Question

Discuss the big bang theory of the universe:

Why do we believe the Universe had a beginning?

What is the evidence that the Universe is expanding?

What is dark energy and how is that related to what the Universe looks like and what will happen to it in the future.

What is inflation?

How does Einstein’s theory of General Relativity fit into this?

Is this changing our view of our place in the cosmos as drastically as the Heliocentric theory changed?

What is the multiverse theory and how does it fit into religion?

Answer 1

Big Bang theory states that at t=0 all mass of the universe was centred at one point and that point in the space is called singularity. Then an explosion tak place and then all particle and elements came into the existence.

According to the Hubble's law where v is velocity and d is distance, farthest point movig with higher velocity indicates that at some time in past object in the space were closer in distance and now they moving. It suggest that there is possibility that everything started from one point.

If we observe cosmic microwave background (CMB) photons today they lie in microwave band of electromagnetic radiation and this wavelength is keep on increasing which is a good example to prove that universe in expanding and as stated above Hubble's law also prove expansion of universe.

It is believed that a special type of energy exist in the universe which is yet not possible to detect but provides the force for the expansion of this universe. In future it this energy will expand this universe in larger extent.

In early time of the universe, it expanded exponentially for some time which known as inflation of universe.