# Questions tagged [gravitational-redshift]

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### About redshift and distant objects observation

I did a few Time&Length dilation factor calculations. This is for a distant clock away from any field and a clock on Earth on the equator with the moon passing over clock coordinates, the factors ...
1 vote
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### Numerical evaluation of gravitational light bending

I am looking into how light is being bent by objects of large masses with the intention of creating a numerical simulation of this (basically a ray tracer taking this phenomenon into account). I was ...
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1 vote
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### How would a person under gravity observe a person on a nearby planet but under 1000 times of that gravity?

So, imagine I am standing in a region in space where the gravity is, say 1g. Now, on a nearby planet, there is my friend who is under the influence of much stronger gravity, like 1000g. According to ...
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### When e.g. a star falls into a black hole would that part of the event horizon extend for a while?

When e.g. a star falls into a black hole would a part of the event horizon at that point extend for a while due to extra gravity due to the incomming star? And when the star starts to disappear even ...
• 2,255
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### Components in the calculation of the Sun to Earth redshift

When I see calculations of the Sun’s redshift as seen from Earth I believe, as I understand it, that 1) the gravity potential at the emission point near the Sun is taken into account, then 2) the Sun’...
194 views

### Why the CMBR redshift is so higher than the redshift of the most distant therefore oldest galaxies in the universe?

Why the CMBR redshift is so higher than the redshift of the most distant therefore oldest galaxies in the universe? We know that cosmological redshift rises with distance from the object but at ...
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1 vote
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### Does a blueshift mean that time goes faster?

This is a follow-up question to this answer. The assumption in this answer is that time dilation always causes a small redshift when an observer looks at an object moving at a significant fraction of ...
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### Do gravitational redshift depends on reference frames?

I just want to know is the effect of redshift depending on the frames of reference or the photon really does lose energy when it escaped from a gravitational well? Imagine a spaceship is shooting a ...
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### Clocks in gravitational field

"In a gravitational field clocks slow down" - this is an effect of gravitational redshift. Are the following statements correct? If I take a "clock" from the surface of the Earth ...
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### Is gravitational redshift reversible?

Imagine a scenario where a LASER beam is shot from the surface of one planet to a detector on another. Assume there are no atmosphere and nothing affects the beam in any way between the planets. ...
138 views

### Can a photon lose all of its energy due to gravitational redshift?

Imagine a photon that is emitted by a star that is at infinity with respect to me. We can observe the gravitational redshift happening to that photon with respect to my reference frame. I was ...
365 views

### Do particles at rest gain energy in an expanding universe?

It is commonly understood that as the Universe expands with scale factor $a$ the energy of a photon drops like $1/a$ whereas the energy of a particle at rest is constant. In the analysis below I ...
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