3 ms·
There is a very interesting image in the article. It shows a bunch of light coming into a block and emerging as a beam. It also has a caption saying this is imp
by pontifier 8y ago
There is a very interesting image in the article. It shows a bunch of light coming into a block and emerging as a beam. It also has a caption saying this is impossible.
It struck me as very similar to the setup in this video.
https://youtu.be/awADEuv5vWY https://youtu.be/awADEuv5vWY
At about 4 minutes in, a nearly identical setup is shown with a beam of light emerging from a block of opaque material using holographic techniques.
It seems plausible to me that a specially designed anti-moon hologram could allow reconstruction of the incident light from the sun, thus allowing a fire to be started without violating any law of thermodynamics.
- pontifier 8y agoI think I finally realised what rubs me the wrong way about these xkcd musings, and the related discussions. [Start rant] They take the situation to its absurd conclusion, then quit with a full finality that people take as truth. Further absurd conclusions are ignored, and their word is law. Some more absurd arguments for why you will be able to light a fire with a magnifier and moonlight are as follows: 1: use a pre-magnifier to create a spot on the moon with the same temperature as the sun, then magnify the light from that spot to start your fire. 2: wait a long time... eventually a meteor will hit the moon creating a spot bright enough to focus. 3: wait even longer... Eventually the random mollecular collisions between the wood and the (presumably oxegen rich) air around it will convert it into carbon dioxide and water while serendipitous individual high energy blackbody photons help break it down. 4... insert absurd^4 answer that brings in tunneling effects, or moving mirrors, or some other "impossible" reason that is only impossible because they didn't think of it for you. [End rant]