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1.
THE UNIVERSE
For thousands of years humans have wondered about the composition and origin
of the Universe. The science that studies the origin and evolution of the Universe
is
astronomy
.
1.1.
The origin of the universe
Throughout history, astronomers have suggested different hypotheses to explain
the origin of the Universe. Today, the theory most widely accepted by scientists is
the Big Bang theory.
1.1.1.
The Big Bang theory
According to this theory, before theUniverse originated, all matterwas concentrated
in one point. There was so much matter and energy accumulated in this point that
the temperature was extremely high.
As a consequence, there was a
huge explosion
13700 million years ago and
this is the origin of everything that exists. Matter was released in all directions
and the Universe expanded rapidly, in less than a second
Since then, the expansion of the universe has not stopped, although it expands
at a slower rate.
The
Universe
or
Cosmos
is defined as everything that exists.
In the expansion phase the first atoms were formed, such as hydrogen and
helium, and the first molecules that were mainly gaseous. Matter and energy
started to group together in certain areas of the Universe. This is how the first
stars formed, that joined to form galaxies and the other bodies in the Universe.
The expansion of the Universe
Analyse
1.
What would happen
if we painted some
galaxies on a balloon
and we continued to
inflate it? What would
happen to the galaxies?
Would they get closer
or further apart?
As the
universe expanded
, the first atoms, hydrogen
and helium, formed. During this process the first
molecules also formed.
