James Davis August 22, 2013 07:00 AM Any chance storing the excess electricity from the solar panels as cryogenic air for use in an on board Dearman esque engine would mean that the air compressors might not need so much power to add more airflow? Does that make sense? Marcus Kornmehl August 22, 2013 09:11 AM To avoid the strong lateral G forces of turns with smaller radii, the seats within the capsule could be made to uniformly swivel parallel to the vector of acceleration. This would be experienced by the passenger as more tolerable anterior-posterior G-forces rather than lateral acceleration. This could be a passive mechanical-spring correcting seat configuration for simplicity. Mzungu_Mkubwa August 22, 2013 10:01 AM @Marcus: I assumed that the whole capsule would / could rotate within the cylindrical tube, riding up the sides around the corners much like you do when you slide down a tube slide at a water park, or like the bank on the turns of an oval NASCAR track. If this happens (and it would need to be tightly controlled, I'd guess, at those high velocities) then there is no need to rotate the passengers independently. It would just naturally occur with the capsule's rotation. I think this would be necessary, anyway, with the "ski" design, as you want the relatively narrow skis to be oriented to support such g-forces and avoid contact between the capsule walls and the tube walls.A bigger challenge that I see is maintaining the precision surfaces of the tube's interior required to maintain a sub-millimeter gap that appears to be needed for the "air bearings" to operate properly, given such high velocities. That sucker's gonna have to be smoother than a baby's bottom, and defect-free along its entire length! Yikes. piperTom August 22, 2013 11:41 AM This is one of the best article ever to appear on Gizmg. Thanks due the author for (finally) showing how this scheme can work. August 22, 2013 11:59 AM Why does this have to be for passengers. A less expensive way of introducing this is technology may be to first use it for mail and freight movement. Likely to be economical and provide a proof of concept this would entail fewer risks. Either a rail line or freight company may be the best to introduce it or be first customers. Slowburn August 22, 2013 12:16 PM The problem is not with the engineering. The problem is the tube costs a fortune to build and without huge subsidizes the operation will not service the interest on the debt incurred to build it. It also lacks flexibility going from San Francisco to LA and an earthquake or terrorist takes out the LA terminal everybody already on their way are screwed; airliners divert to another airport. This might have some value doing something like tying Chicago's various airports together so you fly into Midway and half an hour later make your connecting flight out of O'Hara. venusvegasvada August 22, 2013 01:24 PM I like the idea but I don't think the seating position or "hyper-cramped" cabin space is not going to be a real world, viable proposition that the public will embrace. Is this a transportation system for those in excellent health and fitness only? I know the leaned back position is supposed to be comfortable and saves space but it's not a real world option for the elderly, anyone with respiratory issues, people with weight issues, etc. In the real world people need to be able to sit down, not just lie back. I'm sure the airlines would have loved to make an airplane they could load passengers into like a box into a cargo plane but it doesn't work that way. People know cheap when they see it and they associate cheap with small. Cheap is also associated with unsafe too. Not the message you want to send the public after spending a fortune to build it.To knock it out of the park, they need to be able to sit down and stand up as well. Even if it's only in the center aisle. Sounds like a little thing but it's actually very important to many people. The size gives people an assurance and a comfort that will be critical.Sized this small, this is a design that only the bean counters will love. I imagine if built like this they will wind up with freight hauling as the bulk of their business. hummer boy August 22, 2013 01:25 PM 700 mph? in a enclosed tube?? Are you guys really buying this nonsence? GIVE ME A BREAK!! The only prctical high speed system introduced in the last 25 years is the Northrop-Grumman track guided wing-in-ground effect vehicle. That system outguns the mag-lev by a mile, one tenth the cost,yet seems to have been put on "hold" over politics. It was also "shot" by a steam catapult system very similar to the system aboard Navy Aircraft Carriers. Nils J. Tvengsberg August 22, 2013 01:27 PM Interesting project...I did a project with my Daugherty Olea 10 years ago. A 50 person shuttle in vacuum tunel through tres Maria's mountains. Cuernavaca center Mexico City in 11 minutes. Socialwealth August 22, 2013 01:55 PM I have to differ on the suggestion that the Hyperloop cost estimates are being under-represented--but only if we agree that Musk were to run the project.All public projects suffer from cost inflation, mostly this is due to the warped incentives of RFP contract pricing that includes line item payments on a percentage of total project costs under the added intoxicating influence of litigious business environments that force excessive redundancies into design and execution practices, simply to check boxes and create a paper trail in preparation for when one gets sued. And one always gets sued on big, expensive public projects with multiple and diverse vested interests all wanting a piece of the action.If Musk were to do a prototype with private investors you can bet that his costs would be exactly the 1/10th of what you expect the public teat would be forced to squirt out. Exactly the cost savings he's already proven he can achieve on big public projects formerly run by government agencies and beltway bandit contractors through SpaceX manufacturing and launching rockets.Who knew? He did.