Frame dragging effects on speed of light

In summary, the conversation discusses the potential blue shift of light passing near a rotating black hole due to frame dragging. It is stated that light cannot exceed the speed of light in a vacuum, and it would therefore be blue shifted. The idea of the source appearing brighter on one side due to being "closer" in space-time is also mentioned. However, it is argued that the color shifts and surface brightnesses would not be different between each side, leading to a contradiction. It is also noted that the light would not locally travel faster than the speed of light, but rather there is "less space" in that direction.
  • #1
carpodoubt
3
0
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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  • #2
Light cannot exceed the speed of light in a vacuum. It would be blue shifted.
 
  • #3
Could you explain in detail why it would be blue shifted.
 
  • #4
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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1. What is frame dragging?

Frame dragging is a phenomenon in general relativity where the rotation of a massive object, such as a planet or a star, causes the space-time around it to be dragged along with it. This has the effect of distorting the space-time fabric and can impact the motion of objects near the rotating body.

2. How does frame dragging affect the speed of light?

The frame dragging effect on the speed of light is a result of the distortion of space-time caused by the rotation of a massive object. As the space-time fabric is dragged along with the rotating object, the path of light is also affected, causing it to appear to move faster or slower depending on the direction of its motion relative to the rotation.

3. Can frame dragging cause the speed of light to exceed its constant value?

No, the speed of light is a fundamental constant in the universe and cannot be exceeded. The frame dragging effect can only affect the perceived speed of light, but it will always remain constant at approximately 299,792,458 meters per second in a vacuum.

4. Are there any observable effects of frame dragging on the speed of light?

Yes, there have been several experiments and observations that have confirmed the frame dragging effect on the speed of light. For example, the Gravity Probe B satellite measured the tiny changes in the speed of light caused by the frame dragging effect of Earth's rotation.

5. How does frame dragging impact our understanding of space and time?

Frame dragging is a crucial aspect of general relativity and helps us understand the interconnected nature of space and time. It also provides evidence for the curvature of space-time, which is a fundamental concept in our understanding of the universe and its workings.

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