Discussion in 'Physics & Math' started by Hayden, Jul 15, 2018.

1. ### Q-reeusValued Senior Member

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Treating the sun's surface as a static blackbody radiating surface, it's straightforward to calculate gravitational redshift. However, a search and it turns out there are significant contributions from convective motions that have to be factored in. Here is the article setting out all the significant contributions: https://arxiv.org/abs/1207.0177
That finally received on Earth's surface will have a slight added gravitational blueshift component as a result (only the difference in gravitational potentials counts), but will far below the solar redshift contribution.

3. ### DaveC426913Valued Senior Member

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Just as a photon emitted before Earth arrived at its current position may well now intersect the Earth, whereas before it would not have.

5. ### DaveC426913Valued Senior Member

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Technicality:
One cannot observe the path of a photon. It is unobservable until it strikes something.

However, we can imagine what the path of a hypothetical photon would be.
1. Rotation of the Earth about its own axis. The photon and the Sun will move across the sky as a unit. In 8 minutes, both will - as a unit - appear to move (24h/8m = 180) 2 degrees across the sky.
2. Revolution of the Earth around the Sun. In 8 minutes the Earth will have moved about 8880 miles, or about 13% more than its own diameter. A hypothetical photon will start out from the Sun heading directly toward us, but over the 8 minutes will appear to veer off course, ultimately missing us by a little more than the Earth's diameter.

7. ### HaydenRegistered Senior Member

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[Agreed you can't see the photon untill it strikes, what would be the curved path as calculated by an observer on earth with its spinning, rotating, lateral motion also along with solar system, motion along with galaxy;]. With respect to the emitting point co-ordinate in the space, the path would be straight-line.

8. ### James RJust this guy, you know?Staff Member

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The fusion processes ultimately determine the output spectrum of a star, thousands of years delay or not.

9. ### iceauraValued Senior Member

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More the temperature and composition of the outer layers of gas - ?

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11. ### James RJust this guy, you know?Staff Member

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Which are determined by the fusion processes! Well, partly.

Last edited: Jul 20, 2018

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13. ### HaydenRegistered Senior Member

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Composition of outer layer of gases surely not determined by present fusion process. Yes, He etc is outcome of fusion only, but can we say that since fusion created outer layer He and others so the spectrum is dependent on the fusion process taking place in the core?

14. ### Q-reeusValued Senior Member

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Via a PM (now we call them 'conversations'), was informed that the mod who locked the thread had a long standing personal issue with Ken G. They made up much later.
How exactly, and by whom?

What that thread does well is expose one to alternate conceptual arguments that hopefully stimulates deeper thought about the subject. As always, it's up to the reader to decide which pov makes the best sense.

15. ### James RJust this guy, you know?Staff Member

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Sure. It's a thought-provoking read. It strikes me as a bit chicken and egg.

16. ### ForcemanMay the force be with youRegistered Senior Member

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In most facts concerning the photon, on would be that it, when stretched out, doesn't normally follow a triangular path: coordinates could point to it being more like a star if with a quantum state. The stretch is then more for a lepton coming to the Earth exciting out of more variables like time and space spin around Euler path and Euler coordinates. Normal force is more like a cool then a rush. Earth can then take more of the spin: time can then take more of the absolute value of i for more like a normal path. Imaginary is then more like for light like in art. This perspective is that of a broader spectrum including red/blue and magenta. Normal path is then frequency, but flares coming in makes the sun seem more like a time variable consideration then a quantum consideration. The path is then f = j like in frequency for flares rather then i for f(j) for flare spectrum unless in Earth and the ground. Red/blue is more like for electrons then for the omega rather than redshift coming in from a space outside of the i or j like pi or 03 for -3 for earth of spin considering the arbitrary s and p orbitals of electron that put off the spin of photons into the earth because of magnetism. The earth's core can then take way more radiation then the sun's centre and this makes the sun's faster spin wave light to the earth out of flatness rather than magnetism no difference for earth or space in terms of light but a differential like with radiation already on the earth and temperature and perspective differentials.

17. ### James RJust this guy, you know?Staff Member

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Forceman:

Your post makes no sense, and this thread is in one of our Science sections. Please post coherently here, or not at all.

DaveC426913 and Confused2 like this.
18. ### iceauraValued Senior Member

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There may be a role for a bot-testing subforum here.

19. ### Q-reeusValued Senior Member

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Forceman's #33 - Aug 10 (last date he has posted anything so far). Response #34 - Aug 22. 'Strike while the iron is hot'-> 'Wait until iron is rusted through'. Such is SF.
Re #35 - quite some bot if 'it' can actually sign up at SF. But then this is SF.

20. ### DaveC426913Valued Senior Member

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So it had a little help getting in the door. One ticky box is all that stands between a bot and SciFo.

21. ### Q-reeusValued Senior Member

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You think? Refresh your memory and attempt a fake signup. If a bot can pass all that (including followup email verification), humanity is doomed already. Time for the bots to take over.

22. ### sculptorValued Senior Member

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solar output ain't static

23. ### James RJust this guy, you know?Staff Member

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I didn't look at the date on his post. The thread has apparently had no replies at all between Aug 10 and my post. I had assumed it was still active.