Astronomy
The universe is literally everything, the sum of all existence. It includes all
matter, like stars and galaxies. The universe also includes all radiation
and all other forms of energy. No matter where or when you exist, you
are a part of the universe, as is everything you experience. There is
nothing outside the universe, because anything that exists is
automatically included in the definition of the universe.
WHERE DID IT ALL BEGAN
a massive expansion ( not
an explosion ) from a
single point. It was the
start of time and the
Universe
has
expanding ever since.
been
WHERE DID IT ALL BEGAN
scientists have noticed an increase in the
wavelength of light ( shifted towards the red
end of the visible light spectrum ) coming
from far away galaxies. Measurements of
red shift show that far away galaxies in all
directions are moving away from us.
Galaxies further away have greater red shift
than those closer which shows that far away
galaxies are moving away faster.
If galaxies are moving away from us that
means they were once closer
• He suggested the idea of the expanding
universe.
• He is considered as the first proponent of
the big bang theory.
• He established the Hubble’s law which
provided an evidence that the universe
was not static but expanding
• They discovered that microwaves with
wavelengths of about 7 centimeters were
present in space.
• These waves were referred to as the
cosmic microwave background (CMB)
radiation.
• It failed to explain how the universe was created.
• It just explains how it evolve and not where it
originated.
• It also failed to explain how the galaxies formed.
• It states that the universe has no beginning and no end.
• It suggests that the universe has always been here and
will always be present.
• It also suggests that the universe always looks the same
in any time or space, but the universe continuously
expands while simultaneously creating matter.
• During expansion, the density of the universe remains constant; hence, the
name steady state.
• It also explains that the rate of the death of stars is equal to the rate of birth
of stars. Hence, as a whole, the universe is not evolving over time.
The steady state
theory
was
proposed
by
Hermann
Bondi,
Thomas Gold, and
Fred Hoyle in 1948
• It is is not parallel with the law of conservation of
energy and mass.
• The discovery of the cosmic microwave background
radiation significantly supported the explanations
given by the big bang theory and led many
scientists to reject the steady state theory in 1965.
• It suggests that the universe is expanding and will
contract once all the energy after the big bang has been
used up, only to expand again once it approaches the
point of singularity.
• It is also referred as the pulsating theory.
• Proposed by Richard
Tolman,
chemistry
a
physical
and
mathematical physics
professor at California
Institute
of
Technology (Caltech).
• It suggests that the universe would collapse
on its own after it reached its full expansion,
which would violate some current laws of
physics, such as the postulated existence of
dark energy