The big problem with planes is that they are too slow, inefficient, and unpredictable. The culprit is of course friction. However, there is a way to do with out it. The idea of a vactrain has been around since 1910. Essentially, it is a train that levitates on magnets and runs in a vacuum tube. There would theoretically be no friction and the train could go at extremely high speeds with incredible energy efficiency.
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| Nice looking train. Too bad shape is completely irrelevant when there isn't any air resistance... |
The question is: how should the train be accelerated and decelerated? If the magnets are used to decelerate the trains, which could be done, a large percentage of the energy would be lost, even with attempts to re-store it. There is a better way to do it though: gravity.
Why not start and end the train high up? Then it will accelerate down one hill to reach a high speed and decelerate up another to stop. That way no energy is ever lost. Basically, I believe that giant roller-coasters are the future of transportation!
(Amazingly, I am not the first to think of this. Who would have thought that using giant roller-coasters in vacuum tubes as a transportation system would be an unoriginal idea? Still, I couldn't resist talking about it a little. Unfortunately though, roller-coasters actually can't go that fast. Even with a drop in altitude of a mile, the train would only reach a speed of about 500 mph. Maybe, a little energy loss isn't that bad after all.)
I've always loved this concept. It would forever change transportation. North America and Europe would be less than an hour apart instead of an overnight flight. Entire regions would become, for transportation purposes, a single city. A worldwide network (with affordable fares) of these trains could end commercial air travel and long-distance driving, which would be a huge benefit for the environment. It's also just really, really freaking cool. Trains going thousands of miles per hour? How awesome is that?
ReplyDeleteI have to agree with your footnote that a little energy loss might need to be accepted. Still, a gravity assist would be a huge help in saving energy. Plus, with no friction, the amount of energy would already be much lower than anything else we have.
The caption made me smile... unnecessarily aerodynamic trains seem to be a common thread in vactrain graphics. Actually though, the picture says that their concept is for only a partial vacuum, so aerodynamics would probably still be a factor. Generally though, I'd expect the trains to by cylindrical, like ISS modules. Much easier to pressurize than a train with sharp corners, even though a rectangular cross-section would be nice from an interior space perspective.
Very insightful! I'm glad to see I could keep keep your mind turning. You're right, no vacuum is ever perfect. That makes me ask: what does a vactrain sound like?
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