It might look something like this.
It will shoot passengers through a tube at twice the speed of the fastest train on earth, using air.
And will go on a direct route from San Francisco to Los Angeles.
It will built on pylons, so it doesn't take up too much space, and they will be pre-fabricated so they can drop into place.
The plans will be open source, which Musk hopes will encourage someone else to build the design. He's too busy designing the rest of the future, like electric cars.
And building rockets, with SpaceX.
But even billionaire geniuses are not immune from the pain of all-nighters, it seems.
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