well, it should be noted that the condition 1) does not occur after harvesting 2) may cause an increase of sweetness, and 3) cause the apple to quickly degrade during storage.
As to the causes of this disorder, there are a number of theoretical factors for causation: Genetic defects, water regiment, temperature, minerals, leaf-to-fruit ratio, maturation and ripening, sorbitol metabolism and altered transport. These are discussed to some degree in both the WSU article and this MSU article
| https://cooking.stackexchange.com/questions/84939 |
cooking | Ginger starting to sprout - can I still use it? | I have two beautiful ginger roots (rhizomes) which I had planned to turn into gari (pickled ginger). But I also have two children and the ever-changing schedule that goes with this. So the ginger sat in a bowl for a while, waiting.
While Wikipedia states that the rhizome
...it is immediately scalded, or washed and scraped, to kill it and prevent sprouting.
mine obviously weren't and appear to have gotten spring fever and started to sprout:
Now, I could put them in a planter, let them grow and harvest in fall when they start to wither, but before I sneakingly sell them to hubby as the latest addition of our ever-growing collection of plants I'm wondering:
Can I use sprouting ginger? Just like regular/dormant ginger? Or is there something to keep in mind?
My main focus is on the culinary aspect: While sprouted ginger isn't toxic, I'm wondering whether it requires special or different preparation, how to handle the sprouts, and do sprouting ("growing") and mature ("dormant") ginger taste differently in dishes.
(Should I decide to plant my ginger, I will ask the guys over at Gardening SE for advice, if required...)
| VQAonline_00007261.png | From a culinary perspective, I find that when sprouted, the ginger just loses a bit of flavour, that's all. If you let it grow for a very long time and it becomes all shriveled, then you are talking about a flavourless piece of ginger. I've even used such shriveled and even moldy (cut the mold off, though) pieces... no flavour at all!
| https://cooking.stackexchange.com/questions/57645 |
crafts | Paper's preservation (fixative not working) | Apparently, my (acid-free) paper (from 'SoHo Studio'; shown below) is yellowing, I have Krylon Workable Fixatif Spray Coating.
Obviously, fixatives prevent this issue to happen, what should I do?
Is there anything special I should do to my paper?
I don't think you can see the yellowing, but just trust me, it is yellow
| VQAonline_00007790.png | Paper will yellow over time because of lignin in the pulped wood.
Choosing an archival, acid-free fixative means that the fixative itself should not yellow over time. Unfortunately, the primary purpose of the fixative is to prevent smudging of the media that is on your paper. While it can slow down paper yellowing over time (by reducing the surface area of the paper that is exposed to air), it doesn't neutralize those oxidizing chemicals.
There are ways to treat the paper to prevent the yellowing from getting worse, and you can also put it behind UV-blocking glass to protect it from further oxidization due to air and light. However, the current yellowing may not be reversible.
| https://crafts.stackexchange.com/questions/9018 |
crafts | Advice on preserving an old painting | The image attached is of a painting which is deteriorating around the edges of the frame. The paint appears to be falking off of the canvas.
It is between 70 and 80 years old, I don't know what type of paint although I would guess oil.
Is there anything I can do to prevent further damage?
| VQAonline_00007748.png | You should consult a professional conservator.
If you're not even sure what kind of paint was used for this painting, chances are high anything you do'll cause more damage.
A conservator can see what kind of paint was used, what may have caused the damage (moisture, too much tension, deterioration of the paint?) and how to effectively stop the damage from spreading. Usually they would have a look at the painting and give you an estimate of the current value as well as an cost estimate for the preservation or repair before you have to decide whether or not you want to engage them.
| https://crafts.stackexchange.com/questions/5763 |
crafts | How do you properly store tins of turpentine? | Is there a proper way to store tins of turpentine? I have attached a picture of the type of container my turpentine comes in:
In the past where ever I store the container, turpentine smell would inevitably leak out and it's not really a pleasant smell. Initially I had stored it in the corner of my bedroom closet. I quickly moved it to a storage closet built into the stairwell. It's dark and cooler than room temperature usually.
I also made the mistake of putting the tin of turpentine inside several plastic bags. This helped with the smell that leaked out but when I took the tin out of the plastic bags, the whole tin was sticky with what I assume is the dried turpentine gas trapped inside the plastic bag.
| VQAonline_00007677.png | In a general sense it is a very good practice to refer to the material safety data sheets (MSDS) for products like this. The product labels, in theory, should also contain similar information.
MSDSs will always contain more information though. They will break down all the information needed about the product when it comes to safety. It should be safe to assume that householdproducts.nlm.nih.gov is a good source of this information. I located the sheet for your specific product. Most other MSDS's for turps cover the exact same sentiment as far as storage and handling is concerned. For completeness sake I have also included some basic handling as well in the information quoted below.
HANDLING:
Isolate from oxidizers, heat, sparks, electric equipment & open flame.
Use only with adequate ventilation. Avoid breathing of vapor or spray mist. Avoid prolonged or repeated contact with skin. Wear OSHA Standard goggles or face shield. Consult Safety Equipment Supplier. Wear gloves, apron & footwear impervious to this material. Wash clothing before reuse.
Avoid free fall of liquid. Ground containers when transferring.
Do not flame cut, saw, drill, braze, or weld. Empty container very hazardous! Continue all label precautions!
STORAGE:
Keep in fireproof surroundings.
Keep separated from strong oxidants, incompatible materials. Keep cool. Keep inside a well-ventilated room.
Keep container tightly closed & upright when not in use to prevent leakage.
Text is copied as is. Formatting and emphasis is my own.
Keep it cool, ventilated and away from sources of oxidants and sources of ignition. Ensure the container is seal and cleaned between uses.
I am not sure about the cause of the leaking. Chris Johns has a good theory though. Assuming you follow the instructions above it should not happen.
Related I found a discussion between users and the smells created by turpentine like yours and artist grade. Consensus is that the "cheap" stuff has a more offending odor
| https://crafts.stackexchange.com/questions/598 |
crafts | How can I laminate with contact paper without leaving bubbles? | I have to cover some books with adhesive contact paper. Although I try to do it slowly and with the help of a ruler, I systematically get some bubbles between the book and the cover.
Is there a good trick to do that properly?
| VQAonline_00007668.png | Try removing the paper off the plastic foil during the process, not before like removing a little bit of foil, sticking it on the edge, then pulling away the paper flat on the book.
| https://crafts.stackexchange.com/questions/183 |
crafts | How to keep scratch art paper clean and free of pencil and eraser marks? | I was introduced to scratch-art in high school and have loved it ever since. The problem I repeatedly encounter is in keeping the surface of the paper unmarked where I want it to remain black. I have tried a number of solutions as far as a storage is concerned, like keeping it between two pieces of paper and even buying a folder carrier for my projects to keep them protected. I don't wear jewellery when I work and that helps a lot.
I find though, that my faint pencil sketch I do before starting often shows up and is difficult to erase. the pencil is very shiny and reflects a lot more light than the paper does. The eraser makes more ugly marks than the pencil does. Further, I haven't figured out what to do if I do make a mistake.
Does anyone have tips for preventing ugly marks on scratchboard paper or fixing them once they've occurred?
Is there a suggested medium to sketch with on this sort of paper to lay out the outline of a design?
Here's an example of one of my projects:
| VQAonline_00007691.png | I have not done any sort of serious scratch-board art, but here are some suggestions, to answer your two part question:
Use black colored pencil instead of regular pencil.— it isn't as reflective as regular pencil, so you will just barely be able to see it while you're working.
Paint over the nicks/stray pencil marks— If you paint over the scratches and stray pencil marks with ink, it will probably cover it up and not show. You should try this on a scrap piece of paper first, to be sure.
| https://crafts.stackexchange.com/questions/2342 |
crafts | How to Trim Poofy Sleeves | I purchased a boho maxi dress a while ago.
I lost weight and it is now big for me.
How to narrow the sleeves to maintain their poofy shape?
Can I simply trim along the seam of the sleeve, or is there something more involved?
I know how to alter the bodice as I've had successful experience (based on this tutorial).
And I'm unsure if I'd attempt to narrow the skirt (length is absolutely perfect though) - I'll save that for another question if the time comes.
Here is a pattern of the dress in question (note the poofy arms)
| VQAonline_00007765.png | An assembled sleeve isn't much more than a tube of fabric, but completely disassembled, it looks more complicated.
If you are inexperienced with tailoring, this "quick and dirty" tutorial looks like a good start: How to tailor a sleeve. It requires you to put on the shirt (or dress) inside out, gather the surplus fabric at the existing seams and pin it to your desired size. You then open the original seams, sew along the pin lines and trim and neaten your new seams.
What it doesn't explain is how you match the new sleeve seam to the existing side seam of the bodice.
If you want to reduce the size of the bodice as well, it's perfect to do both at the same time. Otherwise you either need to match the new sleeve seam up to the original side seam (which preserves the puffiness at the shoulders) or you need to sew the sleeve seam in a crooked line back down to the side seam (which artificially narrows the arm hole).
I suggest going with the first solution, because it's the neatest and an armhole that's too narrow is very uncomfortable. This solution is shown in this video: Resize oversized sleeves
The professional way is to dissassemble the sleeves, adjusting the cut of the pieces and reattatching them to the dress. Of course this is more complicated, but if the "quick and dirty" solution doesn't look good, this is the only way to make it look perfect.
First of all, mark which sleeve is the left one and which is the right one, because they may differ very slightly from each other and sewing the left sleeve to the right armhole looks strange and feels uncomfortable.
Then take your measurements as described in Create custom sleeve pattern. Keep in mind that you want to measure your desired sleeve, so if you don't want it to be skin tight, don' t measure skin tight.
Follow that same instruction and construct your new sleeve on a big sheet of paper. Once you're done, measure the circumference of the armhole in your bodice. Then measure the length of the "sleeve crown", the curved line on top, from seam to seam. The sleeve crown should be slightly longer than the circumference of the arm hole.
If your sleeves have cuffs like shown in the picture, reattach them after closing the long sleeve seam.
At the end, sew the sleeves back onto the bodice as shown here: How to insert sleeves.
| https://crafts.stackexchange.com/questions/7522 |
crafts | Is it okay to cast off for neckline near crosses (cables)? | My wife is knitting me this wonderful cabled sweater pattern: https://knitrowan.com/en/free-patterns/cole and she is about to finish the back panel. However, the very last RS row before casting off for the neck has a Cr12F and a Cr12B in it. Then there was a WS row, and then casting off for the neck. Before she continues doing the front as well, the cast-off stitches look a bit twisted because of these two large crosses. Will this fix itself when picking up these cast-off stitches and knitting the ribbing around the neck, or will this cause a strangely twisted shape in the whole neck? If so, what is the best way to fix this?
E: added a picture
| VQAonline_00007774.png | Looking at the photo of the front, there is a crossing in the cable just two rows below the cast off/pick up for the neck.
I would go with the pattern, and see how the stitches work out in the casting off.
When you see them pulling so much that you do not like it you can unpick that bit of casting off, drop all the stitches of the cable, let them run down to just below that last cross and pick them up in knit without the twist. A crochet needle and a (short) cable needle will make the picking up easier.
Alternatively, you can just forget to make that last crossing, (not following the pattern,) but do so on both sides of the front and/or back, not just on the left or on the right (easy mistake to make.)
You can make the last crossing on the front but not on the back, if you think that is best.
| https://crafts.stackexchange.com/questions/8118 |
cs | Recurrence equation calculation | I have a recurrece equation
Changed notations:
$\qquad\displaystyle G(W) = \max \{ G(W - s_i) + v_i \mid 0 \leq i \leq n, w_i \leq W \}$,
I am not sure if I understand $\ w_i $ correctly.
On each iteration my $ w_i \leq W $ . So my $ w_i $ will be previous $ W-s_i $ since G takes one argument?
| VQAonline_00008270.png | Here is pseudocode for computing your function:
Parameters:
Integer $n$
Arrays $W,V,S$ of length $n$
function G(w):
If $w = 0$, return $0$
Let $\mathrm{max} \gets -\infty$
For $i$ from $1$ to $n$:
If $W[i] \leq w$:
Let $x \gets G(w-S[i])+V[i]$
If $x > \mathrm{max}$, let $\mathrm{max} \gets x$
Return $\mathrm{max}$
I used the notation $W[i],V[i],S[i]$ rather than $w_i,v_i,s_i$.
| https://cs.stackexchange.com/questions/90662 |
cs | Confusion in CLRS's version of Prim's algorithm | The algorithm is as follows:
MST-PRIM(G,w,r)
1 for each u ∈ G.V //initialization
2 u.key = ∞
3 u.π = NIL
4 r.key = 0
5 Q = G.V //end initialization
6 while Q ≠ ∅
7 u = EXTRACT-MIN(Q)
8 for each v ∈ G.Adj[u]
9 if v ∈ Q and w(u,v) < v.key
10 v.π = u
11 v.key = w(u,v)
All vertices that are not in the tree reside in a min-priority queue Q based on a key attribute.
v.key is the minimum weight of any edge connecting v to a vertex in the tree
v.π points to the parent of v in the tree
G is a graph, w is a weight function, r is a root
The example given is as follows:
I am confused, why in step (c), edge $(b,c)$ is added instead of edge $(a,h)$. Below the diagram, there is a note saying:
In second step, the algorithm has a choice of adding either edge $(b,c)$ or edge $(a,h)$ to the tree since both are light edges crossing the cut.
However still I think that according to the line 8 in algorithm, all adjacent vertices of $a$ not in the tree must be added first to the tree. Thus $h$ should also get added immediately after $b$, before $c$.
The line 8 says for **each v** ∈ G.Adj[u](i.e. for each adjacent vertex $v$ of $u$), why only adjacent node $b$ of $a$ is considered, but not $h$ (which is also adjacent to $a$).
If what author says should occur, then there should be something like break construct on line 12 inside the if construct's body, which will result in exiting for loop and hence grabbing next u = EXTRACT-MIN(Q).
Am I correct? or I must be missing something very stupid. What's that?
| VQAonline_00008023.png |
Question 1: However still I think that according to the line 8 in algorithm, all adjacent vertices of $a$ not in the tree must be added first to the tree. Thus $h$ should also get added immediately after $b$, before $c$.
You are confusing the resulting MST tree (denoted $T$) with the intermediate priority queue $Q$.
All the vertices are already in $Q$ at the end of initialization (Lines 1 ~ 5). However, $T = \emptyset$ at this time point.
A vertex $u$ is extracted from $Q$ and becomes a member of tree $T$ at line 7.
In the loop starting from Line 8, vertice $v$ satisfying the requirements of Line 9 are not inserted into the tree $T$; instead their keys in the priority queue $Q$ are changed (in fact, decreased).
Question 2: "My point is when the line 8 says "for each adjacent vertex $v$ of $u$", why only adjacent node $b$ of $a$ is considered, but not $h$ (which is also adjacent to $a$)."
Yes, $h$ is also considered, but in the way different from what you describe. In the iteration for $a$, both $b$ and $h$ are considered (satisfying Line 8 and Line 9): their keys are updated (i.e., decreased) in the priority queue $Q$ (Line 11) and their parents are updated accordingly (Line 10). (Note that these updates are not finalized and may be updated again during the algorithm.)
The key point is: neither $b$ nor $h$ has been added into the resulting MST tree $T$. Vertex $b$ will be extracted from $Q$ and added into $T$ in the next iteration at Line 7 (shown in step (b)).
Also note that the figure in CLRS only shows the changes on $T$; it does not show the states of $Q$.
| https://cs.stackexchange.com/questions/50964 |
cs | How to find vertices of bounded region made by intersection of lines | Suppose we have random lines made with 2 points. and point has (x,y)
For example:
Now when we draw a random line you will see many lines intersect with each other. This eventually gives rise to bounded regions. How to find the vertex points for each bounded region?
My approach:
First we find all the intersection points of the various lines. In some cases multiple lines intersect at the same point.
However I am not sure how to pick the points that make up a bounded region.
Thanks in Advance.
| VQAonline_00008274.png | Finding the all the vertices for all of the bounding regions is roughly the same amount of work as creating a doubly connected edge list (DCEL) that represents your regions, so I will show how to construct a DCEL from a set of line segments. After that, finding all the boundary points for each region from a DCEL is a simple operation.
First, we find all line segment intersections between the segments we start with. This can be done efficiently with the standard sweepline algorithm for line segment intersection, which is described in various references, such as in these slides. This can be done in $O(n\log n + K)$ time, where $n$ is the number of line segments and $K$ the number of intersections between these lines.
For the next part, we construct a set of endpoints $P$ and a set of line segments $L$, where for each segment $l\in L$, we also store the pair of points $(p,q)$ from $P$ that are the endpoints of segment $l$. First, add all original line segments to $l$ and the corresponding endpoints to $P$.
Then, at every intersection point $p$, split the segments that intersect at that point into two segments 'separated' by $p$, store the point $p$ in the set $P$, remove the old segment from $L$ and add the new segments to $L$, setting their endpoints accordingly.
In the end, we have represented our regions with a graph $G=(P,L)$, where the vertex set $P$ are all points in our 2D space (including the intersection points) and the set of edges $L$ contains all segments connecting these points. Note that the graph $G$ doesn't have any crossing edges by construction, so it is planar.
From this planar graph, we can construct a DCEL, as shown in this answer, which is mostly bookkeeping.
In the DCEL, each region is associated with a representative half-edge. From that half-edge, we can find all half-edges that form the border of the region. Then, the vertices of the region are all vertices of those half-edges.
It is possible to skip the DCEL and find the vertices directly, but likely you need to do almost the same thing. The main advantage of using a DCEL as an intermediate step is that someone else already has made an algorithm to construct a DCEL.
| https://cs.stackexchange.com/questions/90880 |
cs | Why does RAID-5 require an additional disk for parity blocks? | I know that RAID-5 consists of block-level striping across multiple disks, but using an additional parity-check block on each disk .. and that at least two disks are required for striping.
And it's obvious that each parity block is specific to each disk it belongs to (and so there is no need for allocating an additional disk).
Image from Wikipedia.
However I've been unable to understand why in fact there is an additional disk required for parity checks, as I found on this article:
The minimum number of disks in a RAID 5 set is three (two for data and
one for parity).
Any idea?
| VQAonline_00008338.png | I think you've misunderstood what the parity data is. They're not parity checks, so it's not true that "each parity block is specific to each disc it belongs to." The parity data is to allow recovery from a failed disc.
Let's go back to RAID-4 for a second, and assume we have three discs: discs $0$ and $1$ are data and disc $2$ is parity. "Parity" means that the $b$th block of disc $2$ is the xor of the $b$th blocks of discs $0$ and $1$. The point is that, if any single disc fails, we can recover its data because the $b$th block of any disc is the xor of the $b$th block on the other two discs. For this to work, it's crucial that the parity data is on a separate discs. If you only had two discs and put the parity data on those discs (e.g., each disc was two-thirds data blocks and one-third parity blocks) then the failure of a single drive would destroy some blocks and their corresponding parity data, so you'd be unable to recover the data using just what was left on the remaining disc.
RAID-5 is the same idea except that, instead of putting all the parity data on the last disc, it's spread across all the discs. So, for a three-disc set-up, a third of the blocks would have parity data on disc $2$, a third on disc $1$ and a third on disc $0$.
The point of using RAID-5 rather than RAID-4 is that every time you write data, the corresponding parity block must be updated. If all parity data is on the same disc, that disc will be written to much more than the other discs ($k$ times as much, in a $k$-disc sytem), so it will fail faster. Spreading the parity data across the discs evens out the wear on them.
| https://cs.stackexchange.com/questions/99180 |
cs | timed automata - advance only in certain states | I am currently looking into timed automata for a project.
I am thinking about a timed automaton where a clock only advances when the automaton is in a certain state.
However, my little knowledge in the domain makes me wonder whether somebody already defined timed automata like that.
As an example:
I.e. I have a timed automaton with two states: L0 and L1.
My clock is c - the total time that the automaton spent in time L1.
The clock c should only advance when the automaton is in state L1.
(see upper part of drawing)
Solution with my existing knowledge (not very elegant):
I can see a way where I could use event-clock automata (1) to achieve this, by triggering an event a and on entering L1 the value of c is set to:
c := c - xa
where xa is the time since event a.
(See lower part of the drawing)
However, I'm not convinced of this solution as it is inelegant, further I'm not sure whether timed automata allow for the setting of clocks. So far I only read about reset to zero.
(1) http://pub.ist.ac.at/~tah/Publications/a_determinizable_class_of_timed_automata.pdf
| VQAonline_00008253.png | So, after looking deeper into the subject I found the solution. Posting in case somebody else needs an answer and is unfamiliar with the subject.
What I was looking for is called a Stopwatch Automaton (SWA) and allows the time to stop or advance (by specifying the derivative of a clock c' = {0, 1}).
Reference: The Impressive Power of Stopwatches. Franck Cassez, Kim Larsen
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.123.669&rep=rep1&type=pdf
Further I discovered that Hourglass automata also allow time to stop, but additionally also to reverse: c' = {-1, 0, 1}.
They however require the specification of a maximum clock value after which "all the sand passed through the hourglass" and the clock does not advance further.
Reference: Hourglass Automata.
Yuki Osada, Tim French, Mark Reynolds, Harry Smallbone
https://arxiv.org/abs/1408.5965
| https://cs.stackexchange.com/questions/88411 |
cs | Finding recursion for runtime of code | This is the first time we have to do recursive/closed form expressions WITH code in class and I really have no idea how to approach this. My course notes that the prof put up don't really help as he put up a basic example, but this one has lots of recursive calls in it.
I know that the first part len(lst)$ \leq 1$ will be linear time because of it will just return whatever in the conditional. How do I tackle the rest, and ultimately come up with the recursive $T(n)$? The question is below:
| VQAonline_00007931.png | Base cases: $T(0) = T(1) = a, T(2) = b$. How did we get these base cases? Well, from the code:
if len(lst) <= 1:
return
This tells us that for n < 2, T doesn't depend on the input list size; hence, the function takes some constant amount of time for these input sizes.
if lst[0] > lst[-1]:
...
if len(lst) >= 3:
...
This part tells us that for input sizes between 1 and 3, exclusive (i.e., for 2) we do some more work than in the n <= 1 case but not as much as in the n >= 3 case. THe amount of work done still doesn't depend on the input size, so it's constant, but it might be difference from that of the n <= 1 case.
Now we consider the n >= 3 case.
Recursive part: $T(n) = 3T(\frac{2}{3}n) + c$. Notice that the three recursive calls each use a list two thirds the size of the input list. To see this, let's consider the code:
if len(list) >= 3:
split = len(lst) // 3
do_something(lst[0..len(lst) - split - 1])
do_something(lst[split..len(lst) - 1]
do_something(lst[0..len(lst) - split - 1])
First off, we see that split will be equal to one third the length of the input list, rounded down (we assume // means integer division). We then have three recursive function invocations. To get the input size for these recursive calls, we have to see how big the lists we're passing are. All three are slices of the original input list; we can determine the size of the lists being passed to recursive calls by computing the indices used to determine slices. Observations:
The first and third slices use the same indices.
0 .. len(lst) - 1 is the entire list, size n.
split is one third the list size, equal to n/3.
The second slice uses split .. len(lst) - 1; to get the size of this slice, we can use simple subtraction of the size of the smaller interval (0..split) from the bigger interval (0..len(lst) - 1): n - n/3 = 2/3 n.
The first and third slices work similarly: if we take a slice of size n and stop it n/3 indices earlier, we get n - n/3 = 2/3 n.
Now that you have a recurrence relation, you can resolve it using any of a several of techniques.
| https://cs.stackexchange.com/questions/31850 |
cs | Transform inverse result | let us assume that:
f is a grayscale image of size NxN, and F is the Fourier transform of f.
G is a 2Nx2N transform obtained by inserting 0 between every value in F:
What is the inverse transform of G?
solution:
so i have programmed it, and the picture will be 4 times bigger with the picture 4 times in it. g= [f f;f f]
can you please explain why this is the answer?
| VQAonline_00007844.png | Think of it the other way around.
If you duplicate an image then you get zeros in between the transform (
This can intuitively be explained:
duplicating an image is like convolving with 2 deltas (comb) of wavelength 1/2 the new image size. so is equivalent under convolution theorem to multiplying with comb of freq size of image / 2 which gives a comb with delta every other pixel -> every other pixel is zero.
| https://cs.stackexchange.com/questions/9449 |
cstheory | NP-completeness of a problem using a "T-gadget" | Working on a problem I came up with the following "T-gadget":
It has 3 connectors (A, B, C); each connector has two wires (A1,A2; B1,B2; C1,C2);
it can be rotated (0, 90, 180, 270 degrees);
two gadgets X and Y, can be linked together (one connector of X is joined with one connector of Y);
the wires used to link the T-gadgets cannot overlap.
A signal is propagated on the wires; and it can use 1 or 2 connectors to traverse a T-gadget. Suppose that it enters through wire A1, then it can:
go back through wire A2, OR
choose among connector B or C - suppose that it chooses connector B; then it can exit the gadget through wire B1, re-enter through B2 and exit again through A2
When a signal enters a gadget and exits from the same connector, the gadget is "activated".
Possible traversals of a T-gadget:
(OUT) - A1 - A2 (OUT)
(OUT) - A1 - B1 - (OUT) - B2 - A2 - (OUT)
(OUT) - A1 - C1 - (OUT) - C2 - A2 - (OUT)
(OUT) - B1 - B2 (OUT)
(OUT) - B1 - A1 - (OUT) - A2 - B2 - (OUT)
(OUT) - B1 - C1 - (OUT) - C2 - B2 - (OUT)
(OUT) - C1 - C2 (OUT)
(OUT) - C1 - B1 - (OUT) - B2 - C2 - (OUT)
(OUT) - C1 - A1 - (OUT) - A2 - C2 - (OUT)
The signal starts on wire A1 of a gadget (with connector A unlinked) and must return to A2.
Question: is the problem: "Given a set of T-gadgets linked together, does exist a path that activates all of them?" $NP$-complete?
If we omit option 1 (go back through wire A2) I think that the problem is $NP$-complete (through reduction from Hamiltonian path problem on cubic planar graphs).
| VQAonline_00008641.png | You're asking whether the underlying 3-regular graph has a Hamiltonian path, which is NP-complete. Your activation signal must traverse every edge in this path exactly twice.
See also this question and this one.
| https://cstheory.stackexchange.com/questions/10405 |
cstheory | Series-parallel DAG characterization | According to this Wikipage series-parallel graphs are characterized like this:
2-connected series-parallel graphs are characterized by having no subgraph homeomorphic to $K_4$.
I couldn't find a similar characterization for series-parallel directed acyclic graphs (DAGs), however I think that the prohibited subgraph in this case can be a little simpler ($K_4$ minus one edge plus specific orientation):
Is it correct? Is it proven anywhere?
| VQAonline_00008693.png | The two-connected series-parallel DAGs are also called 2-terminal series-parallel graphs. The graph in the figure is also known as Wheatstone graph and is known as the example graph for demonstrating Braess' paradox in algorithmic game theory.
It was shown [1, Theorem 5.3] that a DAG is 2-terminal series-parallel if and only if it does not contain a subgraph that is homeomorphic to the Wheatstone graph.
1 Pietro Cenciarelli, Daniele Gorla, Ivano Salvo: Inefficiencies in network models: A graph-theoretic perspective. Information Processing Letters 131 (2018) 44–50.
| https://cstheory.stackexchange.com/questions/47645 |
cstheory | Dealing with duplicates in Genetic Algorithm | I'm using Genetic Algorithm to create a rota for home-care organisation. All the groundwork is complete, I'm getting the results, but results are not as good as expected.
If I calculate fitness for existing rota made by somebody, I get about £6000 (I measure fitness in money - great point for management).
When I run my GA, the best I manage to get is £8K after about 30K generations.
So I know the better solution exists and I'm trying to get better result.
I have tried different approaches - big population, small population, different number of crossover points, swap-mutation, random-mutation, hill-climber-mutation.
And nothing improved the results.
The resulting curve looks like this:
I can run GA much longer, but it does not give me any better results - the curve is just flat horizontal to the right.
I figured that I get quite a lot of duplicated individuals in final population. And that slows down the improvement of the solution.
I learned how to find duplicate individuals. But what do I do with them? I have tried replacing them with randomly created solutions, but usually their fitness is much worse then every body else in the solution space, so they get "killed" quite soon without giving any offsprings or other influence to the solution space.
Any ideas/suggestions/papers will be highly appreciated, as I've run out of ideas and research papers and almost no time left.
UPD: some description of the problem:
There are number of visits(shifts) that are located in different geographical places (distances between locations are known). Currently I work with 700 visits per week with durations from 30 minutes to 5hrs. There are workers with different levels of contractual arrangements: some have 0 contracted hours - relief workers, there are part-timers and full-timers.
I need to allocated workers for every shift in a best possible manner with this factors in mind:
Minimise travel distance for workers. When they have number of shifts in a day, the locations should be roughly in the same area
Workers should not do a lot of overtime hours
Workers should not work less than their contract says
Workers with 0-contracts should be allocated no or very limited working hours
Minimise waiting time between shifts. So no situations when somebody starts one visit at 9am to 10am, and next visit is at 6pm.
There is a limit of total number of hours that can be worked per day
There is a minimum of working hours per day: nobody should be deployed for only 30-minute visit and no other visits per day.
At least 2 days off allocated for anybody, but can be more
At least 2 days off must be adjacent.
And other minor fitness function adjustments.
I hope this is sufficient for description.
| VQAonline_00008634.png | What you've hit upon is the basic mechanism that drives GAs -- convergence to some fixed point that you hope is near optimal. In your case, clearly it isn't. So the name of the game is to try and balance this tendency to drive convergence with the competing interest of exploring the space looking for other solutions. There's no silver bullet for this problem -- you always end up tuning things to suit your particular problem.
In general, there are two ways to do this. One is to delay convergence for longer, thus giving the algorithm more time to find better solutions. You can switch to a weaker selection operator (binary tournament selection for example), you can increase your mutation rate, etc. The other option is to allow the algorithm to converge, but figure out a sensible way to restart the search (as you mentioned, putting random points in tends not to work because their fitness is too low to allow them to survive and contribute to the search).
I'll give an example of the latter approach. There is a relatively-little known algorithm called CHC (Eshelman 1991) that tends to work really well for a lot of problems. Unfortunately, one reason it's little-known is that the only way to access the original paper is to buy the printed proceedings of the first FOGA conference, but you can probably find a little bit of information online, hopefully enough to get you started. I can give you something of a quick overview though. In rough pseudocode, CHC looks like
delta = k/4 # k = chromosome length
while not done
create new child population
for i = 1 to n/2 # n = population size
select p1, p2 from population without replacement
if hamming_distance(p1, p2) > delta
c1, c2 = HUX crossover(p1, p2)
insert c1, c2 into child pop
end if
end for
if child pop is empty
delta = delta - 1
else
take best n individuals from union of parent and child populations as next population
end if
if delta < 0
keep one copy of best individual in population
generate n-1 new population members by flipping 35% of the bits of the best individual
delta = k/4
end if
The HUX crossover operator is like uniform crossover, but instead of choosing randomly between the parents independently for each bit, it exchanges precisely half the differing bits from the parents.
You then just keep running this loop until you decide to quit, either because you've found a good enough solution, you've exhausted the amount of time you have to spend on the problem, or whatever other criteria you desire.
| https://cstheory.stackexchange.com/questions/7849 |
cstheory | One-shot quantum hitting times | In the paper Quantum Random Walks Hit Exponentially Faster (arXiv:quant-ph/0205083) Kempe gives a notion of hitting time for quantum walks (in the hypercube) that is not very popular in the quantum walk literature. It is defined as follows:
One-Shot Quantum Hitting Time: A discrete-time quantum walk has a $(T,p)$ one-shot $(|\Psi_0\rangle,|\Psi^f\rangle)$-hitting time if $|\langle\Psi^f|U^T|\Psi_0\rangle|^2 \geq p$ where $|\Psi_0\rangle$ is the initial state, $|\Psi^f\rangle$ is the target state, and $p>0$ is the hitting probability.
Normally you would like to know the minimum $T$ such that $p>0$. It is not possible (correct me if I'm wrong) to define a notion of average hitting time because you will need to make measurements during the walk, and that would collapse it to a classical walk. That's why we have the one-shot notion. In the same piece of work, there is an application to quantum routing (cf. section 5).
In order to know that the walk arrived at the target vertex, you need to make a measurement only at that node. For example, in the $n$-dimensional hypercube with $2^n$ nodes if you start at node $|\Psi_0\rangle=|00\dots00\rangle$ and have as target node $|\Psi^f\rangle=|11\dots11\rangle$, the paper shows that $T=O(n)$ with bounded error probability, i.e. $p\to 1$ as $n$ becomes very large. So in order to detect that the walk arrived at $|11\dots11\rangle$ you make a measurement after $\Omega(n)$ steps. This is an exponential speed-up.
Questions:
To use this notion of hitting time for search you need to know at least the distance of the target vertex from the origin, because that's how you know when to apply your measurement. Let's say that you have a graph $G$, and set as initial vertex $v_0$ and want to reach $v^f$. Assume also that $T=O(dist(v_0,v^f))$ and $p\geq 1/2$. Well, $T$ is obvious because you need at least that many steps to reach it. Does it make any sense using this hitting time for search? If you know where the node is there is no meaning in searching, but having a piece of information like "distance from the starting vertex" but not knowing exactly where the target is, does this notion of hitting time gives any interesting (worth to study) search algorithm?
Does the application to quantum routing makes any sense? In the paper it says that it can be used for routing packages, but it seems to me that you can only send 1 bit, e.g. does it arrived at destination or not? Can you actually send a quantum state in this framework? In the paper this issue is not being addressed.
This is maybe a silly question to ask, but here it goes. Can you use this notion of hitting time for constructing a "Generalized Mach-Zender Interferometer"?
I'm aware of the other notions of hitting times for quantum walks (like Szegedy's or Ambainis's). I'm particularly interested in this specific hitting time.
Update (9/24/2010): Thanks to Joe Fitzsimons questions 2 and 3 were completely answered. Although question number 1 still remains. First, I will restate question 2 in more specific terms now that I finished reading the paper that Joe recommended me and a couple more (for example see arXiv:0802.1224), and then I'll give a concrete example of what I have in mind for question 1.
2'. If you are sending a concrete message (like a sequence of classical bits), you can use a more complicated unitary that will copy this information during the steps of the walk. To send quantum states you need something more. The spin-chains channel uses a linear array of qubits with a fixed coupling. You can put the state (pure state, I don't know if it works for mixed states) you want to transmit in one end and it goes to the other end with high fidelity according to numerical results. I still have to give it more thought but I have two ideas: i) put a chain on each link of the graph, or ii) make the walk, find the target state, then make the channel between initial state and target and then send the state. Are any of these approaches plaussible? Does it work with mixed states?
1'. Consider a walk on a 2-dimensional grid centered in the origin with $n$ nodes with each side with length $\sqrt{n}$. Set the initial state at $v_0=(0,0)$ and the target state at $v^f=(\sqrt{n}-1,a)$ where $a=0,\dots,\sqrt{n}-1$. Because the walk is symmetric we have that the same hitting time and hitting probabilities hold for any target somewhere on the border of the grid as shown below.
Therefore the information we have is that $dist(v_0,v^f)=\Omega(\sqrt{n})$. We can use this to know when to make the measurement. Can the one-shot hitting time be used to search this grid? Here you need that information. An open problem in searching a grid is that we know that $\Omega(\sqrt{n})$ is a lower bound for search, and for grids the best upper bound is $O(\sqrt{n\log n})$. Either we are not being able to find a better algorithm, or the techniques for proving lower bounds when you use them on grids are giving a weak lower bound. Can you show that the only way to go below $\sqrt{n\log n}$ is having "a piece of information" as the one in the question? This would imply a way of proving a lower bound for grids. Does it make any sense?
| VQAonline_00008623.png | I'm not so familiar with this paper, but I will try to give a rough answer to each of your questions after a cursory skim.
Grover's algorithm can indeed viewed with this notion of hitting time. You need to decide when to measure the system, and even though T is constant for all results, it is still important to calculate. Here T is certainly not $O(\mbox{dist}(v_0, v^f))$ (which in this case is 1), but rather $O(\sqrt{n})$, so your assumption that $T=O(\mbox{dist}(v_0, v^f))$ is not valid here.
I assume the author is taking an entire packet to do the random walk. Obviously this requires a somewhat more complicated unitary, but I don't really see an issue. Alternately, Burgarth and Bose have a very nice scheme for encoding information across identical graphs which would work too if you simply replace their 1d chains with the network of choice (quant-ph/0406112).
Well, you don't quite need this notion of hitting time. Hypercubes have perfect state transfer (see for example quant-ph/0309131 and quant-ph/0411020), so you can view transport on a hypercube as an interferometer with the Mach-Zender interferometer corresponding to the 2d case.
UPDATE: (To answer the updated question regarding random walks on a grid or other lattice)
One approach to the measurement issue you highlight with the spatial search problem is to simply make a measurement at each timestep such that it returns 1 iff the the vertex the walker is currently at (say $v_t$) is equal to $v^f$ and the current timestep t is the hitting time for that vertex. This should avoid the issue of collapsing the wave function, as the measurement is only made for each vertex once the hitting time is reached, and it only registers collapses onto a location if that location is the correct result.
| https://cstheory.stackexchange.com/questions/1400 |
cstheory | What's the logical counterpart to jumps with arguments on CPS terms? | It's well known that the CPS (continuation-passing style) translation often employed in compilers corresponds to double negation translation under the Curry-Howard isomorphism. Though often the target language of a CPS translation is the same as the source language, sometimes it's a specialized language which only allows terms in CPS form (i.e., there are no direct style functions anymore). See, e.g., this or this.
As an example, consider Thielecke's CPS-calculus, where commands are defined as either jumps or bindings:
$$b ::= x\langle\vec{x}\rangle\ |\ b\ \{\ x\langle\vec{x}\rangle = b\ \}$$
And one-hole contexts (commands with holes) are defined as follow:
$$C ::= [-]\ |\ C \ \{\ x\langle\vec{x}\rangle = b\ \}\ |\ b\ \{\ x\langle\vec{x}\rangle = C\ \}$$
If we try to see these languages under the Curry-Howard isomorphism, we don't have implication anymore, but rather we use negations and products alone. The typing rules for such languages demonstrate we're trying to derive a contradiction:
$$\frac{\color{orange}{\Gamma\vdash} k{:}\ \color{orange}{\neg\vec{\tau}}\quad\quad\color{orange}{\Gamma\vdash}\vec{x}{:}\ \color{orange}{\vec{\tau}}}{\color{orange}{\Gamma\vdash} k\langle\vec{x}\rangle}(J)$$
$$\frac{\color{orange}{\Gamma,}k{:}\ \color{orange}{\neg\vec{\tau}\vdash} b\quad\quad\color{orange}{\Gamma,}\vec{x}{:}\ \color{orange}{\vec{\tau}\vdash} c}{\color{orange}{\Gamma\vdash} b\ \{\ k\langle\vec{x}\rangle=c\ \}}(B)$$
(Note that these look similar to the (AXIOM) and (CUT) rules from linear logic, though on the other side of the sequent: we have a conjunction rather than a disjunction.)
Reduction rules in intermediate languages such as the ones above allow jumps to be performed to bound continuations, immediately replacing arguments (hence the name "jump with arguments" sometimes employed). For the CPS-calculus, this can be represented by the following reduction rule:
$$\frac{}{C[\color{blue}{k\langle \vec{x}\rangle}]\ \{\ k\langle\color{red}{\vec{y}}\rangle=\color{red}c\ \} \longrightarrow C[\color{red}{c[\color{blue}{\vec{x}}/\vec{y}]}]\ \{\ k\langle\color{red}{\vec{y}}\rangle=\color{red}c\ \}}$$
$$\frac{a\longrightarrow b}{C[a]\longrightarrow C[b]}$$
...though similar languages have similar notions of jump. I'm not totally sure, but I believe that the reduction rule would corresponde to a cut inference rule similar to the following (quickly sketched):
...where we're allowed to copy a bound proof tree and replace the jump subtree with it (in the example above, replacing subtree a with a copy of subtree b, though with a different context).
I'm interested on how such an intermediate language could be seen by the Curry-Howard isomorphism. So, my actual question is twofold:
Has a similar implication-free subset of some logic (e.g., propositional logic) been studied somewhere? I mean, has a "logic without implication" been proposed?
What is the equivalent of a jump with arguments in logic? Assuming the cut rule I sketched above is correct (and it corresponds to the reduction rule), has something similar to it appeared elsewhere?
| VQAonline_00008696.png |
Such a logic of continuations (or a syntax of continuation that arose from logical considerations) would be Laurent's “polarised linear logic” (LLP): Olivier Laurent, Étude de la polarisation en logique (2002). A good explanation of what is going on from a categorical perspective is given in Melliès and Tabareau, Resource modalities in tensor logic (2010). A detailed description of the correspondence between LLP and CPS along the lines of your question appears in my PhD thesis (2013) (Chapter III, pp.91-95,153-199). (There are a lot of other references in this area; the bibliographies should provide you with a good starting point.)
The two rules (J) and (B) you wrote are derived as follows (in the notations of Laurent's PhD thesis):
\begin{array}{c}
\dfrac{\dfrac{\vdash\mathcal{N},!(P_{1}^{\bot}\mathbin{⅋}\cdots\mathbin{⅋}P_{n}^{\bot})\qquad\dfrac{\dfrac{\vdash\mathcal{N},P_{1}\quad\cdots\quad\vdash\mathcal{N},P_{n}}{\vdash\mathcal{N},\dots,\mathcal{N},P_{1}\otimes\cdots\otimes P_{n}}}{\vdash\mathcal{N},\dots,\mathcal{N},?(P_{1}\otimes\cdots\otimes P_{n})}}{\vdash\mathcal{N},\mathcal{N},\dots,\mathcal{N}}}{\vdash\mathcal{N}}\\
\dfrac{\dfrac{\vdash\mathcal{N},?(P_{1}\otimes\dots\otimes P_{n})\qquad\dfrac{\dfrac{\vdash\mathcal{N},P_{1}^{\bot},\dots,P_{n}^{\bot}}{\vdash\mathcal{N},P_{1}^{\bot}\mathbin{⅋}\cdots\mathbin{⅋}P_{n}^{\bot}}}{\vdash\mathcal{N},!(P_{1}^{\bot}\mathbin{⅋}\cdots\mathbin{⅋}P_{n}^{\bot})}}{\vdash\mathcal{N},\mathcal{N}}}{\vdash\mathcal{N}}
\end{array}
LLP is a sequent calculus and as such is finer-grained: it makes explicit structural rules and (what corresponds to) left-introduction of negation.
Visible above, it also internalizes duality (all formulae on the right-hand side, like in linear logic). While Laurent does not cite Thielecke's works, Thielecke's PhD thesis previously suggested that having a “duality functor” could be useful to clarify the duality aspects of CPS.
Laurent's graphical syntax will let you interpret linear substitution, but one would have to look at the details to see if it is exactly the same as the one you mention.
| https://cstheory.stackexchange.com/questions/50964 |
cstheory | Is the D-Wave architecture a close implementation of quantum interactive proof? | A very high level architecture is, as mentioned here, shown in this picture.
The component on the left is classical while the one on the right is the D-Wave box. I understand that in QIP, Arthur is BQP. Here the classical component is always in BQP if we are not too restrictive. On the other hand, the D-Wave box although don't have unbounded computational resources is not violating any law of quantum mechanics. Let's consider this as not-so-strong Merlin.
Can we say that this architecture is an restricted implementation of quantum interactive proof system? My motivation for this question is that if we want to do the complexity analysis of the D-Wave architecture should we model it as QIP?
| VQAonline_00008650.png | This question seems a little confused. The class of decision problems solvable efficiently on a quantum computer is BQP, while on a classical computer it is either P or BPP depending on exactly how you define things. An interactive proof is something entirely different. It is a protocol which allows a prover to prove, beyond reasonable doubt, the outcome of some decision problem, and allows the prover and verifier to interact. QIP is the class of interactive proofs where the verifier, not the prover, has access to a quantum computer. It turns out that this doesn't help very much since you can prove exactly the same things to a fully classical verifier. I think what you have in mind is something different: an interactive proof where the prover is limited to quantum computation. This is something that has been studied in recent years (see for example arXiv:0807.4154, arXiv:0810.5375 and arXiv:1209.0449). The extent of our current knowledge is that you can basically prove anything in BQP if you have either some limited quantum power for the verifier (the ability to prepare single qubit states, for example) or if you have several provers who do not communicate, but share entanglement.
The DWave machine does not implement anything like these schemes, and does not constitute any form of interactive proof. Actually, the problem of implementing such a scheme on DWave hardware has been something that has interested me for a while. There are a few hurdles to doing this. All of the known schemes are based in the circuit model or the closely related measurement based model, while the DWave machines use a very different model of computation. This introduces a few problems, as their system is not a general purpose quantum computer, and so cannot implement any of the known schemes directly. Further, it cannot really accept any kind of quantum input, which rules out many of the tricks used to construct the known schemes.
However, I don't mean this to be a criticism of DWaves device: virtually no other quantum device has been used to implement such a proof. The closest you get are things like violations of Bell's inequalities and the recent experimental demonstration of blind quantum computing in linear optic (arXiv:1110.1381). At this point, no one has yet published an experimental demonstration of a quantum prover interactive proof, so DWave isn't any better or worse in this respect than anyone else.
By the way, I apologise for linking to two of my own papers in the above, but this is a question I have been very interested in in recent years, and I think those papers are relevant to the question at hand. It's not intended as self-publicity.
| https://cstheory.stackexchange.com/questions/17679 |
cstheory | Degree sets for linear extension graphs | A linear extension $L$ of a poset $\mathcal{P}$ is a linear order on the
elements of $\mathcal{P}$, such that $x \leq y$ in $\mathcal{P}$ implies $x \leq y$ in $L$ for all $x,y\in\mathcal{P}$.
A linear extension graph is a graph on the set of linear extensions of a poset, where two linear extensions are adjacent exactly if they differ in one adjacent swap of elements.
On the following picture there is the poset known as $N$-poset, and its linear extension graph, where $a=1234, b=2134, c=1243, d=2143, e=2413$.
(This figure is taken from the work.)
When you study linear extension graphs (LEG) you can come up with an idea (conjecture) that if $\Delta$ - maximal degree of a LEG, $\delta$ - respecrively, minimal degree, then the degree set of any LEG consists of $\Delta,\delta$ and each natural number between them. For example, let's take a poset, known as chevron, then in its LEG $\mathcal{G}$ with $\Delta(\mathcal{G})=5$ and $\delta(\mathcal{G})=2$, and also, according to our conjecture, vertices with the degrees 4 and 3 are contained in the graph. So, the question is can we prove or disprove this conjecture?
About LEGs and how do they look like one can read in the dissertation of Mareike Massow here. Chevron and its LEG can be seen on the page 23 of the dissertation.
On the degree sets there is the classical paper "Degree sets for graphs" by Kapoor S.F. et al.
| VQAonline_00008625.png | I think I proved it yesterday. Thus here goes the sketch of the proof.
At first, the following lemma is proved.
Lemma. Let $\mathcal{P}$ - a partial order, $G(\mathcal{P})$ - its linear extension graph and $v_1,v_2$ - two adjacent vertices of $G(\mathcal{P})$. Then $|deg(v_1)-deg(v_2)|\leq 2$.
The sketch of the proof.
At the same time, $v_1,v_2$ are linear extensions of $\mathcal{P}$ such that one of them, say $v_1$, can be transformed into $v_2$ by one transposition of adjacent elements (adjacent transposition). It is easy to see (consider, for instance, $d$ and $e$ from the above figure) that any element $x_i$ of any linear extension $L=x_1x_2\dots x_n$ can change the number of incomparable adjacent elements on at most two:
If $x_i$ can be transposed at all then at least one its neighbor, say $x_{i+1}$, is incomparable to it ($x_i\parallel x_{i+1}$, if comparable then $x_i\perp x_{i+1}$). Note: before transposing we have $L_1=\dots x_{i-1}x_ix_{i+1}x_{i+2}\dots$ and immediately after - $L_2=\dots x_{i-1}x_{i+1}x_{i}x_{i+2}\dots$.
Let us consider how the number of incomparabilities (degree of the linear extension as the vertex in $G(\mathcal{P})$) in $L$ could change. We consider at first the pair $x_ix_{i+2}$. For $x_{i-1}x_{i+1}$ the same conclusion follows by symmetry.
If $x_{i+1}\parallel(\perp) x_{i+2}\land x_{i}\parallel(\perp) x_{i+2}$, then $deg(L)$ doesn't change.
If $x_{i+1}\perp(\parallel) x_{i+2}\land x_{i}\parallel(\perp) x_{i+2}$, then $deg(L)$ increases (decreases) by one.The sketch of the proof is completed.
Theorem. Let $G(\mathcal{P})$ - a linear extension graph. If $G(\mathcal{P})$ contains vertices $v_1,v_2$ with $deg(v_1)=k,deg(v_2)=k+2$, then there is $v_3\in G(\mathcal{P})$ such that $deg(v_3)=k+1$.
The sketch of the proof.
Suppose $v_1,v_2,deg(v_1)=k,deg(v_2)=k+2$ are adjacent in $G(\mathcal{P})$, otherwise any vertex with degree $k$ in $G(\mathcal{P})$ is adjacent with some vertex if such exists with degree $k+1$.
Let us consider the case where we have $L_1,L_2$ from the previous lemma such that
$$x_{i+1}\perp x_{i+2}\land x_{i}\parallel x_{i+2},$$
and
$$x_{i-1}\perp x_{i}\land x_{i-1}\parallel x_{i+1},$$
Thus $deg(L_2)=deg(L_1)+2$.
Let us now start transpose $x_{i+1}$ in the direction of $x_1$. It is easy to see that eventually we could stop at the position where
$$x_{j}\perp x_{i+1}\land x_{i+1}\parallel x_{j+1},$$ for some $j<i-1$.
The sketch of the proof is completed.
| https://cstheory.stackexchange.com/questions/2902 |
diy | What is the name of the tool that the guy in this video is using to level up the mud on ceiling? | What is the name of the tool that the guy in this video is using to straighten up the ceiling?
https://youtu.be/YuUoZZ6v6MU?t=528
He is even indicating the name but I don't understand what he is saying. I am looking to buy one of those.
| VQAonline_00011799.png | There is a link in the video for Tyzack Plasterers Spatulas. I've also heard them called "skimming blades" in the US.
| https://diy.stackexchange.com/questions/239646 |
diy | Can I use existing wiring for installing an OTR Microwave? | We are looking at installing an over the range microwave in our house but I have a few questions concerning the electrical hookup before we pull the trigger and get one.
Currently there is a range hood above our stove. I took it down and there is an electrical cable coming directly out of the wall into the hood. I know that it is advised that an OTR microwave be on its own dedicated circuit (or something like that) from anything else.
However, I’m not entirely sure if it is or not. I’ve narrowed down which breaker it’s on and I’ve attached an image below. The stove is on the same one. Does that mean I will not be able to use that wiring? I’m mainly confused by the circle with two slashes in it afterward, does that mean anything specific?
Edit: sorry for the sideways image. Stack exchange rotates the image when I upload it for some reason.
| VQAonline_00010794.png | You should be fine
If this breaker truly is only serving the hood (I'd double check that with a plug-in radio in each of the kitchen outlets with this breaker off), then you'll be fine with putting the microwave/hood on there. If there are kitchen outlets on this breaker, then I would limit the input (nameplate) power of the microwave/hood to 1.2kW (which will mean a relatively small microwave) to avoid violating NEC 210.23(A)(2):
(2) Utilization Equipment Fastened in Place. The total rating
of utilization equipment fastened in place, other than luminaires, shall not exceed 50 percent of the branch-circuit ampere
rating where lighting units, cord-and-plug-connected utilization
equipment not fastened in place, or both, are also supplied.
As to that symbol...
The two-parallel-lines-in-a-circle symbol you see on your loadcenter's directory label, by the way, is the standard symbol used to denote a receptacle on North American electrical floorplans.
| https://diy.stackexchange.com/questions/171040 |
diy | Botched grounding in receptacle junction boxes | Background: I recently moved into an apartment building in Canada (built in 1969). I don't know much about the electrical code, how grand-fathering works within it, etc., but I have an intermediate knowledge of household wiring.
Some previous electrical shenanigans raised my suspicions and induced me to do some investigation in my new apartment's electrical work.
My first observation: none of my receptacles' junction boxes have grounding wires going into them. I figure that's a byproduct of the age of this building. My circuit tester doesn't complain about an open ground. I've read that electrical cable conduit could be used to provide grounding, so I figure that must be what's going on. Is this correct?
Second observation: None of the receptacles' junction boxes have grounding screw terminals. Instead, a knockout cover was punched out on one side, and used to improvise a clamp that holds down a short ground wire.
Seeing that made my jaw drop. There's barely no mechanical retention here. I was able to pull that cable loose with practically no tension at all.
So my questions:
There's no way that's legit, right?
Is is possible that the building is grand-fathered onto old electrical code rules, and doesn't need to provide proper grounding?
| VQAonline_00010865.png | The conduit's fine...but that ground wire sure isn't
While a properly installed conduit system provides quite solid grounding performance, the pigtail from the receptacle isn't what I'd call an acceptable level of workmanship by any stretch of the imagination. I would get a proper 10-32 grounding screw and use it to attach the pigtail to the ground hole in the back of the box if I were in your shoes.
| https://diy.stackexchange.com/questions/177753 |
diy | What is the difference between a "handle tie" and "common trip" in circuit breakers? | This image shows a quad-breaker with handle ties.
Image borrowed from this DIY question
One of the comments noted that despite the "handle ties", this is not a "common trip" breaker. I, in my ignorance, previously assumed that a trip on one of the tied breakers would have forced the tied mate to trip as well and that this would, therefore, also be a "common trip". It seems I was wrong.
What is the difference between a "handle tie" and a "common trip"? For bonus points, when should each be used?
As was pointed out in an answer on that original question, this quad-breaker is labeled
ALL POLES HAVENO COMMON TRIP
Does this mean that "common trip" is internal to the breaker and can only be identified by reading the labeling, while "handle tie" is the external plastic/metal piece that physically ties the handles together? If so, does that mean (theoretically) that one could have a common trip breaker without a handle tie?
| VQAonline_00011251.png | It ain't about the handle-tie
Common trip does NOT work by one handle tripping, and that action dragging the other handle over via the handle-tie. That is not how that works.
That wouldn't work because the handles "trip free" - that is, if the breaker needs to trip and a padlock or naughty human is impeding the handle from moving, the breaker just trips anyway. So if the other half of the breaker impeded the handle from moving, the side that tripped would just trip anyway, and common trip would not occur.
This means you cannot 'bolt on' common trip by adding a handle-tie.
Common trip works by an internal mechanism within the breaker. Either the breaker has it, or does not. In the case of this Siemens breaker, it does not. Eaton also makes a line of non-common-trip quadplex breakers just like these, but they also make nearly identical breakers with common trip inner and outer. Other makers build them with inner common-trip and outer independent trip.
So from a common-trip perspective, a handle-tie is nothing but "trip theater".
The real purpose of a handle-tie, as manassehkatz discusses, is to assure common shutoff when the handle is used as an "off" switch. And provide a visual cue that the circuits are related.
| https://diy.stackexchange.com/questions/201543 |
diy | How can I use existing satellite coaxial cable to carry my internet connection? | I recently moved to another internet provider who provides FTTH (Fibre To The Home).
Now my powerline adapters are incapable of taking full advantage of the increased speeds. I'm currently using Wifi and losing some speed, and don't really want to run CAT5 cable throughout the house.
Considerations:
I considered buying newer powerline adapters that can handle speeds up to 1000Mbps, but I doubt I will get speed anywhere near that. I only get 70-80Mbps with my current powerline adapters which state they handle anything up to 300Mbps. Wifi gets me to 800Mbps.
I currently have unused coaxial cable wired into all rooms in my house. They were used for satellite TV. The thicker cable in the photo is either RG6 or RG59 cable. The thinner cable is the type used for landline telephones (RJ11/RJ45).
My questions are:
Can I use some kind of adapter to make either one of these cables compatible with ethernet ports i.e. be able to plug 1 end into my router and the other end into my computer?
Would performance be worse than if I had just used CAT5?
| VQAonline_00012023.png | To answer your question, what you are looking for is a MoCA (Multimedia over Coax Alliance) adapter. It will allow you to media convert from ethernet to coax.
IMHO, I would run new ethernet cable as you'll get much better performance with less points of failure. MoCA's have performance claims that sound great but from reviews don't live up to the hype. Never used one personally and don't plan to.
| https://diy.stackexchange.com/questions/259350 |
diy | Ice In Radon Mitigation System | I have a fan powered radon mitigation system installed in my house. It was installed in 2016 and I have not had any issues with it until this winter. I live in northern Iowa where we have been getting some unusually extreme temperature variations this winter (10F - 55F on some days).
I believe the system is exhausting warm moist air which is then freezing within the 4" exhaust pipe. As the pipe heats above freezing, this ice releases and falls into the exhaust fan. This causes some extreme noises (Much like marbles in a blender) until the ice has been chopped to small enough pieces by the fan to fall further under the slab.
The installer claims that the fan is designed for this, but I have to think that this happening on a daily basis will shorten the life of the fan (Not to mention the whole house panic when this happens in the middle of the night (Due to loud noise)).
What are my options to prevent this ice from making noise and destroying my radon fan?
Note: Basement has no water issues, and radon manometer shows normal readings.
| VQAonline_00010604.png | Maybe you could splice in some sort of 45 degree sanitary tee at that curve right above the fan? That way, when the ice falls down the pipe, it gets caught. Maybe also some kind of filter there to restrict airflow but allow water to melt out on warm days.
| https://diy.stackexchange.com/questions/154248 |
diy | What type of caulk can I use between the furnace vent pipe & flashing on a roof? | Looking to seal a gap between my furnace's vent pipe & the flashing on the roof, specifically here:
I'll have to check if there's a missing storm collar too, but should I use High-temp silicone, or go with the Big Box's recommendation of roofing asphalt (sounds burny).
| VQAonline_00009609.png | I'd recommend Not using any petroleum-based sealant on any surface subject to heat (it will soften and melt). For a positive and weatherproof seal use any 100% silicone caulking (Dap, Owen-Corning, etc.). For an even better and longer lasting seal against water go with any exterior Urethane caulking. Well worth the slight cost increase, but is U.V resistant and stays pliable indefinetly. And there is no need for a high temperature rated sealer. Unless the area you are sealing is in close proximity to the heat source. Than you will need some type of refractory-type caulking.
| https://diy.stackexchange.com/questions/71999 |
earthscience | Why does the color of this hillside rock vary? | Below is a roadcut in central Marin County, California, in an area maps show to have Franciscan melange. I assume this is graywacke, but as you can see it varies from gray on the sides to a buff color in the center. Is the buff section due to some chert content, or did that section weather differently (and if so why)? Thanks!
| VQAonline_00012107.png | It's pretty hard to say anything about this kind of weathering without actually being there and having a closer look.
Usually, the simplest explanation for reddish or brownish colours in otherwise grey rocks is the presence of iron oxides. You can see that the brown area is on a fault or joint face. This leads me to think that maybe this was a conduit for groundwater that oxidised the rock. When the road cut (or whatever it is) was made, this part was exposed. Notice that you have some brown elsewhere - it could be that those are faults or joints cut perpendicular to the face, so that's why you only see a brown streak instead of a surface.
| https://earthscience.stackexchange.com/questions/6689 |
earthscience | Easy homework questions about seasons and daytime | The following homework assignment is supposed to be easy, but there seems to be information missing from the questions asked (or at the very least knowledge from OP).
At which width circle does the sun shine perpendicularly?
How long is a day south of the south polar circle?
Which season is starting in the southern hemisphere?
The following picture was included.
| VQAonline_00012177.png | The figure depicts the Northern hemisphere summer solstice, given that, there is no information missing:
At which width circle does the sun shines perpendicularly?
The one labeled "13 1/2 uur" that corresponds to the Tropic of Cancer
How long is a day south of the southpole circle?
If we understand "day" as the length of daytime, the answer is zero: The sun never rises that day south of the southern polar circle.
Which season starts at the southern hemisphere?
Winter
| https://earthscience.stackexchange.com/questions/13622 |
earthscience | Why is the eastern Pacific full of stratocumulus clouds, and why do they have so much variation in net radiation? | They can be seen in the diagram below (of the CERES radiation dataset - supposedly they contribute a lot to the total variance in net radiation, which is the sum of SW and LW) - just west of Peru and Mexico (my supervisor, Dargan Frierson, said these are stratocumulus regions). I'm just wondering - why are stratocumulus clouds so abundant there?
(the diagram is taken after taking the 12-month running mean of the dataset, which smoothes out a lot of features).
| VQAonline_00012070.png | On the east side of the Pacific Ocean, there are cold currents coming the poles going towards the equator. The cold currents makes it so there is almost a permanent cold air mass above the eastern portion of the ocean. As warmer air is blown over this colder air, it must go above the colder air. The warmer air expands, temperature decreases, becomes saturated and the stratus clouds form!
The cold currents are there because of the semi-permanent high pressure system in the mid-latitudes of the ocean. The winds are equator-ward on the east side of high pressure systems. This drives the ocean currents to be equator-ward on the east side of the ocean.
| https://earthscience.stackexchange.com/questions/987 |
earthscience | What causes the Earth to have magnetic poles? | A compass can tell me the directions of the Earth's North and South poles? What is it about the Earth that produces this "polarity" such that a compass can pick it up?
The first thing that jumped into my head was the Earth's rotation, but if that is the explanation, why have I heard from people that the Earth's polarity can switch every million years or so?
| VQAonline_00012052.png | Well, firstly it's important to recognise that the poles are merely the extremities of the shape of a magnetic field - the earth's magnetic field. All magnetic fields have polarities as such.
However, you're asking why the field itself even exists, I gather. In this case it's generated by electric currents in the conductive molten iron (and other metals) in the core of the earth, as a result of convection currents generated by escaping heat. This is known as a geodynamo, and is one way of generating a magnetic field. However, exactly why this occurs is still under investigation.
More is available in this Wiki piece - specifically on the physical origins of the earth's magnetic field.
| https://earthscience.stackexchange.com/questions/99 |
earthscience | Why would a Martian tsunami travel at only 200 km/hour, four times slower than on Earth? | The news article Impact crater linked to Martian tsunamis describes results of numerical calculations which address the possibility that a giant martian tsunami triggered by an impact has left recognizable features on the martian landscape. The research is published in the Journal of Geophysical Research - Planets, but as of this moment the DOI link there doesn't seem to work. However, it seems to be:
Costard et al. 2017, Modeling tsunami propagation and the emplacement of thumbprint terrain in an early Mars ocean, DOI: 10.1002/2016JE005230,
ABSTRACT:
The identification of lobate debris deposits in Arabia Terra, along the proposed paleoshoreline of a former northern ocean, has renewed questions about the existence and stability of ocean-sized body of water in the early geologic history of Mars. The potential occurrence of impact-generated tsunamis in a northern ocean was investigated by comparing the geomorphologic characteristics of the Martian deposits with the predictions of well-validated terrestrial models (scaled to Mars) of tsunami wave height, propagation direction, runup elevation, and distance for three potential sea levels. Our modeling suggests several potential impact craters ~30–50 km in diameter as the source of the tsunami events. Within the complex topography of flat-floored valleys and plateaus along the dichotomy boundary, the interference of the multiple reflected and refracted waves that are observed in the simulation may explain the origin of the arcuate pattern that characterizes the thumbprint terrain.
Also see Editor Highlight
I can not access the article yet, but the BBC interview with Costard leaves me puzzled about the speed of tsunamis:
Two successive waves were formed during the event, says François Costard.
"It was a really large-scale, high speed tsunami. At the very beginning, a crater of 70km in diameter was created by the impact. This expelled a huge volume of water, with wave propagation at 60m/second," he explained. (emphasis added)
"The initial wave was about 300m in height. After just a few hours, that tsunami wave reached the palaeo-shoreline located at a few hundred km from the impact crater."
This gigantic wave washed over hills and plateaus and through valleys, leaving behind the lobate flow deposits.
"Finally... due to the Martian ocean filling in that crater, which produced a kind of rebound, there was a second wave propagation," Dr Costard added.
60m/s is 216 km/h, and this is consistent with a few hundred km in a few hours also mentioned.
Question: If I just google the speed of a Tsunami on Earth, I see 800 km/h. The surface gravity on Mars is about 3.71 m/s^2, or about a factor of 2.6 lower than that of Earth. Does this explain the factor of 4 slower speed of the Tsunami wave quantitatively?
below: "The thumbprint terrains probably formed when two sets of tsunami waves interacted." from here.
| VQAonline_00012151.png | The linked paper does numerical modelling of a hypothetical tsunami and predicts speeds between 60 m/s (at its point of origin) and 30 m/s (nearer to shore). We can try a back-of-an-envelope approximation to see if we get close, and to understand why the speed would be so much lower than on Earth.
A tsunami behaves as a gravity wave with a very long wavelength. In shallow water (and pretty much anywhere in Earth's oceans counts as shallow water for such a long wave), the speed at which it moves is approximated by
$$V = \sqrt{gD}$$
where $V$ is the wave's speed, $D$ is the depth, and $g$ is the acceleration due to gravity.
On Earth, $g = 9.81$ m/s2 and, in the deep ocean, we might assume a depth of 4 km and obtain a speed of 198 m/s, or 713 kph.
Let's try this for Mars. As you've identified, the acceleration due to gravity on Mars is about 3.8 m/s2, and the linked paper gives assumed depths of the ocean on Mars as between 100 and 1200 m (forgive me if this is not quite right - I've only skimmed the paper, and these figures come from Table 1). Let's assume a 1000 m depth, since the highest speeds will be found in deep water:
$$ V = \sqrt{ 3.8 \times 1000 } = 61.6\ \textrm{m/s} $$
which is close enough to their value for comfort. So a tsunami on the Mars described here would be much slower than on Earth due to the weaker force of gravity and the shallower depth of the ocean.
| https://earthscience.stackexchange.com/questions/9966 |
earthscience | Does Earth's air leak into space over time? | From my current understanding, Earth's atmosphere and air are held by the balance of two forces: 1. Earth's gravity and 2. Air pressure from air out to space.
Is my understanding correct?
So, do these two forces always stay the same? If they are not the same, have the earth lost its air into space? And if so by how much each year?
| VQAonline_00012063.png | Earth's atmosphere does escape over time, albeit very slowly.
The distribution of kinetic energies of molecules in a gas obeys (more or less) a Maxwell-Boltzmann distribution. Notice that the graph is asymptotic, so in a suitably large population of gas molecules, there is a non-zero probability that some of those molecules will have a an arbitrarily large kinetic energy. This implies that in the population of gas molecules constituting Earth's atmosphere, some of them will have kinetic energy such that their velocity exceeds the Earth's escape velocity and provided that their paths are oriented away from any obstacles (including the Earth's surface itself) and they don't collide with anything, those molecules can escape. On average, only a small number of molecules will actually achieve all these conditions. The end result is that atmosphere does indeed escape, but the effect is tiny - only on the order of grams per second due to the process described above according to this article I found.
This is not the only process responsible however, phenomena like the solar wind also have a role in liberating gas molecules from the Earth's atmosphere.
The effect is much more pronounced on other rocky planets in the Solar system, for example Mercury has very little atmosphere due to it i) being extremely hot and ii) being bombarded by highly energetic particles from the sun much more than we are. Similarly, Mars has a predominantly carbon dioxide atmosphere that is thought to have been much thicker in the past than it is now, and therefore must have escaped somehow (assuming you don't believe stories like Total Recall where the atmosphere is intentionally held captive ;) - although in fact the Martian atmosphere does condense at the poles leading to a significant amount of atmospheric agitation with the changing of the seasons)
| https://earthscience.stackexchange.com/questions/736 |
earthscience | Was the last glacier too hard for the Neanderthal? | I know several theories are proposed to explain Neanderthal extinction:
Consanguinity.
Homo Sapiens competence.
Climate change.
But Finlayson et al (2008) quote the last ones lived south of the Iberian Peninsula. This make me think Europe's climate was too cold for them, so they migrated to South.
This surprises me as I have allways considered Neanderthal a cold specie adaptated to glaciar.
The oldest potential Neanderthal bones are dated to 430 kya (Neanderthal, Wikipedia); they had faced to a previous glaciation and they survived.
I am not asking if the climate related extinction theory is the correct one. I am asking if there are evidences the climate on Europe was too cold for this specie. Also I would like to know if there are evidences they also migrated to South in the previous glaciar peak, around 150 kya ago.
Clive Finlayson, Darren A. Fa, Francisco Jiménez Espejo, Jóse S. Carrión, Geraldine Finlayson, Francisco Giles Pacheco, Joaquín Rodríguez Vidal, Chris Stringer, Francisca Martínez Ruiz (2008): "Gorham's Cave, Gibraltar—The persistence of a Neanderthal population". Quaternary International, Volume 181, Issue 1, Pages 64-71, ISSN 1040-6182.
https://doi.org/10.1016/j.quaint.2007.11.016.
| VQAonline_00012225.png | First things first, the reasons for the Neandertal(N) extinction are not known definitely. There is though no evidence of violence (*).
There is an overlap in Europe of N and anatomically modern humans (AMH) of several thousand years, even if N find sites are limited to the Mousterien industry alone. This is a conservative limit because N may have used more advanced technology like blade production as well in their last millennia, which would extend N presence to ~32,000BP. Sites like Gorham's Cave fit into that picture, but this long chronology of N is debated and counterdebated :-)). Anyway, long before the last glacial maximum (~23 to 20ky BP) they were gone.
Somewhat outdated is the view that N is a cold adaptation of the human lineage. The appearance of tools for clothing (bone needles) drastically rise with the Aurignacien, the first stone tool industry linked to AMH in Europe. That of course does not mean N didn't use clothes, but that they probably had not the same proficiency as Cro Magnon & consorts in making them. Correlation of find sites and climate confirm the picture that N avoided cold climates. N populations were smaller than AMH, though not really endangered by genetic bottlenecks (there is newer work concerning Denisovans, stating they never really split from N, but i can't find it).
By now it pretty clear that N and AMH interbred on many occasions.
So why did they become extinct ? Together with other ice age megafauna in a highly stressed environment, loosing their way of subsistence ? Competition of top predators ? Inbreading nevertheless ? Dwindling numbers and simple merge with AMH ? Bad luck ? Unclear ...
(*) I want to add a remark here to the Shanidar 3 guy mentioned below. First of all, the authors do not exclude an accident. Second, the work has been criticized by Trinkaus et al. for methodological errors, as is cited here. Similar arguments apply to St. Cesaire 1 (healed skull fracture) is likely an accident, the argument for an intentional blow is too weak. I do not categorically exclude violence in the Paleolithic, the accusation is unfair, I only say there is no (undisputed) evidence. The Shanidar burials, as well e.g. La Chapelle aux Saints 1 are seen as examples for compassion for those in need of care among N. Btw.: we haven't been at the meat of that yet, but i am not handing out fuel against my argumentation ;-)
It was stated that
"Our ancestors killed the males of other tribes and raped the few remaining females. That our ancestors killed Neandertals who looked rather different is not a far stretch from killing other anatomically modern humans who looked only slightly different."
Both claims are not backed by science, Cro Magnon and Neandertals were not that different (reconstructions Neandertal Museum, Mettmann, Germany) and normal people don't just attack others. Hunting strategies of late N and AMH in the early Aurignacien don't differ by much.
That men were killed and woman stolen happened in very isolated cases in the Neolithic and contemporary Mesolithic, and violence also becomes evident in the Epipaleolithic/Neolithic precursors ~10kyBP , in sedentary or semi-sedentary groups, but that's not the point here. Rather not did it happen in the cold steppe of oxygen isotope stage 3 in Paleolithic Europe for obvious reasons: when the loss of a hunter could endanger the whole group; and women - having one child at a time to keep up the pace of mobility - moved around with the group. At the time 40kyBP population was low, it must rather be assumed that any accidental meeting was a cause of celebration and interchange, as is reflected in the genome.
| https://earthscience.stackexchange.com/questions/19002 |
economics | Why are there infinitely many indifference curves? | If an indifference curve shows quantities where a consumer's utility from consuming two goods are equal, then why are there infinitely many indifference curves? From the diagram, you can have Q1,Q2 on IC1, but then you'd have Q1,Q3 on the other indifference curve, wouldn't that mean the consumer would receive the same utility from consuming Q1 and Q2 as well as if he had consumed Q1 and Q3, i.e. for a given Q1, the consumption of Q2 gives the same amount of utility as Q3? Shouldn't this mean that the indifference curve should be unique?
| VQAonline_00012320.png | Utility is constant for all points $(q_B,q_A)$ on an indifference curve. So there is a number $u_1$ such that
$$
\forall (q_B,q_A) \in IC_1: \ U(q_B,q_A) = u_1.
$$
Similarly there is a number $u_2$, such that
$$
\forall (q_B,q_A) \in IC_2: \ U(q_B,q_A) = u_2.
$$
If $IC_1 \neq IC_2$ then $u_1 \neq u_2$.
| https://economics.stackexchange.com/questions/15090 |
economics | Is there unnecessary duplication for borrowing in this circular flow of income diagram? | Here is a circular flow of income that I took from Krugman's macroenomics textbook.
We can see that when firms want to borrow they can go to the financial sector and borrow savings of national and foreign households. BUT, it seems like there is also another way for firms to borrow money: the factor market. Capital is a factor of production. And there are different kinds of capital, in our case we're interested in financial capital, specifically in financial capital that is basically a pile of money. And how can we, sort of, buy such financial capital? By borrowing it! So firms "buy" financial capital from households and then pay them interest (you can see that interest is paid to households from the diagram).
I don't get the purpose of this duplication. Why use financial sector for borrowing when we have the factor market? Or why use the factor market for borrowing when we have the financial sector? Is there some kind of important difference between them that makes both of them necessary in borrowing? Or did I make a mistake in my reasonings and firms can't get borrow money from the factor market? If yes, then why do households get paid interest from the factor market?
| VQAonline_00012422.png | No because the financial markets do not provide firms with capital they provide them with funds to buy capital which is a difference. You can call those funds financial capital but it’s not capital in economic sense.
In common usage in English capital is often used as a synonym for money. For example in Oxford dictionary under the word capital the second entry is simply money (see here).
However, in economics capital, especially when we are talking about factor markets, is used in the following definition:
“The equipment and structures used to produce goods and services.”
The above definition is taken from Mankiw and Taylor (2014), Economics the 3rd edition. In different textbooks the exact wording may change but to my best knowledge no conventional textbook would include money as it’s definition.
Also generally money is not considered a factor of production in itself hence it’s a tautology that factor markets should provide only factors of production.
Moreover, generally financial markets are often considered quite distinct from other economic activity. In fact often you can hear economists speak of ‘real’ economy and financial markets separately. This is due to the classical dichotomy which makes sharp distinctions between real and monetary (nominal) variables. Factor markets are considered to be part of real economy, where real goods, services, and factors circulate, while financial markets are part of monetary sector which covers the circulation of money and other financial goods and services.
In comment @user161005 asks additional question of why the arrow going to factor markets includes interest, since answer to this might be of interest (no pun intended) to other users who skip comments I put the answer also here:
In economics the income derived from labor is called wages, the income from land rent, and income derived from capital interest.
The last often confuses students because many textbook models call the interest earn from capital $r$ instead of $i$ but this is because $i$ is already used widely in other macroeconomic models.
The profit is what is left after the wages are paid to the labor, rent to landowners and interest to capital owners. Profit is considered to be the reward for entrepreneurship which can be considered as another factor of production.
A good entry level explanation of this is provided in this FED St. Louis podcast that you can listen to (or read transcript to) here.
| https://economics.stackexchange.com/questions/36611 |
economics | Understanding a multi-player Tragedy of the Commons game | In the formulation of the Tragedy of the Commons below, what does $n$ exactly represent? Is a threshold? The text is from plato.stanford.edu website on Kuhn's Prisoner's dilemma.
Also, it says that $\bf D$ strongly dominates $\bf C$ for all players, and so rational players would choose $\bf D$ and achieve $0$, while preferring that everyone would choose $\bf C$ and obtain $C+B$.
I don't understand the last part. The reason $\bf D$ dominates $\bf C$ is because either the player gets $B$ or $0$ which are better from $C+B$ or $C$. Why would rational players prefer everybody to cooperate?
| VQAonline_00012389.png |
what does exactly represent? Is a threshold?
Yes, $n$ is the threshold above which the benefit $B$ realizes. Think of this as a situation where a public good with benefit $B$ is provided only if more than half of the population votes for it. $C$ is the cost of voting, and $n=\lceil\frac12N\rceil$ is the smallest integer greater than half of the population size ($N$).
Why would rational players prefer everybody to cooperate?
While a rational player would choose $\mathbf{D}$ regardless of what others would choose, he/she would still prefer the outcome with benefit $B$ to the outcome with $0$ benefit. Hence, he/she would prefer everyone else chooses $\mathbf{C}$, i.e. bearing the cost of providing benefit $B$, while he/she enjoys $B$ without incurring any cost by choosing $\mathbf{D}$.
Additionally, suppose there are $N$ players, and that $n<N-1$. Then with all the other $N-1$ players playing $\mathbf{C}$, it doesn't really matter if the remaining player chooses $\mathbf{C}$ or $\mathbf{D}$. So arguably it's less morally objectionable for the last player to choose $\mathbf{D}$.
| https://economics.stackexchange.com/questions/26810 |
economics | Are there two deadweight welfare losses associated with a Pigovian tax? | I am constructing a diagram for an indirect tax (specific) imposed to correct a negative externality of consumption.
There is a deadweight welfare loss from the externality (represented in blue) because, although it is reduced,the tax does not achieve to shift the supply curve to a point where MSB=MSC (Qm).
However, the tax itself also should produce a deadweight welfare loss (represented in green). Is it correct that there are two deadweight welfare losses in this situation or is there no deadweight welfare loss associated with a Pivogian tax?
| VQAonline_00012351.png | The Pigovian tax is responsible for neither of the deadweight losses in your diagram.
The Pigovian tax has partially, but not wholly, corrected a deadweight loss that was caused by the negative externality.
There is a deadweight loss associated with Pigovian taxes: that is the administrative cost of collecting the tax. This is not pictured in your diagram.
| https://economics.stackexchange.com/questions/20685 |
economics | Plotting the isoquant curves | I have the following equation
$$Q_1(K, L) = AK^α L^β, A, α, β > 0$$
I'm asked to derive the isoquant curve which yields the following diagram:
Could anyone please explain to me how the form of the graph was found?
I have 5 unknowns in this equation and I just can figure out how would it be possible to plot the graphs.
Thank you very much in advance for your help!
| VQAonline_00012393.png | Each curve shows the rate at which K can be substituted for L, or vice versa, while keeping output constant. The Marginal Rate of Technical Substitution (MRTS) equals the absolute value of the slope. The MRTS tells us how much one input a firm can sacrifice while still mainting a certain output level. Then the MRTS is equal to the following ratio: $$\frac{\text{Marginal Productivity of Capital } (MP_{K})}{\text{Marginal Productivity of Labour } (MP_{L})}$$
Then the substitution of Labour (L) for Capital (K) is given by:
$$ MRTS_{K,L} = -dL/dK = MP_{K}/MP_{L}$$
Now, note that in your equation $\alpha$, $\beta$ and $A$ are exogenous parameters (i.e. given to you). What your equation will then defined is, given these parameters, how your inputs (K and L) result in some amount of output given your production function.
You can find the isoquant curve that yields that diagram by varying the fixed level of output and by "playing with the fixed parameters".
| https://economics.stackexchange.com/questions/27687 |
economics | Income Elasticity of Demand vs. shift in demand curve | I've just read an econ textbook and want to verify a statement/definition about income elasticity of demand.
Changes in income shift the demand curve, and we can measure the responsiveness of demand to income changes by calculating income elasticity of demand as follows:
Question: Where does this change in quantity demanded come from? Is it from a movement along demand curve, or from a shift of demand curve?
| VQAonline_00012349.png | Short answer:
Denoting income by $I$, price by $p$, the demand function by $D(I,p)$ and income elasticity of demand by $\eta$, the definition of point elasticity of income is
$$
\eta = \frac{\text{d}D(I,p)}{\text{d}I}\frac{I}{D(I,p)}.
$$
So the change in demand comes from a change in income.
Long answer:
Without specifying your coordinate system the terms "movement along the curve" and "shift of the curve" are meaningless.
Consider the function $f(a,x) = a/x$. Suppose this function determines the value of a variable $y$, that is $y = f(a,x)$. Given $a$ we can plot $f(a,x)$ in the $(x,y)$ coordinate system. If $x$ changes there is movement along the curve in this coordinate system. If $a$ changes the curve shifts in this coordinate system.
However treating $a$ as a variable and given $x$ we could also plot $f(a,x)$ in the $(a,y)$ coordinate system. Then change in $a$ would mean movement along the curve and change in $x$ would shift the curve.
As quantity demanded usually depends on both income and price, you face a similar situation, where $q = D(I,p)$. Income elasticity examines a change in income, but without specifying if your curve is ploted in $(p,q)$ or $(I,q)$ you cannot classify the change in $I$ as either "movement along the curve" or "shift of the curve".
| https://economics.stackexchange.com/questions/20273 |
economics | How to determine regressive tax | I have a mock-up exam that my teacher gave me and one of the questions was the following:
Given these four graphs, which one represents regressive tax?
I'm quite sure it's graph A, but I don't seem to be able to find a proper reason why. Any help and/or tips are welcome!
Thanks in advance
EDIT: As per request. How I interpret this: regressive means the higher the income, the lower the tax. Thus: tax drops with higher incomes. But I can't really determine to which graph this applies.
(T is tax, Y is income)
| VQAonline_00012286.png | You're correct it is graph A. Regressive tax means that the lower income you have the higher %tax you have. If you imagine at the lowest level of income, you still have a flat tax(The intercept).
Since the slope is constant the %tax component is the same for all income levels.
Therefore this flat tax component is the part you need to look at. The flat tax represents a larger proportion for lower income earners. As a whole (%tax + Flat tax) the tax is then a higher % for lower income earners, hence regressive taxation.
| https://economics.stackexchange.com/questions/5902 |
ell | The remaining parts of an ancient city | What do you call the remaining parts of an ancient city like what you see within the picture that sometimes archeologists discover and unearth?
1- Remnants of a city
2- Remainings of a city
To me they both work, but I am sure there is a fixed term to it. Also, I wonder if there is a better choice.
| VQAonline_00013012.png | Cities do not have remnants. Remaining parts of something does exist in general but is not an archaeological term per se.
Remnants is a word applied to objects. Not a site.
The proper term is remains:
"Sites may range from those with few or no remains visible above ground, to buildings and other structures still in use." [Wikipedia]
The remains of a city or archaeological remains of a city.
remains
| https://ell.stackexchange.com/questions/215303 |
ell | To pinch or to grab someone's face? |
"She pinched my face. That hurt."
"She grabbed my face. That hurt"
What word is more suitable for the action illustrated in the image below?
| VQAonline_00012857.png | I'd call that a pinch. You can be more specific and say "she pinched his cheek", which means exactly what's shown in the picture.
| https://ell.stackexchange.com/questions/146191 |
ell | What's the idiomatic way of saying "hide your lips"? |
What's the idiomatic way of saying "hide your lips"? I thought "bite your lips", but you're not biting your lips, your putting your lips inside your mouth. So what's the proper way to say it? I added a pic of someone doing it.
| VQAonline_00013016.png | Lambie's answer describes the action of curling one's lips inwards. But if the OP is looking for a shorter expression, then I would say that the young mother in the photo appears tight-lipped.
1 : having the lips closed tight (as in determination)
2 : reluctant to speak : TACITURN
Merriam-Webster
Cambridge Dictionaries has
Someone who is tight-lipped is pressing their lips together to avoid showing anger, or is refusing to speak about something:
| https://ell.stackexchange.com/questions/216508 |
ell | All vs. For all | According to the fourth edition of English Grammar in Use by R.Murphy, we can't use for + all:
However, I can often hear people use for + all. They might say, for example:
I wanted to remember it for all my life.
I've been waiting for this moment for all my life.
But as for "all day", I think it's really better to day "I've been working all day" or "I've been working for the whole day".
So, do people break the grammar rule saying something like "For all my life, you'll be the one"?
| VQAonline_00012945.png |
"However, I can often hear people [...] say, for example:
I wanted to remember it for all my life.
I've been waiting for this moment for all my life."
So, do people break the grammar rule saying something like "For all my life, you'll be the one"?
Let's cut to the chase. Yes, in each case, these examples, represent people breaking rules of grammar. However, I would qualify this by saying that in spoken English, either form is acceptable.
This subject has been canvassed in this place at least once previously Is there a grammatical rule impeding the presence of 'for' in “I have lived here 'for' all my life”?. On that occasion there were views for and against. Some relying on standard academic publications to reinforce their views. The most popular answer was "I think you just have to accept that when all comes before words that express any length of time, it cannot be preceded by for".
J.R (reputation >94K in this community) also entered the fray and his comments are most relevant to this question. He said "Unless the for is not starting a prepositional phrase (as in, "That is what I've been hoping for all my life," or, "This is what I've been waiting for all summer")."
The topic has also been canvased, to a lesser extent, on "English language and usage" Difference between “my whole life” and “all my life”?. Interestingly, the responses there were somewhat less didactic
The questioner asks specifically about the sentence "For all my life, you'll be the one". I don't think there is any doubt that this breaks the formal rule of not using "for" in a prepositional phrase. But how easy is it to imagine two lovers saying these words to each other? At that time and place, do the laws of grammar apply? Which is why I believe that in spoken English the rules are not so hard and fast as they might be for written English.
In any event, though I am a stickler for grammar (or at least the bits that I know of), I think grammar rules are made to be broken. How else does language relate and respond to daily life, new experiences and events, if not through constant change? The rules of grammar are written at a given point in time and space in the world. And even in that time and space, one might find that within a radius of several kilometres, or even several hundred kilometres, there are marked cultural and language differences which reinforce that often such "rules" are written by and for the benefit of the reigning middle and upper classes, and have little relevance to the working man's use of language.
| https://ell.stackexchange.com/questions/183364 |
ell | Vegan fish fillet or vegetarian fish? | We normally say "vegan fish fillet" shown in the image below. Here is the product
List of ingredients:
Water, Soybean Fiber, (soybean protein, wheat starch, wheat protein, soybean oil), Soybean Protein, Soybean Oil, Tapioca Starch, Spice,Raw Cane Sugar, Sea Salt, White Pepper Powder, Laver, Yeast Peptone Powder, Natural Vegan Flavor.
Can we instead say "vegetarian fish" to describe this food?
| VQAonline_00012849.png | Yes, it sounds fine to me. The word vegetarian plays the role of an adjective and it combines with fish to create a compound noun. The noun implies the fish is for vegans or made by/belongs to a vegan.
| https://ell.stackexchange.com/questions/143314 |
ell | what is the opposite of the stretch? | As I have checked some online dictionaries, I have found 'shorten' and 'shrink' as opposites of the 'stretch' word. But, I am not sure, yet.
As an example, suppose that shrink is the correct word, then I say in this figure
I am shrinking the plot from top to bottom or stretching vice-versa.
| VQAonline_00012592.png | Shrink can work. I would also consider "compress" as a good option. "Reduce" can also work
I reduced the plot vertically
You could ask this on English Language and Usage to get additional ideas.
| https://ell.stackexchange.com/questions/46791 |
ell | What does "something are down" mean? | I saw this picture on the Net...
What does "The computers are down" mean? Thanks.
| VQAonline_00012539.png | Literally, "computers are down" means that those computers are off-line, usually because of some kinds of problems (such as power failure, software failure, operating system crash, etc.).
I don't know if there are any deeper meaning. But it seems to me that the comic hints that people nowadays rely too much on computers. Even a guru still needs computers to provide a good answer. (In this case, "the meaning of life".)
PS. This reminds me of a novel by Douglas Adams, Hitchhiker's Guide to the Galaxy. In order to get "the answer to life, the universe, and everything", a supreme being had to create a computer to provide such an answer. After a long time past, the computer gave the answer, 42. (The computer that was created in the story was actually our Earth, including us human beings.)
| https://ell.stackexchange.com/questions/13927 |
english | What does "Do you haz teh codez?" mean? | There is a banner in StackOverflow pointing to the careers website (programmers):
Do you haz teh codez?
My questions about the sentence/question are:
What's the question in plain English?
Why do they write it like that?
Is it like a word game?
How should I read it in terms of pronunciation?
| VQAonline_00013261.png | Literal translation is "Do you have the code?" but what is implied is "Please can you write my application for me?" or "Please solve my problem so I don't have to put any effort in."
It is written like that as a mockery of people who ask questions on Stack Overflow, and other such websites, where their question is a thinly veiled, or completely unveiled, attempt to get someone to do their work for them. So the questioner won't have even have tried to solve their problem and will possibly be asking for an entire software application to be written.
I'm not sure what you mean by "Is there like a word game?" If you mean is this like a word game then not really, it's just a joke.
It should be pronounced "Do you haz (as in Mazda) teh (as in meh) codes?" and in IPA: /duːjuːhæztɛkəʊdz/.
For an example of the type of thing this is mocking: http://thedailywtf.com/Articles/plz-email-me-teh-codez.aspx
| https://english.stackexchange.com/questions/13231 |
english | "Neither of us are" -vs- "Neither one of us is" | This cartoon was recently posted on Facebook. My sister (who is a retired HS English teacher) says the grammar is wrong and that the correct wording should be: "Neither one of us is." but I disagree.
I am not an English teacher but I believe that "US" relates to "WE" and the correct wording for that pronoun is "WE ARE". On the other hand "ONE OF US" relates to "I" and "YOU" but the correct wording for those pronouns would be "I AM" or "YOU ARE" ... There absolutely is no place in English where we correctly use "I IS", "YOU IS", or "WE IS" so why would "US IS" be correct?
| VQAonline_00013900.png | Your sister appears to be correct. 'Neither of us' is understood as 'neither one of us' and is treated as singular. From the Commnet "Guide to Grammar and Writing":
The pronouns neither and either are singular and require singular verbs even though they seem to be referring, in a sense, to two things.
Neither of the two traffic lights is working.
Which shirt do you want for Christmas?
Either is fine with me.
According to Ngram, it is also the most conventional usage.
| https://english.stackexchange.com/questions/470158 |
english | What do you call the strips on shoes that are often used instead of laces? | Some shoes uses laces and so you lace them. But some shoes use these long strips (see picture below for an example).
How do you call these strips and what is the proper alternative for the verb to lace in this case?
| VQAonline_00014010.png | It is called Velcro strips:
the brand name of a type of fastening tape consisting of opposing pieces of fabric, one piece with a dense arrangement of tiny nylon hooks and the other with a dense nylon pile, that interlock when pressed together, used as a closure on garments, luggage, etc., in place of buttons, zippers, and the like.
(Dictionary.com)
Usage examples from Lexico.com
I can't manage things like zips, so they took the zips out and put Velcro in instead.
You may find yourself going out and buying shoes that have Velcro fastenings instead of laces as the child cannot grasp how to tie their own laces.
| https://english.stackexchange.com/questions/581514 |
english | What is ridin in "We're ridin' with Biden"? | What is ridin in "We're ridin' with Biden"?
Source: [Dantri.com]
| VQAonline_00013985.png | Ridin’ means riding. It is meant figuratively: It does not mean literally riding in the car, just “we are along with him- we support his candidacy.”
The term for dropping a sound (in this case g) is elision.
“Ridin” has the benefits of rhyming (close enough) with Biden and also having a folksy sound, which is part of the soon to be president’s persona.
EDIT: Thanks to comments by shoover: Ridin(g) also alludes to Biden riding the train from Delaware to DC and the sign is from a transit workers’ unit.
| https://english.stackexchange.com/questions/558038 |
english | Toasters don't toast toast, toast toasts toast, or does toast toast toast? | I saw this funny meme from someeecards:
It has me a little confused: To me it sounds like toast toasts toast, not toast toast toast. Is this meme wrong or am I missing something Either they (toast) toast toast. Or, it (the idea of toast) toasts toast?
| VQAonline_00013846.png | Your interpretation is correct, but so-called Internet memes are not overly concerned about grammaticality or idiomacity or logic.
The humor fails on multiple levels. As Edwin and Dan point out in the comments, there are various practical objections, for example, that toasters toast bread. But it is an attempt to be humorous, after all, not really a political argument, so the bad analogy is beside the point.
The attempt lies primarily within the thrice-repeated toast. This forces the reader to pause to work out how each toast functions. Toast is not the grammatical verb form, however, which spoils the attempt. Guns and people are plural whereas the middle toast, being used as an uncountable noun here, is treated as singular. The grammatical form doesn't succeed as there is no confusion as to which words serve which roles in toast toasts toast as compared, for example, to Buffalo buffalo Buffalo buffalo buffalo buffalo Buffalo buffalo.
You need a noun which shares a form with a related verb and which can also serve as its object or other complement. Consider
Fishermen don't fish fish, fish fish fish.
| https://english.stackexchange.com/questions/428900 |
english | What is a "hood" in this context? | A forum poster was giving an account of his visit to his friend who is an owner of a burger shack, and in one part he said:
We smoked some of the Mr. Nice I brought along to give him and his employee for the trouble and blew it up into the hood in classic poverty restaurant style :coolface:.
What is a hood? Is that the ceiling of the restaurant? I was thinking this couldn't be the folding hood of the car.
Edit:
This is the picture of the kitchen he posted (couldn't scale it down unfortunately I'm on iPad :(), not sure if that device on the top left corner is the extractor or not, but could possibly be since I think there's what it looks like a fryer on the far right below it.
| VQAonline_00013430.png | In this context, sense 9 of hood applies: “A metal covering that leads to a vent to suck away smoke or fumes”.
The “classic poverty restaurant” / burger shack will have a big heated stovetop, or grill, with a noisy fan to move smoke from grease burning on the grill – or in this case from the joints they smoked – out of the restaurant.
| https://english.stackexchange.com/questions/122264 |
english | A Word For A Typographical Illusion or Typo Blindness? | Sometimes typographical errors are exceedingly difficult to catch - often because of typographical illusions.
This image is a good example of what I mean:
You may have missed the double "the" as many do!
I am curious if a word exists for this strange process of the brain "glossing over" the typo. Humorously, these typos are sometimes difficult to spot even when another person points them out.
I've heard this described as "Typographical blindness" but am looking for something more succinct.
| VQAonline_00013633.png | The specific illusion would probably fall under Future Perception, where the second "the" is consumed as we have already guessed what will come next.
https://en.wikipedia.org/wiki/Optical_illusion#Future_perception
A term I have seen for this specific occurrence concerning written text, is Typoglycemia. -- It does have an urban dictionary entry, so take it for what you will.
https://en.wikipedia.org/wiki/Typoglycemia
| https://english.stackexchange.com/questions/289485 |
esperanto | How do you say "empanada" in Esperanto? | How do you say "empanada" in Esperanto? I've tried to find a term for it but failed.
From Wikipedia:
An empanada is a type of baked or fried turnover consisting of pastry
and filling, common in Latin American and Filipino cultures.
Image source link
| VQAonline_00014033.png | I didn't find the exact word for empanada but I think (fritita) pastopoŝo is close enough. According to PIV if the empanada is small and the filling is sweet it is named dariolo and if the filling is meat, fish, etc. risolo.
From PIV:
dariol/o Fritita kukaĵo, speco de pastopoŝo kun, interne, dolĉaĵo.
risol/o Pastopoŝeto aŭ bulo, entenanta muelitan viandon, fiŝaĵon aŭ ĉasaĵon, k fritita en graso aŭ oleo.
| https://esperanto.stackexchange.com/questions/5451 |
esperanto | Ĉu estas bona traduko por la angla vorto «gate»? | Kiel oni povas traduki la anglan vorton «gate», ekzemple por priskribi ĉi tiun objekton (la pordon en la barilo):
La vortaroj de Lernu kaj John Wells havas pordego, sed al mi tio ŝajnas ne taŭga ĉar tiu pordo fakte estas pli malgranda ol normala pordo. Eble tio estas ĉefe por io kiel la Brandenburga pordego.
| VQAonline_00014026.png | Pordego is a large door for closing off a gateway - this is often appropriate for large gates in exterior walls.
Barila pordo is a small door through a fence.
Pordejo or is a gateway, and seems appropriate for the picture, since it doesn't look like it can be closed.
| https://esperanto.stackexchange.com/questions/2678 |
esperanto | Kiu nivelo de domo estas la "unua etaĝo"? | La maniero per kiu oni kalkulas etaĝojn estas malsama en la germana kaj la sveda. En la sveda, la normo estas ke la "unua etaĝo" staras sur la grundo. Tie kie oni eniras la domon estas la unua etaĝo. Mi lernis ke en la germana la "unua etaĝo" estas super la surgrunda etaĝo. Kiel oni nombras etaĝojn en Esperanto? Kiu estas la unua etaĝo? Ĉu a aŭ b?
| VQAonline_00014027.png | Vortaro.net ankaŭ mencias ĉi tiun problemon:
La maniero kalkuli la etaĝojn ne estas la sama por ĉiuj popoloj: iuj inkluzivigas la teretaĝon (do nomatan unua), aliaj ekskluzivigas ĝin.
| https://esperanto.stackexchange.com/questions/3219 |
esperanto | Nomo por skota bovo-specio: "Highland cow" | Kio estas la kutima nomo de la jena skota bovo-specio en Esperanto? Mi ne sukcesis trovi ion ajn interrete. Mi kontrolis en Vikipedio, PIV, ReVo kaj la vortaro de John Wells. En la angla oni nomas ĉi tiun beston "Highland cow", en la nederlanda oni diras "Schotse hooglander". Mi improvize uzis la esprimon "skota altlandulo", sed eble ekzistas pli tradicia esprimo.
What is the usual name of the following Scottish cow species in Esperanto? I couldn't find anything online. I checked Wikipedia, PIV, ReVo and John Wells' dictionary. In English this animal is called "Highland cow", in Dutch it's called "Schotse hooglander". I improvisationally used the term "skota altlandulo", but maybe there's a more traditional expression.
| VQAonline_00014032.png | Laŭ mia scio, Skota Altlandulo estas la plej senca kaj tute taŭga nomo por tiu besto, kun aliaj alternativoj ekzemple "Skota Altlanda Bovo". Ĝenerale plej gravas ke la uzita esprimo komuniku taŭge la koncepton al la parol-partnero.
| https://esperanto.stackexchange.com/questions/5395 |