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201 MPH Pod Run Wins SpaceX's Second Hyperloop Competition (geekwire.com)
An anonymous reader quotes GeekWire:
The speediest team from SpaceX founder Elon Musk's first Hyperloop pod competition has done it again: WARR Hyperloop from Germany's Technical University of Munich won today's second contest by sending its magnetic-levitation pod through a nearly mile-long test tunnel at a peak speed of 201 mph [video]. Musk announced WARR's victory to a crowd in the stands at SpaceX's headquarters in Hawthorne, California, and in a tweet... This weekend's competition brought about two dozen teams to Hawthorne, including a student group from the University of Washington. Each of the teams developed a pod that was designed to test engineering approaches for Musk's Hyperloop rapid-transit concept, which calls for sending people and cargo through low-pressure tubes at near-supersonic speeds.
Musk also tweeted that it "might be possible to go supersonic" in the 0.8-mile test Hyperloop tube, though he conceded it would require an extremely high acceleration (and deceleration) because of the short distance.
"For passenger transport, this can be spread over 20+ miles, so no spilt drinks."
Musk also tweeted that it "might be possible to go supersonic" in the 0.8-mile test Hyperloop tube, though he conceded it would require an extremely high acceleration (and deceleration) because of the short distance.
"For passenger transport, this can be spread over 20+ miles, so no spilt drinks."
https://en.wikipedia.org/wiki/Shanghai_Maglev_Train
"At full speed, the journey takes 7 minutes and 20 seconds to complete the distance of 30 km (18.6 mi), although some trains in the early morning and late afternoon take about 50 seconds longer. A train can reach 350 km/h (217 mph) in 2 minutes, with the maximum normal operation speed of 431 km/h (268 mph) reached thereafter."
Impules to Warp speed is immediate, and back agian. THis is stpido. Musk is wack.
This .. is not an accomplishment. Not yet, anyway. The French TGV cruises at these speeds (320 kmph / 200 mph) since 1988 (and 170 mph since 1978!)
They have a record of 574 kmph / 357 mph in non-commercial speed-run.
And this is on conventional wheels on above ground surface track that really isn't all that different to a normal train track.
When 267mph maglev is already in service in other countries?
Shanghai's maglev does the 430 km/h just for show, 2h30 per day and it loses money continuously. It was made as a political statement. Even if Hyperloop only did 320 km/h, but did so at a low cost (and profitably), you'd have something the the Shanghai maglev doesn't have. I'm not saying it does, but you're comparing apples to oranges.
In non-retard units.
Maglev in evacuated tubes can, in theory, be one of the most energy efficient ways of transportation. There is no loss to friction–so not much to fear from Thermodynamic's second law, making the process reversable in theory. And if you can then use the Maglev technology to recover most of the kinetic energy, you're there.
My opinion of the hyperloop concept is based mostly on this critique by "thunderf00t" (youtube link):
https://www.youtube.com/watch?...
I think wilful ignorance and blind optimism fuels these things. Maybe they're a good thing, in that they show the general public why engineers "can't just" do this or that. Think of the history of the Concorde - that was actually quite simple from an engineering standpoint, yet it was a long way off from being practical, even decades later.
The energy cost of maintaining a near-vacuum in very large containers, such as hundreds or thousand of kilometers of tube, and keeping magnets cold enough to be superconducting over such a distance is not to be underestimated.
Japan is also building a Maglev system with an operating speed of 505km/h (has hit over 600 in tests but not expected to operate at that speed). Just because China have made a bit of a pigs breakfast of it doesn't mean everyone will, also I have to question some of the ridiculous cost savings Elon often quotes for hyperloop. some of the biggest costs for any system is the Land and construction. He seems to base his savings on the belief everyone will just let him build this free of charge on top of existing infrastructure which simply isn't reality and besides which you could do the same with a maglev anyway.
It really puzzles me that a website geared towards engineers, scientists and other nerds from across the world would use imperial units in such a news article.
so not much to fear from Thermodynamic's second law, making the process reversable in theory
Care to enlarge on that?
Yes but building the pipes to contain the vacum is not a simpel or cheap.
Building the pipes to also handel ground movment is just horrible we have enogh troble to get the railway track to stay put can hardly imagine the problems with a long vacum tube where small compromises could lead to horrible results
Would you care to explain what the second law of thermodynamics has to do with friction?
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
Can that maglev do 0-267-0 in 0.8 miles?
This was a bunch of students doing this for a project, and it reached that speed on a 1.7 km test track. With a longer track and more budget, they expect to go supersonic eventually. This is nowhere near a finished product, so don't compare it to one.
Why is everyone so pessimistic about everything Musk does? Even here on a supposed nerd site? Jeez, I know the guy uses a lot of hyperbole and has impossible ideas like, say, landing rockets on barges (o, wait, that actually worked) or making usable electric family cars that outperform two seat supercar monsters (o wait, he did that too). Maybe just see where this idea goes? We need more people like him, billionaires that are not afraid to push boundaries and try new things that may well fail but might just make a huge difference in the world, instead of just buying big yachts. I know he's crazy. That's what makes all the difference in this world of paralysing risk averseness.
When 267mph maglev is already in service in other countries?
It was a test run. When you are developing something you don't go full throttle right away, you step it up progessively in a series of trials; standard engineering practice.
But Musk is primarily a showman who wants every possible opportunity to listen to his own voice and seeks the adulation of others listening too. As a result, we are going to subjected to a Musk-managed shitstorm of media hype time a test vehicle has gone faster than in the previous test. In any normal project this would be dome without any fuss, at least unti some real record was broken
You forget one thing: The test track is not even a mile long, and the pod has to accelerate AND decelerate in that short span. Your comparison Maglev can't eaven rech 50mph in the same distance (and forget about stopping :) ... this is just a small scale test, in a very sub-length tube to test power and propulsion systems - if the pod had a length of say 10 miles, I'm sure they could reach the proposed 700mph. But that is far out, and the test track for that still has to be built.
Sorry, I meant the comparison to be with a normal bullet train, not the maglev in question..but still, that can't get up to full speed in that short distance either.
When 267mph maglev is already in service in other countries?
Let's face it, there is no innovation in Hyperloop. It's just vaporware.
Elon didn't invent maglev technology, the electric car, or the solar panel. Apple didn't invent the portable music player either. These companies are known for innovating by taking designs to the next level. When it comes to high-speed transit, the innovative part would be delivering a product before the generation who needs to use it dies, and perhaps deliver a profitable design.
Can that maglev do 0-267-0 in 0.8 miles?
No. It was design to carry human passengers without killing them.
Claus
+1
No sig today...
And how fast did the very first maglev prototype go? I bet it wasn't 430km/h.
No sig today...
No. But neither can humans if they wish to remain humans.
We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
What strikes me with Hyperloop is Elon Musk's very limited investment. He does a bit of sponsoring (mostly through SpaceX) but he owns none of the companies involved.
What he own are companies that would be suppliers : Tesla for the batteries, and maybe motors, Solarcity for the solar panels he intends to put on the track, The Boring Company for the tunnels. Interestingly his design calls for batteries, which are not strictly necessary, and solar panels, which are nothing more than a nice addition, as for tunnels, I don't remember hearing about them before he founded his tunnel company. So my conspiracy theory is that he is using Hyperloop as a relatively inexpensive way of promoting his real, profitable companies.
Well, then why not build a test course that's, say, 50 miles long?
Probably because it would take about a year to evacuate between tests...
We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
The real technical challenge is not how to build a pod that can accelerate to supersonic speed inside the near-vacuum, the real challenge is how to build a very long vacuum tube that would be safe and cost-efficient to operate. So all those hyperloop competitions do nothing to advance the hyperloop idea -- it is just a show for a gullible public.
They're saying that energy spent accelerating a craft can be recovered in decelerating it.
In practice, while maglev is low friction, it's not frictionless, so your craft will suffer some deceleration.
He's just being nice so my real father won't freeze him in carbonite and sell him for spice.
1) Requirements for straightness on HSR and Hyperloop are the same, for a given speed. And there are standard solutions which very much work well for thermal expansion and are widely used in industry - either floating the object that would expand and allowing its expansion in a controlled manner, expansion joints, or resisting the expansion. Hyperloop Alpha proposed to use the first one, although any of the three could work. High speed rail generally uses the latter - pretensioned rail and heavy sleepers.
2) Building vacuum lines is no more complicated than building pressure lines, contrary what biochemists-pretending-to-be-engineers on Youtube would have you believe. There are standard guidelines and formulae for them, and no, a properly designed vacuum line does not suffer cascading failures.
He's just being nice so my real father won't freeze him in carbonite and sell him for spice.
kinetic energy is converted to heat due to friction. To maintain the kinetic energy you need to put more energy into the system.
they expect to go supersonic eventually.
What is the speed of sound in a vacuum, or a near-vacuum?
Exactly right, the negative attitude has always surprised me in respect to Musk, who at least is pushing the boudaries of technology.
On a tech nerd site, its rather ironic. If we had listened to all the negative Nellys in the past, we would still be arguing over what colour the wheel should be. To the B ark with them.
At 1g acceleration, it takes around 11 seconds to travel half the distance in this tube (assuming that the other half is spent decelerating). That's a peak speed of 110m/s, or around 245 miles per hour, so this train had less horizontal acceleration than humans experience vertically just by being on this planet. Give them a comfy chair and they'll happily manage that level of acceleration for 30 seconds to a minute. And you can always trade a little bit time for comfort. Half the acceleration and accelerate for two minutes instead of one and you'll add two minutes (one at each end) to the total travel time, which won't make much difference in a half-hour journey.
I am TheRaven on Soylent News
And they leave a lot of U's out of words. Sad.
Your parent simply does not know how short a mile is :D
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
Dear Friend.
Musk is a business man who is also very successful at engaging the interest of the masses because this raises the profile of his companies and directly improves their stock price, making him more money.
If you think critically about Musk's endeavors for a moment you will realize that over half of them are pure hype. He will not send people to Mars. He will not build the Hyperloop and revolutionize ground transport. This is not being pessimistic: we did not land men on the Moon by being optimists.
Once you realize what his strategy is, it becomes a lot easier to separate the bullshit* from the rest. Yes, he's done some great things with SpaceX and Tesla, but that does not obviate the fact that he is firstly a business man, and he *needs* media attention and healthy investment if the successful parts of his empire are to succeed.
*Any "technical" announcement that is based on 3D renders, talk about the spacesuits (see recent media release from last week) and what colour/shape they will be, basically any fluff that catches people's attention and distracts them from the actual hard engineering challenges.
"So my conspiracy theory is that he is using Hyperloop as a relatively inexpensive way of promoting his real, profitable companies."
It's not a conspiracy theory. This is *exactly* what he is doing.
In a near vacuum it's about the same as at higher pressure at the same temperature. Obviously it makes no sense in a total vacuum, but then just take the speed of sound outside the tube.
Can that maglev do 0-267-0 in 0.8 miles?
No. It was design to carry human passengers without killing them.
Hmm, is there an error in my maths then?
ignoring trivial rounding that is...
267 mph = 430 kph = 120 m/s
0.8 miles = 1.3 km
Assuming a constant acceleration, from rest, to peak speed, followed by constant deceleration, to standstill, pod will use half the track to reach peak speed.
i.e. distance to reach peak speed = 0.65 km = 650 m.
Using: v^2 = u^2 +2as gives:
'v' and 'u' are interchangeable, depending on whether we're accelerating or decelerating. 'a' will have the same magnitude in both cases...
120*120 = 0 + 2*a*650
=> a = 120*120/(2*650)
=> a = 11 m/s^2
Are you really trying to tell us that a human body can't accelerate at 11 m/s^2?
For reference acceleration due to gravity is roughly 9.8 m/s^2
Unless there's an error in my maths of course - it has been 30+ years since I studied these equations in school...
No. But neither can humans if they wish to remain humans.
Hmm, is there an error in my maths then?
ignoring trivial rounding that is...
267 mph = 430 kph = 120 m/s
0.8 miles = 1.3 km
Assuming a constant acceleration, from rest, to peak speed, followed by constant deceleration, to standstill, pod will use half the track to reach peak speed.
i.e. distance to reach peak speed = 0.65 km = 650 m.
Using: v^2 = u^2 +2as gives:
'v' and 'u' are interchangeable, depending on whether we're accelerating or decelerating. 'a' will have the same magnitude in both cases...
120*120 = 0 + 2*a*650
=> a = 120*120/(2*650)
=> a = 11 m/s^2
Are you really trying to tell us that a human body can't accelerate at 11 m/s^2 without being 'smushed'?
For reference acceleration due to gravity is roughly 9.8 m/s^2
Unless there's an error in my maths of course - it has been 30+ years since I studied these equations in school...
they aren't DONE yet, moron. this is a ONE MILE test track.. proof-of-concept, if you will. give it a reasonable length, and it will be able to go faster.... much faster.
and hyperloop would augment his upcoming SELF DRIVING cars. that's what he wants: to RENT the fucking things, not sell them.
do you even know how to breathe, bluegutang?
Fuck off.
Hugs and kisses,
Juan Epstein
People like you have been bitching and moaning about this for a long time, and at this point I think you just enjoy complaining. Slashdot isn't going to change, get used to it. Or join the horde of people who don't come here any more. Either way, STFU with the stupid metric flame.
Shutting down free speech with violence isn't fighting fascism. It IS fascism!
Just more bullshit from the MuskRAT.
Anakin Skywalker! In his homebuild pod with his unusually high midichlorian count... he has a lot of jedi juice inside him!
The math is correct, but gravity doesn't go away, so total acceleration with horizontal track is sqrt(11^2+9.8^2) m/s^2=14.7 m/s^2 = 1.5g. Not deadly. Still, killing jokes is no laughing matter.
Yes, damn them for sponsoring a student competition.
Next up: SpaceX hands out food to the homeless. "Oh, wait, SpaceX is manipulating the homeless to get rid of their extra food? WTF is up with that?"
He's just being nice so my real father won't freeze him in carbonite and sell him for spice.
Watch your language, young man.
Lovingly,
Epstein's Mother
Slashdot isn't going to change
Given what we have witnessed on this site in the past 10 years, how can you honestly say that with a straight face?
The goal is to convert the electric energy mostly into kinetic energy, and not into heat. The second law of thermodynamics implies that you cannot recover heat energy completely.
People like you have been bitching and moaning about this for a long time, and at this point I think you just enjoy complaining. Slashdot isn't going to change, get used to it. Or join the horde of people who don't come here any more.
Do you often write to yourself like this?
Always a crybaby in the bunch.
Here, math nerd, let me convert it for you: 200 miles per hour = 3,234,78 hetcometers per hour.
Happy now?
This is America, bitch. We use mph.
The second law of thermodynamics is: entropy is increasing over time.
So your explantation is wrong.
However all laws of thermodynamics imply that you cannot recover heat energy completely.
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
Why is everyone so pessimistic about everything Musk does? Even here on a supposed nerd site? Jeez,
It's not just Musk, it's anything outside the comfort zone or cutting edge technology. Slashdot is very different than it was when it was new. I think the average age of user on here is much older than it used to be.
We have old jaded engineers, IT staff, etc, as the majority of visitors now. Anything that wasn't possible to do with tech when they were in school must therefore always be impossible. Because one or two technologies didn't take off as quickly as expected... no technology will.
This is a much more pessimistic place than it was 10+ years ago.
"That's the way to do it" - Punch
Acceleration is no problem. You are just pressed into the seat with a bit more than your "weight".
Deceleration is however, as you will fly into the front of the cabin with more than earth gravities acceleration.
So you better have safety belts.
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
Speed of sound varies with temperature rather than pressure, slightly counter-intuitive I know.
"Slashdot isn't going to change"
Please send me the contact to your dealer cus you must be on some good shit thinking that slashdot wont change. History tells a different version.
It really puzzles me that a website geared towards engineers, scientists and other nerds from across the world would use imperial units in such a news article.
Most English-speaking people use antiquated units for measurement of distance, and many of them still use them for measurement of volumes as well. You're just going to have to build yourself a bridge.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
This is a technology demonstrator. You're comparing it to a mature product. That's where your confusion lies.
Man, you put a lot of effort into that troll!
At that acceleration, you can walk on the rear wall of the pod. Anyone standing on the floor will fall over. All luggage in overhead racks ends up in a heap at the rear of the pod.
Braking at 11 m/s^2 is unpleasant if you're strapped into a 4-point seat belt, because the belt straps carry your full weight. Without a belt, you'll be squashed into the seat in front of you. I tried braking at about that deceleration once (emergency stop in a high-performance sportscar). All the loose shit in the cabin went flying. My passenger damn near ended up in the footwell.
Acceleration is no problem. You are just pressed into the seat with a bit more than your "weight".
Deceleration is however, as you will fly into the front of the cabin with more than earth gravities acceleration.
So you better have safety belts.
Since we have safety belts in cars and humans still ignore them, I think you meant to say you better not have fucking idiots on board.
That filter is becoming increasingly impossible to apply.
Turn the seats around as soon as you hit speed. Safer that way anyway.
Watch for Penguins, they eat Apples and throw rocks at Windows.
Don't worry, all those solar roadways will power it.
Oh? Since when does USA = "most English-speaking people?"
Does it hit 200mph and stop in less than 5280 feet?
That test track is short. If it was 4 miles long, much higher speeds should be attainable.
Oh? Since when does USA = "most English-speaking people?"
Since when was it just the USA that did this?
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Because Musk is a hypeman taking credit for what his employees are creating while inventing nothing himself, plenty of us here realize that he's not a real-life Tony Stark but instead a 21-st century Thomas Edison.
Anyhow there are plenty of other sites where the audience engages in perpetual circle-jerk over the tiniest bits of "progress", perhaps you'd be happier there. On the other hand there is a need for a place like here were the more jaded curmudgeons can hang out and view things a bit more critically.
It's not just Musk, it's anything outside the comfort zone or cutting edge technology. Slashdot is very different than it was when it was new. I think the average age of user on here is much older than it used to be.
I've been visiting slashdot since the late 90s and it's been like that as far back as I can remember. It's kind of the asshole attitude of "if I didn't invent it, it's a stupid idea and it won't work." The question is just what percentage of the slashdot community did it represent.
Honestly it's just long been considered "cool" to trash new things or different ideas. Slashdot and a certain portion of the *nix world (especially the older part) was very insular, cliquish and incrowd-y. And I say that as a full time linux user. I think that's probably true of a lot of communities or groups of people. Outside people and ideas are bad. Again, not agreeing with it.
Ok, fair enough - Myanmar and Liberia have also not officially adopted SI units.
The entire rest of the world uses metric.
If this is ever built for public service in the US, every Podunk it passes will demand a station, so it'll never get to go more than 45 mph before it has to stop for the next station.
the obvious reparation is to return those people to their homeland
Those people died a long time ago. Their descendants are full U.S. citizens. This is their homeland now. But you knew that; which makes you an anti-immigrant racist contrary to your denial.
1) Requirements for straightness on HSR and Hyperloop are the same, for a given speed.
What a tricky way to put it. Yes, the requirements for straightness are the same for a given speed. However, Hyperloop is being sold to us as being much faster than a regular train. As such, the requirements for its straightness are much stricter. It is, after all, meant to go much faster.
I've been visiting slashdot since the late 90s and it's been like that as far back as I can remember. It's kind of the asshole attitude of "if I didn't invent it, it's a stupid idea and it won't work." The question is just what percentage of the slashdot community did it represent.
That's about when I first started visiting Slashdot. I thought it was better back then, but maybe I'm remembering Slashdot of old with rose-coloured glasses on.
Your point of "I didn't invent it, it's a stupid idea" is a very valid one. I've noticed that with a lot of people in the IT field actually, even in the workplace. Something in the psyche of an IT worker seems to distrust other people's achievements. Probably because there a lot of people in the industry who are intelligent, and used to being told they are and that's how they identify themselves. The don't like others getting praise they feel should be landed on them.
"That's the way to do it" - Punch
The space shuttle did 18,000 mph! Why build anything else?
PS, You are an idiot.
So decelerate over a longer distance. For long travels, doing this won't add much to the travel time.
If you want a vision of the future, imagine a youtube comments section scrolling - forever.
Not everything, just this. For me the biggest challenge will be actually building the thing. Not from a technical point, but from a political one.
And that means that it will be dragged out and that could mean that it is no longer financially sound to do so, as the investment needs to be spread out over many more years.
Don't fight for your country, if your country does not fight for you.
Musk actually mentioned that it is not aimed at super long distances (to compete with aircraft), but rather for shorter ones, when the whole "get to airport, through security, onto plane, lift off, landing" is too much of an overhead.
It was several hundred of kms, not much more.
Your argument is tantamount to appeal to authority. Because Musk is successful in one area means now he is successful in all areas. He's a great entrepreneur, but like Tesla, some of his ideas just won't pan out. Hyperloops were thought of more than a century back and were deemed infeasible each time. Not just on a "oh if we only had a better material" level but on a fundamental level.
I cannot see how the downsides of hyperloops will be overcome, even if you bury it 100 feet into the ground (expansion issues reduce, but now crushing forces and in earthquake country). I don't see what upsides it has compared to airplanes.
The only thing holding airplanes back is regional planes died due to economy (subsidies can easily rectify this) and overly hamfisted and expensive homeland security. Other countries have thriving regional flight business which is no more complicated than taking the bus. OTOH, hyperloop is all the dangers of space with very few advantages.
You don't even have to be in a high performance car to hit the brakes hard enough to send everything flying to the dash - anything with anywhere close to modern disc brakes and good tires will do.
Deceleration is no joke.
Slashdot still doesnâ(TM)t support Unicode after it was added to the HTML standard in 1997.
I think it's gotten worse. There used to be many more engineers (mostly software, but all sorts) here, and fewer (on a percentage basis) "IT guys". System administration tends to create a skeptical to cynical mindset. I agree that there has always been some reflexive negativity, but I think in the past it was more often offset by the pragmatic mix of optimism and caution that engineers tend to have. Today, if we didn't have the likes of Rei and a handful of others, it would be nothing but negative. If that handful ever bails it will become completely worthless.
Note to ACs: I usually delete AC replies without reading them. If you want to talk to me, log in.
I'm sure that in his day, Andrew Carnegie had to eat a lot of shit for building all those libraries in a nation with such a low literacy rate.
Nobody has a problem with it today. History has a way of self-correcting over the long term.
The reason the classical system is used is because we are Actual Nerds (Occultists, students of The Obscure). Our ancient measures are based on universal truths and natural harmonies. Suck it, noob.
you sound sweet, bitter tits
Luckily there are young trolls like yourself to represent.
fuck off.
Hugs and kisses,
-jct
The entire rest of the world uses metric.
You should talk to the UK about that, because they still have problems with it here and there. Meanwhile, more and more stuff in the US is metric, like everything in our cars finally.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
How many times have I told you that open hand slaps don't work!
Caringly,
Epstein's Grandmother.
. . . at this point I think you just enjoy complaining.
Wrong. He's just looking for easy mod points. You know the sheep automatically mod shit like this up.
1) Requirements for straightness on HSR and Hyperloop are the same, for a given speed.
What a tricky way to put it. Yes, the requirements for straightness are the same for a given speed. However, Hyperloop is being sold to us as being much faster than a regular train. As such, the requirements for its straightness are much stricter. It is, after all, meant to go much faster.
I think that goes hand in hand with Musk's boring company.
It's probably going to be easier to build in straight lines underground where there are fewer things to get in the way than above ground where existing buildings and infrastructure (and hills and mountains) get in the way.
"That's the way to do it" - Punch
Acceleration is no problem. You are just pressed into the seat with a bit more than your "weight".
Deceleration is however, as you will fly into the front of the cabin with more than earth gravities acceleration.
So you better have safety belts.
Point taken, although, it'll probably be the other way around. Because the pods will be unlikely to have windows (who needs a window if you're travelling in a tube) there is no reason to face forwards.
If there is no reason to face forwards it is better to face backwards for safety reasons.
"That's the way to do it" - Punch
From the video deceleration looked far faster than acceleration. Probably about 4-10 times as quickly. So they used most of the track for acceleration.
USA+UK still != most of the English-speaking world.
That would be safer but less practical. You can't cram as many people in like sardines if the seats rotate- and in a pod space is at a premium.
Airline industry is probably the best industry to compare how passengers are likely to be treated.
Also, if the seats rotate, wouldn't that be more dangerous in an accident? During an accident if it cause the seats to rotate (impact breaks position locking) that could be dangerous.
Best just to have the seats always facing backwards.
"That's the way to do it" - Punch
Why is everyone so pessimistic about everything Musk does?
People who think they know, but don't know, are the worst. You can't tell them they are wrong, but because they "know" everything needed to know, come to all the wrong conclusions. These are the people who will tell you you are wrong, what you're actually thinking and your full mental abilities, having read something on the internet about you. They know you better than you know yourself, having never met you.
They are pessimistic about Musk because he is actually doing what they said couldn't be done. Again. They are hoping he fails, because that will legitimize their own lack of initiative/drive.
Agent K: A *person* is smart. People are dumb, stupid, panicky animals, and you know it.
Less than a mile track over a short timespan is not anywhere close enough to integrate steel's linear expansion...
I see you're unfamiliar with the UK and Canada. I've not been to Australia so I can't speak to it though. But the UK and Canada confuse me. The US at least consistently uses imperial units, but UK and Canada pick and choose. The English speaking Canadians I've met can't tell me how tall they are in meters nor can they say what they weigh in kilos, but only know the temperature in Celsius. The UK by far has me the most baffled though. Why list distances to other cities in KM and speed limits in MPH? Surely if you use KM for distance you'd want KPH for speed so it's easy to estimate how long it'll take to get somewhere given a specific speed? But apparently no, they don't like that convenience. Also to the brits, why the hell do you weigh yourselves in stones?
Slashdot was founded in the US, is based in the US, and the majority of it's users are, too.
Please stop complaining about how the general population appreciates imperial units more than your precious metric system, FFS. Also, nerd doesn't necessarily mean everybody on here is a goddamn physicist. And, it's not like americans travel to europe and constantly bitch at them to switch what side of the road they drive on, or japanese traveling to mexico and constantly whining about how they mostly speak spanish.
Just knock it off, already. It's super disrespectful.
One reason I like this whole process of seeing the Hyperloop developed is that as far as I can see, it is not the benefit of any government funding.
When these people are putting their own money on the line, I expect a higher chance of a workable solution.
When Fascism comes to America, it will call itself Anti-Fascism, and tell you to give up your guns.
I understand that the technical challenge is doing this in mild vacuum, but European trains routinely reach these speeds in scheduled routes on open-air track. For example the LGV Oceane (Paris-Bordeaux) does this 20 times a day.
Put the seats, the drink trays, or maybe even the whole passenger compartment (or sections thereof) on a pivot so "down" turns to match acceleration. Presto: no spilt drinks.
Not really - maglev embeds a large amount of fairly sophisticated technology in the tracks themselves, which makes for considerable per-mile construction and maintenance costs. Hyperloop is just an airtight tube with some passive backup rail to help stabilize the car when it begins to drift. You need occasional vacuum pumping stations to counteract the inevitable leakage, and the big linear motors anywhere you need to accelerate or decelerate the cars, but by and large the tubes are passive, low-tech infrastructure, and the cars themselves are hovercraft-gliders responsible for concentrating the low pressure air into a cushion beneath them. That makes the per-mile infrastructure cost considerably lower, and the more expensive cars can be added as needed and re-allocated to different routes as demand shifts.
The other major cost-saver is due to the small cars - a high-speed train subjects the rails to infrequent *heavy* loads, and you need to build the foundation to handle that. A steady stream of small cars subjects the infrastructure to much lower peak loads, low enough that you can suspend it from pylons and dramatically reduce the required ground-level infrastructure.
Theoretically you could do the same with rail, even maglev, by using small cars instead of trains, but a great deal of the efficiency of rail comes from the drastic reduction in air resistance provided by being an extremely long, thin vehicle that doesn't have to push much air out of its way compared to its bulk. You could wrap the rail lines in a low pressure tube instead and have mini passenger-engines - but then you're basically back in hyperloop territory.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
Slashdot isn't going to change
Given what we have witnessed on this site in the past 10 years, how can you honestly say that with a straight face?
Perhaps he should say "this aspect of Slashdot isn't going to change". It's an American site, and a primarily American readership. Always has been, and there is no indication that's likely to change. And for better or for worse (mostly worse), Americans use the Imperial system, except when we don't even follow that, e.g. US vs Imperial gallon.
[The history of the gallon difference is kind of interesting. The UK had several definitions of "gallon" including the wine gallon (231 in^3, standardized in 1706), the ale gallon (282 in^3, standardized in 1700), the Winchester gallon (272 in^3, standardized in 1697) and the Irish gallon (217 in^3, standardized in 1495). The US standardized on the wine gallon, and that remains the US gallon today. In 1824 the British established a new Imperial gallon which didn't match any of their previous gallons. It was defined as the volume of 10 pounds of water at 62F.
While I'm being pedantic, it's also worth noting that the US gallon wasn't originally well-defined, because the inch wasn't well-defined. The inch was vaguely-defined per the old British definition as the length of three barleycorns, though as of 1814 the canonical inch was a measure stored in the Exchequer chamber in the UK. In 1866, the US inch was defined as 1/39.37th of a meter, which gave it, and therefore the US gallon, a precise measure. In 1959 it was redefined as 1/36th of a yard, which was in turn defined as 0.9144 meters, making the inch exactly 2.54 cm long, and decreasing its length by two millionths, thereby shrinking the gallon by ~6 millionths.
Actually, you can argue that the length of the inch, and hence the gallon, was changed -- or at least clarified -- three more times, when the definition of the meter changed. In 1889 the International Bureau of Weights and Measures replaced the prototype bar in France and created calibrated copies which were distributed around the world. The US received #27, which was calibrated at 0.9999984m ± 0.2 m. That was used to establish the size of the US inch. In 1960 the meter was redefined as 1,650,763.73 wavelengths of the orange line of krypton-86. Then in 1983 the length of the meter was redefined as the distance traveled by light in vacuum in 1/299,792,458 of a second.
This, of course, means that lengths are now defined in terms of time measurements, which raises the question of the definition of a second. The second was defined in 1967 as the duration of 9,192,631,770 cycles of a cesium-133 atomic clock. In 1980 this was further clarified to be a clock at mean sea level, and in 1997 clarified again to specify that the cesium atom should be at rest at 0K (which none are, but corrections to measurements of real atoms can be applied). Future refinements in the definition of a second are all but inevitable, especially since the definition of mean sea level is problematic in various ways.
The US survey inch, by the way, is still defined as 1/39.37th of a meter. So a survey mile is about 1/8th of an inch longer than a regular mile. Over long distances, the difference matters.
And, yes, this post is the result of an hour-long tumble into a wiki-hole which started with a desire to find the history of the difference between US and UK gallons.]
Note to ACs: I usually delete AC replies without reading them. If you want to talk to me, log in.
The math is correct, but gravity doesn't go away, so total acceleration with horizontal track is sqrt(11^2+9.8^2) m/s^2=14.7 m/s^2 = 1.5g.
Isn't the gravity force meant to be cancelled out by the maglev?
I always sit backwards in trinas, for exact that reason :)
And if I'm in the restaurant and have a beer in front of me, I prefer it not falling away from me, albeit if it would drop on me it would be more nasty. Anyway, the beer is usually secure.
Looking out if the window, I like it if I ride backward. Somehow if something catches you attention you can watch it for quite a while.
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
What's the point in using clumsy units that are completely alien 95% of the world?
Not to mention that they can be manufactured in a factory instead of onsite.
When Fascism comes to America, it will call itself Anti-Fascism, and tell you to give up your guns.
Well, I'd say: permissions, bureaucracy and cost - a good mix of the three, and the most important: for what they are testing at the moment, the short track is enough.
That is incorrect.
The USA are not the 'most english speakers'.
From the head of my mind we have Canada, UK, Australia, Newsealand and .... India. Then there are plenty of states like Belize or Grenada that mostly speak english, or half or Kamaroun ... now I could be nitpicking and point oit that basically every European below age of 50 and above 10 speaks english as a second language :)
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
I think the average age of user on here is much older than it used to be.
We have old jaded engineers, IT staff, etc, as the majority of visitors now.
It's more diverse than ever. There are plenty of other places awash in binary groupthink: all crapping on everything, or all cheer leading.
This is a much more pessimistic place than it was 10+ years ago.
The majority of the highest modded comments on this story are neutral or generally positive. Negativity is most pronounced when a highly-political story is pushed on the front page... as intended by the editors.
The Daddy casts sleep on the Baby. The Baby resists!
Because the hyperloop is undermining real science.
https://www.youtube.com/watch?v=RNFesa01llk
Hyperloop holds us back.
Unless it's for freight.
For hire.
Because the hyperloop is undermining real science.
I fundamentally disagree with that statement.
Even if Hyperloop doesn't work. Even if it doesn't ever move a single person... that's not bad science. As long as it is improving our technological abilities in any way (or even if it doesn't improve anything, but teaches us something doesn't work) that's not bad science.
Back in High School science they should have taught you that getting a result different than your hypothesis is not a failure. You learn things even if the results are not what you expected. (even if it is that your preconceived notions were wrong)
If Hyperloop doesn't transport a single person it's not a failure, it's trying something new, and I'm sure humanity will learn something from it.
"That's the way to do it" - Punch
Since the British switched to normal units (for the most part) decades ago.
Are you fucking stupid or something ? 2nd law of thermodynamics is IRREVERSIBLE... THAT'S WHY IT'S THE 2ND LAW... IDIOT !!!
o look ... another 'believer'... trust me... it's vaporware. The only thing Elon wants are the subsidies so he can fix the holes in his 'creative' bookkeeping.
Just what sort of small compromise are you imagining will lead to horrible results? Any break in the tube and the air rushes in, rapidly and passively decelerating all the cars approaching it.
A fault in a car's air supply or containment is certainly an issue, but not significantly more so than in an airplane. And in a real catastrophe you've always got the option of blowing the safety valves on the tube to let fresh air in, rather than hoping you can fly low enough before the pilot passes out. Rapid decompression is very unpleasant, but it won't kill you right away - you'll pass out within seconds but they'll have a couple minutes to pressurize the tube before you suffocate.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
Meanwhile, more and more stuff in the US is metric, like everything in our cars finally.
Take a look at your tires. In the size there is a R## guess what the units of that number represent.
Yeah, but with safety belts you could handle a LOT more than 1G of deceleration - 1G deceleration is the equivalent of hanging face down while the car balances on its nose - uncomfortable, but unlikely to be dangerous. Heck, automobile seatbelts are required to restrain about 4000 pounds, roughly 200lbs x 20Gs of deceleration, though the bruising from that is unlikely to get you a lot of repeat customers.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
Isn't it just *amazing* how exactly the same set of troll comments come out every single time there's a Hyperloop story!
yeah yeah yeah I know I must be new here -- but I'm not. Just disappointed.
https://app.box.com/WitthoftResume Code: https://github.com/cellocgw
Or, easier to achieve, you'd better not give them the option of removing their seatbelts. Extreme roller coasters with 3- or 5-point harnesses come to mind.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
What's the point of using kph when mph works perfectly fine.
Exactly what sort of accident are you expecting? There's no oncoming or cross traffic and you're restrained in a tube only slightly larger than your vehicle, so you can't really go off the rails. Worst case scenario something broke off the car in front of you and gets jammed under yours, acting as a drag-brake as it jams your car against the wall/ceiling.
Well, I suppose *worst* case is that something suddenly breaks the tunnel right in front of you, too close for the inrushing air to slow you down considerably... in which case I rather doubt you have much chance of surviving no matter what kind of seat you're in
--- Most topics have many sides worth arguing, allow me to take one opposite you.
I know, it's almost as if they are committed to skepticism and don't actually want to learn anything about the project.
And the hubris... They all seem to think they've hit upon some crucial flaw that the designers and engineers, despite their best intentions and expertise, were just too ignorant to notice!
Hmm, it just occurred to me, there's another method for comfortable deceleration - recline the seats and provide a solid footrest. If you're lying at 45* while decelerating at 1G, then it'll feel like you're standing up at 1.4Gs while strapped to a padded wall for support. Not really pleasant for extended periods, but your body is designed to withstand acceleration in that direction.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
The UK by far has me the most baffled though. Why list distances to other cities in KM and speed limits in MPH? Surely if you use KM for distance you'd want KPH for speed so it's easy to estimate how long it'll take to get somewhere given a specific speed?
No idea where that notion comes from, I've never seen a UK road sign showing a distance in KM, they all show them in miles.
The odd one is the tendency to switch between celcius and farenheit, Celcius for cold temperatures (it's -2 today) and farenheit when it's hot (it's in the 90s)
Orbital velocity at ground level is roughly 8km/s, so no.
Probably because it's still in the brainstorming-test phase, and would cost at least 50x as much to build a 50-mile version, while delivering minimal advantages (and good luck acquiring 50 miles of contiguous property to build it on. Meanwhile there's plenty of private estates a mile across),
Assuming for the moment that you did make it 50x as long, just put in 50x as many vacuum pumps and it evacuates just as fast. That's going to be pocket change compared to everything else.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
I think that goes hand in hand with Musk's boring company.
How can you call Tesla, Space-X and Solar City boring?!?!
I'm going to guess my maths was right then, as no-one has since posted a correction.
My point was that death was not the likely result of such acceleration.
Having said that I still feel that you're exaggerating a little bit too:
Without a belt, you'll be squashed into the seat in front of you
Well, if done with no warning, absolutely. But, since most people can quite easily manage one push-up, you could simply put your arms out to hold yourself in your seat. Certainly not 'squashed', per se.
I tried braking at about that deceleration once (emergency stop in a high-performance sportscar).
For (slightly topical) comparison a Tesla model X P100D does 0-100 kph in 3 seconds. That's an acceleration of roughly 10 m/s^2, which is close enough to the number I arrived at in the previous post to make no real difference. While I'm sure we'd feel that accelerating, you're right, we'd feel it a lot more if we were decelerating at the same rate. Interestingly I arrived at a stopping distance of about 40 m from that speed, at that rate, which, while being roughly 2/3rds the recommended braking distance in the UK, is probably achievable in virtually any modern car.
All the loose shit in the cabin went flying. My passenger damn near ended up in the footwell.
And this is why seat belts are now a legal requirement in most countries. "Discomfort not death" the battle cry of the modern day road warrior... ;-)
" Hyperloop is just an airtight tube.....cars themselves are hovercraft-gliders responsible for concentrating the low pressure air into a cushion beneath them"
If they can make it work it'll be amazing, but are any of the current designs/competitions employing it? Hyperloop One (one of the bigger players) sounds like they have completely abandoned the air cushion idea and are using a maglev system. Even if they can't make the air cushion concept work the simple fact of the decrease in weight, air resistance, higher speed, etc will mean decreased construction costs but just not nearly as significant as those of an air cushion system.
Why is everyone so pessimistic about everything Musk does?
The left hates him because he is a billionaire and loves capitalism.
The right hates him because Tesla took money from the government in the form of environmentalism loans, many of which they predicted would never be paid back (and as they predicted, many didn't, although Tesla paid back theirs, early.)
"His name was James Damore."
An excellent point. I should have said that *Musk's* Hyperloop design is just [...]. Once he threw the preliminary designs (and the name?) into the public domain, it became anyone's game.
It does seem like the vacuum tubes are the only common thread between things calling themselves "Hyperloop" now, and the biggest immediate advantage of the evacuated tubes would seem to be that they allow for individual cars to travel roughly as efficiently as a long, thin train, while avoiding all the problems of heavily concentrated peak loads that a train brings with it - hence allowing for suspended routes and the like.
But maintaining that vacuum comes at a cost, probably a substantial one, and it seems to me if you're also employing maglev or other expensive per-mile technology, then the economics of the proposal become increasingly questionable. Might still pay off, but you're going to have to milk that speed advantage a lot harder, which further restricts your potentail routes and/or increases the "roller coaster" quality of the trip.
Now, maybe if they included a VR helmet so you could include your choice of high-acceleration safari adventure with the option of a visible track/no stomach-dropping surprises instead of just sitting in a windowless transport pod they could make that "roller coaster" effect into a feature. Heck, create a VR map of the actual route and ride a low-altitude fighter jet to work...
--- Most topics have many sides worth arguing, allow me to take one opposite you.
Many people complain that they get sick when they sit backwards on a train. I've no idea why that is -- maybe a superstition like the lactose and gluten thing -- but why not just let people choose which way they prefer to face?
Slashdot more diverse than ever? My impression is that is has become a choir of cynical Trumpist old white male supremacists.
Exactly what sort of accident are you expecting?
Tunnel breaks. Collision with debris (or non removed pod) due to human or computer error. Integrity of pod failing and breaks apart. Door lock fails and attempts to open mid trip.
The titanic was badged as "unsinkable".
"That's the way to do it" - Punch
But the horizontal component of that force is still 11m/s^2. How will the vertical component (gravity) cause discomfort or damage when you are already used to it?
> The titanic was badged as "unsinkable".
Nope.
But by all means, ponder failure modes.
The horizontal acceleration adds to the total acceleration. It doesn't replace gravity. The total acceleration is greater than gravity or the horizontal acceleration alone, and it points in a different direction than either of those.
It's not the speed that kills them... it's the sudden stop at the end.
-2 Off topic
+5 Interesting
+5 Informative
Well, I addressed debris, and like I said, if a tunnel break happens close enough in front of you that air resistance doesn't stop you long before reaching it, then it's unlikely you'll survive anyway. Similarly collision with a stalled pod, or having your pod break apart at speed. Some risks are sufficiently severe that you simply have to trust that they won't happen because there's no cost effective way to protect against them. You do that every time you step outside without protection against lightning strikes, meteor impacts, or rabid wildlife.
And if the door pops open, then depressurization and asphyxiation isn't really going to care which direction your seat is facing. But hey, at least you'll only have about 15 seconds to suffer the pain and fear before you pass out from lack of oxygen, and hopefully the emergency tunnel re-pressurization will kick in so that you wake up again.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
once you start building an airtight tube of any length the costs quickly skyrocket to maintain its integrity, also the reality is the road does NOT follow an optimal path so land, tunnels etc etc still need to be bought. low pressure air brings its own risks of building in expensive escape mechanisms for passengers too.
I think it's gotten worse.
It's always been here to some extent. I mean, come on:
That said, it is surprising just how cynical this place has gotten. If there are legitimate technical objections to something, it's fun to have a conversation about it, but a lot of the commenters lately are just reactionary naysayers.
Perhaps he should say "this aspect of Slashdot isn't going to change".
Then he'd still be wrong. There are countless stories where the TFA is in imperial yet TFS has converted to metric. Hell we frequently pick on the fact that the conversions were done wrong.
Also I take issue with you saying this is an "American" readership. There is far more "universal nerd" in the readership than there is "general American" and many fields even in America use metric as a standard.
And, yes, this post is the result of an hour-long tumble into a wiki-hole which started with a desire to find the history of the difference between US and UK gallons.]
We once argued about how long a foot was here in the Netherlands only to find that each city had historically it's own different definition of foot. That of course then lead to the question of which city to buy a boat in, because you know ... for some reason boats resist the temptation to be measured metrically even in metric countries :-)
Sometimes I wonder if we should just reboot the world to clear out the many centuries of "updates" :-)
Why is everyone so pessimistic about everything Musk does?
Because on reddit he's God. We must bring balance to The Force. Seriously though, as others have pointed out I think it might have something to do with demographics. Slashdot==old farts, reddit==millenials. Not that a "hive mind" is really a fair representation of any particular person on a site; but I also don't think you can deny that collective opinion is a thing. You definitely feel the pessimism here on Slashdot sometimes, and you also feel the naivety on reddit.
For all intensive purposes, "whom" is no longer a word. That begs the question, "who cares"?
The point is not whether there are any circumstances under which the human body can withstand slightly more than one G but whether it is plausible that frequent commercial transport could subject the general public to such acceleration. For comparison, a commercial airplane with belted passengers barely hits 0.2G and a train with unbelted passengers is maybe 0.05G.
"Safer that way anyway."
Safer in terms of decelerating force applied directly to the body. More dangerous in terms of objects breaking lose and hitting you in the face.
You might be right about the costs, though there are plenty of potential solutions. How well they'd actually work... well that remains to be seen. If it's *just* a passive tube as in Musk's original "hovercraft-car" plan, rather than using maglev rails, I could certainly see it comparing quite favorably to high-speed rail, possibly even traditional rail - it's hard to overstate how expensive the "foundation" for a high-speed railway is to construct, and that's before you even consider acquiring the necessary right-of-ways. Suspended tracks for small individual cars can have *much* smaller ground-level footprint (the most valuable real estate) with a much less foundation work, so will be MUCH cheaper. Basically, everything except the foundation can be built at a factory, and it's on-site construction that incurs most of the cost.
That's not to say that it's cheap - but rail is expensive. We're talking at least a million bucks per mile just for a low-speed siding, several times that for moderate-speed rail, and even is comparatively inexpensive China their high-speed rail system averaged around $30 million per mile to construct.
As for "escape mechanisms" - I don't see how they'd be particularly expensive. The most urgent problem is air, and you've got plenty of that just on the other side of the tube wall. Add open-air emergency bypass valves to your vacuum pumps and you can refill the tube reasonably quickly for minimal additional cost. For more urgent response, occasional remote-operated explosive-bolt escape hatches along the tube should do the job almost instantly, and still not add much to construction costs.
For anything else - if tube and car integrity are still fine then you're probably down to medical emergencies and mechanical car failure. For car failure, assuming even the backup systems have failed, you just send another car to push it to the nearest exit. For medical emergencies... frankly most of the time proceeding to the next exit is likely to be the fastest course of action. Otherwise you wait to blow one of those emergency escape hatches so that the car coasts to a stop right by the new exit, presumably strategically chosen to be as close as possible to a hospital.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
There are only limited resources available for research. So yes, by funding this junk, other better projects will miss out.
when you have a line that is potentially several hundred miles long creating that low pressure will be hugely expensive, re-pressurising that environment in a safe way will also be many times more expensive and complex resulting in this cheap tube suddenly becoming a very expensive tube. Add in the hugely increased costs of stations in order to maintain that low pressure environment without exposing people too it and those little problems suddenly add hundreds of millions if not billions to the cost. maybe it will be cheaper, but Musk certainly didn't do any sort of real cost evaluation so we have nothing to base it on.
That you don't need to multiply by 1.609344 before you know what velocity is discussed. Very convenient.
Wile that *might* be true, it's still science. But this reasoning has no argumental value; wherever you put the budget in whatever scientific domain, other domains will claim it could be better used on theirs.
And especially with all the 'experts' on Slashdot, they always know what's best and where money should be spend. ;-)
IMHO, what's really being a waste are government expenditure in researching things that aren't science at all but pseudo-science, like the EM-drive. In contrast, this still is science/engineering stuff, and if Musk puts his own money in it who are we (well, you) to complain? I've been sponsoring and spending money on the Planetary Society's Lightsail; some have told me that was a waste of money too. Well, maybe to them, but not to me. And I do with my own money whatever I want. It's not their concern in what endeavour I put it, nor do I feel bound by what others find worthwhile or not.
So, I can concur with what you said if it handles public money - with the caveat that it's impossible to ever determine in any absolute sense 'what is the best scientific bang for the buck', since this always involves some subjectivity. But, granted, some scientific committee might weed out the worst proposals. However, with private money it's just none of our business where people spend their money on what scientific project. As science-proponents ourselves, we should already be content IF they spend it on ANY scientific endeavour, since most millionaires just spend it on yachts or mansions with 5 swimming pools. The point is, private money is spend on what the billionaires like, not on a 'most science' basis... meaning if they don't spend it on a scientific/engineering concept - meagre as it might be - they like, it won't therefore go to a more worthwhile effort with more science but which they don't like. It doesn't work like that. With private money, there are no communicating vessels there, and no overall budget, where if doesn't go that ay, it becomes free to spend on something else and goes from one to the other depending on scientific output.
--- "To pee or not to pee, that is the question." ---
One would hope there would be a middle ground, for persons who are rational.
I'm not understanding Elon Musk-bashers as much as I don't understand the blind idolizing of rabid Musk-fans.
I mean, surely it's possible to see and note that he's no superhuman, and has made mistakes, and isn't a genius in the sense Einstein was - yet at the same time give him some praise for the things he did accomplish? Give to the man what he deserves, nothing more, nothing less. and he HAS done some worthwhile things.
And yes, I agree with some he uses a bit of the hype he creates (and can create) to bolster his companies, and that he is a business-person in the first place, but I do not agree Elon Musk is putting up an act and ONLY interested in lining his own pockets or driving his stock up. In contrast to almost all other CEO's, I truly believe he's genuine in his wish and longing for his ultimate goals, like going to Mars. Look at some of the interviews he gave when speaking about it: he's really passionate about it. And he's actually working on a system to reach Mars. Yes, he spends less than 5% on it, but that's normal, IF you want to keep your company healthy. I think he's seeing it long term, and you can't go to Mars during his lifetime neither by doing nothing, nor by burning all the money into it, and going bankrupt. As said, the middle-ground isn't a bad position to take.
Of all billionaires and CEO's, I have the most faith in Musk that going to Mars is actually his dream, and that he's *actually* trying to accomplish his dream. Is he therefore a saint or a genius? No. Is he perfect? No. But that doesn't change anything to the above.
--- "To pee or not to pee, that is the question." ---
Is "Solar Freakin' Roadways!" also good?
--- "To pee or not to pee, that is the question." ---
That's my impression exactly. Most people on Slashdot have their entire self worth wrapped up in being the "smart guy". Once they get in another room (or slashdot comments) where they might not be the smartest or have the best idea, it really affects their self identity and value. That's my guess, anyway.
It's become the "cool thing to do". To shoot down ideas that aren't yours or anything that the Group Think hasn't already predetermined is "ok".
I'm not sure why you think creating a vacuum will be that expensive. It requires about 100kJ to create 1m^3 of near-vacuum at sealevel (the latent energy in 1m^3 of air at STP). Say the tube is 3m across and 100km long - that's pi*1.5^2*100,000 =~ 700,000m^3. So 70,000,000kJ, or about 20,000kWh to evacuate it. At $0.10/kWh that's only $2000. Of course that's idealized, and pump inefficiencies will increase that substantially so it's not something you really want to do any more frequently than absolutely required, but it's pocket change in the grand scheme of operating costs. You could do it every day for 160 years and it would still be cheaper than the $124,000,000 it would cost to build 100km of low-speed railway.
Also, exactly what dangers do you imagine suddenly repressurizing the tube will involve? You're going from a stressed state(keeping atmospheric pressure out) to an unstressed state (equal pressure inside and out), not trying to overpressure it. That's a pretty low-risk operation. The biggest danger to repressurization itself will be that a long column of inrushing air hits the end of the tube and rapidly builds pressure until it ruptures - but that can be easily mitigated by opening the emergency escape hatches as it approaches so that it has a way out again, as well as immediately beginning to repressurize the intact tube in a more controlled fashion so that the air-column can be slowed more gracefully.
The only real danger is of the inrushing air pushing the cars ahead of it, and there are a number of strategies that can help mitigate that, including at the crudest, strategically opening emergency hatches on the other side of the car to provide counterpressure. Strategically placed Inflatable airbag "corks" could also go a long way to limiting the length of tube affected by repressurization, without introducing any complicated mechanical airlocks into the line.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
A couple of nits.
1: Once you start going fast, the majority of air resistance on a train is skin resistance along the sides. You could have a squared off nose and it'd make very little difference. Noses are primarily sculpted to stop them lifting and you're expending tens of megawatts just pushing air aside.
2: Rail is only profitable for freight and only just got past "barely profitable" with the advent of containerisation. All that wagon-load handling along with freight yards, etc was a massive drain on resources as well as a vulnerability for theft.
3: Passenger rail simply isn't profitable and never will be directly. The wins come from knock-on effects such as reductions in car numbers and associated vehicle infrastructure in urban areas as well as substantial pollution reductions and _that_ is why most european countries run ~80% subsidies on their passenger rail systems. I can't see hyperloop being directly profitable either.
4: Hyperloop pods can carry anything - as long as they're large enough.
Passenger transport is subject to ebbs and flows (ie, peak periods) and will need freight to make up the difference. The problem is that unless the freight is containerised, handling costs will eat up any pricing advantage.
You could use aviation containers but they're not particularly robust and in general are packed/unpacked like railway wagons of the old days (airfreight has similar handling and theft problems to that of rail in the old days)
In any case, there's been a standard intermodal container size in play for over 60 years and it doesn't make sense to have a new transport system that's incapable of accomodating it. My pick is that unless hyperloop is built to a diameter large enough to handle pods capable of carrying shipping containers, it will have a hard job breaking even in the long term.
A hyperloop with podded freight containers means that unlike rail you can intersperse freight and passenger operation on the same lines without major handling problems and ideally you can run the pods from depot to depot, meaning less handling damage and lower costs. Overnight you can increase the ratio of freight to passenger operations.
Because of the nature of the operation, running 2 tubes is a non-starter.
You'll need to run 4 for resiliance. This allows you to shut down one line for maintenance without interrupting traffic. The alternative of overnight shutdowns and 6 hour windows to get 25 minutes of work done by the time you get everything into and out of a worksite is a nightmare regularly endured by London Underground, resulting in some sections of tunnels still running on century-old track because they can't shut them down for long enough to replace the stuff without causing massive disruptions for 12 million people.
But at this point you have a problem. The original right of way for small diameter hyperloop tubes has grown to about the same size as a dual-track railway line. What do you do? On one hand it will cost a fortune to install but on the other it will be much cheaper to operate than conventional rail.
"If there is no reason to face forwards it is better to face backwards for safety reasons."
People insist on facing forwards. You can take care of that by rotating the pod after the doors are closed or using other illusions to make them think they're facing the direction of travel as they take their seat.
"Elon didn't invent maglev technology, the electric car, or the solar panel."
He didn't even invent the hyperloop concept. It's been floating around for at least 60 years.
Some excellent points, though your phrasing is confusing on (1) - only the nose pushes air aside to a significant amount, and my understanding is that it is a significant amount as speed increases. The sides of the train instead create drag due to the air velocity shear. I wonder if anyone has explored the possibility of mimicking dolphin skin texture, adapated for the dynamics of air of course, to reduce the skin drag on high speed trains? Via creating a boundary layer of micro-vortices I believe.
I would agree that being able to handle standard intermodal cargo containers would certainly improve the flexibility and potential profitability. I would suggest though that it might actually be a very limited benefit - the only reason you really need intermodal containers is if you're shipping by sea at some point. For the most part neither trains nor trucks care overmuch about the size of their containers - loading four ~4x4x20' containers would be slightly more time consuming, but probably not dramatically more prone to theft. And some clever engineering could probably get them to quickly lock together into a standard intermodal-sized bundle at the hyperloop station so that it wouldn't actually make a whole lot of difference to any other shippers.
I'm also not sure how realistic frequent depots are, since you've got to consider that unlike rail, roads, etc, where you can essentially just pull off on a relatively cheap siding, a hyperloop depot will require several miles of (or very powerful) linear motor for acceleration and deceleration, probably along a "parallel" tube so that acceleration and deceleration can be done without interfering with the primary tube's carrying capacity (an awful lot of cars can pass you going 700+mph in the time it takes you to get up to speed. Even if you your cargo can handle several Gs). Makes the necessary airlocks seem cheap in comparison. Perhaps if you can have a depot servicing a dense enough industrial zone... that would also help with synchronizing the acceleration of incoming and outgoing cargo of comparable mass, so that you can transfer the momentum between the two pods and drastically reduce costs.
You've got to figure that passenger cars would likely be roughly be the same size though, which means either a lot of passengers (double decker since they'll likely be heavily reclined to handle deceleration comfortably?) or a lot of space per passenger. Potentially both kinds of cars would have their use, but it's a really sub-optimal size.
Another question is, is it really worth it for cargo at all? By and large cost is the deciding factor for cargo transport. Hyperloop can do substantially faster, but that mostly only matters for passengers. if it can't also do cheaper than road or rail, then it's going to be serving a very limited niche in cargo transportation.
As for right-of-way - you're forgetting that one of the big appeals of hyperloop is that it can be suspended overhead. It doesn't really make a huge amount of difference how big the tubes are, within reason - they still only need relatively small periodic pylon footings at ground level where space is at a premium. That doesn't solve the right-of-way issue, but it does simplify it. Stacking the tubes vertically instead of side-by-side is also a possibility, though it does somewhat complicate construction and maintenance.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
My guess that Musk was looking at the feasibility of launching rockets in a tunnel (tube) bored at a 45 degree angle within a mountain. This has been proposed years back. Place the rocket on a maglev sled in a vacuum tunnel and speed it up to the summit, pop the lid at the last second, and light rocket. Sled is recovered downrange after parachuting back to surface. Repeat.
"I'm also not sure how realistic frequent depots are, since you've got to consider that unlike rail, roads, etc, where you can essentially just pull off on a relatively cheap siding, a hyperloop depot will require several miles of (or very powerful) linear motor for acceleration and deceleration"
That's something I'm unsure of too. These issues need exploring for long-term viability, including questions like "Do you need the evacuated tube for low speed local running?"
WRT merging/routing traffic, in the long term whether cargo or passengers this is something that will need addressing and given the nature of evacuated tubes the added complication of stub switching needs to be considered.
The question of "is it useful for cargo" comes down to this point: If it's not being used, it's losing money. Cargo can soak up capacity outside of peak passenger periods and ensure consistent revenue - and in terms of income per cubic foot moved, cargo generates a lot more than passengers do. Even in aviation where mass is critical, cargo is an important component of passenger flight economics - to the point that airlines flying A380s don't increase the seating from ~550 up to the max 850pax, because it cuts too much into the cargo carrying capacity,
WRT hyperloop being suspended overhead - yes, but that was proposed for smaller diameter tubes with light loading. In any case you can effectively do that with high speed rail too - the chinese run much of their nationwide 300-350km/h(*) high speed rail network on elevated sections as it's easier than grading the ground.
The issue is that whilst it may be elevated, you're still going to need a cleared space under the tubes, if only to install them in the first place.
(*) Speed limits were reduced to 300km/h after the crashes a couple of years back. Increases back to 350km/h were announced recently.
Okay, a fine point that cargo can help to stabilize demand - though if you're waiting to ship during off-peak passenger hours, then you lose a lot of the speed benefit, and the question as to whether it can be shipped more cheaply than truck becomes even more pressing. So long as actual operating costs are low enough, shipping even with razor-thin profit margins helps pay down the initial investment. If those margins have to dip negative to attract any business though, then you're better off letting the tub sit idle - it's not actually losing money that way, it's just wasting capacity which *could* be used to lose money.
As for whether the evacuated tube is necessary - I'd say almost certainly if you want any of the Hyperloop benefits. Though I could well see potential within an industrial park surrounding a depot to even do away with the tube entirely and just have compatible track, possibly augmented with power-delivery, so that the same automated cars could switch to "trolley mode" and trundle their cargo to/from the final endpoints, eliminating the need for inter-modal cargo transfer.
I'm not sure I follow you on "the added complication of stub switching" in evacuated tubes. Why would it be any more difficult than in open air? It's not like you need airlocks between branches - they're all evacuated after all. Obviously you need to be able to seal off side branches in case of a breach or repressurization for maintenance, but that has nothing to do with switching, though it will likely be done in roughly the same region.
Oh, and in regard to your previous post suggesting 4 lines for resilience - that seems like overkill to me, a lot of capacity going to waste. I would think just adding a third, designed to be operable in either direction (probably not a big change - anywhere you accelerate in one direction you probably decelerate in the other) would do the job nicely. Then you can take any one tube off line and still maintain bidirectional service. As well as normally using the third tube to allow for heavier traffic in one or the other direction at different times of day - e.g. to handle commuter traffic into a city in the morning, and out again in the evening.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
Certainly you *could* do it with high speed rail, but it needs *much* sturdier suspension to handle the far more concentrated loads. Plus, you lose the Hyperloop efficiency benefits.
There's nothing magical about hyperloop for suspended transport - suspension is a wonderful option for a lot of things. Hyperloop just reduces the instantaneous loads (and thus construction costs) dramatically compared to a train, while still potentially having a comparable throughput.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
Once you pop the top... wouldn't the outside pressure and negative pressure behind it suck the rocket back in and dangerously fast? A bullets has expansive pressure behind it, not negative pressure.