The Really Big Bang
by Dr. Richard Muller
Professor of Physics
University of California, Berkeley
To begin Dr. Muller's talk you can click here or read this brief overview, below, that provides links to the best places in the talk for specific topics.
There are more galaxies in the universe than stars in the Milky
Way and there are an estimated 10 billion stars in the Milky
Way. What Hubble observed is that all these galaxies
are moving away from us and that the ones that are further away
are moving away faster. We seem, from our vantage point on Earth,
to be the center of the universe; however, from any perspective
in the universe, galaxies appear to be moving away. Really, there
is no center to the universe.
The universe began in an explosion we call the Big Bang.
This was not an explosion of matter into a previously empty space,
but an explosion of space itself. When did the Big Bang occur?
By using the velocity at which galaxies are moving it is possible
to calculate the time when everything was on top of everything
which is estimated to be 10 to 20 billion years ago. This early
universe was extremely dense and hot according to Gamov.
An important confirmation of the Big Bang is the discovery by
Penzias and Wilson of microwave radiation--a 4000 megahertz
signal coming from distant space associated with what appears
to be a black body spectrum. By measuring the uniformity of
this radiation, we can ascertain whether or not the Earth
is moving. Penzias and Wilson measured a red shift to this radiation
confirming the Big Bang.
Determining the dominant matter of the universe is the
key to understanding it. This is one of the outstanding issues
of science. Probably 10 to 20 percent of matter is made out of
protons, neutrons, and electrons; the rest we don't know.
Another issue: Matter is slowing down. Will it eventually fall
back in? The current research suggests that the universe will