Freethought & Rationalism Archive

sophie · 07-05-2003, 10:27 AM

Hi ya all again,

Does anyone have the percentage breakdown of the composition of the universe.

(1) What percentage of the universe would be visible.

(2) What percentage are all those protons and atom stuffing.

(3) What percentage is mass and what percentage is pure energy.

(4) Any other facinating information which is available.

Jesse · 07-05-2003, 10:51 AM

For #1, I believe the current best guess is that the universe is probably "flat" (Euclidean geometry) and infinite in size, which would mean the visible universe is just an infinitesimal fraction of the universe as a whole. As for #2 and #3, the recent Wilkinson Microwave Anisotropy Probe (WMAP) allowed cosmologists to refine their estimates of things like the percentage of mass/energy made up of atoms:

http://www.cnn.com/2003/TECH/space/0...smic.portrait/

Quote:

By measuring temperature variations in the microwaves, down to a millionth of a degree, scientists on the WMAP team were able to create a picture of the early universe, before galaxies and stars were even formed.

With those findings, scientists were able to make the most precise calculations yet about the age and make-up of the universe, including:

-- The universe formed about 13.7 billion years ago, give or take about 200 million years.

-- Only about 4 percent of the universe is composed of atoms -- the "ordinary matter" making up the physical universe we know. About 23 percent is "cold, dark matter," about which scientists know little, and 73 percent is "exotic dark energy," about which they know even less.

-- The first stars were "turned on" within about 200 million years of the "big bang" -- much earlier than scientists had previously believed.

-- The geometry of the universe is flat, and WMAP's measurements support an "inflation" model, which holds that the universe formed with the "big bang" and expanded rapidly over a short period of time, before slowing to the rate of expansion seen today.

That expansion will continue, said Dr. Charles Bennett of NASA's Goddard Space Flight Center.

"The universe will expand forever. It will not turn back on itself and collapse in a great crunch," he said.

glycolysis · 07-08-2003, 02:19 PM

I think the idea that only one electron exists, moving foraward and back through time creating reality is pretty fun concept to entertain.

I read about it in a Kaku book (Beyond Einstein). I'll look up the relevant info and hand it back. They also mention the composition of the universe, which If Im not mistaken is about <10% visible. I also think they where proposing an expanding spherical universe on which our 3 dimensions exist.

I would double check anything Ive posted rather than take it for fact, though...Im kinda dense.

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07-05-2003, 10:27 AM	#1
sophie Veteran Member Join Date: May 2003 Location: On the road to extinction. . . Posts: 1,485	Universe make-up Hi ya all again, Does anyone have the percentage breakdown of the composition of the universe. (1) What percentage of the universe would be visible. (2) What percentage are all those protons and atom stuffing. (3) What percentage is mass and what percentage is pure energy. (4) Any other facinating information which is available.

07-08-2003, 02:19 PM	#3
glycolysis Junior Member Join Date: Mar 2003 Location: earth Posts: 7	I think the idea that only one electron exists, moving foraward and back through time creating reality is pretty fun concept to entertain. I read about it in a Kaku book (Beyond Einstein). I'll look up the relevant info and hand it back. They also mention the composition of the universe, which If Im not mistaken is about <10% visible. I also think they where proposing an expanding spherical universe on which our 3 dimensions exist. I would double check anything Ive posted rather than take it for fact, though...Im kinda dense.

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