"What is going to
happen?” is something everyone of
us are interested in. All of us want to know what is future. By All I also mean
science lovers. Science lovers are interested in finding the future of
universe, I mean the ultimate fate of
universe.
Our scientists are
working on it. According to them the Ultimate fate can be determined by three
values:
 |
1. The rate at which our universe expands. This is called Hubble’s constant. It was named after famous astronomer Hubble who
actually measured the expansion of the universe.
Here we must also discuss about Metric Expansion of Space. It refers to the increase in distance
between two distant parts of the universe with time. We can say the scale
itself changes with time.
2. Density Parameter Ω (Omega) or the average density of matter in our universe.
Ω = Ωm + Ωrel + Ωλ
Total Density Parameter is the sum of total mass density of
ordinary and dark matter and total density of relativistic particles such as
photon and neutrinos and effective mass density of dark energy.
3. Lambda or the cosmological constant of our universe. This term was introduced by Albert Einstein in 1917.
| One thing we must understand is that omega which is density of matter can also be defined in terms of gravity (as the gravitational force is determined by mass of the body). Now let us look at few possible scenarios taking lambda to be about zero: |
1. Omega greater than one
This means that there is
sufficient matter in universe to generate enough energy to reverse the
cosmological expansion of universe. This means universe will start shrinking.
Let's name this big
crunch.
It has also been
observed that if this is the case the curvature of universe is negative,
something similar to a saddle and space and time are infinite. Such a universe
is called open.
 |
2. Omega less than one
This means that there
isn't sufficient matter in our universe to reverse the cosmological expansion.
This means universe will expand forever. As universe keeps expanding the
temperature will start falling. Hence the ultimate fate of universe will be big freeze or big chill.
It has also been
observed that if this is the case the curvature of universe is positive,
something similar to a sphere and space and time are finite. Such an universe
is called closed.
3. Omega exactly equal to
one
If omega is equal to one
then universe is flat and will expand forever. However the matter present in universe is just
sufficient enough to maintain the temperature, not leading to big freeze.
