Evacuated underground maglev has been proposed at least for 30 years now. I've first read about it in a popular magazine. Speed figures up to 10000 km/h were thrown around (assuming near perfect vacuum).
Evacuated underground maglev has been proposed at least for 30 years now. I've first read about it in a popular magazine. Speed figures up to 10000 km/h were thrown around (assuming near perfect vacuum).