The source of cosmic background radiation

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Discussion Overview

The discussion revolves around the nature and origin of cosmic background radiation (CMB), questioning whether it is a remnant of the Big Bang or a result of radiation from visible matter in the universe. Participants explore the characteristics of the CMB and its distribution, as well as its comparison to light matter radiation.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • Some participants suggest that the distribution of background radiation appears filamentary, similar to the distribution of visible matter in the universe.
  • Others argue that the number of photons from light matter is significantly lower than that of CMB photons, implying that light matter cannot account for the observed CMB.
  • One participant questions the filamentary nature of the CMB, asserting that it is actually extremely uniform and that the differences in temperature are much smaller than the average temperature of 2.7K.
  • Another point raised is that the CMB would not exhibit a perfect black body spectrum.
  • It is noted that the average energy per photon from light matter is much higher than that of CMB photons, yet the number density of light photons is lower than that of CMB photons.

Areas of Agreement / Disagreement

Participants express disagreement regarding the filamentary nature of the CMB and its implications for its origin. Multiple competing views remain on the relationship between CMB and light matter radiation.

Contextual Notes

Some claims depend on specific interpretations of the CMB's distribution and characteristics, which may not be universally accepted. The discussion includes unresolved aspects regarding the nature of the CMB spectrum and the comparison of photon densities.

Lesnick
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All stars and Galaxies appear to give off the whole spectrum of electromagnetic radiation.
If one views images of the distribution of background radiation in detail it appears to be filimetary in nature. Also if one views the distribution of visible matter in the universe it also appears filimetary in nature, it looks as though one could super impose one on top of the other.
Why do we think that background radiation is radiation left over from the big bang and not just the radiation from all of the visible matter in the universe.
 
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The number of photons created by light matter (which by the way were generated after the CMB was aleady in existence) is several orders of magnitude less than the number of CMB photons. Thus, these light matter photons cannot account for the observed number of CMB photons.
 
Lesnick said:
If one views images of the distribution of background radiation in detail it appears to be filimetary in nature.
No, it's not filimentary at all. And it's even worse for this view than a naive glance at the picture Nabeshin posted would imply: that image is not the temperature, but the difference in temperature from the average. The average temperature is 2.7K. Those little differences are 100,000 times smaller than the average. The CMB isn't filimentary: it's extremely uniform.
 
It would not be a perfect black body spectrum.
 
That's another point: the average energy per photon from light matter (locally) is several tens of eV (about 1000x that of the CMB, and CMB photons are in fact local), yet the number density of light photons is lower than the CMB number density.
 

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