Timeline for Why doesn't gravity speed up light?
Current License: CC BY-SA 3.0
19 events
| when toggle format | what | by | license | comment | |
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| Nov 21, 2022 at 17:18 | comment | added | Peter Bernhard | Refering to abkds: does the angle of bending depend on the wavelength? | |
| Mar 2, 2016 at 19:52 | history | protected | Qmechanic♦ | ||
| Mar 2, 2016 at 19:47 | answer | added | Gary Godfrey | timeline score: 3 | |
| Mar 2, 2016 at 13:26 | history | edited | Qmechanic♦ | CC BY-SA 3.0 |
edited tags
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| Feb 27, 2014 at 8:14 | vote | accept | Yashbhatt | ||
| Feb 18, 2014 at 0:43 | vote | accept | Yashbhatt | ||
| Feb 27, 2014 at 8:14 | |||||
| Feb 11, 2014 at 21:10 | answer | added | Wouter | timeline score: 6 | |
| Feb 11, 2014 at 19:14 | answer | added | Alfred Centauri | timeline score: 15 | |
| Feb 11, 2014 at 18:57 | comment | added | abkds | Gravity does bend light but doesn't speed it up . Gravitational Lens | |
| Feb 11, 2014 at 18:46 | comment | added | Wouter | As David alludes to, gravity isn't considered a force in GR. Instead, free-falling is defined as being free of any external forces, feeling only the effects of the local gravitational field. This is backed by the (Einstein) equivalence principle and means we have to view spacetime as being curved due to mass (and energy), which changes the free-falling paths. Light always follows these paths, or (null) geodesics, and therefore bends in the presence of mass/energy, but there is no force accelerating it because gravity isn't actually a force. | |
| Feb 11, 2014 at 18:41 | comment | added | Kyle Oman | @DavidZ agreed, which is what I tried to mitigate with the second part of the comment. Probably reads better if you ignore the words "couples to". Photons don't experience gravitational force but do experience gravitationally curved spacetime. | |
| Feb 11, 2014 at 18:30 | comment | added | David Z | @Kyle I'd actually say that's quite misleading because gravity couples to all forms of energy, not only mass. (Otherwise it would have no effect on light at all!) But its effect on light is not something that we would recognize as a force. | |
| S Feb 11, 2014 at 18:18 | history | edited | Brandon Enright | CC BY-SA 3.0 |
Added relativity tag and made some other minor changes
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| S Feb 11, 2014 at 18:18 | history | suggested | Hunter | CC BY-SA 3.0 |
Added relativity tag and made some other minor changes
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| Feb 11, 2014 at 18:13 | comment | added | Kyle Oman | To expand slightly: the easiest way to see this in the formulation of the theory is that gravity is a force that couples to (acts on) mass, and light (photons) have zero mass. Gravity does not exert a force on light. In terms of light curving, it's more accurate to think of bending light as light travelling in a "straight path" within a curved spacetime than light travelling on a curved path within a flat spacetime. | |
| Feb 11, 2014 at 18:09 | review | Suggested edits | |||
| Feb 11, 2014 at 18:18 | |||||
| Feb 11, 2014 at 18:07 | comment | added | Carl Witthoft | Among other considerations, "no" because $c$ is invariant according to the theory(ies) of relativity. | |
| Feb 11, 2014 at 18:06 | review | First posts | |||
| Feb 11, 2014 at 18:09 | |||||
| Feb 11, 2014 at 17:48 | history | asked | Yashbhatt | CC BY-SA 3.0 |