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Author Topic: How many atoms are in the Universe?  (Read 36753 times)

Offline Bored chemist

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Re: How many atoms are in the Universe?
« Reply #50 on: 08/08/2010 19:02:12 »
Is there some sort of award for the most pointless resurrection of an old thread? I think Tangoblue's contribution there must be a contender.
 

Offline preeti28

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How many atoms are in the Universe?
« Reply #51 on: 09/08/2010 12:05:41 »
The visible universe is estimated to contain between 1078 and 1080 atoms.
(One estimate at the higher end of the range is 4 x 1079.)

This is the estimated number of atoms in the observable universe, but since we do not know the absolute size of the universe, we cannot be certain.
(Most of the matter in the universe is still hydrogen.)
 

Offline marriemb

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How many atoms are in the Universe?
« Reply #52 on: 13/08/2010 06:24:54 »
goto bed  [O8)] [:0] you guys havent sleep deprived it seems
 

Offline tommya300

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How many atoms are in the Universe?
« Reply #53 on: 13/08/2010 17:55:55 »
i bet you can't tell me... ;D

It occured to me as I was driving by a cemetary, someone asked how many dead bodies are in that cemetary?
How many?

 ALL of them 

.
« Last Edit: 13/08/2010 19:36:07 by tommya300 »
 

Offline chemgeek

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How many atoms are in the Universe?
« Reply #54 on: 13/08/2010 18:48:58 »
I know wikipedia isn't the most reliable source in the world but this was quite inteseting:

Two approximate calculations give the number of atoms in the observable universe to be a minimum of 10^80.

1.Observations of the cosmic microwave background from the Wilkinson Microwave Anisotropy Probe suggest that the spatial curvature of the Universe is very close to zero, which in current cosmological models implies that the value of the density parameter must be very close to a certain critical value. This works out to 9.910−27 kg/m3,[25] which would be equal to about 5.9 hydrogen atoms per cubic meter. Analysis of the WMAP results suggests that only about 4.6% of the critical density is in the form of normal atoms, while 23% is thought to be made of cold dark matter and 72% is thought to be dark energy,[25] so this leaves 0.27 hydrogen atoms/m3. Multiplying this by the volume of the visible universe, you get about 810^79 hydrogen atoms.
2.A typical star has a mass of about 210^30 kg, which is about 110^57 atoms of hydrogen per star. A typical galaxy has about 400 billion stars so that means each galaxy has 110^57 410^11 = 410^68 hydrogen atoms. There are possibly 80 billion galaxies in the Universe, so that means that there are about 410^68 810^10 = 310^79 hydrogen atoms in the observable universe. But this is definitely a lower limit calculation, and it ignores many possible atom sources such as intergalactic gas.[26]

newbielink:http://en.wikipedia.org/wiki/Observable_universe#Matter_content [nonactive]

whoa numbers  :)
 

The Naked Scientists Forum

How many atoms are in the Universe?
« Reply #54 on: 13/08/2010 18:48:58 »

 

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