Maslo has answered the OP's question well enough... but there is one thing I want to reply to...
Originally posted by VariableConstant
I have a very intelligent friend who asked me a good question the other day, as we were debating the currently accepted theory as to the creation of
the universe. He talked about black holes, which as far as we know are nothing more that incredibly dense matter that have such a pull that nothing
can escape from them, not even light. So if you consider that, according to the bang theory, all matter in the universe, including all the stars,
collapsed or otherwise, along with all the planets and everything else, were once concentrated into a "primordial egg."
This ball of matter would contain everything that currently makes up our universe, and would therefore have a mass and density beyond our ability to
comprehend. Its gravitational pull would be inescapable. So how could anything ever escape from this central point, regardless of the violence of any
explosion?
I'm not an astrophysicist, so maybe someone else would be able to answer this, but it seemed like a pretty good question to me.
Your friend should familiarize himself with cosmology theories that aren't 60 years old.
The current "Big Bang" theory is, in fact, not a Big Bang theory at all. It's called LCDM (Lambda - Cold Dark Matter) Cosmology. "Lambda" refers to
the Cosmological Constant of Einstein's field equations, which is responsible for the expansion of the universe and is the mathematical description of
what is now called Dark Energy. "Cold Dark Matter" refers to the addition of additional matter-density that is undetectable by traditional means, and
is responsible for anomalous galaxy rotation curves.
LCDM says that, in the beginning (so-to-speak), it was very possible that the universe was infinite. In fact, my preferred view is that the universe
was an infinite void, containing nothing at all. The difference between this empty universe and our current universe, though, is its level of
zero-point energy. This energy is found in Quantum Mechanics, and is the energy contained within a vacuum. That is, in QM, a vacuum is not a
region containing absolutely nothing, as we often consider it to be - a vacuum is, in fact, a region having the lowest possible energy level. I tend
to liken this to walking on the ground. When you walk along the ground, you are effectively at your lowest possible energy level. But, what happens if
you happen upon an abandoned mine shaft and fall through? Suddenly, your once-"lowest possible energy level" has collapsed to an even lower "lowest
possible energy level." Essentially, this is what modern cosmology says occurred within that original universal void.
When the vacuum of that initial void spontaneously collapsed to a lower energy level, the potential (zero-point) energy it had been containing was
released, and this massive release of energy is what drove that initial sudden period of rapid inflation (during what's called the Inflationary
Epoch). Eventually, once the energy had dissipated enough for the inflation to slow significantly, the universe was allowed to cool, and the energy
condensed to form particles and, ultimately, matter.
This is the current theory. Now you can bring your friend up-to-speed.
edit on 19-7-2011 by CLPrime because: (no reason given)