Questions About the Big Bang

[Alex K]

The temperature and fluctuations of the cosmic microwave background, the cosmic redshift of supernovas, the structures found in large scale galaxy distributions and the abundance of light elements together give us enough data points to fix the age very precisely, and to be very certain that the universe was once hot and dense.

Remarkable. I’m reading about the CMB right now. So it seems that was your primordial soup of loose fermions and bosons that eventually combined into atoms. I wonder, is the CMB showing up in the red, i.e. moving away? And why is it called recombination, as if it had happened before?

I want to read further to get a better understanding of how the CMB is an “echo of the Big Bang.” So far, my lay conclusion is that the isotropic nature of the CMB supports Jonathan Strickland’s (author of Min’s link) statement that this was not an explosion.

I will look at the other things you listed, but not tonight. Going to bed, g’night. Sleep tight.

1. Oh yes! The CMB was once a 3000 centigrade hot yellow-white flash of light (because that's the temperature when recombination roughly starts), the fact that it is now a *Microwave*background rather than a bright yellow light coming from everywhere, tells us thaz it has been red shifted by a factor of 1100!

2. good point, I don't think the name "recombination" is very sensible

3. it wasn't an explosion because itis not stuff flying away from point (that wouldn't really explain why far away stuff seems to move away faster at such a precise relation). It is an expansion of a radiation and matter filled space.



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But again everyone, cosmic redshift is not a doppler shift. Doppler shift is proportional to the speed of the source and target at the points in time when the radiation was emitted and received. Cosmic redshift is the sum of all expansion that has happened during the light travelling - a very very different thing