Timeline for As light travels upward in the earth’s gravitational field, it loses energy, and so its frequency goes down?
Current License: CC BY-SA 4.0
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| Aug 16, 2019 at 21:41 | comment | added | dmckee --- ex-moderator kitten | Leaving aside the practical difficulties associated with unstable equilibria, light orbiting in the photon sphere of a black hole retains it's energy and frequency over time despite being subject to the field at that radius indefinitely. | |
| Oct 3, 2018 at 4:50 | comment | added | MacThule | That's an excellent question. I don't have the formula to answer it, but to the best of my personal understanding it's because gravity is actually a stretching of spacetime. Since the photon's path and wave is mapped onto spacetime, it also gets stretched; the waves grow farther apart. The next question then is why doesn't the wavelength rebound once the photon reaches flatter spacetime, and I don't know the answer to that. | |
| Oct 3, 2018 at 4:26 | comment | added | Árpád Szendrei | "it's the increasing length of time that the photon is exposed to a strong gravity well at all. " but why does the gravity well cause the photon to decrease its energy? | |
| Oct 3, 2018 at 2:55 | review | First posts | |||
| Oct 3, 2018 at 3:47 | |||||
| Oct 3, 2018 at 2:52 | history | answered | MacThule | CC BY-SA 4.0 |