Reply To: The plasma torch?

[Duke Leto]

1. The assumption is that inter metro traffic would be handled by maglevs going in evacuated tunnels where there is no wind resistance, thus having a cruising speed in the 1000s of mph. Thus New England and Metro NY would each have their own regional commuter networks and somebody interested in living in Portland, Maine but working in Wilmington would in theory be able to do so by piggybacking from the super-MTA to the super-AMTRAK via Boston and then leaving super-AMTRAK to pick up super-SEPTA in Philly.

Realizing Eric’s vision of an inter-city supersonic network means buying AMTRAK and partnering with Union Pacific and the other freight carriers, not that that would be a big expenditure to the FF patentholder or a major headache for congress, which I think would be happy to rid itself of the current AMTRAK.

2. Remember that deceleration is handled by the same magnetic impulse motors that do acceleration on a MagLev train, so the decelerating force is equal to and opposite of the accelerating force and spread out over the same time period. (Slightly less if you have air resistance.) You’d probably start braking a bit after the midpoint of the 2.5 mile journey.

Let’s imagine this metricly and make 5 km do the work of 2.5 miles. Let’s say that our train has a constant accelerating force of .25 G acting on it during its acceleration period. MagLevs by definition have no wheel friction so it is only a question air resistance, and we’ll factor that out for the sake of argument. The entire train thus accelerates 2.5 m/s every second. This means that after 30 seconds, it is going at 75 m/s, which is 170 mph for those keeping track at home. Unless I’m really losing my Physics/Calc teeth after all these years, The integral over 0 to 30 of 2.5x is going to be 1.25x^2 or 1125 m, or a bit more than a fifth of the journey. Cut the accelerating force to .10 G and it goes all the way out to a 70 second acceleration period of 75 seconds and a distance of 2812 m, which is about when you’d want to start applying the equal and opposite decelerating force.

So the question is whether a quarter or a tenth of a G is going to be enough to knock people off their feet.