Timeline for Has the speed of light changed over time?
Current License: CC BY-SA 3.0
22 events
| when toggle format | what | by | license | comment | |
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| Dec 6, 2018 at 13:25 | comment | added | Alan Gee | @JamesCooper does that not depend on whether or not the dark energy is able to collaborate - in other words even though it may be small in density there is certainly enough of it to get the job done. | |
| Apr 24, 2018 at 1:59 | history | protected | AccidentalFourierTransform | ||
| S Feb 14, 2017 at 10:22 | history | suggested | eddie | CC BY-SA 3.0 |
fixed grammar
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| Feb 14, 2017 at 8:57 | review | Suggested edits | |||
| S Feb 14, 2017 at 10:22 | |||||
| Nov 1, 2014 at 18:05 | comment | added | user4552 | related: physics.stackexchange.com/questions/144262/… | |
| Aug 4, 2013 at 4:29 | answer | added | user4552 | timeline score: 10 | |
| May 9, 2013 at 5:36 | comment | added | Michael | If the speed of light is lower than it was in the past, where is all the energy going? i.e. e=mc^2, so with a lower value of c, the amount of energy in matter is decreasing, but this violates the conservation of energy, unless that energy is leaving the system. How is it doing that? By my (8 year old) calculations, we are talking onthe order of 1.77kW/kg... | |
| Sep 13, 2012 at 22:04 | review | First posts | |||
| Sep 14, 2012 at 15:46 | |||||
| Aug 25, 2012 at 4:16 | comment | added | David Z | @James: when something about an answer is unclear, it makes for a much better question if you edit your original question to ask it in a way that identifies the thing that is confusing you, rather than just posting an extra-long reply to the poster in the question. | |
| Aug 25, 2012 at 3:17 | comment | added | user11647 | @James:Perimeter institute is a very well respected theoretical physics center. Cutting edge. I doubt he's a crackpot...if he is he would have to be a very smart one. | |
| Aug 25, 2012 at 2:47 | history | edited | James Cooper | CC BY-SA 3.0 |
added 1775 characters in body
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| Aug 25, 2012 at 2:44 | vote | accept | James Cooper | ||
| Aug 25, 2012 at 1:03 | answer | added | Mark M | timeline score: 12 | |
| Aug 24, 2012 at 23:07 | comment | added | Qmechanic♦ | Related: physics.stackexchange.com/q/12805/2451 and links therein. | |
| Aug 24, 2012 at 23:01 | comment | added | Zo the Relativist | @JamesCooper: the author of that seems to be confusing dark matter and dark energy. And the size of the cosmological constant is such that it is very small when compared to almost any other fundamental physics constant. Changing the value of $c$ is actually a much, much more violent adjustment to physics than dark energy is. | |
| Aug 24, 2012 at 22:59 | history | edited | Qmechanic♦ | CC BY-SA 3.0 |
It is no soft-question
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| Aug 24, 2012 at 22:39 | comment | added | James Cooper | @Nogwater Thanks, great article. I think that'd answer any question I might have. Except hearing what t'hoofts opinion is ;p. The shocking claim from the opfocus.org I linked is that redshifted galaxies might not be speeding away from each other at all: "if c were decreasing over time, the Hubble effect would turn out to be a simple optical effect, eliminating the need to postulate the existence of the dark matter." Now that seems like something easy to disprove and label as crackpottery. Right? | |
| Aug 24, 2012 at 22:32 | comment | added | Zo the Relativist | I'm sure that there are very rigorous constraints on this. There's no way to change the speed of light without affecting the fundamental way that the electromagnetic force works, which in turn, would show up in all sorts of processes. That's not to say that something like this COULDN'T happen, just that the amount by which it HAS happened probably has a rigorous constraint upon it. | |
| Aug 24, 2012 at 22:23 | comment | added | Nogwater | I don't know if he's a crackpot or not. I think it's an interesting question. Here's more to check out: en.wikipedia.org/wiki/Variable_speed_of_light | |
| Aug 24, 2012 at 22:17 | comment | added | James Cooper | I googled my question and found that a physicist J.W. Moffat supports the hypothesis:"physically consistent theories in which the speed of light is varying in time can indeed be developed in a safe and rigorous way." He works at the perimiter institute. Does that mean crackpot? opfocus.org/index.php?topic=story&v=8&s=4 | |
| Aug 24, 2012 at 22:08 | comment | added | Nogwater | I'm not an expert, so I'm not going to create an answer. When I've asked about this before, I've heard that if the speed of light was different in the past, then things like stars would work differently. If stars worked differently in the past, we would see this by looking at far away galaxies. We don't see any difference like this, so no... the speed of light hasn't changed. | |
| Aug 24, 2012 at 22:00 | history | asked | James Cooper | CC BY-SA 3.0 |