Photon frequency loss over time?

In summary, there was once a theory that part of the red-shift observed in far away galaxies could be due to a time or distance related decrease in the frequency of light, in addition to the doppler effect. This theory has been abandoned by mainstream science due to evidence from multiple cosmological tests, including the cosmic microwave background, the formation of large scale structure, and the evolution of star formation with redshift. The "tired light" theory was proposed in the 1920s by Fritz Zwicky, and while it was viable for a few decades, it has since been disproven by various experiments and observations. Other theories, such as inflation, have been able to provide more accurate explanations for the observed red-shift in distant galaxies.
  • #36
So, would the photographic plate be exposed on both galaxies or only one?
This is what energy conservation is about (and forums for that matter too!)
 
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  • #37
ratfink said:
This is incorrect. Energy conservation in GR is in dispute. Some say that energy is not conserved others say it is due to 'curvature'. I hope that this is not a 'warning' because you wish to avoid answering valid questions.

The only dispute is in appropriate definitions of energy in GR. See here:

http://math.ucr.edu/home/baez/physics/Relativity/GR/energy_gr.html" [Broken]

Unless I'm to interpret your previous post as advocating a particular pseudotensor definition of energy, then it belongs in IR.
 
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  • #38
This is not peer reviewed and who are they?
 
  • #39
OK,
Let me spell this out.
B/W paper is not sensitive to red light. That is why we have red safelights in photographic darkrooms.
Light from a distant galaxy is redshifted.
I say that there must be a point where the paper is not exposed anymore.
You and Garth say "Oh the pricinciple of conservation of energy does not apply".
I say B**-t either the paper is exposed or it is not. It is all to do with the photoelectric effect.
Nothing to do with reference frame - we all see the same result.
So I will ask again. If the photon has enough energy to excite and expose a photographic plate on galaxy X, will it once it has been redshifted, be able to expose it on galaxy y?
 
  • #40
No need to be rude.

Energy is not generally conserved in GR because of the time dilation caused by space-time curvature. The energy of a system can only be consistently defined at null infinity where curvature effects and gravitational waves become insignificant.

The reason this is so is energy is a frame dependent concept, moving frames, or frames at different gravitational potential, measure energy differently from one another. We do not all see the same result - that is the whole point of relativity, certain measurements are relative.

In GR it is energy-momentum, or particle rest mass, that is conserved.

Your photographic plate question is irrelevant. The exposed plates X & Y both record the photon, but at a later cosmological time, after more cosmic expansion, the plate Y records a redder image. That is what Hubble red shift is all about.

Garth
 
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  • #41
That's enough, the OP's questions have long since been answered. I'm locking this.
 
<h2>1. What is photon frequency loss over time?</h2><p>Photon frequency loss over time refers to the decrease in the frequency of a photon as it travels through space. This phenomenon is a result of the expansion of the universe and the interaction of photons with matter and energy.</p><h2>2. How does photon frequency loss occur?</h2><p>Photon frequency loss occurs primarily due to the expansion of the universe, which causes the wavelengths of photons to stretch out over time. This stretching leads to a decrease in frequency, as frequency is inversely proportional to wavelength.</p><h2>3. What is the impact of photon frequency loss?</h2><p>The impact of photon frequency loss is significant in understanding the evolution of the universe. It affects the measurement of cosmic distances and the properties of light from distant objects. It also has implications in the study of dark energy and the fate of the universe.</p><h2>4. Can photon frequency loss be reversed?</h2><p>No, photon frequency loss cannot be reversed. Once a photon's frequency decreases, it cannot be increased again. However, the effects of photon frequency loss can be accounted for in calculations and measurements.</p><h2>5. How is photon frequency loss measured?</h2><p>Photon frequency loss is measured using various techniques, including spectroscopy and redshift measurements. These methods involve analyzing the wavelengths of light from distant objects and comparing them to the expected values based on the expansion of the universe.</p>

1. What is photon frequency loss over time?

Photon frequency loss over time refers to the decrease in the frequency of a photon as it travels through space. This phenomenon is a result of the expansion of the universe and the interaction of photons with matter and energy.

2. How does photon frequency loss occur?

Photon frequency loss occurs primarily due to the expansion of the universe, which causes the wavelengths of photons to stretch out over time. This stretching leads to a decrease in frequency, as frequency is inversely proportional to wavelength.

3. What is the impact of photon frequency loss?

The impact of photon frequency loss is significant in understanding the evolution of the universe. It affects the measurement of cosmic distances and the properties of light from distant objects. It also has implications in the study of dark energy and the fate of the universe.

4. Can photon frequency loss be reversed?

No, photon frequency loss cannot be reversed. Once a photon's frequency decreases, it cannot be increased again. However, the effects of photon frequency loss can be accounted for in calculations and measurements.

5. How is photon frequency loss measured?

Photon frequency loss is measured using various techniques, including spectroscopy and redshift measurements. These methods involve analyzing the wavelengths of light from distant objects and comparing them to the expected values based on the expansion of the universe.

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