Download How and when did the universe begin

How and when did the universe begin?
The Big Bang
Adherents of the Big Bang believe that this small but incredibly dense point of
primitive matter/energy exploded. Within seconds the fireball ejected matter/energy
at velocities approaching the speed of light. Where in the sky each galaxy lay didn't
matter—all were redshifted. Some galaxies showed just a slight redshift.
An Expanding Universe
So if all the galaxies are moving away from Earth, does that mean Earth is at the
center of the universe? The very vortex of the Big Bang? Since the Big Bang
explosion, they reason, the universe has been expanding. Space itself is expanding,
just as the cake expanded between the raisins in their analogy. Galaxies farther from
you move faster away from you, because there's more space expanding between
you and those galaxies. That's how Big Bang theorists explain why light from the
more distant galaxies is shifted farther to the red end of the spectrum. In 1965 two
scientists made a blockbuster discovery that solidified the Big Bang theory. Since the
Big Bang affected the entire universe at the same moment in time, the afterglow
should permeate the entire universe and could be detected no matter what direction
you looked.
How Lumpy Do You Like Your Universe?
The Big Bang model is not uniformly accepted, however. One problem with the
theory is that it predicts a smooth universe. Instead of an even distribution of matter,
the universe seems to contain great empty spaces punctuated by densely packed
streaks of matter.
Big Bang proponents maintain that their theory is not flawed.
The Steady State Theory
But the Big Bang is not the only proposed theory concerning our universe's origin. In
the 1940s a competing hypothesis arose, called the Steady State theory. This theory
didn't depend on a specific event like the Big Bang. The Big Bang predicts that as
galaxies recede from one another, space becomes progressively emptier. The
Steady State theorists admit that the universe is expanding, but predict that new
matter continually comes to life in the spaces between the receding galaxies.
Naturally, continuous creation of matter from empty space has met with criticism.
Astronomers can figure out how old a galaxy or star is by measuring its distance
from Earth. Since astronomers haven't found quasars that formed recently, they
conclude the universe must have changed over time.
The Plasma Universe and Little Bangs
Not happy with either the Big Bang or the Steady State theory? A minority of
astronomers are formulating other views of the creation of the universe. Called the
Plasma Universe, his model starts by noting that 99 percent of the observable
universe (including the stars) is made of plasma. This theory states that the Big
Bang never happened, and that the universe is crisscrossed by gigantic electric
currents and huge magnetic fields.
In the Plasma Universe, galaxies come together slowly over a much greater time
span than in the Big Bang theory, perhaps taking as long as 100 billion years.
Meanwhile, another group of astronomers is developing a steady-state theory that
actually conforms to astronomical observations. Like its predecessor, this steadystate theory proposes a universe with no beginning and no end.
The End of the Universe
Will the universe continue expanding?