Comments on: The Laser Elevator http://blag.xkcd.com/2008/02/15/the-laser-elevator/ The blag of the webcomic Sat, 07 Nov 2009 20:23:58 +0000 http://wordpress.org/?v=2.8.4 hourly 1 By: Paul http://blag.xkcd.com/2008/02/15/the-laser-elevator/comment-page-8/#comment-32898 Paul Mon, 02 Nov 2009 04:00:12 +0000 http://blag.xkcd.com/2008/02/15/the-laser-elevator/#comment-32898 Diffraction and Doppler shifts aside, wouldn't most of the photon's energy be lost to heat from imperfect reflection? An "infinite hallway" with mirrors at both ends appears to get quite dark after only about 10 reflections. Is there some new material with significantly better reflection; perhaps at a specific frequency? Diffraction and Doppler shifts aside, wouldn’t most of the photon’s energy be lost to heat from imperfect reflection? An “infinite hallway” with mirrors at both ends appears to get quite dark after only about 10 reflections. Is there some new material with significantly better reflection; perhaps at a specific frequency?

]]> By: Box http://blag.xkcd.com/2008/02/15/the-laser-elevator/comment-page-8/#comment-32741 Box Thu, 22 Oct 2009 18:16:15 +0000 http://blag.xkcd.com/2008/02/15/the-laser-elevator/#comment-32741 I like how you went from laser elevator, to sun-powered deathray. I like how you went from laser elevator, to sun-powered deathray.

]]> By: Zach http://blag.xkcd.com/2008/02/15/the-laser-elevator/comment-page-8/#comment-32666 Zach Sun, 18 Oct 2009 03:24:52 +0000 http://blag.xkcd.com/2008/02/15/the-laser-elevator/#comment-32666 I am very much pro death ray. I am very much pro death ray.

]]> By: Jeremy http://blag.xkcd.com/2008/02/15/the-laser-elevator/comment-page-8/#comment-32324 Jeremy Tue, 06 Oct 2009 21:02:47 +0000 http://blag.xkcd.com/2008/02/15/the-laser-elevator/#comment-32324 It was my understanding that a laser elevator relied on the gas under the elevator being heated by the laser. This then raises the pressure under the elevator, creating an upward force. The pressure is the driving force for raising the elevator, not the momentum of the photons. This only works in an atmosphere, of course. It was my understanding that a laser elevator relied on the gas under the elevator being heated by the laser. This then raises the pressure under the elevator, creating an upward force. The pressure is the driving force for raising the elevator, not the momentum of the photons. This only works in an atmosphere, of course.

]]> By: leon http://blag.xkcd.com/2008/02/15/the-laser-elevator/comment-page-8/#comment-31377 leon Fri, 11 Sep 2009 05:00:03 +0000 http://blag.xkcd.com/2008/02/15/the-laser-elevator/#comment-31377 (I am a french canadian and i'm in arts so I'm putting great effort to actually explain my idea lol) What I would do is a ship with multiple ''photon containers'' around it. A photon container would actually be a crate with a tiny hole but an incurved surface inside to make the photon bounce indefinitly(until it loses all his energy). If you are able to calculate the resulting angles from the bounce and making it so that the photon never goes out the crate it will result in a great amount of energy(especially if your ship has a lot of them ) I will post eventually a blue print on my website www.bananacomix.com to explain it better. (I am a french canadian and i’m in arts so I’m putting great effort to actually explain my idea lol)

What I would do is a ship with multiple ”photon containers” around it. A photon container would actually be a crate with a tiny hole but an incurved surface inside to make the photon bounce indefinitly(until it loses all his energy). If you are able to calculate the resulting angles from the bounce and making it so that the photon never goes out the crate it will result in a great amount of energy(especially if your ship has a lot of them ) I will post eventually a blue print on my website http://www.bananacomix.com to explain it better.

]]> By: Chris http://blag.xkcd.com/2008/02/15/the-laser-elevator/comment-page-8/#comment-31351 Chris Thu, 10 Sep 2009 21:47:06 +0000 http://blag.xkcd.com/2008/02/15/the-laser-elevator/#comment-31351 Dear people; We wouldn't get kicked out of orbit by this any more than blasting off with a rocket would kick us out of orbit. Stop being silly and look at the mass of the Earth compared to the tiny momentum being added. There would be kickback because light has mass; lasers concentrate and focus light by bouncing it between a couple mirrors; when the light exit one end, it's not canceling its force on that end, meaning there's a net force on the other end. Since we're firing the laser outward, the net force is inward; we would have to cancel it with an equal laser/force the opposite way. Sorry about the late post, I only keep up with XKCD blag through stumbleupon. Dear people;
We wouldn’t get kicked out of orbit by this any more than blasting off with a rocket would kick us out of orbit. Stop being silly and look at the mass of the Earth compared to the tiny momentum being added.

There would be kickback because light has mass; lasers concentrate and focus light by bouncing it between a couple mirrors; when the light exit one end, it’s not canceling its force on that end, meaning there’s a net force on the other end. Since we’re firing the laser outward, the net force is inward; we would have to cancel it with an equal laser/force the opposite way.

Sorry about the late post, I only keep up with XKCD blag through stumbleupon.

]]> By: Nick http://blag.xkcd.com/2008/02/15/the-laser-elevator/comment-page-8/#comment-30254 Nick Sat, 22 Aug 2009 17:15:56 +0000 http://blag.xkcd.com/2008/02/15/the-laser-elevator/#comment-30254 Well, if the output by the lasing cavities actually made the sun start moving in the opposite direction, the gravity of the sun would cause Earth to follow it around. So then we could go taking trips around the universe, and what not. Well, if the output by the lasing cavities actually made the sun start moving in the opposite direction, the gravity of the sun would cause Earth to follow it around. So then we could go taking trips around the universe, and what not.

]]> By: Doc Brown http://blag.xkcd.com/2008/02/15/the-laser-elevator/comment-page-8/#comment-30070 Doc Brown Tue, 04 Aug 2009 10:31:48 +0000 http://blag.xkcd.com/2008/02/15/the-laser-elevator/#comment-30070 1.21 gigawatts? 1.21 gigawatts? Great Scott! 1.21 gigawatts? 1.21 gigawatts? Great Scott!

]]> By: radyo dinle http://blag.xkcd.com/2008/02/15/the-laser-elevator/comment-page-8/#comment-29759 radyo dinle Sun, 19 Jul 2009 14:51:55 +0000 http://blag.xkcd.com/2008/02/15/the-laser-elevator/#comment-29759 In the normal setup (i.e. Earth, mirror and the sail, marked with 9P and 8P), there is at least one problem. After starting a number of sails this way, Earth will gain momentum and may be kicked out of orbit, and that’s then how to meet our doom :-) In the normal setup (i.e. Earth, mirror and the sail, marked with 9P and 8P), there is at least one problem. After starting a number of sails this way, Earth will gain momentum and may be kicked out of orbit, and that’s then how to meet our doom :-)

]]> By: :Wa-Mx: El blog de Culiacán » Vela solar http://blag.xkcd.com/2008/02/15/the-laser-elevator/comment-page-8/#comment-29750 :Wa-Mx: El blog de Culiacán » Vela solar Sun, 19 Jul 2009 09:31:04 +0000 http://blag.xkcd.com/2008/02/15/the-laser-elevator/#comment-29750 [...] a b c «The Laser Elevator» (en inglés). Consultado el 15 de marzo de [...] [...] a b c «The Laser Elevator» (en inglés). Consultado el 15 de marzo de [...]

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