Frame dragging effects on speed of light

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Discussion Overview

The discussion centers on the effects of frame dragging on the behavior of light near massive rotating objects, such as black holes. Participants explore whether light would experience a blue shift and the implications of its speed in relation to the speed of light in a vacuum.

Discussion Character

  • Exploratory, Debate/contested, Conceptual clarification

Main Points Raised

  • One participant questions whether light passing near a rotating massive object would be blue shifted or if it would travel faster than the speed of light.
  • Another participant asserts that light cannot exceed the speed of light in a vacuum and would indeed be blue shifted.
  • A request for a detailed explanation of the blue shift is made, indicating a desire for deeper understanding.
  • A different viewpoint suggests that while light may be brighter from one side due to the geometry of space-time, the color shifts would not differ between sides, as this could lead to contradictions in the observed images over time.
  • The same participant emphasizes that light will not locally travel faster than the speed of light, suggesting a conceptual framework of "less space" and "extra time" in the direction of the massive object.

Areas of Agreement / Disagreement

Participants express differing views on the effects of frame dragging on light, with some asserting a blue shift and others contesting the implications of brightness and color shifts. The discussion remains unresolved with multiple competing perspectives.

Contextual Notes

Participants have not fully explored the assumptions underlying their claims, particularly regarding the nature of light's interaction with curved space-time and the implications of frame dragging.

carpodoubt
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I had a question that I was hoping someone could answer for me.

If light passes next to a massive rotating object such as a black hole, would the affects of frame dragging cause a blue shift or would the light essentialy travel at a speed faster than the C?
 
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Light cannot exceed the speed of light in a vacuum. It would be blue shifted.
 
Could you explain in detail why it would be blue shifted.
 
I think that's wrong. The light lensed from one side should certainly be brighter than the other (since the source is effectively "closer" in space-time from that side).

No, actually, that's too sloppy. There will be more light from one side, because the "closeness" will cause the source to subtend a bigger angle on that side.

But the colour-shifts (and hence also the surface brightnesses) will not be different between each side. If light frequencies were different, then the entire image would also be evolving at different rates on either side. So although you might initially see two images of the source at approximately the same point in the image's history, if you waited long enough then you would end up seeing simultaneous images of two arbitrarily separated points in the source's history. That will lead to a contradiction.

Note to the OP: It won't locally travel faster than c either, maybe it helps to think of there as being "less space" (and extra time) in that direction.
 
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