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Author Topic: How does starlight curve around the sun?  (Read 1653 times)

Offline Northstar

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How does starlight curve around the sun?
« on: 02/08/2015 19:15:29 »
Einstein theorized and calculated that a massive object like the sun had such strong gravity that it would bend the light of a star around the outer edge of the sun.  Astronomers proved Einstein was correct.

How can gravity attract the photons traveling toward us unless gravity also contains an electrical facet?  Aren’t photons electrically neutral?   Space is “warped” by gravity like the bank on a car race track.  But what does the photon push against to curve around the space warp?  Or is it held in a curvature path like a bucket on a rope.  How is space warped if it is a vacuum?   Scientists say that space is full of dark matter.  Does that play a role?


 

Offline wolfekeeper

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Re: How does starlight curve around the sun?
« Reply #1 on: 07/08/2015 16:39:45 »
Well, I'm personally electrically neutral, yet, I'm still affected by gravity, so I don't see why photons would be any different, and the experimental data supports that they are curved by gravity.

The idea of relativity is that space is actually curved; for example if you take a caliper and measure the diameter of the earth from the outside, it would be smaller than if you drilled a hole through the Earth and dropped a tape measure down. There's actually more volume inside the Earth than you would expect from its exterior dimensions (although the difference is small).

But light will, in addition to falling under gravity, be refracted by the shape of space towards the Earth- it has to go further to meet back up with the light that stays further outside the gravitational field; and that delays the wavefront and causes the wavefront to twist so that it bends towards the Earth, much like light does when it gets slowed by water.
 

Offline Northstar

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Re: How does starlight curve around the sun?
« Reply #2 on: 11/08/2015 18:28:32 »
Wolf said: "if you take a caliper and measure the diameter of the earth from the outside, it would be smaller than if you drilled a hole through the Earth and dropped a tape measure down."

So, I think you are saying that gravity compresses everything.  And the difference in the apparent compression versus volume gives the effect of a warping of space.  Interesting.
 

Offline PmbPhy

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Re: How does starlight curve around the sun?
« Reply #3 on: 15/08/2015 13:43:14 »
Quote from: Northstar
How can gravity attract the photons traveling toward us unless gravity also contains an electrical facet?
Since photons have energy they have an equivalent mass and since it has mass its attracted by a gravitational field. You can find this explained in this way by Richard Feynman in the Feynman Lectures on Physics

Quote from: Northstar
  Aren’t photons electrically neutral?
Well, they do scatter off of electrons through what's known as the Compton effect.

Quote from: Northstar
   Space is “warped” by gravity like the bank on a car race track.
That's a misconception. If the space around the sun wasn't curved then the light would still be deflected. The amount of the deflection would be half the correct value. But I think that you're confusing curved space with curved spacetime. They're not the same thing. And a gravitational field that has no spacetime curvature can deflect light too. In fact Einstein's first example of a gravitational field was one that had no spacetime curvature, i.e. the uniform gravitational field.

Quote from: Northstar
  But what does the photon push against to curve around the space warp?
I don't understand why you'd think that the photon would need to push against something. You don't push against something when you fall in a gravitational field, do you? Neither do photons.

Quote from: Northstar
How is space warped if it is a vacuum?
Spatial curvature is measured by measuring distances between points. If the distances are not one would expect from a flat geometry then there is a change in the distances between points and that's caused by the presence of nearby matter.

Quote from: Northstar
   Scientists say that space is full of dark matter.  Does that play a role?
Not regarding to your question, no.

You can read more about curving at http://www.eftaylor.com/exploringblackholes/Curving150523v1.pdf
« Last Edit: 15/08/2015 13:44:48 by PmbPhy »
 

Offline Space Flow

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Re: How does starlight curve around the sun?
« Reply #4 on: 05/12/2015 10:09:31 »
And for a more novel answer to the above standard accepted interpretations of General Relativity, Try this one.
http://www.thenakedscientists.com/forum/index.php?topic=65064.0
 

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Re: How does starlight curve around the sun?
« Reply #4 on: 05/12/2015 10:09:31 »

 

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