Timeline for Perpetuum Mobile
Current License: CC BY-SA 2.5
34 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Mar 10, 2017 at 9:42 | history | edited | CommunityBot |
replaced http://lh6.ggpht.com/ with https://lh6.ggpht.com/
|
|
| Nov 13, 2011 at 16:21 | answer | added | Rod Schmidt | timeline score: 0 | |
| Aug 23, 2010 at 19:14 | history | edited | François G. Dorais |
edited tags
|
|
| Jul 15, 2010 at 3:35 | answer | added | paulmurray | timeline score: 2 | |
| Jan 24, 2010 at 22:09 | vote | accept | Anton Petrunin | ||
| Jan 24, 2010 at 20:09 | comment | added | Ilya Grigoriev | I have to second jc's point. What is the magical Liouville measure? How does it solve this problem completely? | |
| Jan 24, 2010 at 2:53 | comment | added | Harry Gindi | Did anybody else thing that this was going to be cell-phone related? | |
| Jan 24, 2010 at 1:53 | answer | added | Mark Levi | timeline score: 8 | |
| Jan 8, 2010 at 21:11 | history | edited | Anton Petrunin | CC BY-SA 2.5 |
added 189 characters in body
|
| Jan 8, 2010 at 20:58 | history | edited | Anton Petrunin | CC BY-SA 2.5 |
added 49 characters in body
|
| Jan 8, 2010 at 20:38 | history | edited | Anton Petrunin | CC BY-SA 2.5 |
added 164 characters in body
|
| Jan 7, 2010 at 18:16 | comment | added | Gerald Edgar | Wow, "foci" and "focuses" in the same sentence. Since both are acceptable plurals of "focus", why not? | |
| Jan 7, 2010 at 4:27 | history | edited | Anton Petrunin |
edited tags
|
|
| Jan 7, 2010 at 4:26 | comment | added | Anton Petrunin | @jc, I will do it but not momentarily... | |
| Jan 6, 2010 at 19:02 | comment | added | j.c. | Hi, after reading the answers and comments, I'm still not sure I understand what the resolution of the problem was. Anton, could you update your question with the solution? | |
| Jan 6, 2010 at 6:44 | history | edited | Anton Petrunin | CC BY-SA 2.5 |
added 36 characters in body
|
| Jan 6, 2010 at 6:37 | history | edited | Anton Petrunin | CC BY-SA 2.5 |
added 180 characters in body; Post Made Community Wiki
|
| Jan 6, 2010 at 6:36 | answer | added | José Figueroa-O'Farrill | timeline score: 12 | |
| Jan 6, 2010 at 6:03 | comment | added | Theo Johnson-Freyd | Geometric constructions like this are well-known (I learned some from Sergei Tabachnikov). In any case, I don't think that the OP is asking a math question here. There are probably some interesting geometric optics questions, and perhaps OP wants to rewrite to make the post into one (I don't know geometric optics, so I can't suggest any). | |
| Jan 6, 2010 at 4:42 | answer | added | Yuri Bakhtin | timeline score: 2 | |
| Jan 6, 2010 at 4:36 | answer | added | S. Carnahan♦ | timeline score: 7 | |
| Jan 6, 2010 at 4:34 | history | edited | Jonas Meyer |
edited tags
|
|
| Jan 6, 2010 at 4:31 | comment | added | Anton Petrunin | @Scott, sure but from very small ones :) | |
| Jan 6, 2010 at 4:23 | history | edited | Anton Petrunin | CC BY-SA 2.5 |
added 249 characters in body
|
| Jan 6, 2010 at 4:02 | comment | added | S. Carnahan♦ | Are the mirrors made out of atoms? | |
| Jan 6, 2010 at 3:58 | comment | added | Anton Petrunin | @Qiaochu it is vacuum :) | |
| Jan 6, 2010 at 3:55 | comment | added | Anton Petrunin | @Scott, look at the picture, say 50% of energy of red focus ccomes back... | |
| Jan 6, 2010 at 3:55 | comment | added | Qiaochu Yuan | I cannot help but think the resolution to this problem is not in the mathematics, but in the physical model, so I'm tempted not to think of this as a mathematics question. For example, what assumptions are you making on the nature of the air in the room? | |
| Jan 6, 2010 at 3:54 | comment | added | S. Carnahan♦ | If they start at the same temperature, then each body will give and receive 4\pi radiative flux. Why should we expect the temperatures to change? | |
| Jan 6, 2010 at 3:52 | comment | added | Anton Petrunin | @Qiaochu, you start with two bodies of equal temp.and one pass it energy to the other --- that is enough for Perpetuum Mobile | |
| Jan 6, 2010 at 3:50 | comment | added | Anton Petrunin | I think it has perfect math-sense --- it just simpler to formulate in these terms. | |
| Jan 6, 2010 at 3:48 | comment | added | Qiaochu Yuan | I don't follow. Why don't you think thermal equilibrium is achieved? | |
| Jan 6, 2010 at 3:46 | comment | added | Harrison Brown | Downvoted because this seems more like a physics question than math, and although this question isn't itself cranky, allowing questions like "Why doesn't this perpetual motion machine work?" seems like it could be dangerous. | |
| Jan 6, 2010 at 3:41 | history | asked | Anton Petrunin | CC BY-SA 2.5 |