Sounds like Linus is Disagreeing with thunderfoot on the hyper loop not agreeing - Page 1
Forum section: electronics / general

author: Beamin
author_rank: Super Contributor
timestamp: September 23, 2017, 12:15:05 pm
content: Another thunderfoot busted video where he says linus tech tips changes his tone about the hyper loop sometime later on his wan show. And says its debunked.But his tone and phrasing say "Its like all the people crying debunked on the hyperloop assume that the creators didn't read 11th grade physics" (not exact quote watch the video I skipped to the exact spot)It sounds like he saying: The people crying bullshit seem to think that the creators don't know rudimentary physics. But obviously they do and the critics are dumb for assuming they didn't already think of this. Like when some one comments on a video saying "Its obvious why the plane blew up: Kerosine is flammable and the fuel tanks were full of vapors". When in reality they don't understand that a tank full of vapors must be in a specific % to explode and too much air actually won't blow up, but they have no actual knowledge of combustion limits but think they know everything because they have seen vapors explode.I think Linus is calling the critics idiots on some small aspect but to know what hes actually talking about you would have to watch his whole video. Also why are his voice inflections making it sound like the critics are dumb if hes trying to make the creators sound dumb? Some times thunderfoot will go off on a stupid detail like a line on a map on that Sarkasian womans video; when the map isn't relevant at all to the point but he's doing a bill oreilly where he distracts by focusing on a little detail because his whole argument is weak.My 0.02$https://youtu.be/ktO6IvLT2eg?t=20m40s

author: steve30
author_rank: Frequent Contributor
timestamp: September 24, 2017, 05:29:28 am
content: I saw the Thunderf00t hyperloop video the other day. I think the reason the hyperloop travels so slowly is because there are speed limit signs all along it.

author: Ampera
author_rank: Super Contributor
timestamp: September 24, 2017, 05:48:28 am
content: In my experience I have stayed out of the hyperloop crap because I honestly do not have the time in order to research exactly why it's bad or if it's not. i will sit here and wait until it is either finished or never finished.Thunderfoot is an interesting character. He is half in and half out of a group known off hand as the YouTube "Skeptics", with popular examples including some of my personal favourites Bearing and MundaneMatt. They are not a unified group with a unified opinion, outside the concept that everything should be taken with a grain of salt, and that they are just there to give their opinion on the matter.Linus is a guy a lot of people here hate, but I rather like him. Be it my personal standards of entertainment are so low, or what have you, I enjoy his mad videos on just doing crazy shit for views. Idk, he does have some quality content, including some interesting videos. Just stay away from Tech Quickie, the channel that takes a note from the mainstream media and sees it more important to educate people than actually conducting research into what they are educating. They are most of the time alright, but there are just some videos that make me want to slap the writer in the face for being so totally and inexcusably stupid.

author: Fungus
author_rank: Super Contributor
timestamp: September 24, 2017, 06:09:32 am
content: I'm on a hyperloop team so I get a kick out of threads like this.

author: Lightages
author_rank: Unknown
timestamp: September 24, 2017, 06:39:24 am
content: Quote from: Fungus on September 24, 2017, 06:09:32 amOK, tell us about it.

author: lukier
author_rank: Unknown
timestamp: September 24, 2017, 11:01:29 am
content: Quote from: TwoOfFive on September 24, 2017, 05:48:28 amI'm in the same camp - regarding the physics of it. It might be doable, but will require man-years of R&D effort and years to iron out the edges to make a production grade system.So I'm doubting the economics of it. I cannot see how on earth this is going to be cheaper than conventional high speed rail. The latter is proven technology, already in the field (TGV,Shinkansen) for decades, so the R&D costs are almost zero and the manufacturing and running costs must be surely lower, no massive pipes, no vacuum to keep, simpler power trains and so on.High speed rail (non-maglev) would be of course slower, but the Hyperloop total travel time, including going through the locks, pumping and acceleration/deceleration might not be significantly better.

author: nctnico
author_rank: Super Contributor
timestamp: September 24, 2017, 11:13:17 am
content: Quote from: lukier on September 24, 2017, 11:01:29 amIt depends on where you are. In the US it makes sense due to the long distances but in the EU 'conventional' high speed rail is an easier solution. AFAIK the French pushed the TGV to about 520km/h in a test.

author: Beamin
author_rank: Super Contributor
timestamp: September 24, 2017, 10:38:44 pm
content: The thesis of this thread has nothing to do with the hyperloop. I'm asking if thuderfoot is quoting linus out of context to further his cause when really linus is calling the critics idiots.As an aside I think the hyper loop is stupid when you could just use a maglev for a fraction of the cost at almost the same speed using technology that you can order today and build tomorrow no R&D needed or big accidents with loss of life to get through the learning curve.Back on point: Thunderfoot is twisting Linus's words.

author: coppice
author_rank: Super Contributor
timestamp: September 25, 2017, 12:11:31 am
content: Quote from: Beamin on September 24, 2017, 10:38:44 pmWhere can you order a solid practical cost effective maglev system today, which requires no additional R&D?

author: Fungus
author_rank: Super Contributor
timestamp: September 25, 2017, 02:09:42 am
content: Quote from: Lightages on September 24, 2017, 06:39:24 ama) Nothing is fixed in stone. Any or all of the assumptions in thunderfoot's video may be completely wrong.eg. "Vacuum" isn't part of any written specification that I've seen.Theonlyfixed design requirement is "SPEED IN A TUBE!". The rest is up to you.(OK, "less than atmospheric air pressure" is probably helpful)

author: EEVblog
author_rank: Unknown
timestamp: September 25, 2017, 02:45:07 am
content: Quote from: lukier on September 24, 2017, 11:01:29 amAny competent engineer (who is not blinded by belief that it's "cool", and "anything is possible") can instantly see the countless complete show-stopper problems with such a massive scale vacuum based Hyperloop.There are good reasons it has sat on the shelf for over 100 years.But there is will always be engineers willing to work on impractical "cool" projects just because they are fun, and I guess there is nothing wrong with that if some sucker (not taxpayer) is willing to fund it.QuoteBingo, that's the other major issue that will kill it cold even if they magically got it carrying passengers.The trade-off of double the potential speed vs the ridiculous absurd engineering issues wit the Hyperloop, will always make it an impractical solution.I've been on a maglev at 430kmh, they work. Double the speed for an almost infinite amount more system implementation and maintenance complexity kill this whole idea cold.

author: EEVblog
author_rank: Unknown
timestamp: September 25, 2017, 02:48:54 am
content: Quote from: Fungus on September 25, 2017, 02:09:42 amOMFG!Theentireconcept of the Hyperloop is based on the vacuum premiseBut of course no one wants to solve the vacuum problem, because everyone knows it is a fundamentally stupidly impractical idea. So, lets just dick around with Maglev in a tube and call it Hyperloop, because, you know, hype.

author: cdev
author_rank: Super Contributor
timestamp: September 25, 2017, 03:25:39 am
content: Do you know anything about a condition called narcissistic personality disorder? A very high percentage of politicians seem to me to have this affliction, which is also sometimes called "delusions of grandeur". For them, everything has to be "paradigm shifting" or "record shattering". Also underlying it is simple greed and a desire to funnel away taxpayers money.Also, WTO GPA..figures into this.. Since its government procurement.if they did something that's been done before, the companies that did it before would all be overseas, and obviously they could do the same thing cheaper, again, so they would win the bid. They don't want that so they have to do nothing or come up with something no other countries firms would be dumb enough to bid on. Then they can get the contract."Oh what a tangled web we weave when we practice to deceive".- Old saying

author: raptor1956
author_rank: Frequent Contributor
timestamp: September 25, 2017, 04:19:58 am
content: I just wish we in the USA had any trains that averaged more than about 100kph -- yes, some of the Amtrak trains peak as high as about 150kph but the average is almost certainly less than 100kph. It is unlikely we here will see anything better in the foreseeable future as a good many people have a political hatred of trains so no government money is going to future projects and the only long distance passenger service, the Amtrak I mentioned before, is way underfunded and has had one foot in the grave since the 70's. We in the USA like trucks and big cars -- anything that consumes huge quantities of fuel per passenger/pound.Brian

author: cdev
author_rank: Super Contributor
timestamp: September 25, 2017, 05:07:36 am
content: There is much more to this than that, the US started an international association in 1994 thats pushing to progressively privatize what used to be public services unless they are completely noncommercial, and free, everywhere.So they cant create any more public anything. They can only privatize it.Countries still have freedom to enact any law as long as its consistent with these goals and doesn't decrease profits.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: September 25, 2017, 05:20:42 am
content: The things that bother me the most about thunderf00t's video are:1. Sure, expansion, fine. WHAT ABOUT YOUNG'S MODULUS, YOU RETARD? Steel is flexible! It is certainly not a fagot of strands, as his expansion diagram would suggest.2. No discussion about actually solving the "show stoppers". Example: rust istrivially* solved by merely switching to stainless steel.*At no small cost, mind, but it's trivial on the drawing board. Somewhere inbetween lies the real answer. Galvanized or aluminized steel for example, or just good old paint.Flex is a particularly bothersome issue, because he's mentioned it several times, yet he still hasn't realized the existence of actual pipelines crisscrossing the continent already. It's a solved problem.Now, not necessarily that it's solved on precisely the same scale, no. Most of those pipelines are filled with a fluid (water and petroleum being the most important), which keeps the temperature consistent across the pipe and from day to day.But then, there are pipelines crisscrossing major fault lines, subject to Earthquakes at least as strong as California has ever seen, that see enormous seasonal temperature swings: Alaska. And they're fine. They solved that by giving lateral freedom on the supports, and zig-zagging the pipeline across the countryside.A "Hyperloop" would have to have much softer bends in it, because of its contents; but there's no on-the-face reason that this factor is a complete game breaker.Tim

author: Jeroen3
author_rank: Super Contributor
timestamp: September 25, 2017, 05:43:18 am
content: This is like the Concorde.It's cool, everyone wants it. But it's turns out to be expensive and dangerous, and it will be cancelled.But this doesn't mean nothing can be learned!

author: filssavi
author_rank: Frequent Contributor
timestamp: September 25, 2017, 06:41:57 am
content: What really bothers me in this hyperloop charade is how easily engineers, people who should know better, fall for the hype train...I mean it isn't that hard to see that the whole thing is just hot hair, without even doing a single addition with just common sense and critical thinking (ok granted seen how popular votes went last year that seems to be in exceptionally short supply)here just few of the countless argumentations:- why is Elon Musk "open sourcing the idea" (whatever that means) and not really putting his own money/companies into that, for f**k sake he basically started his own nasa, so don't tell me he can't make bold moves and open up new industries/Sectors-The economics of it just aren't making any sense...let's just look at maglev it is a proven technology, it has been in use for more than a decade now in shanghai and still you can count the number of operational and under construction lines on two hands, and all but one (Ch?? Shinkansen) don't even reach 100 km in lenght and most of them just run between an airport and the center city.The problem is that the upfront costs of building the damn thing are just too great, the running costs might be shlightly smaller, and in the long run it might even save you some money (and I doubt it) but still no governament (excluding China) has that much money to throw at a project upfront, we haven't got them in europe, and shure as hell you haven't got them in america, the governament is risking shutdown each year and i don't see a decrease in military spending anytime soon.So maglev technology is struggling to find a place in the market and the briliant idea to decrease the cost is to run a maglev train in high vacuum at twice the speed?? how on earth will that decrease costs? it won't.And that is why unless some really huge breakthrough in this field happens the hyperloop will always remain a pipe dream....Ok I was joking there is so much media hype around this thing that it can't die, the most probable outcome is that the specs will be gradually decreased until the hyperloop will become just a standard maglev run in a low vacuum tube.

author: filssavi
author_rank: Frequent Contributor
timestamp: September 25, 2017, 06:45:09 am
content: Quote from: Jeroen3 on September 25, 2017, 05:43:18 amThis will be even worse than Concorde, as that plane made sense when it was designed in the sixties as fuel was dirt cheap back then, it's the steadily climbing oil prices that killed supersonic passenger flightThis hyperloop isn't even making sense now

author: amspire
author_rank: Super Contributor
timestamp: September 25, 2017, 07:50:27 am
content: Quote from: EEVblog on September 25, 2017, 02:48:54 amThis is just getting caught up in semantics. The Tesla proposal suggested 1/1000th of an atmosphere which for all safety aspects is the same as a vacuum.https://www.tesla.com/sites/default/files/blog_attachments/hyperloop_alpha3.pdfThey had done a fair bit of calculations which make it sound theoretically feasible, but the safety and disaster recovery issues would be monumental. I am not sure the estimated costs come near reality.In peak hour carriages are leaving every few minutes and so in the case of a problem they would probably have to apply the emergency brakes to all the carriages and open the whole tube to air while people are waiting to be rescued. There will be thousands of people in the tube, so they probably need fail-safe ventilation hardware all along the length to ensure there is adequate air quality for the passengers being rescued. They will have to slowly drive the carriages to an end on battery power (if possible) and then when the problem is fixed, re-empty the tube of air.How long is that going to take?Not sure what the protocol will be when they have to cut the tube open to rescue people. How much will it cost to have fully equipped rescue crews all along the length of the tube? When they have to cut the tube open, how long will it take to repair and safety check the tube?I cannot help thinking that the Hypertube somehow depends on it being so reliable, it never fails.

author: Artlav
author_rank: Frequent Contributor
timestamp: September 25, 2017, 08:12:34 am
content: In case some people are confused, this isn't talking about Linus the creator of Linux, but rather Linus from a "PC and related stuff" advertisement YouTube channel "Linus Tech Tips".Having seen both videos, i wonder why either take it so seriously. On Linus's side, it's obvious that engineers working on the hyperloop demo knew their basic physics. They also knew that this was a quick PR project, to be made at just enough cost and quality to last through the demo day. It should also be obvious to a "tech" person that challenging an idea is a default mode of communication among scientists and engineers.On the other side, Thunderf00t got his typical corrosive drive-point-home-ness about what is obviously just a Musk's pet research project. Hyperloop lets engineers work on a cool, if impractical, idea while being paid for it by a guy who got spare money for that. I don't see a problem with that, it's not like this is an another crowdfunding scam like solar roadways or anything.

author: CJay
author_rank: Super Contributor
timestamp: September 25, 2017, 08:38:43 am
content: Quote from: filssavi on September 25, 2017, 06:45:09 amConcorde never made sense, it was always a loss making enterprise and was designed as a 'flagship' product to promote the cause of supersonic travel, the start of a new era in trans continental transport.It is however an astonishing engineering feat, a beautiful plane and an amazing way to travel (I'm told, I never flew in one but my Uncle did), the history is fascinating and a great read if you have some time to spare.The Concorde which crashed in France that caused the whole Concorde fleet to be grounded was essentially used as an excuse to be rid of the increasingly heavy financial millstone.

author: coppice
author_rank: Super Contributor
timestamp: September 25, 2017, 02:01:04 pm
content: Quote from: filssavi on September 25, 2017, 06:45:09 amYou must be young. Living through the development of Concorde, there was almost weekly news of something which made it seem a dumber and dumber idea. Cheap oil would not have overcome the bans on it flying overland, and the volume of Concordes made for pure over ocean flying would never have made the project make sense.Most bad projects which people say only look bad with hindsight were not being very critically observed going forwards.

author: cdev
author_rank: Super Contributor
timestamp: September 25, 2017, 03:25:21 pm
content: Leon Festinger was a psychologist who studied group dynamics and he put together a body of knowledge about something called cognitive dissonance. His work indicated that people will believe what they want to believe even given only a shred of evidence supporting it and a large body of evidence against it, IF they have invested heavily emotionally in that position and integrating the new knowledge would require some action on their parts..Clearly part of the function of projects like the hypeloop is propaganda- hiding how and why the system has changed - and won't ever return to the way it was 30 years ago, without the underlying things that have been done being brought out into the open and debated.

author: CJay
author_rank: Super Contributor
timestamp: September 25, 2017, 03:43:38 pm
content: Quote from: cdev on September 25, 2017, 03:25:21 pmIf he's still alive I bet he's having a field day with all the recent events, massive confirmation of his theories, the biggest ever, the greatest .

author: Beamin
author_rank: Super Contributor
timestamp: September 25, 2017, 09:13:28 pm
content: Quote from: blueskull on September 25, 2017, 07:07:52 amYou can't really compare it to going into space. Every one agrees that space travel is the future of any living organism. Going twice the speed of a plane in a tube is not.Filling it with something other then air doesn't solve anything. Helium would too expensive and we are going to run out of it if we don't use it wisely. The reason why it has to be a vacuum is that the air in front of the train needs some place to go. If you have a train in a tube you are pushing not only the train but a cylinder of air in front of it like an air compressor. Air is made of atoms that are already light; nitrogen is 14 and oxygen is 16 helium is 4. Its a giant gas compressor.Yes rich people can afford it but to make money off it you have to able to let average people afford it. Look at airlines.Look how long it takes to pump a vacuum. This tube will have leaks and it will need a massive amount of pumps just to maintain the leaks. How do you terror proof hundreds of miles of something? Look how much resources and time it take to secure the boarder of mexico; and people still cross daily.The train really only connects two places. How many people need to go from LA to san Francisco? Would there be that many people to justify the cost? With a train you can make the track split with almost no additional cost. To make a hyper loop split would have massive cost as you can just lay down track next to the existing ones.Then there is safety if it gets stuck or the inside catches fire. How many rescue doors do you put on the tube? How can you get fire fighters to a locations that's 10's mile from the nearest road? What happens when you open the door to the tunnel? Does massive amounts of air rush in? That would cause huge damage to the opening probably sucking the steel around the door in causing massive damage.When one part of track is damaged the whole thing shuts down. The slightest air leak on one part shuts the whole system down unlike a train where spare track could be laid.The whole things solves a problem that doesn't really exist. Not once have I heard anyone complain that it takes too long to fly or drive up California.

author: cdev
author_rank: Super Contributor
timestamp: September 25, 2017, 10:56:22 pm
content: Beamin,I lived in CA for basically 2/3 of my life up until now and people do complain about the time it takes to get from SF to LA and back all of the time. Driving takes most of a day, but flying only takes around an hour (of actual flight) but getting in and out of the airportsdoublestriples that, easily. Or more, sometimes.The logical solution is a bullet train like the civilized countries have. But no, they want --- unproven technology.. don't get me started..You're right, its sheer insanity to attempt to use a vacuum - for the reason that becomes incredibly obvious when you take that airplane flight you will see it as plain as the nose on your face, because you fly along it the whole way, the San Andreas Fault line.. dividing the state.Earthquakesand larger than life engineering projects coexist only with difficulty. Its nuts to build a system thats suspended in a tube that goes deep underground in an earthquake prone state. Plus, the deeper you go, the hotter it gets. You know why they claim they need to use a vacuum, Because people know its hot underground from hot springs, which the state also has a fairly large number of. If the train stopped, and vacuum was lost, how would they cool the tunnel? People would rapidly bake alive in there.Let me tell you the story told to me by a lady I was briefly dating around a year after this happened.. She was driving over the (old) Bay Bridge to San Francisco, which means she was on the top deck, and suddenly she saw cars driving the WRONG WAY on the top deck back towards Oakland, and they were gesturing wildly to her - as if to say "Go Back" ... she didnt go much farther because she saw it, a huge gap had opened up and a BUS was balancing on it, there had been a huge earthquake..She was one of the lucky ones, at the same time, one of the highways in Oakland had collapsed killing dozens of people who had been trapped below the top deck when it fell.......

author: boffin
author_rank: Unknown
timestamp: September 25, 2017, 11:27:10 pm
content: Quote from: raptor1956 on September 25, 2017, 04:19:58 amIndeed; while it's really competitive for distances over 1000km (or perhaps a little more), it's brilliant for the 400-800km journeys.You just need to ride the 2½hr AVE from Madrid to Barcelona (625km to drive) once to be a believer. For us here in Vancouver, that would mean Seattle in one hour and Portland in two.

author: cdev
author_rank: Super Contributor
timestamp: September 25, 2017, 11:43:28 pm
content: I don't think Americans have a "hatred of trains" at all. We certainly all (those of us with common senseprefer riding a train over taking a bus in traffic.Energy-wise, trains are one of the most energy-efficient means of transportation. Countries with good passenger rail systems use a lot less fossil fuels.Riding on a train is very relaxing.

author: Beamin
author_rank: Super Contributor
timestamp: September 26, 2017, 12:28:13 am
content: Quote from: cdev on September 25, 2017, 11:43:28 pmI would ride the train. The bus is a horrible experience in America used by the poorest most degenerate people (not all poor people are bad but all poor people who ride the bus are bad). It is too unreliable to get to work on it; even lines in the city that come every 30 minutes can take over an hour and a half.

author: cdev
author_rank: Super Contributor
timestamp: September 26, 2017, 12:33:29 am
content: I don't share your opinion at all. generalities that broad "are never true".And of course, there are no poor Americans, just millionaires in waiting- in between their entrepreneurial adventures. But, frankly, I was just talking about the traffic and the relative comfort of bus versus train travel.Public transport is a great asset and towns that dont want it always regret it afterwards.. and the privatizers are the worst, they are just nuts to want to get rid of it. Huge mistake.I am rooting for trains to make a big comeback.

author: Corporate666
author_rank: Unknown
timestamp: September 26, 2017, 03:16:33 am
content: I haven't watched the Linus video, but Thunderfoot has gone off the rails (pun intended) about the hyperloop.There are legitimate criticisms and it may very well (likely) never see the light of day, but he does serious damage to his credibility by harming on things that are simply non-issues. He also makes lots of fundamental mistakes - either because he doesn't understand what he's talking about, or because he willfully portrays his criticisms in a dishonest manner because he thinks his audience is too dumb to know any better.There are plenty of legitimate criticisms of the hyperloop to have to go out and make stuff up.Quite a few on here have fallen into the same trap with their criticisms of the hyperloop.As for Thunderfoot, I think he is annoyed that Elon Musk is so successful and well respected and he (TF) is getting by on public servant wages, yet considers himself more learned and intelligent. This comes through loud and clear with his incessant repetition about crowdfunding scams and how he could be earning $$$ if only he weren't so darn honest (yeah, right!). I also think he did pretty well on his original debunking video, according to Social Blade, and he's trying to replicate what earned him the most $$.

author: EEVblog
author_rank: Unknown
timestamp: September 26, 2017, 04:57:57 am
content: Quote from: T3sl4co1l on September 25, 2017, 05:20:42 amExcept that they are apples and oranges.1) Pipelines are pressurizedinside, not from the outside with vacuum inside.2) They aren't even close to the same diameter.3) They don't have to carry humans or massive moving projectiles at 1000kmhhttp://naturalgas.org/naturalgas/transport/

author: EEVblog
author_rank: Unknown
timestamp: September 26, 2017, 04:59:53 am
content: Quote from: cdev on September 26, 2017, 12:33:29 amI like trains. Even our ones in Sydney where we stupidly run heavy rail right into the CBD.I'm amazed when I go to cities like Paris et.al that have expansive underground rail systems

author: Brumby
author_rank: Unknown
timestamp: September 26, 2017, 05:12:53 am
content: Sorry - but I just had an amusing mental image when I saw this oil pipeline...

author: Jeroen3
author_rank: Super Contributor
timestamp: September 26, 2017, 05:33:25 am
content: Not many people know about this, but there is also a gase pipe network here in the netherlands and belgium.No, not natural gas, bus stuff like Hydrogen, Oxygen and Carbon monoxide.Building pipes shouldn't be the challenge.

author: vk6zgo
author_rank: Super Contributor
timestamp: September 26, 2017, 08:08:26 am
content: Quote from: blueskull on September 25, 2017, 07:07:52 amI guess you meant "a century"!Even then, not everybody thought it was impossible.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: September 26, 2017, 08:09:25 am
content: Quote from: EEVblog on September 26, 2017, 04:57:57 amThanks, interesting, high pressure natural gas (although I don't know where they get the 600x volume figure), that'll definitely help with rigidity.I don't know enough about tubing, offhand, to know if that's enough on its own, or if the sheer size of pipe required to hold in the pressure (we're talking 2-5cm thick walls, I think?) will dominate on stiffness.Does seem likely that, at only 15 PSI, they can get away with less. Especially if they do something to help the rigidity, like wrap a spiral rib around the tube to prevent crushing collapse (insert train car implosion gif here).Pipelines that bighavebeen made, though:https://www.materialstoday.com/composite-applications/features/worlds-largest-high-pressure-large-diameter-grp/Here they talk about water pipes 2m around. That's enough to stand up in, or launch a car with two columns of reclined passengers.But that doesn't matter much. I'm no structural engineer, I don't know more than the basics of calculating what size of pipe is needed here. As I've not seen any numbers presented here, at all, I'm going to go out on a limb and guess no one else here is, either...Tim

author: Fungus
author_rank: Super Contributor
timestamp: September 26, 2017, 08:41:25 am
content: Quote from: vk6zgo on September 26, 2017, 08:08:26 amI thought he meant the people who believe we haven't gone yet.But yes, people used to believe there was air all the way to the moon, that birds migrated there, etc.In the 18th century plenty of people thought it was just a case of the Montgolfiers making a better balloon.

author: Fungus
author_rank: Super Contributor
timestamp: September 26, 2017, 09:06:31 am
content: Quote from: T3sl4co1l on September 26, 2017, 08:09:25 amPipes can be built. We started installing ours a couple of weeks ago. Other (richer) teams have had one for about a year.

author: Fungus
author_rank: Super Contributor
timestamp: September 26, 2017, 09:27:26 am
content: Thunderfoot doesn't have any amazing insights that nobody else thought of instantly. I'm not sure why people think he's saving the world or who he's saving it from. Nobody's being scammed or ripped off (unlike Batterizer, uBeam, Solar Frikkin Roadways, etc.)Elon Musk has set up a team of real engineers who go overallthe plans submitted by Hyperloop teams. They ask for more details about certain things, point out where the likely problems are, suggest improvements, etc. The teams themselves are there for ideas/imagination and to try out the different approaches to the problem.Yes, that means Elon's getting a while bunch of R&D done for free but mostly it's just university students who:(a) Are gaining experience building real stuff(b) Can put "Hyperloop" on their CV(c) Got to go to California for a week and take selfies standing under the SpaceX rocket.No harm done, I say, and the queue to be on this year's Hyperloop team was a mile long after all the selfies were uploaded.

author: EEVblog
author_rank: Unknown
timestamp: September 26, 2017, 09:50:56 am
content: Quote from: Fungus on September 26, 2017, 06:42:14 amGood to see you realise anything vacuum based on this scale is impractical.So why are the test tracks obviously designed to be vacuum sealed with inches think port windows and complete welds?I presume you agree that is a complete waste of time and money?

author: EEVblog
author_rank: Unknown
timestamp: September 26, 2017, 10:31:15 am
content: I have split the Hyperloop UPV Design into a new thread, given that we have one of the design team on the forum:https://www.eevblog.com/forum/chat/hyperloop-upv-design/

author: vk6zgo
author_rank: Super Contributor
timestamp: September 26, 2017, 01:02:53 pm
content: Quote from: Fungus on September 26, 2017, 08:41:25 amThere was a great difference between ideas current among the general public in the 18th Century & scientificthought in 1917.https://www.grc.nasa.gov/www/k-12/rocket/BottleRocket/20thBeyond.htm

author: cdev
author_rank: Super Contributor
timestamp: September 26, 2017, 01:05:46 pm
content: Blueskull,I smiled when I read your comment.Don't you know the legend of Wan Hu, who 3600 years ago,mayhave been the world's first "astronaut"? (A picture is attached below)"Early in the sixteenth century, (BC) Wan, a regional government official "decided to take advantage of China's advanced rocket and fireworks technology" to launch himself into space.He supposedly had a chair built with forty-seven rockets attached. On the day of lift-off, Wan, splendidly attired, climbed into his rocket chair and forty seven servants lit the fuses and then hastily ran for cover. There was a huge explosion. When the smoke cleared, Wan and the chair were gone, and was said never to have been seen again."There are agreat manyvariations on this interesting and colorful story.There must be some truth to the story, but the story also serves as a caution to would be astronauts, as the way its told, its just as likely that he was seriously injured and never left the ground.Still, the story is one that has left a mark on many of us and now also the Moon, one which will likely live on forever as a crater on the far side of the moon is now officially named after Wan Hu.https://history.msfc.nasa.gov/rocketry/06.html<<<- This web page at MSFC was where I first read about Wan.https://en.wikipedia.org/wiki/Wan_Huhttps://en.wikipedia.org/wiki/Wan-Hoo_%28crater%29I should note that Blueskull was right in the sense that many Chinese in fact did think it was impossible a just a few decades ago because there was a tendency there to express the opinion that the space missions of the US (and perhaps also Russia?) were fabrications on some level and were propaganda.I joke about this with my Chinese friends.Now of course we're all exploring space and likely at some point in the near future, I strongly feel we'll be exploring it together. How would we not be?I cried while I watched the first Chinese spacewalk. It was such a amazing moment for all of us."We come in peace for all mankind"Quote from: blueskull on September 25, 2017, 07:07:52 am

author: cdev
author_rank: Super Contributor
timestamp: September 26, 2017, 01:25:16 pm
content: New York's subway and public transit system is extremely popular,used by everybody who lives there(almost) and its a huge asset to that city.The city could not function as it does without its subway. The same goes for San Francisco which has one of the best in the country. They make it easy to live in both cities without a car. A car, if you own one, basically just sits in your insanely expensive garage (which costs more than rent does to many people) and just gets used for shopping and trips outside of the area that's served by the transit systems. Its a great way to live where you can do it.LA, in contrast, lost its trolley system in the 50s and 60s and they basically had to rebuild one, at tremendous cost. When I was growing up, the opinions expressed earlier were typical of LA residents who seem to have had their really great Red Cars (before my time but family members who grew up there told me about them) replaced by freeways by means of an extensive indoctrination that cars were good and public transit bad. It was a huge mistake that has left us at the mercy of the energy industry!Quote from: EEVblog on September 26, 2017, 04:59:53 am

author: CJay
author_rank: Super Contributor
timestamp: September 26, 2017, 01:42:54 pm
content: Quote from: cdev on September 26, 2017, 01:25:16 pmAs is the Tube in London, it's an amazingly efficient system that works.It's not pleasant to travel on as it's overcrowded at peak times, unless of course you enjoy being crushed and experiencing other people's armpits but it definitely gets you from A-B and it's fast.

author: cdev
author_rank: Super Contributor
timestamp: September 26, 2017, 02:58:29 pm
content: I could go on and on about the strange things and people I've seen on subways and buses in SF and NYC. Both cities have "Night Owl" buses and trains that run all night long, also. I wonder if there would be a "Night Owl" hyperloop between SF and LA!???I am sure that if there is, it would become the setting for a great many film plots, its just inevitable.Both BART and Caltrain trains can go >70 MPH when there is a straight run of track and no stops right ahead.Currently, you can take BART pretty far southward. Suppose a train linked San Jose with the Santa Cruz/Aptos/Monterey area, then either followed the route taken by Hwy 101, (and the San Andreas Fault!) or (how?) went inland (over the Coast range which means mountains) and went down the Central Valley to somewhere in what might now be considered to be LA's northern suburbs... a fast train would work if it didn't had to slow down for freight traffic.If you go via the Central valley, Grapevine Pass is the main obstacle a very fast train meets going from north to south into the LA basin. Its a very long, gradual ascent and descent.

author: coppice
author_rank: Super Contributor
timestamp: September 26, 2017, 03:13:50 pm
content: Quote from: CJay on September 26, 2017, 01:42:54 pmTry the clean efficient metro systems in many Asian cities, like Hong Kong and Singapore, and you'll see the London Tube for the broken down piece of junk it really is. While these Asian cities had to face the full cost of building from scratch in recent decades, often with the massive impact of carving through a dense city landscape, London only had to stump up reasonable maintenance costs for the older lines. They have consistently failed to. My kids, raised in Hong Kong, think its hilarious being shaken around on the London Tube trains.

author: CJay
author_rank: Super Contributor
timestamp: September 26, 2017, 03:29:10 pm
content: Quote from: coppice on September 26, 2017, 03:13:50 pmOh I don't disagree that it's in dire need of a lot of money being spent but it still works, it's fast, reliable and not that expensive, there is a lot of investment being made too but it's far from enough.Public transport in London compared to most of the rest of the UK works really well, that's not to say it's a pleasure to use or it doesn't have its problems.

author: Beamin
author_rank: Super Contributor
timestamp: September 26, 2017, 06:30:53 pm
content: I wouldn't doubt if thunderfoot thinks his veiwers are dumb and keeps this in mind when he makes his videos. I saw him arguing with some chritian guy at some festival I forget his name but he's not very bright probably has an IQ of 90 but thunderfoot couldn't seem to understand that to win a debate with someone you have to make sure the other person can understand your point. He just uses concepts and goes over the guys head. He didn't win that debate because he didn't get the other side to understand his argument. I can't find the video since thunderfoot has so many mainly some weird obsession with the "video games are sexist" woman. All thunderfoot had to explain to the guy was that TF's and the bible guys particular views didn't matter to the question does god exist. Bible guy kept saying "But YOU don't go to church" or some sort of ad hominin attack like the "al gore has a heated pool argument". So my point is that his videos could be better if he gave his viewers more credit and not just treat them like they were vastly inferior to him. Plus he repeats the same things and shows the same clips and sound bites multiple times in one video.

author: mtdoc
author_rank: Super Contributor
timestamp: September 26, 2017, 08:07:27 pm
content: I am skeptical that a hyperloop will ever be built - but that will be due to the economic/political realities rather than any fundamentally insolvable technical challenges. I could be wrong of course. It may turn out that engineering challenges are too large to overcome but there is no more basis for claiming that now than there was for similar claims made about many past "impossible" engineering challenges.Is it overly hyped by the media ? - yes of course. All things Musk related are.In my view thunderfoot has proven himself to be intellectually dishonest several times over. IMO he is a carnival barker. He has identified a market (primarily Musk haters) and exploits it to get youtube views and patreon supporters. It amazes me that this is not obvious to any educated person looking at his videos. (que thunderfoot fanboy attacks)That said - it's not that I think all of his hyperloop criticisms are invalid. He raises some valid questions - most of which have been addressed by actual engineers with expertise in the relevant fields. There are some good discussions on reddit and other places on this. He also makes some very flawed arguments that have exposed his ignorance. It's telling that he refused to engage directly with hyperloop engineers when offered.Even though I don't think it is likely to ever be built, I see value in these kind of grand engineering challenges - they inspire people and new engineers. Fungus's Hyperloop team challenge is one example. I feel the same way about those who are working on a manned Mars mission (which I also believe will never happen).

author: Beamin
author_rank: Super Contributor
timestamp: September 26, 2017, 08:20:01 pm
content: Quote from: mtdoc on September 26, 2017, 08:07:27 pmI bet the reason why we won't go to mars is that male astronauts start to go blind after long periods in space. Plus the trip is just too long we will need to go faster before we can plan on going there. Rockets are not the way to go.

author: lukier
author_rank: Unknown
timestamp: September 26, 2017, 10:34:05 pm
content: Quote from: coppice on September 26, 2017, 03:13:50 pmI like Singapore MRT, it is clean and slightly cheaper than London's but you are not comparing apples and apples here. Singapore's MRT is much smaller, 178 km of tracks vs 402 km, 106 stations vs 270. Also, besides MRT/LRT and busses there isn't much else there, while in London you have additionally the national rail trains, DLR, Overground, tram, ferries, TFL Rail, Crossrail/Thameslink and so on.But there is even more important reason for the mentioned differences - the infamous "historical reasons". The Tube is over 150 years old, so every modernization is much more difficult and expensive. For example that's why the disabled access is almost non-existent.It is often much easier to build something from scratch and if it was completed recently of course it would be nice and shiny.

author: coppice
author_rank: Super Contributor
timestamp: September 26, 2017, 11:09:40 pm
content: Quote from: lukier on September 26, 2017, 10:34:05 pmThis is self deception of the highest order. What relevance do national transport services have to the need to serve London commuters? London had most of its tracks in place before the towers went up. Do you know how much difficulty weaving new metro lines around the foundations of the towers in Hong Kong and Singapore created? If you can't maintain a system for a small fraction of the cost of building from scratch there is something broken about your practices. There is certainly no systemic maintenance complexity forcing London Transport to continue with trains that belong in a museum. They do, however, need those deeply sprung seats which Asian metro trains lack. You'd have severe spinal issues using hard seats on London's tracks.

author: lukier
author_rank: Unknown
timestamp: September 26, 2017, 11:27:26 pm
content: Quote from: coppice on September 26, 2017, 11:09:40 pmI'm not saying the Tube doesn't require investment - it does, massively! The current austerity ideology is not helping. Actually, new rolling stock is probably one of the easiest things to buy. But even here I guess there are some limitations. For example in the deep lines, the proper tube, the tunnels are tiny because history. Are you going to use more volume of the carriage for shock absorbers and similar devices or for the cabin space for passengers?Another, IMHO significant, problem with the deep tube lines - no ventilation or AC. Only the piston action from the trains. Putting AC on the trains won't help as it would move the heat onto the platforms and the tunnels and these cannot absorb any more:http://www.citymetric.com/transport/londons-tube-has-been-running-so-long-its-literally-raising-temperature-earth-around-itQuoteSolving this problem properly would be a huge cost - new service tunnels, ventilation shafts, turbines, affecting buildings on the surface, new rolling stock with AC. Probably comparable to building a smaller MRT system in a smaller city elsewhere.Similar story goes for the disabled access. It would require major, often underground, building works in a way that doesn't interfere with the existing infrastructure and historic parts of the city - expensive.

author: CJay
author_rank: Super Contributor
timestamp: September 27, 2017, 06:07:07 am
content: Quote from: Beamin on September 26, 2017, 08:20:01 pmIn my admittedly limited research, a large percentage of women tend towards myopia too...

author: Fungus
author_rank: Super Contributor
timestamp: September 27, 2017, 09:17:36 am
content: Quote from: mtdoc on September 26, 2017, 08:07:27 pmI don't really care if it ever works or not, that's Somebody Else's Problem. Right now it's fun to believe it might and fun to imagine how to do it.(with the bonus that we're getting a huge metal tube and some massive magnets to play with)(and some fancy test gear, although a DS1054Z and a couple of AN8008s would probably do the job just as well)

author: cdev
author_rank: Super Contributor
timestamp: September 27, 2017, 10:05:14 pm
content: Concentrated is definitely better for getting things doneQuote from: blueskull on September 27, 2017, 06:13:02 am

author: T3sl4co1l
author_rank: Super Contributor
timestamp: September 27, 2017, 10:44:39 pm
content: Everything living scales as about 4/3 power. The metabolism of living creatures, the productivity of cities. That includes positive and negative productivity, by the way: just as diversity and economic development scale, so too does crime, traffic and so on.Tim

author: EEVblog
author_rank: Unknown
timestamp: September 28, 2017, 01:29:22 am
content: Quote from: mtdoc on September 26, 2017, 08:07:27 pmThat's a bit of a stretch.He does many different types of debunking videos, it's one of his usual video "segments". Hyperloop is just another think to debunk. It's not like he's devoting his entire channel to it and building his entire audience around Hyperloop and anti-Musk. If anything he knows it might cost him viewers instead of gaining them, just like I knew my Solar Tiles video would likely lose me viewers if anything.

author: orion242
author_rank: Unknown
timestamp: September 28, 2017, 01:46:58 am
content: Just looking at his last video on the loop and seeing the construction up close, there is no way and professional engineer can get behind this.What struck me was the connections to the concrete supports. Its clear its expanding and contracting by several inches on a regular basis. You can clearly see this in the rust and rubbing patterns where the tube meets concrete. The $hitty rubber isolators are getting displaced and soon it will be metal on stone. Just as he pointed out, the expansion issues alone will deep six this and his close up shots sure brings that home for me.Working in HVAC I seen steel piping with 90F+ temp swings. If expansion is not accounted for properly, it will lead to an epic fail. This looks to have all the hallmarks of failure to account for the expansion/contraction of steel. Thinking about this with miles of steel tubing, boggles the mind on how much they need to account for. As he points out, just the difference between the top and bottom of the tube is going to be a huge issue that needs to be dealt with and from what I see they have little to deal with this effect.Linus should stick with PCs because he knows jack about mechanical engineering.

author: Fungus
author_rank: Super Contributor
timestamp: September 28, 2017, 02:18:34 pm
content: Quote from: orion242 on September 28, 2017, 01:46:58 amYou're both talking likenobodyat Hyperloop knows this, that they're all idiots and this needs pointing out to them.Reality: It's just one item on the long list of engineering problems that will need to be solved if Hyperloop is going to work. If it's unsolvable then Hyperloop fails, yes. Can you or Thunderfoot prove to us 100% that it can't ever be solved?Railroad tracks also expand/contract with heat/cold but that doesn't stop people laying them, does it? On a long curve the distance between the rails will change so why aren't trains flying off the tracks all over the place?

author: cdev
author_rank: Super Contributor
timestamp: September 28, 2017, 02:24:52 pm
content: It does actually happen not so infrequently that extreme heat causes train derailment due to track expansion. When its extremely hot often trains are halted for that reason.https://www.google.com/search?q=heat+train+derailmentQuote from: Fungus on September 28, 2017, 02:18:34 pmSee image below- they build a gap into the track rails that can handle the expanded rail and move slightly on the ties without failure.That said, if they buried these pipes the extremes in temperature would be replaced by extraordinarily stable cool temperatures a few meters below the surface, year round. However, if they go deep, the temperature rises. Very deep mines are very hot places.https://en.wikipedia.org/wiki/Geothermal_gradient"Do the rails not buckle in Spain?"

author: Fungus
author_rank: Super Contributor
timestamp: September 28, 2017, 03:40:05 pm
content: Quote from: cdev on September 28, 2017, 02:24:52 pmDidn't know that.I don't recall trains ever stopping here in Spain and it gets quite hot here. I thought they laid the lines under tension these days to allow for heat expansion.But anyway, Hyperloop tubes are supposed to be covered in solar panels to help power the thing.The panels will absorb a lot of heat and might even allow for some sort of thermal control of the tube.

author: rsjsouza
author_rank: Super Contributor
timestamp: September 28, 2017, 04:12:40 pm
content: Quote from: EEVblog on September 28, 2017, 01:29:22 amI have a similar felling as mtdoc's when I watched some of his latest solar roadways videos that were clearly clickbaits, with titles that highlighted new developments in the story but were only briefly mentioned halfway through a 10 minute video. That left me with a sour taste about his channel.

author: orion242
author_rank: Unknown
timestamp: September 28, 2017, 05:09:47 pm
content: Quote from: Fungus on September 28, 2017, 02:18:34 pmBecause they design for expansion, something the hyper poop hasn't done.Look at the Alaskan pipeline on how they deal with the issue. Note that they have a fluid flowing through it and don't have to deal with uneven temperature from top to bottom and its insulated as well.Thing zig zags like crazy, which is similar to how they deal with it in HVAC.Something tells me running the hyperloop in a zig zag pattern might be a problem for a 700mph transponder.

author: Fungus
author_rank: Super Contributor
timestamp: September 28, 2017, 09:05:25 pm
content: Quote from: orion242 on September 28, 2017, 05:09:47 pmThey haven't built any tracks yet so how can say that?

author: Kjelt
author_rank: Super Contributor
timestamp: September 28, 2017, 09:32:43 pm
content: Trainrails have gaps between them to allow for expansion, AFAIK this is what makes the typical "kedeng kedeng" repeating noise when traveling.In my opinion at least the hyperloop tries to solve some problem and if succesfull has a benefit.Although cool I can not say the same for human one way travel to Mars, that suicide mission has zero benefits and use for the coming century and might only become beneficial when our planet is unlivable but lets all make sure it never gets that far.Perhaps that is mankinds first and utmost problem to solve.

author: Fungus
author_rank: Super Contributor
timestamp: September 28, 2017, 09:40:00 pm
content: Quote from: Kjelt on September 28, 2017, 09:32:43 pmThe sounds of childhood.These days they put them down under tension (stretched) and weld them. No more "kedeng kedeng" (around here, at least). I don't think "kedeng kedeng" is desirable for 300kph trains.

author: donotdespisethesnake
author_rank: Super Contributor
timestamp: September 29, 2017, 10:06:17 am
content: All engineering is a compromise between what you would like to do and what can be done efficiently. Hyperloop is one of those experiments where you try to take away the main drawback with a design, and then see what other problems that creates. A big problem with fast vehicles is air resistance, so the idea is take away the air, then see how that affects the design. I think the HyperLoop could be made to "work" technically, but the costs involved with the structure will be prohibitive. It will be like one of those futuristic museum exhibits, which has a semi-permanent sign saying "sorry, this exhibit is out of order".There are plenty of other ideas that seem great on paper, but don't work it out well in practice because of all the knock-on impacts and associated costs, e.g. supersonic passenger transport, wireless power transmission, manned space flight, fusion reactors.

author: Beamin
author_rank: Super Contributor
timestamp: September 29, 2017, 05:49:29 pm
content: Quote from: Fungus on September 28, 2017, 03:40:05 pmGreat now It has solar panels on top. Better yet build solar road ways on top so thorium powered cars can drive on it. Put water seers on the side so that the passengers can have a drink. Solar panels thorium reactors water seeres and the hyperloop all get hot though what can we do? We will make the whole thing spin. I can see the "freakin' " future now. Why not have the passengers recharge their phones with Ubeams and have cubio laser engravers and jucieros sold in the gift shop at the station? Diabetic or sick passengers can get their blood checked with the theramos Edison machine!

author: subunit
author_rank: Contributor
timestamp: September 30, 2017, 02:13:34 am
content: Quote from: Beamin on September 26, 2017, 08:20:01 pmI used to work on bone remodelling, and once had the opportunity to speak to a NASA bone guy about Mars missions. He unequivocally stated that the trip was too long with any plausible near-future rocketry to maintain enough bone density (which is lost relatively quickly in micro/low-g) for the astronauts to have unbroken limbs, rib cages etc. when subjected to the landing deceleration. A possible solution would be to build a craft large enough that you could spin it for centrifugal gravity without causing everyone to puke constantly, but this would almost certainly require orbital assembly, massively increasing the cost of the mission. None of the proposed craft I've seen are big enough. I'm not sure why anyone takes Musk very seriously.

author: cdev
author_rank: Super Contributor
timestamp: September 30, 2017, 03:02:54 am
content: Imagine there would be huge profits to be made on air, water, etc. once people were on Mars.

author: cdev
author_rank: Super Contributor
timestamp: September 30, 2017, 03:08:50 am
content: re: spaceflight for extended periods.Please seehttps://www.ncbi.nlm.nih.gov/pubmed/21715682FASEB J. 2011 Oct;25(10):3646-60. doi: 10.1096/fj.10-177295. Epub 2011 Jun 29.Resveratrol prevents the wasting disorders of mechanical unloading by acting as a physical exercise mimetic in the rat.AbstractLong-term spaceflight induces hypokinesia and hypodynamia, which, along microgravity per se, result in a number of significant physiological alterations, such as muscle atrophy, force reduction, insulin resistance, substrate use shift from fats to carbohydrates, and bone loss. Each of these adaptations could turn to serious health deterioration during the long-term spaceflight needed for planetary exploration. We hypothesized that resveratrol (RES), a natural polyphenol, could be used as a nutritional countermeasure to prevent muscle metabolic and bone adaptations to 15 d of rat hindlimb unloading. RES treatment maintained a net protein balance, soleus muscle mass, and soleus muscle maximal force contraction. RES also fully maintained soleus mitochondrial capacity to oxidize palmitoyl-carnitine and reversed the decrease of the glutathione vs. glutathione disulfide ratio, a biomarker of oxidative stress. At the molecular level, the protein content of Sirt-1 and COXIV in soleus muscle was also preserved. RES further protected whole-body insulin sensitivity and lipid trafficking and oxidation, and this was likely associated with the maintained expression of FAT/CD36, CPT-1, and peroxisome proliferator-activated receptor-? coactivator-1? (PGC-1?) in muscle.Finally, chronic RES supplementation maintained the bone mineral density and strength of the femur. For the first time, we report a simple countermeasure that prevents the deleterious adaptations of the major physiological functions affected by mechanical unloading. RES could thus be envisaged as a nutritional countermeasure for spaceflight but remains to be tested in humans.PMID:21715682DOI:10.1096/fj.10-177295Quote from: subunit on September 30, 2017, 02:13:34 am

author: subunit
author_rank: Contributor
timestamp: September 30, 2017, 04:04:43 am
content: Quote from: cdev on September 30, 2017, 03:08:50 amInteresting, but hindlimb unloading for 2 weeks at the earth's surface is not even vaguely comparable to 6-9 months in zero g. You'll also notice that the paper includes zero micro-CT structural data which is pretty much de rigeur for this kind of work. Even if it's possible to maintain BMD with some small molecule supplement (very unlikely over the required timeframe- the gene regulatory networks you're perturbing in order to produce increased osteoblast differentiation will densensitize), what matters for the actual load-bearing properties of bone is the microstructure, not the mass. Correct load-bearing microstructure is produced by bearing loads- the osteocytes which are directing osteoblasts to plate out bone are effectively strain gauges. If all you're doing is keeping osteoblasts active and osteoclasts quiescent, you'll keep bone mass, but you're not necessarily going to get an effective load-bearing structure.

author: cdev
author_rank: Super Contributor
timestamp: September 30, 2017, 04:36:49 am
content: Yes, that makes sense.So "intermittent" is likely what is optimal. I have a number of supplements I take in an on for several days or weeks, off for several days or weeks cycle.this kind of learning is still very much ongoing. It may be useful in osteoporosis too. Seems like it is.

author: mtdoc
author_rank: Super Contributor
timestamp: September 30, 2017, 05:36:20 am
content: Wolff's LawAin't no med or supplement gonna do it.

author: subunit
author_rank: Contributor
timestamp: September 30, 2017, 06:09:19 am
content: Quote from: cdev on September 30, 2017, 04:36:49 amIt is, in fact, osteoporosis research in microgravity research drag. There is close to zero money for basic bone research, the two main granting streams are osteoporosis/penia and microgravity stuff, so lots of cash-strapped osteoporosis labs will write up microgravity grants to get access to that cash. This is evident in the paper you linked- published in FASEB, using techniques that were considered dated years before publication, etc.Quote from: mtdoc on September 30, 2017, 05:36:20 amYeah, any solution is almost certain to be mechanical. I remember seeing some interesting stuff about loading bedridden patients' legs with some kind of vibrating platform. Something like that might cut down on the overall size of the craft you need to build- maybe you only need to spin it up to .3g or something if you can get the crew on a vibrating platform for a couple hours a day. Either way, the basic operational problem NASA identified is nowhere near solved, and the quantity of resources required to deal with it is totally unknown. Astronauts are notoriously resistant to the notion that they should submit themselves for post-mission sacrifice and autopsy, and with essentially no funding on the basic side of things, this is unlikely to change by 2024.

author: Fungus
author_rank: Super Contributor
timestamp: September 30, 2017, 10:35:37 am
content: Quote from: subunit on September 30, 2017, 02:13:34 amAnd I'm not sure why everybody assumes he hasn't talked to that exact same NASA bone guy.Quote from: subunit on September 30, 2017, 02:13:34 amSo thereisaknownsolution to the problem.Quote from: subunit on September 30, 2017, 02:13:34 amEither that, or ... two small craft joined together with a long piece of string.Quote from: subunit on September 30, 2017, 02:13:34 amMaybe because of his history of doing the "impossible".

author: Kjelt
author_rank: Super Contributor
timestamp: September 30, 2017, 11:44:16 am
content: Just build a capsule for one human and launch it into a net a few hundred miles away, proven technology since the 19th century and small infra structure neededhttps://en.m.wikipedia.org/wiki/Human_cannonball

author: subunit
author_rank: Contributor
timestamp: September 30, 2017, 02:08:02 pm
content: Quote from: Fungus on September 30, 2017, 10:35:37 amIn other words, an upscaled, orbitally assembled Tempo3, requiring years of prototyping and testing, rather than what SpaceX actually announced?Quote from: Fungus on September 30, 2017, 10:35:37 amI don't think anyone considered online payments, solar panels, or electric cars to be impossible before Elon Musk got into them. He's been very successful at pursuing ventures that are good candidates for government subsidies and the like, but it's a bizarre kind of Great Man theory to think that somehow trumps decades of institutional experience built up by the only organisations with actual operational experience with long term manned spaceflight.

author: Fungus
author_rank: Super Contributor
timestamp: September 30, 2017, 07:45:51 pm
content: Quote from: subunit on September 30, 2017, 02:08:02 pmYep. It's quite an old idea for dealing with microgravity without building something the size of a city. Perfectly sound in principle and already used in many movies.Quote from: Fungus on September 30, 2017, 10:35:37 amI think SpaceX announced a three month journey. That system wouldn't be necessary for a three month journey, no.Here's the thing: They're allowed to change their designs/plansat any time, just like Hyperloop.I really don't know why people bother going over the fine details of "engineering plans" which are really just artists impressions for press release purposes.Quote from: Fungus on September 30, 2017, 10:35:37 amA lot of people said they'd never work out financially.(...and a lot of people arestillsaying that, despite the half million pre-orders on the latest car, etc.)I'm not an Elon Musk fanboy by any means but Iamon a Hyperloop team so I know first hand that there's a huge gap between what the press is printing and what people are actually building behind the scenes.

author: EEVblog
author_rank: Unknown
timestamp: October 01, 2017, 12:57:27 am
content: Quote from: donotdespisethesnake on September 29, 2017, 10:06:17 amDefinitely.And right there the Hyperloop should have never left the back of the envelope.Any competent systems design engineer with any sort of sense of commercial and practical reality should have just considered that 1000km of several meters wide vacuum tube and went NOPE, let's try some other way.Yet look what we have ended up with. This concept being taken as and almost given, countless people and all of the media talking as if it's just a few years away when practically no real enigneering has been done at all on solvingthemajor problem with the concept. It's an embarrassment to engineering.Compare that to say Space-X. There was a little bit of hype when Musk announced working on reusable rockets, yet it wasn't until full scale tests were happening that people went crazy about it. Hyperloop is arse-backwards.

author: Fungus
author_rank: Super Contributor
timestamp: October 01, 2017, 02:40:40 am
content: Quote from: EEVblog on October 01, 2017, 12:57:27 amIs there any difference at all between Hyperloop and uBeam?

author: mtdoc
author_rank: Super Contributor
timestamp: October 01, 2017, 03:55:45 am
content: Quote from: EEVblog on October 01, 2017, 12:57:27 amCould you explain how you know this?

author: Beamin
author_rank: Super Contributor
timestamp: October 01, 2017, 06:50:28 pm
content: I imagine the people would have to take a lot of things to preserve the bone loss like drugs similar to HGH and testosterone; probably even for females. People going to mars would probably be significantly chemically altered and I'm sure the ones that come back would have permeant health problems and risk of cancer from radiation.

author: Kjelt
author_rank: Super Contributor
timestamp: October 01, 2017, 07:07:07 pm
content: Mars is a one way ticket, they can not bring enough fuel for the return journey.Even then there were alot of volunteers to go, five minutes of fame but when they arrive they might have second thoughts while aur and water is running out and they take the suicide pill.

author: orion242
author_rank: Unknown
timestamp: October 12, 2017, 07:04:45 pm
content: Richard Branson now tosses an untold sum into hyperpoop.https://techcrunch.com/2017/10/12/hyperloop-one-becomes-virgin-hyperloop-one-with-virgin-group-investment/

author: R005T3r
author_rank: Frequent Contributor
timestamp: October 12, 2017, 07:12:13 pm
content: I just don't care about the hyperloop anymore: the US goverment/investors are foolish enought to invest into that? I certanly doubt it!Anyway,

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 13, 2017, 12:18:24 am
content: Wow, SpaceX gets a huge break. They conned the majority of their liability off on someone else.Tim

author: Unknown
author_rank: Unknown
timestamp: October 13, 2017, 08:30:30 am
content: An 'article' by the BBC on Branson's joining the circus. Most of it is just cringe worthy, un-researched bandwagon jumping sound bytes.http://www.bbc.co.uk/news/technology-41595297There is an interesting statement by hyperloop one's Josh Giegel though:Quote.Proven technology, well they are keeping that a well guarded secret, all they have shown are laughable student projects.

author: EEVblog
author_rank: Unknown
timestamp: October 13, 2017, 08:58:57 am
content: Quote from: Kjelt on October 01, 2017, 07:07:07 pmErr, making fuel on Mars isn't hard. Several groups already have working systems.

author: EEVblog
author_rank: Unknown
timestamp: October 13, 2017, 09:00:15 am
content: Quote from: Fungus on October 01, 2017, 02:40:40 amYes. uBeam got the world's best acoustic experts to work for them, Hyperloop has, what, student contests?

author: Kjelt
author_rank: Super Contributor
timestamp: October 13, 2017, 09:59:38 pm
content: Quote from: EEVblog on October 13, 2017, 08:58:57 amThen why does NASA not buy this tech instead of still trying to work things out as they stated last julyhttp://www.wired.co.uk/article/nasa-rocket-fuel-marsThen there are many other problems/challenges : oxygen, cosmic radiation causing cancer, boredom , psychology and we can continue.The biggest question: what is the point to go to Mars? It is not that there is an alien race we want to meet and start diplomatic relations.It is cool as a young boys dream but it costs billions of $ and serves zero practical use. The reason we build boats and explore the earth was that we gained more than it cost and it was unknown territory. Mars is well known , well explored and mapped but we haven't put a human on its surface.I rather wished the world would spent it on practical use as discover new cures, new energy sources, higher crop productivity, influence the weather, distribute fresh water over the planet so people will not die from thirst or hunger etc.

author: Fungus
author_rank: Super Contributor
timestamp: October 14, 2017, 12:45:56 pm
content: Quote from: EEVblog on October 13, 2017, 09:00:15 amuBeam is (now) a deliberate con game, milking VCs for all they can get.Hyperloop may be frivolous but it has a few "Plan B"s and right now the students are learning some real engineering (and quite a bit of marketing, too - our students have to go around trying to scrounge money from big companies).

author: EEVblog
author_rank: Unknown
timestamp: October 14, 2017, 01:01:06 pm
content: Quote from: Fungus on October 14, 2017, 12:45:56 pmWell, to be fair, uBeam could have had a Plan B too and pivoted the idea to niche markets.Hyperloop will have to pivot too of course, the vacuum parts of it is just plain real world impractical and any team with any clue will quickly come to realise this if they are serious about moving to real full scale testing of something.

author: EEVblog
author_rank: Unknown
timestamp: October 14, 2017, 01:06:40 pm
content: Quote from: Kjelt on October 13, 2017, 09:59:38 pmOr simply spendslightlyless on new military toys and go to mars instead with the leftover change, and you know, re-ignite the dreams of an entire new generation, which, you know, kinda makes life worth living...

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 14, 2017, 05:33:34 pm
content: Heh, here's a thought:If hyperloop takes off, imagine how many turbopumps will be manufactured. Just for a short path.The cost of production will plummet, making high vacuum applications cheaper in general.And, when hyperloop inevitably crashes and burns, all those massive turbopumps will be sold off for pennies on the dollar. Ever wanted a vacuum chamber the size of your house, but too afraid to pump it down? Just wait a few years.Tim

author: Beamin
author_rank: Super Contributor
timestamp: October 15, 2017, 06:09:21 am
content: Quote from: EEVblog on October 13, 2017, 09:00:15 amDude didn't you see the RC car go like 60mph at almost 100 meters? Who do I make the check out to?

author: SeanB
author_rank: Super Contributor
timestamp: October 15, 2017, 07:49:03 am
content: Actually I can see Hyperloop being a pioneer in low cost tunnel boring, probably making a system that is capable of working with almost no human involvement, and in making a prefabricated tunnel segment that is faster than the existing methods, and capable of being used fast in existing cities as a transport enabler. current methods are good, but a new approach to them in either lowering cost per kilometer, or in increasing build speed or in lower footprint for the starting yards will be good. you still will need the older methods for the more challenging tunnels, like hard rock or fractured rock and fault zones, but a cheaper system that works in most alluvial sediments ( where you generally find large cities) that will work and do a good waterproof tunnel fast will make it possible to change existing infrastructures to some mass transit that is less intrusive, and reclaim roadways for other purposes.The vacuum side is less possible, but still usable as a goods transit method between hubs in a city, so that you can keep heavy trucks off the roads a lot more, only having smaller, probably electric, local distribution for the last part. A win in both cases, as in the original post office systems, where you send bulk to a local office for local delivery, and vice versa for the return stream. You could probably combine the delivery process with recyclable collection as well, using the unused space in the vehicle both ways, rather than doing 2 separate trips for delivery and collecting the packaging.

author: Fungus
author_rank: Super Contributor
timestamp: October 16, 2017, 06:50:39 am
content: Quote from: SeanB on October 15, 2017, 07:49:03 amYep. I think if 'vacuum' is ever going to happen it has to be undergound (or a mixture of underground and sections encased in concrete). Bare steel tube on legs just won't work out.At these speeds you can't simply follow the terrain, either. Large earthworks will be mandatory.Secondly: All the logistics of acquiring the land, fighting with NIMBYs, etc. will make overland tubes impossible.Quote from: SeanB on October 15, 2017, 07:49:03 amYep. Replacing trucks is a big part of the team discussions I'm seeing at the moment.eg. If we can avoid container ships entering the Mediterranean and send them back to China a week earlier then that's worth a fortune in itself.What Thunderfoot (and many others) aren't seeing is the vibe that it's more about finding out what's possible on the engineering side and seeing what business plans emerge as it goes. It may fall flat on its face in the long run but if nobody proposes it or acts like they're really building it then we'll never know.

author: Fungus
author_rank: Super Contributor
timestamp: October 16, 2017, 06:53:21 am
content: Quote from: EEVblog on October 14, 2017, 01:01:06 pmI'm not sure what market would think ultrasonic charging at a distance is a billion-dollar idea compared to the alternatives.

author: amspire
author_rank: Super Contributor
timestamp: October 16, 2017, 07:00:19 am
content: Quote from: Fungus on October 16, 2017, 06:53:21 amDoesn't have to be anything to do with charging. There might be military, industrial or medical uses for ultrasonic arrays. They might be able to make transducers that are not currently on the market.If they can make cheap high element count arrays, is there anyone else on the market that offers anything similar?

author: Howardlong
author_rank: Super Contributor
timestamp: October 16, 2017, 07:54:20 am
content: Quote from: Z80 on October 13, 2017, 08:30:30 amThat’s just Branson and Virgin increasing their own brand awarenesses. He rarely puts any significant amounts of money into anything, usually just enough to get the word “Virgin” on the product, and his name in the papers. Increasing his brand awareness will probably be one of the few success stories of the project.