2. What happened before the Big Bang?
The universe came into existence approximately 13.799 billion years ago. Its origin is still shrouded in mystery. Many theories have been proposed and none has been able to completely explain the events that led to the formation of the universe as we know it today.
Big Bang and Cosmic Inflation
The current explanation relies on the Big Bang Theory. In simplified terms, the universe initially existed as a hot and dense mass of energy that expanded and subsequently cooled. This initial hot, dense state is called the Plank Epoch that lasted a mere 10-43 seconds. Scientists have suggested a phase of initial exponential spurt called ‘Cosmic Inflation’ before gravity modified the expansion to its present state.
Stephen Hawking and James Hartle proposed the ‘No Boundary Proposal’ that indicated that the cosmos was shuttle-cock shaped and the universe expanded from the tip that had zero diameter. They derived a formula that described the whole shuttle-cock called the ‘wave function of the universe’ covering the past, present and future all at once. Therefore, Hawkins is said to famously have said that asking what came before Big Bang was like asking what lies South of the South Pole. There is no notion of time as per this theory.
Chaotic Inflation Theory
As per this theory, there exists a multitude of universes. Each universe births out inflationary bubbles, each of which becomes a universe and this process repeats endlessly creating an immeasurable multiverse.
Black Holes
Some scientists believe that our universe was created inside a black hole and the black holes we see in our own universe are a source of more universes. Theoretically, hence, our universe is a white hole derived from a black hole in another universe. A white hole, hypothetically, is an opposite of a black hole, releasing energy and matter instead of drawing it inwards.
Big Bounce
This theory suggests that a small smooth universe gradually expands and becomes warped and clumpy. After a point it will start to collapse on itself going back to its original smooth shape and size and the cycle will repeat.
We have always been intrigued by our origins. We hope that the advances in science and technology will someday give us the answers we desire. Till such time we must focus on sustaining and promoting life on our planet that is but a speck in the vast expanse of the universe.