Big bang why do you think it happened?

Answer 1

It may be possible that the big bang occured due to the coming up of anti matters closely due to a possible anti-dark-matter althouth physicists believe that events before the big bang cannot be predicted.

Answer 2

Jesuit priest Georges LeMaitre developed Big Bang Cosmology (BBC) when he noted that the equations for general relativity allowed for an expanding universe or a contracting universe, but not for the infinitely steady universe that Einstein believed in. He also suggested that the red shift seen for distant nebulae (which later turned out to be galaxies) could be explained by such an expansion. When Edwin Hubble showed that all distant galaxies have a red shift exactly as predicted by BBC, many scientists accepted LeMaitre's ideas.

Scientists now accept BBC as true for the same reason they accept gravity between planets: the idea matches observations, and alternatives to that idea fail to do so. BBC perfectly explains several undeniable observations about our Universe, and other cosmologies (such as Steady State) either predict we shouldn't observe them or fail to provide any explanation for them.

Plain and simple, BBC "wins," all other ideas fail.

Answer 3

The Big Bang theory posits that the universe began as a singularity that rapidly expanded about 13.8 billion years ago. This theory is supported by evidence such as the cosmic microwave background radiation and the redshift of galaxies moving away from each other. While the exact cause of the Big Bang is still unknown, current scientific understanding suggests that it was a natural event that initiated the formation of the universe as we know it.

Answer 4

Me? Because it's the model that fits the available evidence.