Vacuum trains! That would suck (duck’n & runn’n).
In pure theory, the trains wouldn’t even need power.
Just bore the tunnels as the crow flies through the earth, and gravity would do the rest.
In practice you’d be boring through all kinds of easily shifting material. I’d hate to be down there and have an earthquake happen.
This just isn't true. If you bored through the earth, assuming it was possible, which it isn't, the train would fall under its own power but as it came closer to the center of the earth the slower it would fall, when it reached the center of the earth gravity would hold it there. Everything would be up from the center and as the speed at which the train fell would gradually slow to almost nothing before it even got to the center, it would never get past the center without some type of power input.
yup....NY to LA via gravity ....in theory, it would take as much time as any other 2 points on earth....NY to Bejing would take the same time, if you didnt roast in the core first....