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07-21-2008, 07:49 PM
Smile Re: Can we estimate the volume of the observable universe?

Quote:
Originally Posted by JoeBachofen View Post
Thanks davidgow77 for asking a question I've often wondered about.
From Wikipedia, the radius of the observable universe is about 46 billion light years.

So, the volume of the observable universe is
\frac{4}{3} \times \pi \times \mathrm{R}^3 = 4 \times 10^{32}\text{ ly}^3
with R = 46 billion light years according to Wikipedia and my own calculations.

The same Wikipedia article estimates the visible mass in that volume as
9 \times 10^{21} \ \textrm{solar masses}
or about
1.8 \times 10^{52}\ \textrm{kg} if one solar mass = 2 \times 10^{30}\ \textrm{kg}

Since visible matter is less than 5% of the total matter in the universe, I guess the total is
3.6 \times 10^{53}\ \textrm{kg}
or more.

Wikipedia gave me the dark matter estimate as 22% and the dark energy as 74%

No doubt you have much better answers by now, but this has been a good exercise for me. I suspect I have a bit to learn regarding this editor and how it handles tags.

Thanks
Thanks Joe for such a great response to this question,and welcome to the forum.

warm regards michael.
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