His Awesomeness, Elon Musk, has unveiled conceptual work on his ultra-rapid-transit concept known as the "hyperloop." The full 57-page work is available in PDF form on the Tesla Motors website, divided into two sections - one is a brief description for laymen and the other is a long, highly involved description with technical details for professionals. Basically, Hyperloop is a mid-range transit solution conceived specifically for the case of transportation between Los Angeles and San Francisco, with slower options being more efficient for shorter distances and (hypothetical) supersonic air travel being ideal for longer ones. Musk has done the preliminary conceptual work in the hopes that others will run with it and bring it to fruition, since he himself is too busy with Tesla and SpaceX.
Musk tweeted this illustration this afternoon, and the accompanying paper contained additional illustrations:
If I understand the descriptions correctly, Hyperloop is a tube-transport system with the tube maintained in near-vacuum rather than hard-vacuum because the latter is too difficult, and the transport pod (as seen in the illustration) contains a compressor in the front that deals with heterogeneous pressures by squeezing it out the back. This would presumably come into effect at high speeds, which would initially be achieved and perhaps partly maintained electromagnetically. Musk and his team project that the full system would cost only a small fraction of the planned "high-speed rail" project while vastly exceeding it in speed.
Conceptual artwork of the infrastructure show something science fiction fans would instantly recognize - vacuum tubes on pylons, also with some solar panels:
The technical section goes into extreme detail in many parts, but also includes illustrations that are relatively understandable to the layman:
The route examined in the conceptual work:
I suppose a question that should be asked is whether, if someone does step up and run with this work, would Musk be willing to fund it? The State of California is not going to abandon its rail project in favor of a purely conceptual work with no precedent, so the only way this gets built is privately. Perhaps with some modest initial investment drummed up by Kickstarter? We'll see how the work is received among other entrepreneurs and technologists.
2:57 PM PT: Can't believe I forgot to mention the speeds it's designed for: Depending on the local curvature of the tube, between 300 and 760 mph.
3:57 PM PT: Think of it this way: Hyperloop is basically an aircraft in a can. It flies on air inside the tube without coming in contact with any part of the structure. So it's kind of a fusion of air and high-speed rail.