Redshift - does energy fade or get absorbed?

In summary, the conversation discusses the possibility that redshift, the phenomenon used to support the expansion of the universe, may not be accurately representing the strength of light or energy over long distances due to the presence of particles and dust. However, this theory has been disproven and the redshift is a reliable indicator of the universe's expansion.
  • #1
Corkie2003
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Is it possible that redshift, though correct in it's theory, is not what we are viewing in terms of expansion of the universe?

Is it possible that what we think is redshift is actually the strength of the light/energy fading, being absorbed or blocked over hundreds of millions of light years?

I ask this because it seems to me that in the vast chasms of space between the observer and the observed, there have to be a large number of free-roaming particles of dust that would diminish the light, if only by a minescule amount at a time. Thus the light becomes dimmer, or darker.

Is there any possibility that the universe is not actually expanding like we think it is based on the Redshift theory?

Help me please because I'm a bit thick.
 
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  • #2
The redshift is not the only reason that we know the universe is expanding. When Albert Einstein worked out Relativity and predicted how gravity works his calcultions indicated that the universe must be expanding, he didn't believe it was and so adjusted his calculations to compensate. It was Hubbard who convinced him that the universe really was expanding that his calculations were correct.
 
  • #3
Corkie2003 said:
Is it possible that what we think is redshift is actually the strength of the light/energy fading, being absorbed or blocked over hundreds of millions of light years?

Tzemach is right. In addition you can actually calculate the results of this "tired light" theory, and those calulations don't agree with the observed numbers. So that theory has been falsified. So goes science, then we try another theory.
 
  • #4
selfAdjoint said:
Tzemach is right. In addition you can actually calculate the results of this "tired light" theory, and those calulations don't agree with the observed numbers. So that theory has been falsified. So goes science, then we try another theory.


Nuff said, thanks for your help folks.

I go away slightly less in the dark than when I arrived.

:rolleyes:

What about the effect of miniscule particles though, surely they cannot be calculated, and we observe their effect on white light on the horizon.
 
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  • #5
Corkie2003 said:
What about the effect of miniscule particles though, surely they cannot be calculated, and we observe their effect on white light on the horizon.

If you mean the color of sunset, it appears redder only because much of the blue light has been blocked (scattered out giving that colour to the day sky elsewhere). The astronomical redshifts are where individual photons have all changed uniformly in colour. It might be hard to tell the difference for white light, but some of the atoms in these sources always produce lots of light at several very specific frequencies (so we can compare those lines in different stars spectra).
 
  • #6
Redshift is all about how the universe conserves energy. When space expands, it preserves the net energy between point A and B by smearing it out across space. Without redshift, you have a universe that ignores the laws of thermodynamics.
 

FAQ: Redshift - does energy fade or get absorbed?

What is redshift?

Redshift is the phenomenon in which light from an object shifts towards the red end of the electromagnetic spectrum. This is caused by the expansion of the universe, which stretches the wavelength of light as it travels through space.

Does redshift affect the energy of light?

Yes, redshift does affect the energy of light. As the wavelength of light increases due to redshift, its energy decreases. This is known as the cosmological redshift and is a fundamental property of the expanding universe.

Can redshift be caused by other factors besides the expansion of the universe?

Yes, redshift can also be caused by the Doppler effect, which is the shift in wavelength of light due to relative motion between the source and observer. This is known as the peculiar redshift and is used to study the motion of galaxies.

Does energy fade or get absorbed due to redshift?

Energy does not fade or get absorbed due to redshift. It simply gets redistributed to longer wavelengths. This means that the total amount of energy in a photon remains the same, but it appears less energetic due to the increase in wavelength.

How does redshift affect the temperature of an object?

Redshift does not directly affect the temperature of an object. However, it can indirectly affect the temperature by changing the wavelength of light that is emitted. For example, a redshifted star will appear cooler than it actually is, as its light has been stretched to longer, cooler wavelengths.

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