View Full Version : Mass of the Universe


Canute
08-27-03, 11:22 AM
Anybody know the estimated mass of the observable universe?

Crisp
08-27-03, 11:34 AM
Our new friend <A HREF="http://curious.astro.cornell.edu/question.php?number=342">Google</A> claims that it is about 3 x 10<sup>52 </sup> kg. Try to lift that in one go! :)

Bye!

Crisp

blobrana
08-27-03, 11:35 AM
I remember seeing a figure of 70 x10<sup>22</sup> stars in our observable universe (calculated from deep sky photos)...

It would be a simple case of working out how much Byronic matter there is... (about 0.1 of omega)

Your question also includes dark matter which some people believe brings the value of omega to 1...

So there is 10 times more (dark)mass than all those stars...

Hum, i forgotten how much the sun weighs...10<sup>39</sup> tonnes?
Whoops... got it here <b>mass of the sun = 1.98892 × 10<sup>30</sup> kilograms </b>

http://www.space.com/scienceastronomy/star_count_030722.html

Canute
08-27-03, 01:57 PM
Thanks

Vortexx
08-27-03, 05:47 PM
Since all these galaxies flying appart at great speed, what would the mass of the universe be if the universe was compacted into a singularity and this kinetic energy contributed to the mass of the singularity ???

Beercules
08-27-03, 09:48 PM
Hmmm. The problem is that the galaxies are not flying apart as in an explosion. The space between those galaxies itself is expanding, so I don't know how that relates to the energy involved in a contracting universe.

Pete
08-27-03, 10:48 PM
Google says the total mass-energy of the universe is zero... but I don't understand how that can be. Is there negative energy out there?

gendanken
08-27-03, 11:42 PM
Vortexx:
Since all these galaxies flying appart at great speed, what would the mass of the universe be if the universe was compacted into a singularity and this kinetic energy contributed to the mass of the singularity ???

The same thing, no? Assuming our uinverse is a closed system?

So there is 10 times more (dark)mass than all those stars...
and some say 7 and some say 100. Others say its mirror matter not dark matter. Is the only reasons we know any of this simply based on galaxies moving faster than they should be?

I don't know how many of you already heard this, but I was intrigued when someone compared the visible matter in the universe to a Christmas tree with lights on. The tree being the chunk of dark matter we can't see.

Blobrana:
working out how much Byronic matter there is.....
Byronic matter?

Pete
08-28-03, 01:14 AM
"Byronic matter"

Pertaining to a despairing misanthropic baryon.

Crisp
08-28-03, 03:32 AM
"Google says the total mass-energy of the universe is zero... but I don't understand how that can be."

Google sometimes tells incredible lies aswel. You should only trust Google on the proper domains ;).

Bye!

Crisp

Beercules
08-28-03, 10:54 AM
Originally posted by Pete
Google says the total mass-energy of the universe is zero... but I don't understand how that can be. Is there negative energy out there?

That must mean the net energy of the universe. Energy from matter and radiation is positive, but is matched with an equal amount of negative energy in the form of gravitational potential. The 2 cancel each other out.

Ares
08-28-03, 11:31 AM
Hmm, Byronic matter-seems to be something poetic about that. The breakdowns given on <A HREF="http://www.astro.ucla.edu/~wright/cosmolog.htm" TARGET=new> Ned Wright's page </A> seem to be about 2% Baryonic matter, 13% dark matter, and 74% dark energy. This means the Omega parameter is fairly close to 1, as the big-bang theory predicts.

blobrana
08-29-03, 09:00 AM
Hum,
Tnx, for the correection...

Dark energy is totally differant to dark matter, me thinks....
;)