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February 15th, 2008 - Adventures in Engineering — LiveJournal
The wanderings of a modern ronin.

Ben Cantrick
  Date: 2008-02-15 10:42
  Subject:   We must not allow a laser squirrel space-elevator gap!
Public
  Mood:der uber-nerd
  Music:Electric Laser People - Move Right, Move Left
  Tags:  humor, reddit


This is why solar sails are so slow. It’s not that light doesn’t have that much energy, it’s that it has so little momentum. If you set a squirrel on a solar sail and shone a laser on the underside, do you know how much power would be required to lift the squirrel? About 1.21 gigawatts. This is awful. If we were lifting the squirrel with a motor, railgun, or electric catapult, with 1.21 gigawatts we could send it screaming upward at ridiculous speeds.

This is where Meyer and friends come in. They’ve pointed out a novel way to extract momentum from the photon: bounce it back and forth between the sail and a large mirror (on a planet or moon, perhaps).


bouncy, bouncy...Collapse )

http://blag.xkcd.com/2008/02/15/the-laser-elevator/
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Ben Cantrick
  Date: 2008-02-15 13:33
  Subject:   Teeny, tiny, itty-bitty guns.
Public
  Music:Little Death Orchestra - Putti In My Hands
  Tags:  metafilter, pretty pictures



http://www.craftsmanshipmuseum.com/Kucer.htm
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