Questions tagged [redshift]
Redshift refers to the difference in frequency of an electromagnetic wave as measured by a source versus a receiver in relative motion.
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Is there a wavelength shift between sunlight observed from the ISS versus from Earth's surface?
As gasses are not ideal in transmitting sunlight. Are there differences between sunlight observed from beyond the Earth atmosphere and the one observed from the Earth surface? If so, what are they?
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Doppler Effect and the concept of relative velocity in GR
While reading Sean Carroll's book on General Relativity, I understood that the concept of velocity is ill-defined over large distances in arbitrarily curved manifolds, like the one used to describe ...
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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 ...
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Does gravitational redshift conserve energy?
It is claimed that redshift due to cosmological expansion doesn't conserve energy. Does this exception also apply to gravitational redshift? Why or why not?
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Factor for observed redshift - light dispersion (chromatic aberration) caused by a gravitational lensing
This thought tortured me for a while now, and I can't find if this has been hypothesized/discussed before, and if so, is there a consensus:
Can redshift be to at least some degree a result of a ...
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Stars that have fairly high gravitational redshift and calculation of their surface temperature by Planck emition spectra?
How high can the ratio between gravitational redshift and planck emition spectra be depending on the mass of the star so by how much this gravitational redshift could elongate the Planck spectra of ...
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Distance needed for visible light to be cosmologically redshifted to microwave
What distance will it take for visible light to become a microwave due to cosmological redshift?
I'm not sure how to calculate this, as I'm never good at complex math. I tried googling but didn't find ...
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Could the increasing anisotropy of the universe lead to an additional blueshift?
I'm contemplating the possible sources of a wavelength-shift within our universe:
The CMB had a lot more energy when it was produced (around 3000 K). Due to the expansion of the universe, it has been ...
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$I_{\nu}/\nu^{3}$ which is Lorentz invariant is also invariant for cosmological redshift?
$I_{\nu}/\nu^{3}$ is Lorentz invariant, therefore an observed intensity is boosted by $\delta^{3}$, where $\delta$ is the Doppler factor. If the cosmological redshift is same physical process with ...
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Are there structures or systems that can have a high angular momentun that are not made by protons and/or neutrons?
Cosmic structures such as neutron stars, white dwarfs or black holes can have high amounts of angular momentum (high spin velocities). However, these are all made by protons and neutrons (black holes ...
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Redshift of the CMB
Has the $z\sim 1100$ redshift of the CMB been actually measured by comparing the fingerprint (absorption spectrum) of the CMB with the theoretical radiation pattern of a $2.725\,\mathrm{K}$ blackbody, ...
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Does someone falling into a spinning black hole see the end of the universe?
It is well known that if you fall into the Schwarzschild black hole you cannot see the entirety of the outside spacetime since there are photons which cannot catch up with you before you reach the ...
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In a fast moving space ship, can you harvest energy from the radiation background?
In a fast moving space ship (let's say a meaningful portion of c), radiation coming from the front is blue-shifted, while the one coming from behind is red-shifted. Meaning the part of the universe ...
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Cosmological redshift and distance calculus
I am somewhat puzzled when it comes to understanding the general relationship between the cosmological redshift of a galaxy and its distance, and none of the other questions in the forum have ...
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Resolution of Einstein prediction of brightness loss with acceleration
Stars moving at velocities relative to us nearer to light speed are predicted to have lower brightness as well as red shift. Brightness loss has not been observed, however. Could this be due to ...
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