Questions tagged [redshift]
Questions related to the phenomenon whereby electromagnetic radiation (such as visible light) generated by an object moving away from an observer will have increase in wavelength (i.e. shifted toward the red end of the spectrum) once it reaches the observer.
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Does matter accumulate just outside the event horizon of a black hole?
My understanding is that time slows and approaches stopping when approaching the event horizon of a black hole. I have seen this explained several places, including a brief explanation in the last ...
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In km/h, what actually is the "speed" of Andromeda away from us: cosmologically?
Andromeda is about 2.5 million ly away.
Actually, in this universe, at what "speed" (in km/h) are two objects separating cosmologically - I mean strictly due to the "expansion of the universe" - if ...
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Cosmological redshift vs doppler redshift
I'm reading Harrison's "Cosmology: Science of the universe" because Harrison focuses on the distinction between cosmological redshift (he calls it expansion redshift) and the Doppler redshift.
He ...
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Is there another explanation, apart from the doppler effect, for the redshift observed in distant galaxies?
On episode 10 of the original Cosmos TV series, Carl Sagan mentions that some scientist don't agree that the redshift observed in distant galaxies is evidence of the big bang, stating that probably ...
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Why do linear velocity redshifts correspond to linear pixel shifts when the spectra are binned in constant log wavelength?
In Tonry & Davis (1979), they describe spectroscopic redshift measurement via correlating with templates at known redshift. In Section IIIa, they say "Because the spectra are binned linearly with ...
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How distances are measured in the Solar System, in the Galaxy, and in the Universe?
Distances in our universe can be calculated in several ways:
Stellar Parallax
Standard Candles
Redshift
How are these methods linked, and how they are actually used to calculate distances are ...
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How Do we know about redshift?
Okay so scientists use the red shift to know that galaxies are moving away from us faster than light. How do we know that its not just red light from red stars. i mean most stars are in the infrared ...
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Are there other proofs of the expanding universe apart from the redshift?
The theory of the expanding universe is so widely accepted, that the redshift is sometimes used as a measure of distance to far away galaxies.
But is it still possible that the redshift is caused by ...
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Why are all quasars so far away?
Why are all quasars so far away?
If the universe is homogeneous, we should expect to have a homogeneous distribution of quasars, but all of then seem to be far away from Earth. Why is that?
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Does the universe expand at the same rate everywhere in the universe?
Specifically, I am wondering if some areas of the universe expand faster than other areas and whether the faster expanding areas diffuse the expansion through the slower expanding areas or does the ...
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How do I apply a velocity shift to a wavelength array with uniform logarithmic spacing?
Suppose I have a wavelength array for a spectrum in units of Angstroms. Suppose further that the wavelength has "uniform logarithmic spacing" such that if I just take the difference in Angstroms ...
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How does space time differ within a galaxy?
Not the same question but is similar to other marked duplicate.
How much time dilation does the center of a galaxy can exist and sustain human life from our point of view? What would a day equal to ...
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Where does the energy of light go, when it red-shifts?
When talking about the expansion of the universe, it is said that it can be proven by the red-shifting of light.(As we would need higher than lightspeed to get this redshift by the Doppler effect)
I ...
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Understanding The Turnover Point of Angular Diameter Distance
I am trying to get a better understanding of cosmological distances, in particular the angular diameter distance which I have also seen referred to as angular size distance.
What I am looking for is ...
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Is Webb or any near-future telescopes like ELT capable of observing redshift changes to confirm General Relativity?
The (Davis and Lineweaver (2003)) "Expanding Confusion" paper states that "the expected change in redshift due to cosmological acceleration or deceleration is only ∆z ∼ 10^(−8) over 100 ...
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