darklight03/StackMIAsub huggingface dataset:
You often hear it on the news. Some embarrassing nonsense goes down, and then some honcho steps in front of the cameras looking concerned and goes, "I take full responsibility for what happened." What do they mean by that, exactly? Are they willing to be put on trial? Ready to pay a fine? Eager to resign? Do some community work for free? What? I believe I've heard the President, and some others in high positions, say it on a few occasions. What do they mean when they say it? Today I want to say this, as president and as Commander in Chief I take full responsibility for all of our counter terrorism operations including the one that inadvertently took the lives of Warren and Giovanni. President Obama from the White House (Here's the link)
In this answer on Stack Overflow, the term "several" is used as an indeterminate number, the actual value of which is literally in the quintillions: Zero is one of several values that can be represented exactly. To my ear, this is an exceedingly strange use of "several", which led me to believe that the writer was confused. I realize that trying to truly pin down "several" is probably a hopeless task, but I'm curious if anyone else would use it for such an immensely vast quantity, and if there's regional variation in the usage. So: How many is "several"? Would anyone else use "several" for "quintillions"? This question addresses similar issues, but doesn't seem to have the answer I'm interested in (much of the discussion mentions lower bounds for "several", but not upper bounds).
I'm relatively new to PDEs and ODEs. It seems that PDEs are generally more difficult to solve than ODEs, and so I intuitively have the feeling that one needs more information/knowledge/theorems in order to solve PDEs. I've seen many examples of going from from the ODE domain to the PDE domain, and vice versa. For example, I could set up an infinite series of ODEs that model an infinite line of masses connected by springs. Then one could, loosely speaking, get the wave equation (a PDE) when letting the mass go to density. Or, FEM approximates a PDE as a finite set of ODEs, but by letting each element go to zero size, one could regain the original PDE. Vice versa, the method of characteristics, or the method of separation of variables, allows one to rewrite a PDE as a (finite) set of ODEs. I'm wondering if there are general, perhaps hand-wavy, arguments for when it is possible to do such transformations? I feel that the PDE has to be sufficiently simple, or we need to know some additional information about the solution, in order to rewrite it to ODEs. Likewise I am guessing that only infinite sets of ODEs can be written as PDEs, but I am not sure if all infinite sets of ODEs are equivalent to a PDE.
I'm a software developer, and as such I often use an IDE to fulfill my goals. For those who don't know: An integrated development environment (IDE) is a software application that provides comprehensive facilities to computer programmers for software development. Sometimes while programming I find myself making certain errors. One of them is creating a variable (A name that holds a certain value) that is never used. An IDE can show a certain message and underline the error for me so that I notice it quickly and fix it. I have been using multiple IDE's that have shown me the error shown above, but I just noticed something. In one IDE, the message is shown as "Unused expression", while the other says "Useless expression". Which IDE is saying it right? Is it supposed to be "Useless" or "Unused"?
Can any noun ending in -ism describing some system or belief be changed for -ist to describe a member of that system? My question might be confusing, so I will run through a few examples: Nihilism => nihilist Feminism => feminist Racism => racist This seems to follow a pretty predictable pattern. So, when I learned a new word a while ago - misoneism (having a fear or hatred of innovation or change) - I was expecting to be able to call someone a misoneist, if it ever came to that. Unfortunately, while most dictionaries (online and paper) I have checked so far contain the word misoneism they do not contain the word misoneist. Were my assumptions correct that you can create any -ist noun from a root of -ism, or is this word in the dictionary because it really doesn't exist?
I want to study Mumford's Abelian Varieties in the coming winter break. I tried to study it before, but I didn't find my self really understanding(or memorizing) too much. I guess a better and more solid way to learn something is to go over many exercises. So I'm asking for some exercises(or problems?) on abelian varieties, it would be nice if I can get them online. Thanks in advance. And about the exercises: I wish it would be kind of like the ones in Hartshorne, so that I can solve them if I understand the material well. And not too hard, I guess I'm not looking for some research level questions... Also I wish those exercises may focus more on the algebraic/arithmetic side. I know the description above might seem a little picky, I'd be very appreciated if anyone has any idea or source about this, thanks again in advance...
I've been reading about how the conical shape of train wheels helps trains round turns without a differential. For those who are unfamiliar with the idea, the conical shape allows the wheels to shift and slide across the tracks, thus effectively varying their radii and allowing them to cover different distances while rotating at the same angular velocity. A cross-sectional view of the tracks and wheels generally looks something like: But what about a configuration like the following? I read in an online article that wheels in the second configuration may more easily slip and derail from the tracks (assuming there are no flanges to prevent them from doing so). But I can't convince myself using physics why that might be. Is one of these two configurations actually more reliable than the other?
The following binary relation of the set {a, b, c, d, e} is given: R = { (a,b), (a,c), (b,c) } What I have to do is to find the smallest reflexive / symmetric / transitive / antisymmetric relation including R. I know what these relations are all about, but what I have trouble with is how to find them. For example, I see no reflexive relation in the set. Does "including R" mean that i can extend R with any element from the given set? So for example, if I am looking for a reflexion can I just add (a, a)? If I can extend the set, my solution would be: Reflexive: Add (a,a) Symmetric: Add (b,a) Transitive: Already satisfied Antisymmetric: Already satisfied? I am not sure about this one
In the Wiki page A permutation automaton, or pure-group automaton, is a deterministic finite automaton such that each input symbol permutes the set of states. ..... A formal language is p-regular (also: a pure-group language) if it is accepted by a permutation automaton. The transition monoid of an automaton is the set of all functions on the set of states induced by input strings. See the page for more details. The transition monoid can be regarded as a monoid acting on the set of states. See this Wiki page for more details. In many literatures, an automaton is called strongly connected when the monoid action is transitive, i.e. there is always at least one transition (input string) from one state to another state. The transition monoid of a permutation automaton can be regarded as a permutation group acting on the set of states. If the action is transitive, then the transition monoid is a transitive permutation group. My question is What is the class of the languages accepted by DFAs whose transition monoids are transitive permutation groups? Is this class a proper subclass of p-regular language? Any literatures discussing this class of languages in details? I have searched many books and articles and found nothing helpful so far. I believe I don't have the appropriate key words yet. Thus I am seeking help. Any pointers/references will be appreciated very much. P.S. I asked a related question on CS.SE with more technical details toward computer science.
Recently, two groups working on quantum computers published results on quantum error correction. The first was Rainer Blatt's group, who used trapped ions to perform a topologically encoded qubit using "color code": Quantum computations on a topologically encoded qubit (arxiv). The other one was John Martinis' group, who used superconducting qubits and performed a simplified version of a "surface code": State preservation by repetitive error detection in a superconducting quantum circuit (arxiv). Can anybody please explain to me, what is the difference between "color code" and "surface code"? What are the advantages and disadvantages of those? Why aren't the trapped-ion guys using the "surface code" or vice versa? The Martinis group has shown recently that they are above the threshold for surface-code QEC arxiv. Has any ion group (maybe by Blatt) shown similar quality of single- and two-qubit gates? Are there other groups who have the same level of control over their systems to perform multi-qubits quantum error-correction codes?
Is there any easy (scriptable) way to convert a PDF with vector images into a PDF with raster images? In other words, I want to generate a PDF with the exact same text but with each vector image replaced with a rasterized version. I occasionally read PDFs of technical articles on my Kindle, and have found that reading a PDF directly is frustrating. Thankfully, Amazon's automatic conversion of PDFs to the Kindle format does a good job of reflowing the text portions of most of PDFs I have tried. However, while raster images seem to make it through the conversion process fine, vector images get horribly mangled. It would be great if I could easily convert a PDF so that all of its vector images were rasterized. I am interested in any possible solutions, but a Linux- or Windows-based one would be preferable. I can also get access to Adobe Acrobat if necessary.
Looking at the nCatLab page on chain complexes, it is implicitly assumed at the start of the page that one is working in an additive category. However, the only structure required to define chain complexes is that one be working in a pointed category, so that the notion of a zero morphism makes sense. However, I have not been able to find any papers which consider chain complexes even in categories such as preadditive or semiadditive categories, much less arbitrary pointed categories. I understand that many of the results of homological algebra rely on an Abelian structure to work. Is it simply the case that non-additive categories don't have enough structure to yield any interesting results about these complexes? Or is there a concrete issue that prevents chain complexes from making sense at all in more general pointed categories? Do these issues still arise even when working in preadditive or semiadditive categories?
Can someone please explain extraordinary optical transmission (EOT)? I'm hoping someone can describe the physical process by which light is transmitted through a periodic metal hole array which is optically thick (i.e. thickness > skin depth), for which the holes are sub-wavelength vs the incident light. I'm trying to visualise how this process works but I'm not having much luck. From what I understand, EOT is a mixture of surface plasmon polaritons (SPPs) being excited on the surface of the hole array and wave guided modes for the SPPs(?) to travel through to the opposite side of the array where they are decoupled into transmitted light. I guess it's the wave guided SPPs I'm having trouble with...i.e. why would there be a cut-off frequency due to the wave guide mode if SPPs travel along the metal surface? (Also, the position at which the SPPs would decouple has also been bugging me.) Any help would be great!
I can't quite figure out which of the following expressions is more correct: He is the devil's advocate. He is a devil's advocate. He is playing devil's advocate. The combination of an article with the possessive is what confuses me. Exactly which word(s) does the article apply to? The first form seems to suggest either that he is an advocate of The Devil -- namely, Satan himself -- or even worse, that he is The Advocate of The Devil. (Kill him with fire!) The second form seems to suggest that he is an advocate of a devil (but not necessarily of The Devil, nor the only advocate out there.) This seems to fit better with the way this idiom is commonly used, but I haven't seen this idiom used very often with the indefinite article. It's usually used with the definite article. The third form suggests that he is playing a role named "devil's advocate", with no article attached to it. Similar examples: The King's speech, the Indian's prayer, the mother's room, etc.
I've compiled a LaTeX document successfully by typing latex documentname.tex into terminal when in the correct working directory. The document successfully compiles. I'm using TexLive. I then make changes to the document. For some reason, when I type latex documentname.tex again, it compiles very quickly and gives me the previous version of the document out. I've tried deleting the output file and log file and typing latex documentname.tex yet again, but it still somehow outputs the old version of the document. Same for the pdflatex command - what is going wrong here? Is there some other command I should be using or extra arguments I can pass in? Even changing the filename of the document does not cause the new version to be compiled - I still get the old one out.
Addiction is defined as "the state of being enslaved to a habit or practice or to something that is psychologically or physically habit-forming, as narcotics, to such an extent that its cessation causes severe trauma." But sometimes a person will find something which they do not suffer any withdrawal from when the y stop doing it for a while, and they do not feel any great need to seek out on your own. Yet when they are actively engaged with it, they just do not want to stop and can find it very difficult to pull themselves away from. As an example, "My son is addicted to MineCraft. Once he sits down at it he will play for hours, not even wanting to stop to eat or sleep even when all his friends have gone home. Yet unless one of his friends wants to play it with him to begin with he never touches it." I feel like "addicted" is the wrong word, because while the "psychological enslavement" part is correct, it does not seem to form a habit or exhibit withdrawal symptoms. It's almost like a temporary addiction that goes away whenever the stimuli is removed. Is there a word for this?
As explained in the answers to this post, photons apparently exert a gravitational pull on other objects. It has also been explained on this site, that gravity propagates at the speed of light. I'm wondering, though, how do you reconcile these two facts? I'm trying to imagine the gravitational field made by a photon and it seems like there are some paradoxes. For example, how can gravity propagate ahead of the photon at the speed of light, if the photon is also travelling at the speed of light? My guess is the solution is probably found in relativity, but I certainly can't figure it out. Right now, the best I can do is to think about gravity as sound, and a photon as an object travelling at the speed of sound. Can anyone help me out?
I would like to teach a little nonlinear PDE to an undergraduate who is taking a course in second-order linear boundary value problems. I have never taught nonlinear PDE before, although it is my research specialty. I have a decent book on solitons, but my research specialty is critical point theory in elliptic PDE. Several of my colleagues are experts on solitons. The critical point theory would probably require some Sobolev spaces, which I would like to avoid. I have Evans's great book on PDE, but I think it is too advanced for him. I would like to know if there are any free resources on the Web which I can use, to get readings for myself and the student, and exercises for the student. One more thing: I am interested in PDE that have explicit analytical solutions, or at least can be written as infinite sums of specific functions (I don't want to get into numerical methods for this project).
I am not a physicist but I would really like to know what trained physicists think about this problem that came up in conversation the other day. I have been reading about the search for habitable planets for a little while and about the conditions it takes for a planet to be habitable. I understand that the right amount of heat is important for ideal conditions. Then I caught an interesting documentary on Oppenheimer, Heisenberg and the race for the atomic bomb in world war II. The documentary said something to the effect that a nuclear detonation or any nuclear reaction is very much like a small, very temporary star on earth. It got me thinking that nuclear reactors must also be analogous to mini-stars or suns so I started wondering what it would take to create a nuclear reactor that could make a planet (or moon) more habitable by allowing the heat produced to escape the reactor and warm the planet's surface. As an example, once the technology exists for a nuclear fusion reactor, could it possible to assemble one outside our atmosphere, send it into orbit around, for example, Jupiter's icy moon Europa in order to heat the surface and create more habitable conditions for life?
We are going to establish a company in order to commercialize a stuttering treatment/therapy program. The treatment/therapy is really effective and backed by a lot of scientific research. In our recent discussions, some disagreement has come up whether to market it as the "XYZ stuttering treatment" or the "XYZ stuttering therapy". On one hand, calling our product the "XYZ stuttering treatment" might be advantageous, because in all the research literature it is referred to as such. On the other hand, calling it the "XYZ stuttering therapy" could be better, because all the competition markets/offers their programs as "therapies", and having the term "therapy" appears to be more serious and seems to imply effectiveness. Also, the word "therapy" appears to be more international, which could help if we offer the program abroad. I'm not a native speaker though, so I wanted to hear your opinion and feedback. What's really the difference between "treatment" and "therapy"? Would you rather recommend calling it the "XYZ stuttering treatment" or the "XYZ stuttering therapy"? Why?
I don't understand how a vacuum, the absence of matter, can hold energy. How can it hold energy when Einstein proved that matter is energy? And a second related question; how does the energy in a vacuum allow the Universe to produce itself? And how does that account for why the Universe is expanding? I saw Krauss' lecture on YouTube called Universe from Nothing and only understood some of it, even though he was fantastic at putting things in layman's terms and making these concepts easy to visualize. However, he had a bunch of "asides", so it was a bit confusing. He mentioned that the curvature of the Universe was flat, but then also went on to say how that was the worst possible scenario. Why is a flat Universe such a bad thing?
Often in my studies (economics) the assumption of a "well-behaved" function will be invoked. I don't exactly know what that entails (I think twice continuously differentiability is one of the requirements), nor do I know why this is necessary (though I imagine the why will depend on each case). Can someone explain it to me, and if there is an explanation of the why as well, I would be grateful. Thanks! EDIT: To give one example where the term appears, see this Wikipedia entry for utility functions, which says at one point: In order to simplify calculations, various assumptions have been made of utility functions. CES (constant elasticity of substitution, or isoelastic) utility Exponential utility Quasilinear utility Homothetic preferences Most utility functions used in modeling or theory are well-behaved. They are usually monotonic, quasi-concave, continuous and globally non-satiated. I might be wrong, but I don't think "well-behaved" means monotonic, quasi-concave, continuous and globally non-satiated. What about twice differentiable?
I have always believed in keeping magnets and data storage devices far away from each other. Friends say I'm excessively cautious about it, but I seem to have a lot less data loss than they do! As cell phones have gained popularity, so have cell phone cases with magnetic clasps. Often these clasps are positioned near the center of the phone, in close proximity to where the microSD card is located in the phone. A friend has had two genuine Sandisk microSD cards (purchased at large brick and mortar retail stores) fail in their phone. They keep their phone in one of those cases with a magnetic clasp. Is it likely that the magnet is causing the loss of data, or are such magnets much too weak to result in affecting the data on a microSD card?
I'll start with a disclaimer -- this is not a question about astrology itself, I'm neither trying to refute nor to defend astrology. I'm interested in purely technical things, which are mostly related to astronomy. Given a time and a place (usually related to the moment of birth of a person) one can create a horoscope -- kinda diagram, which represents the positions of planets, Sun and Moon, usually projected on ecliptic. The information about position is usually represented in a form of astrological "houses", which are related to the horizon position. I'm interested in a "reverse" process: given the horoscope with ecliptic coordinates of Sun and Moon and planets, and given those "houses" -- can one find the place and time for which the horoscope was constructed? I'm pretty sure that such kind of problems would be interesting for, say, historians -- maybe there are some research papers or literature describing techniques that allows one to do such things?
First question: I have been reading English: An Essential Grammar by Gerald Nelson and it gives an example of the words 'hard' and 'fast' being used as both adjectives and adverbs: Adverb: John works hard. Peter drives fast. Adjective: John is used to hard work. Peter drives a fast car. I was wondering, can all adjectives be used as adverbs in this manner? E.g. Adjective: Small girl. Are these adverbs??? She is small. She was small. She looked small. Second question: Can present participle verbs be considered as adjectives? E.g. Are these adjectives or are they still considered as verbs? The singing lady. The growing crowd. The advancing army. Third question: Can all past participle verbs be considered adjectives? E.g. The written book. The cooked fish. The bitten apple. And lastly: Can all past participle verbs be considered as adverbs? E.g. The book was written in black ink. The fish seemed to be cooked.
I'm trying to find out whether I should use a singular or plural verb when there are multiple gerunds as the subject of the sentence. For example: Running the correct course and keeping a steady pace are/is necessary in order to win. With either one of these by itself, "is" would be correct: Running the correct course is necessary in order to win. Keeping a steady pace is necessary in order to win. With both gerunds combined, I can't seem to figure out whether the verb should stay singular since each phrase is singular, or if it should become plural since there are two connected by "and". If we just treat the gerunds as regular nouns, then obviously it would become "are", but I'm not sure if gerunds have the exact same rules as regular nouns. I know that if the sentence was: Running the correct course and keeping a steady pace are both necessary. That "are" would be correct, but without the "both" it sounds incorrect to me. Does anyone know the official rule here?