Transcript How many atoms make up the universe?

How many atoms make up
the universe?
Only two things are infinite, the universe and
human stupidity - and I'm not sure about the
former. - Albert Einstein
A Typical Star
• mass about 2x1033 Grams
(for example, sun: 1.9891 ×1030 kg)
• 2x1033 x 6 x1023 ~ 1.2x1057 atoms of
hydrogen per star
Typical Galaxy
• A typical galaxy has about 400
billion(4x1011)stars.
• each galaxy has
1.2x1057 x 4x1011 = 5x1068 hydrogen
atoms in a galaxy
in the Universe
• There are possibly 80 billion galaxies
in the Universe,
• the Universe has about
5x1068 x 8x1010 = 4x1079 hydrogen
atoms in the Universe
The Universe has
• the Universe has about
5x1068 x 8x1010 = 4x1079 hydrogen
atoms in the Universe
But this is definately a lower limit
calculation, and ignores many
possible atom sources
Inflation theory says
• A currently popular Inflation Theory predicts that the mass
density of the Universe should be close to the so-called critical
density that separates an open universe that always grows from
a closed universe that ultimately collapses again.
• This critical mass density is currently equal to 9.9x10-27 kg/m3.
(5.9 Hydrogen /m3)
• 4.6% Atoms. More than 95% of the energy density in the
universe is in a form that has never been directly detected in
the laboratory! (0.27 Hydrogen /m3)
• 8×1079 hydrogen atoms. (0.27 Hydrogen /m3 x3×1080 m3)
References
• Hypertext, Mass of the Universe,
http://hypertextbook.com/facts/2006/KristineMcPherson.shtml
• Wahlin, Lars. The Harmonic Universe [pdf]. The Deadbeat Universe.
Boulder, Colorado: Colutron Research, 1997: 27.
• Hopkins, Jeanne. "Universe." Glossary of Astronomy and Astrophysics.
Chicago: The University of Chicago, 1980: 183.
• Lang and Gingerich. A Source Book in Astronomy and Astrophysics.
Massachusetts: Harvard university, 1979: 724.
• Immerman, Neil. Sacramento Peak: The Universe. University of
Massachusetts Amherst. 21 May 2001.
• Ryden, Barbara. Lecture 40: Curvature of the Universe. 6 March 2003.
• NASA WMAP, WMAP- Content of the Universe.