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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."
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.
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.
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.
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.
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.
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
And how fast did the very first maglev prototype go? I bet it wasn't 430km/h.
No sig today...
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.
Which is why the Hyperloop Alpha proposal was A) for a mild vacuum, not a hard vacuum, and B) did not use maglev. Specifically to address both of those issues.
This student competition is something entirely different. And each of the different companies which have taken on the "hyperloop" name are choosing their own technologies. But as for Hyperloop Alpha (the original proposal), it was very much about majorly reducing the cost of high-speed ground transport.
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.
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.
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...
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.
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.
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
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.
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.
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.
"The difference between scientists and engineers, that's easy--engineers make money; scientists spend it."
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.
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.
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Except that his objections and analysis are incredibly sane and valid. Instead of resorting to ad hominem fallacy, why not dispute the analysis? Or are you simply discounting his analysis because this is outside his field of expertise without examining it at all?
Even without a lot of physics knowledge, we have to acknowledge the tremendous engineering difficulty of maintaining large stretches of vacuum. And the dangers of decompression. Or extreme difficulties of safety. Doesn't take a lot of physics knowledge to understand these problems. Maybe they could be solved, but I am not hopeful.
We can't even build regular high-speed rail trains in the US and those are well understood and the engineering has already been done. Running a vacuum tube on pylons is not going to solve it.
Less than a mile track over a short timespan is not anywhere close enough to integrate steel's linear expansion...
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.]
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I suspect the acceleration is much lower though.
And this is only at the proof-of-concept testing stage of entirely different technologies
I agree this won't set any historical records, but very little does. It is an accomplishment though, in that it's an advancement of the technologies necessary to make this happen. And it continues to be an accomplishment even if it's abandoned before anything substantial is created - there are far more false starts in science and technology than there are successful conclusions, and it's nigh impossible to say which are which beforehand. The failures largely deserve as much respect as the successes, for it is largely chance that determines which explorers eventually find something amazing.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
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.
"Except that his objections and analysis are incredibly sane and valid."
Except they are not.
Or, to be fair, they are valid and reasonable sane in the domain he's an expert in, which is biochemistry. There, his vids are worthwhile watching. The further he deviates from his on field, the more his analysis because insane and invalid. This is most obvious in his 'analysis' (hardly the name worthy anymore) of political-economic topics like the Brexit, and of engineering domains he really doesn't know much about, such as the Hyperloop and SpaceX. For some reason, he has a pretty obvious bias in some regards (or to some persons, like Elon Musk). His arguments are incredibly weak in those instances, and amount to nothing more then a biased opinion without substantiation by hard data and logical arguments - rather resorting to some gleeful smug badmouthing.
This, in stark contrast to his more rational behaviour and analysis about things of his own field of endeavour.
As for this specific case; if you want a good rebuttal against thunderfoots 'arguments' in a logical and rational way, see: https://www.youtube.com/playli...
Though they too have the tendency to be a bot overzealous in their rebuttal, at least their (counter)arguments on themselves make actually sense.
--- "To pee or not to pee, that is the question." ---