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"It wasn't until I was past forty that it bacame clear that I was going to be quote, successful, unquote."
- Isaac Asimov
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| Gravity-assisted Subway | ||
| The fastest way between continents (that does not entail leaving the ground). |
This piece of technovelgy gives a great illustration of the fastest way to get from point A on the surface of the earth to another surface point B.
| The car shot forward and down. Corbell was on a roller coaster. He pulled out a chair arm and hung on. The car fell at a slant for what felt like half a minute. Then there was high gravity as car and tunnel curved back to horizontal. Light inside, darkness outside. Corbell was beginning to relax when the car rolled, surged to the left; rolled, surged to the right, steadied. What was that? Changing tunnels? His ears popped. Peerssa spoke. "Your speed is in excess of eight hundred kilometers per hour and still accelerating. A remarkable achievement. "How do they do it?" "At a guess, you are riding a gravity-assisted linear accelerator through an evacuated tunnel. You are about to pass beneath the Pacific Ocean..." |
| Technovelgy from A World Out of Time,
by Larry Niven. Published by Random House in 1976 Additional resources -
|
The ingenious solution is to dig a tunnel from one point to the other, using the force of gravity to provide some of the acceleration. The beauty of this approach is that, in a frictionless environment, you can speed the train on its way without having to apply any energy - and slow it down the same way!
The questions (for you engineers) are: what is the best shape (or curve) for the tunnel, and how can you avoid those pesky underground temperatures and pressures? See this article on the brachistochrone problem, one of the earliest problems posed in the calculus of variations. Newton solved this problem from scratch in one day in 1696; got your pencil? Ready, set ... go!
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| Nifty Folding Electric Bicycles! |
| Boring Company Drills Asimov's Single Vehicle Tunnels |
| Boring Company Vegas Loop Like Asimov Said |
| SpaceX Rocket Shuttle Point-To-Point On Earth |
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'Space-sickness is one of the most unpleasant sensations that a human being can experience. Not all are subject to it...'
'...I saw a nice black heavy-looking cloud sailing by just now, and I can get the electrical machine out in five minutes to draw it down.'
'From a distance it could resolve the cosmic rays reflected from various substances.'
'The answer to the dumb student's prayer.'
'He had travelled the space-lanes of the solar system for the greater part of his life...'
'The dinner was excellent. It was completely vegetarian — grown in specially prepared gardens in this Moon base...'
'Telepaths had their sensitiveness enlarged to an immense range by the pin-sets, which were telepathic amplifiers adapted to the mammal mind.'
'It was a relief to enter one of the comfortable autos, whisper a direction down the tube, and just know that you would be taken to your destination in the quickest, safest, and cheapest manner.'
'But he didn't get very far with it before another noise in his ear radio scattered his thoughts. George winced...'
