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How many baryons are there in the universe? 
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#1
Jul1709, 09:11 AM

P: 42

Many articles and papers say that 4% of all energy in the universe is baryonic. How many baryons does that make? I do not seem to find any wikipedia article or paper that gives an absolute number. Can anybody help?
Thank you! François 


#2
Jul1709, 09:41 AM

Mentor
P: 6,227

Then number of baryons in the observable universe is usually estimated to be about 10^{80}. See, for example, the solution to problem 6.8,
http://www.physics.ucsb.edu/~tt/PHYS133/hws5.pdf, from Barbara Ryden's excellent book Introduction to Cosmology. 


#4
Jul1809, 03:56 AM

Sci Advisor
PF Gold
P: 9,360

How many baryons are there in the universe?
Good answer, Nabeshin, whatever that meant. Fran asked for a number, George gave the best current estimate. Do you have a rebuttal or are you just sniping?



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