Why Does Light Bend Away From the Sun?

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Discussion Overview

The discussion revolves around the phenomenon of light bending in the gravitational field of the Sun, particularly in the context of early observations during eclipses. Participants explore the implications of this bending, questioning why light appears to bend away from the Sun despite being influenced by gravity.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • One participant references a book discussing the displacement of starlight around the Sun due to curved space around massive objects.
  • Another participant challenges the assertion that light bends away from the Sun, suggesting it is actually bent toward the Sun.
  • A participant points to a diagram that illustrates the bending of light and its implications for the observed positions of stars during an eclipse.
  • Confusion arises regarding the representation of the expected versus actual positions of stars, with some participants attempting to clarify this distinction.
  • There is a suggestion that the arrows in a referenced diagram indicate expected positions while the dots represent actual positions, leading to further discussion about the clarity of the diagram's explanation.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the interpretation of the bending of light. While some argue that light is bent toward the Sun, others contend that the observed positions of stars appear displaced away from the Sun, indicating multiple competing views remain.

Contextual Notes

The discussion highlights potential confusion regarding the representation of light bending and the interpretation of diagrams, as well as the lack of clear explanations in the referenced material.

Carnivroar
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I am reading God's Equation by Amir Aczel and he talks a lot about the early observations of eclipses which showed a displacement of the starlight around the sun, because space is curved around massive objects.

But why does light bend away from the sun? If it's being affected by gravity, wouldn't it be pulled towards it?
 
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Ok, I see your confusion. The light is bent toward the sun. However, if you are comparing the observed direction of a star with the expected direction, it is away from the sun. If you connect the ends of a chord with a straight line, imagine the straight line is the expected direction. Now, the tangent to an end of the chord points further away from the center of curvature (where the sun is).
 
PAllen said:
Ok, I see your confusion. The light is bent toward the sun. However, if you are comparing the observed direction of a star with the expected direction, it is away from the sun. If you connect the ends of a chord with a straight line, imagine the straight line is the expected direction. Now, the tangent to an end of the chord points further away from the center of curvature (where the sun is).

Ah so the arrows are pointing to the expected position, whereas the dots are the actual position under the displacement? Makes sense, but I don't know why they would do it that way. There's no caption in the image, either.
 
Carnivroar said:
Ah so the arrows are pointing to the expected position, whereas the dots are the actual position under the displacement?

I don't think so.
PAllen said:
Ok, I see your confusion. The light is bent toward the sun. However, if you are comparing the observed direction of a star with the expected direction, it is away from the sun. If you connect the ends of a chord with a straight line, imagine the straight line is the expected direction. Now, the tangent to an end of the chord points further away from the center of curvature (where the sun is).

As PAllen has said, bending light towards the Sun produces images that are displaced away from the Sun. See the diagram towards the bottom of

http://www4.ncsu.edu/unity/lockers/users/f/felder/public/kenny/papers/gr1.html.
 

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