Slashdot Mirror
Colorado Company Says It Plans To Test Hyperloop Transport System
Freshly Exhumed writes "Elon Musk's dream of a hyperloop transport system seems to be closer to reality than he anticipated. Hyperloop transportation, referred to by Musk as a "cross between a Concorde, a railgun, and an air hockey table", is a tubular pneumatic transport system with the theoretical capability of carrying passengers from New York to L.A. in about 30 minutes at velocities near 4,000 miles per hour, while maintaining a near-continuous G force of 1. Colorado-based company ET3 is planning to build and test its own version of such a hyperloop system, Yahoo reports." A more critical article would point out that the numbers presented seem absurdly optimistic; $100 for a 4,000mph cross country trip may be "projected," but construction of a cross-country train tube is a long way off, and so are ticket sales.
Let's see how fast it gets fresh salmon from Seattle to Kansas. Build a six inch wide tube or something. If that works out, then maybe think about humans.
Train accidents are bad enough already. 4000 mph? Would there even be anything left for the NTSB to sift through? What happens if the tube decompresses? Musk has some great ideas; but I think he's gone off the rails on this one.
credit for the invention belongs to Dr. Joseph V. Foa who was awarded US Patent 3213802 for a "train in a tube" in 1965. This was the basis for a number of years of research into the concept at Rensselaer Polytechnic Institute in the 1960s.
Yeah, it means even more expensive.
Nearly 3000 miles of travel, at up to 4000 mph, in 30 minutes?
It's a fast 4000 mph, not a normal 4000 mph.
William of Ockham had no beard. The most likely explanation is that it was chewed off by squirrels every morning.
The drunken captain, bad as that was, wasn't the cause of the accident. He was asleep in his bunk, and the ship was being piloted by someone who was qualified. The drunken captain bit was played up to distract from Exxon's culpability, like choosing not to fix a radar that was broken for a year, in order to save a few bucks. See http://en.wikipedia.org/wiki/Exxon_Valdez_oil_spill#Identified_causes
Doesn't anybody read the old masters of science fiction anymore? Slashdot, of all places, should already be familiar with all the details of subsurface evacuated tube transportation. This idea has been around for at least half a century, and has been electrically and mechanically feasible for decades. Financially is another story, which is why the whole thing is the pipe dream so cleverly pointed out by another poster.
But let's talk about the real concept, instead of all the (bad) guesswork.
An absolutely straight tube would be quite bad, especially for that distance. What you want is a great circle arc, and the only way to achieve one that's perfect enough and stable enough is to bury it and bury it deep, to avoid mountains, valleys, cities, etc.
It's not pneumatic. That's just silly. It's electromagnetic. You use coils at either end, accelerating with them on the way out and decelerating (and incidentally storing a great deal of the initial launch energy to be reused) at the end. Your vehicle is ballistic in the middle, in free fall. Helluva way to travel, but very cheap, energy-wise, assuming you build giant ring capacitors at each end to store the recovered energy each time the vehicle arrives. Then you only have to make up the losses in the system, which is reasonable to do. The tube is evacuated to vacuum to eliminate air resistance losses, which is so high at useful speeds that it prevents the whole system from working at all, never mind cost effectively.
And no, you don't switch. The tubes are point to point, and there's only one large vehicle per tube, going back and forth between each end. Of course, while you're at it, you might as well build two parallel tubes, 'cause the marginal cost of boring another hole isn't too bad. Still, the system has a hard capacity limit for each route. It's a very high limit if you build a large enough vehicle, but it's also a very hard limit. Once you hit it, the only way to expand capacity, beyond making the vehicle longer (a process with strictly diminishing returns with its own hard limit) is to bore another hole. Time-consuming and energy-intensive, at best.
Of course, it will never happen. Quite aside from property rights problems (land ownership extends right to the center of the Earth), the time and energy required to bore a hole long enough to be useful is extreme. It took 6 years to build the 50km long Channel Tunnel. At that rate, New York to LA would only take 579 years. (Admittedly the actual boring time wasn't anything like 6 years, but still... The project has all the same problems, magnified.)
We'll all be riding in self-driving all-electric vehicles long before anybody bores a transcontinental train tunnel.