Astronomy/mass of universe

Advertisement

Expert: Jayendra Upadhye - 9/8/2008


Question
Hi Jayendra,

How does science know what the mass of the Universe is?

Thanks robert

Answer
Hi Robert,
As in most such things, it is all empirical.

One knows that the sun is an "average star" and representative of majority population of stars in most galaxies.
Knowing that, and again having estimates of stars in an average galaxy, and again then having total number of galaxies in the "observavle" universe, one arrives at a mass figure.

here is one link:-http://www.cs.umass.edu/~immerman/stanford/universe.html

Also:
http://en.wikipedia.org/wiki/Mass_of_the_observable_universe#Mass_of_the_observa...
[go directly to para "Mass of the observable universe"]

Also: An allied discussion regarding critical density of the universe for a closed universe.
http://library.thinkquest.org/C0126626/fate/fate%20of%20universe.fate%20of%20uni...

Robert, much of this stuff will be as alien to you as it is to me.

As usual i cannot give you more than this.

regards
Jayen

Astronomy

All Answers

Answers by Expert:

Ask Experts

Volunteer

Jayendra Upadhye

Expertise

1 - General questions on most astronomy topics such as:- Solar system, Cosmology, Black holes, Quasars, Dark matter etc. 2 - General questions about the geologies of planets. 3 - General questions about Orbits and laws governing them. 4 - General questions about rockets / spaceships 5 - General questions about stellar interiors and supernovas.

Experience

I was an askme.com expert rated no#1 for quite some time - and was top ten there by the time it closed - in Astronomy and general science categories.

Education/Credentials
Bachelor of Engg. (Electrical engg), Maharaja Sayajirao university of Baroda, Gujarat, India.

Awards and Honors
None to write about except the askme rating if it is any worth!

©2012 About.com, a part of The New York Times Company. All rights reserved.