The-big-bang

The big bang

     About 14 years ago, the
universe materialized out of unknown reasons. Infinitely smaller than an atom
to begin with, the universe expanded to a trillion kms across  in under a second-an event called the big
bangTime cameb into existence
when the universr begen, so the questions ‘’what happened before?’’ has no
meaning. Space also came into existence. The big bang was not an explosion of
matter through space- it was an expansion of space itself.At first the universe consisted of
pure energy , but within a trillionth of a second some of this energy turned
into matter, forming a vast soup of subatomic particles(particles smallerthan
atoms). It took nearly 400,000 years for the particles to cool down  enough to form atoms, and then another 300
millon years before the atoms formed planets stars, and galaxies. The expansion
that began in the big bang continues to this day, and most scientists think it
will carry on forever.

 The expanding universe

     The illustration below does
not show the shape of theb universe, which is unknown. Instead, it is timeline
that  shows  how the universe  has expanded 
and changed  since the big bang we
know the universe is expanding because the most distance galaxies are rushing apart
at fantastic speeds. By running the clock backward, astronomers figured out
that the expansion began 13.8 billion years ago at a single point: the big
bang.

Discovery of the big bang

     The first scientific evidence for the big bang was found in
1929, when astronomers discovered that light from  distant galaxies is reddened. This color
change  happens when  objects are moved away  from us, the more distant the galaxies are,
the faster they  are rushing  away. This shows that the whole universe is
expanding.

Big bang afterglows

      More evidence of the big bang came in  the 1960s, when  astronomers detected faint  microwave radiation coming from every point
in the sky. This mysterious energy is the faded remains of the instance burst
of  energy released in the big bang.

Changing elements

     For hundreds of 
millions of years, the universe consisted almost entirely- the very
hydrogen simplest chemical elements. 
After  stars  appeared, new elements began  to be made in the cores of  dying stars. All the complex in our bodies  were 
forgot in dying  stars this  way.

Big  bounce theory

    What  caused  the big bang? We may never  know for 
sure, but   some scientists have
suggested that  there may have been  lots 
of big bang .ex: universe expands , big bang , universe shrinks.