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The only question I have about this would be the volume of travel - how many people could this presumably take per hour as opposed to current travel techniques.

How much of that time is at the top speed as opposed to the gradual acceleration and deceleration to keep from turning passengers to goo?

Blow up one section of the tube and not only is it no longer evacuated, but all that air rushing in is going to slam all the cars that are in the tubes together at high speed.

There was a demonstration of this at a local tech meeting. Put foil on both ends of a tube, with a ping pong ball on one end. Remove most of the air. Poke a pin hole in the tin foil on the end of the tube with the ping pong ball. The ping pong ball accelerates to the other end of the tube, out of it, and continues _through_ the 3/16 inch thick particle board the demonstrator put at the opposite end.

Oh, the ping pong ball also explodes as a result.

I'm also seriously doubting their cost estimate. They say it's cheaper than train track, but as a maglev device, it can't possibly be cheaper.

Not only that, but there's a reason there are windows on airplanes, despite it being much cheaper to have a windowless airplane. Humans don't like to be cooped up in windowless boxes, especially while traveling. Even subways, where's there's literally nothing to look at, have huge picture windows to decrease anxiety and increase comfort. Airtight evacuated tubes with glass, and airtight cylinders with glass are going to be very expensive.

Guess what happens to the passengers inside when a window breaks?

It's an interesting thought experiment, but there are a few breakthroughs they need to have before it becomes viable.

Yeah, it wouldn't take much to turn a car into what would essentially be a high speed rail gun if there were a failure at any point in the tube.

But hey, if we get transparent aluminum and quantum levitation at room temperature, then everything else is just details.

Actually, very large LCD displays could act as windows if they are done well. They would have to be retina displays, but it might be enough.

stienman said:

But hey, if we get transparent aluminum and quantum levitation at room temperature, then everything else is just details.

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It is worth noting that in a vacuum, it's a lot easier to maintain cold temperatures, and a superconductor + magnet means electricity-free levitation.

It shows how they start, which is quite astonishing, but how do you stop something like that?

And here's a greater explanation.

Yeah, I'm fine in planes as long as the window next to me is open and I can look out. I start to freak the hell out when I'm in the middle seat and the person at the window closes it. It's even worse when the people in front do it too. No way in hell I'd sit in a giant metal bullet for 4 hours.

More important question: will it make that oh-so-satisfying "thwump" noise?

Yeah, 1/12th the diameter of a human hair, lasting 40 femtoseconds before returning to normal, and requiring extraordinary amounts of concentrated soft x-ray to create.

I wonder if the tube will overlook Bachelor Chow Ads.

I think they should start by just using this for the quick shipping of goods. That way the infrastructure would be in place to expanding to passenger travel later.

Soliloquy said:

I think they should start by just using this for the quick shipping of goods. That way the infrastructure would be in place to expanding to passenger travel later.

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I don't know, that hasn't worked out terribly well for Amtrak, who has to lease rail time and space from the cargo lines. In fact, that's one of the many reasons that Amtrak is such a complete and utter failure.

You don't like paying as much as you would for a plane ticket and taking 2-3 times as long to get there?

Covar said:

You don't like paying as much as you would for a plane ticket and taking 2-3 times as long to get there?

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I wouldn't mind that so much, since I honestly can't expect to get someplace as quickly by train as I would by plane, except for extremely local destinations, if I could count on only having to pay as much as a plane ticket and not (for some of the trips I've attempted to price check) two or three times more than I'd pay to go by plane. Not to mention the fact that, at least around here, the service is so unreliable I'd more than likely wind up traveling at least a portion of the distance by bus due to mudslide or scheduling conflict with BNSF's freight lines. If I'm going to be stuck taking a bus, I'll just drive myself, tyvm.

How did tinfoil in that demonstration, which could have a hole poked in it by human force, resist approximately 760 mmHg of air pressure on one side and a vacuum on the other without tearing on its own?

Covar said:

You don't like paying as much as you would for a plane ticket and taking 2-3 times as long to get there?

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If you're lucky. A train ride from northern Mn to San Antonio would have taken me a day and a half. A plane ride is only a couple hours.

If the journey is under 300 miles or so, the travel time should come out to be a toss-up. Since you have to spend so much more time in the terminals for airplanes.

Under 300 miles it would probably be cheaper and easier to drive.

GasBandit said:

How did tinfoil in that demonstration, which could have a hole poked in it by human force, resist approximately 760 mmHg of air pressure on one side and a vacuum on the other without tearing on its own?

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I think it may have been a plastic, rather than a metal foil. I've got a video of it, so perhaps I'll chuck it up online at some point.

Yep. Tianjin to Beijing in less than 30 minutes. Shanghai to Suzhou/Hangzhou/Wuxi in about an hour. Shenyang to Beijing in 4. Comfortable seats, lots of room, and easy to navigate stations.

. . . you commies.

mr_thehun said:

Oh god yes, the last time I was coming back from Qingdao I had the choice of taking a flight with China eastern or the high-speed train. The train was considerably longer and an hour later but the comfort level just trumps anything I've experienced on a plane at that price point. Besides, if you need food you can always bring a pack of instant noodles on with you OR WHATEVER YOU FEEL LIKE. none of this liquid bombs BS. The last time the dude sitting next to me brought a bucket of KFC on with him, I ended up trading him a wing for a can of coke.

But hell, even the standard trains here kick the ass of anything in Canada or the U.S. even if they are mostly made from western systems. We just don't have the population base to support this kind of system nor do we want this many people.

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Woah woah woah woah woah...

woah...

hold on...

You have KFC in China? MY WORLD IS SHATTERED

mr_thehun said:

yeah it's right next to the McDonalds, Burger King and Translation Error*.

*for a time there was a restaurant near a train station named translation error. Apparently somebody put their name in google translate and just accepted the result without confirmation.

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I'd totally go there, that's a great name.

mr_thehun said:

yeah it's right next to the McDonalds, Burger King and Translation Error*.

*for a time there was a restaurant near a train station named translation error. Apparently somebody put their name in google translate and just accepted the result without confirmation.

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Must be a chain or something, because I see Translation Error restaurants everywhere.

maglev trains are one thing. A semi-ballistic railgun cargo shell is another.

Ravenpoe said:

Woah woah woah woah woah...

woah...

hold on...

You have KFC in China? MY WORLD IS SHATTERED

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There's a KFC at the friggin Great Wall for heaven's sake.

Okay, wait --- they'd have to built a tube across the ocean? What the fuck would be the point of that?

Null said:

Okay, wait --- they'd have to built a tube across the ocean? What the fuck would be the point of that?

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Because it's hard to deliver people safely in an ICBM.

KFC is what turned it from a Pretty Okay Wall to a Great Wall.

Kentucky Fried Cats?

I still don't get how the damn thing is supposed to stop. Neither video explains that, aside from running out of nitrogen. But for specific stops, would that not need to be measured?

ThatNickGuy said:

I still don't get how the damn thing is supposed to stop. Neither video explains that, aside from running out of nitrogen. But for specific stops, would that not need to be measured?

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They can switch from permanent magnets in the middle to electromagnets near the stations, or use linear motors (similar thing, just not mixing it with the stuff that keeps the tube afloat). If they do it right, braking will generate 60% to 80% of the power that was used to launch the tube, so sending it off again won't cost as much.

The problem being that to maintain 1G or less acceleration, and achieve high speed in the middle the motors have to be mounted on the train, and the stator mounted on the track for the entire length of the track. You wouldn't ever be coasting, it would always be under motor control - or at least it would be available even if you apply no power.

If it's a linear induction motor, then the stator can be simple aluminum rail that slots into the motor. The motor would be mounted on the tube, and the stator would be one or more rails as part of the track/evacuated tube.

Or, translated for the layman,

stienman said:

Pure fucking magic.

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