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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How did Hubble know the red shift difference between "moving away" and "old"?
My 9yo daughter is very into space at the moment and asked a question that my physics knowledge (6th form college, 20 years ago) is way too poor to answer.
Her space book tells us that as stars age, ...
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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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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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Is there physical evidence to distinguish between the expansion of space and an anthropocentric universe?
When we look in all directions, we see distant objects red-shifted, with the size of the red-shift correlated with the distance from us.
As I understand it, the consensus among cosmologists is that ...
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Could we (Earth, Humanity, Solar System) be falling into a black hole?
With the expansion of the universe, all objects far away from us appear to be moving away (ie: exhibit Redshift). With distance, this acceleration / redshift also seems to increase (~73,000 (m/s) / (...
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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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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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Is it possible to measure galactic red shift using consumer telescope equipment?
I was wondering if it would be possible to measure red shift from distant galaxies using consumer grade telescope equipment and spectroscopy filters. (like this one)
I imagine it would require a ...
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Can the difference between a star and a galaxy which are point sources be detected?
Obviously a star would be a point source. A galaxy should be an irregular blob if close, but if it is far away then it would seem that a galaxy too would be just a point source.
Given that the star ...
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Why are there so many seemingly blue-shifted galaxies in deep space
NASA released this image of deep space. The way light shifting vis-a-vis universe expansion is supposed to work is by making the furthest galaxies appear mostly red-shifted. But NASA's image shows ...
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How do we know if an object is redshifted?
I have some questions about redshift. I think that the first two hang on the last two, but feel free to point out anything you think I should know.
How do we know if an object is actually redshifted,...
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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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Can the gravitational redshift of our sun be measured?
How much of a wavelength change does our sun’s gravity cause in the light it emits? I imagine this could be measured by the shift in its spectral lines. And by extension, does the earth’s ...
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Does the accelerating expansion of the Universe contradict Hubble's law?
Hubble's law gives a linear relationship between the distance to a galaxy and it's recessional speed.
Observations of distant type 1a supernovae showed that their red shift (and therefore their ...
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