Timeline for Is it possible to determine the motion of a vehicle moving at a constant speed of $0.8c$?
Current License: CC BY-SA 4.0
13 events
| when toggle format | what | by | license | comment | |
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| Apr 16, 2022 at 2:33 | comment | added | JEB | @4d_ the problem says were in deep space far from objects so we don't waste time talking about gravity, free-fall, and perhaps tidal effects. | |
| Dec 8, 2019 at 8:35 | comment | added | PM 2Ring | BTW, the passengers on the accelerating rocket consider the backwards direction (i.e., the direction opposite to the acceleration) to be downwards. So if they put a tennis ball on the deck it'll just sit there. | |
| Dec 7, 2019 at 18:46 | vote | accept | 4d_ | ||
| Dec 7, 2019 at 13:21 | answer | added | Professor Sushing | timeline score: 3 | |
| Dec 7, 2019 at 12:41 | comment | added | badjohn | Not an expert hence a comment rather than answer but I don't think that relativity or not matters. Part of the reason that you cannot determine your velocity is that you would first need to specify velocity relative to what. Relativity or not, you will get different answers depending on which you pick. | |
| Dec 7, 2019 at 12:26 | comment | added | 4d_ | @benjamin I am not fully familiar with the special relativity yet. So I put the tag 'Newtonian mechanics'. Though I do know that Newtonian mechanics fails to explain as we approach the speed of light. | |
| Dec 7, 2019 at 12:24 | comment | added | 4d_ | @hdhondt Gravity does have infinite range. But why would the question explicitly say that the rocket is in deep space "far from other objects"? Isn't that implying that the rocket is not in a orbit around another object? Also, can it stay in an orbit around another body when moving at that speed, $0.8$C? Also the question says that its speed is constant. As far as I know, neither earth, nor moon, or any other celestial body orbits another body at constant speed. Their orbit is elliptical? | |
| Dec 7, 2019 at 11:18 | comment | added | bemjanim | Are we assuming special relativity or Newtonian mechanics? If special relativity holds true then it is impossible to determine an absolute velocity. | |
| Dec 7, 2019 at 11:14 | comment | added | bemjanim | Free space (with no gravitational field) is also an inertial frame of reference, not just free fall. | |
| Dec 7, 2019 at 9:07 | comment | added | hdhondt | "the rocket is in deep space far from other objects, how can I be in freefall" Remember that gravity has infinite range. And "forward" movement is not the same as "straight". | |
| Dec 7, 2019 at 8:53 | history | edited | Qmechanic♦ | CC BY-SA 4.0 |
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| Dec 7, 2019 at 6:41 | comment | added | mmesser314 | This was first answered by Galileo. en.wikipedia.org/wiki/Galileo%27s_ship | |
| Dec 7, 2019 at 6:11 | history | asked | 4d_ | CC BY-SA 4.0 |