BIG BANG THEORY
The Short and Skinny on the Big Bang
The big bang theory describes the development
of the universe from the time just after it came into existence up to today.
It's one of several scientific models that attempts to explain why the universe
is the way it is. The theory makes several predictions, many of which have been
proven through observational data. As a result, it's the most popular and
accepted theory regarding our universe's development.
The most important concept to get across when
talking about the big bang is expansion. Many people think that the
big bang is about a moment in which all the matter and energy in the universe
was concentrated in a tiny point. Then this point exploded, shooting matter
across space, and the universe was born. In fact, the big bang explains the
expansion of space itself, which in turn means everything contained within
space is spreading apart from everything else. The illustrations below should
help a little.
Today, when we look at the night sky, we see galaxies separated by what appears to be
huge expanses of empty space. At the earliest moments of the big bang, all of
the matter, energy and space we could observe was compressed to an area of zero
volume and infinite density. Cosmologists call this as ingularity.
What was the universe like at the beginning of
the big bang? According to the theory, it was extremely dense and extremely
hot. There was so much energy in the universe during those first few moments
that matter as we know it couldn't form. But the universe expanded rapidly,
which means it became less dense and cooled down. As it expanded, matter began
to form and radiation began to lose energy. In only a few seconds, the universe
formed out of a singularity that stretched across space.
One result of the big bang was the formation
of the four basic forces in the universe. These forces are:
·
Electromagnetism
·
Strong nuclear force
·
Weak nuclear force
· Gravity
At the beginning of the big bang, these forces
were all part of a unified force. It was only shortly after the big bang began
that the forces separated into what they are today. How these forces were once
part of a unified whole is a mystery to scientists. Many physicists and
cosmologists are still working on forming the Grand Unified Theory,
which would explain how the four forces were once united and how they relate to
one another.
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BLAME
THE NAME
Confusion about the big bang is partly due
to its confusing name -- it sounds like it should be an explosion. Blame that
on Sir Fred Hoyle, a critic of the theory, who dismissively called the model
a "big bang" as an insult. The derogatory comment caught on and the
name stuck.
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We'll take a look at where the big bang theory
came from in the next section.
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