Quantum Bounce

by Jack H

(image source: Jeremy Thomas)

Imagine a basketball being dropped onto level ground. It falls, bounces and rebounds almost to where it began, its origin. In space, when a star or black hole collapses, something very similar can happen. For example, as a black hole gets older, its interior gets stretched out and compressed down until it reaches a point where this cannot happen anymore. The black hole's interior becomes a long line of matter that can no longer be condensed nor stretched, this is called the Planck length and at this point only one thing can happen; the black hole bounces, exactly like our basketball and begins to expand again, the same process reversed in time. This is called a quantum bounce. 

The universe is expanding. What if this is the aftermath of a big contraction of the universe and we exist within the bounce? If the universe ends its expansion (possibly by equilibrium being reached) will it begin to contract and return to its origin, only to repeat this process again? Or is there only one quantum bounce and that is what created our universe in what we call The Big Bang? 

This theory has been deemed The Big Bounce and inflationary theory suggests that we could be one of a possibly infinite number of bubble universes, completely separate from one another, undergoing the same process of repeated contraction and expansion. The contraction that resulted in the birth of our universe could have been that of an old universe, another universe with entirely different fundamental laws and characteristics. However, this may just be a theory…