-from downtown LA to downtown SF in 30 Minutes
-cheaper than airplane ticket
-solar panels on the top to make it self sustaining
-energy would be saved without batteries to run at night
-under no influence of the weather
-safe
(-Sarah Lacy made a reference to a TV show/movie with a tube as transportation system, and Elon said it was kind of like that [can't remember the title])
-Sarah Lacy: "Is it possible?" Elon Musk: "Yes!"
http://en.wikipedia.org/wiki/Launch_loop
Because it's not subject to the rocket equation, it would basically have the same effect on space access costs as a space elevator.
It is possible in principle for such a device to bring a vehicle up to hypersonic speeds, then regeneratively brake the same vehicle to a stop and recover a fraction of the energy.
That would exclude the downtown-to-downtown feature.
Nuke scale energies get dissipated in the atmosphere on a regular basis by thunderstorms. I suspect it may be possible to ensure that most of the mass burns up in the atmosphere and is dispersed.
That would exclude the downtown-to-downtown feature.
A rocketplane could "rendevous" with the electromagnetic loop at high altitude and then be accelerated and decelerated for the bulk of the cross-ocean trip, then land at an airport.
I guess if the transit is efficient enough, you store energy by getting a bunch of mass moving around the loop.
Powering with PV on top of the tube, on the other hand, should be entirely realistic (at least on an average consumption vs average generation basis), and the incremental PV cost will be really low since you'd install it as part and parcel of the tube.
Anyway - the part about electric VTOL aircraft got me really excited. I've been annoyed that no one has tried to do VTOL aircraft with fans yet. If it could be made electric too (I'm assuming on-board generators or fuel cells here), that would turn a lot of things on its head.
The F-35B uses a fan and vectored thrust. It's not quite VTOL though. (Also all helicopters.)