Ah, I see. That's an interesting idea. Sounds impractical - if you're going to do all that engineering work, might as well just get rid of the air in the first place - but cool concept.
As opposed to building this thing, filling it (perfectly) with ultra-high-power resonant soundwaves of the precise characteristics, and flinging in shuttles and hoping nothing goes wrong? I don't know, the evacuated maglev is sort of sounding like the safe, easy option?
The reason evacuated tubes are expensive and difficult is because of the tube, not because of the evacuation. Once you have a great big tube, reducing the air inside isn't going to be that big a deal. You don't even need to get rid of all the air, just maintaining 90% vacuum would be fine, you could whiz down there at 1000kph as easy as kiss my hand.
Anyway, I'm not a physicist, I am just wondering if people have a full understanding of the forces involved flinging stuff around at 1000kph+ in an enclosed space at full air density. It is some serious shit. People are comparing it to aeroplanes, but at sea level it would be 3x the shockwave a plane has to deal with. High speed trains in Europe and Japan already match or exceed the air-displacement issues faced by airlines - and that's one third the proposed speed of this device. I don't know, man. Sure, in ideal circumstances you might be able to engineer some low drag trick. Still sounds like unicycling along the edge of a cliff to me. Near mach 1 in a fully pressurised tunnel? Dear christ.
