Heated debate on evolution with brother

[Alex K]

The big bang is still happening. At an ever accelerating rate.

It's true. When scientists talk about the big bang, they usually mean a whole range of very early times in the universe, not some singular initial point which arguably never occurred anyway, for which we have no reliable theory or much in the way of data, and which is more like a mathematical reference point than a real beginning. Which times you still include in the "big bang" is not really strictly defined. For example, Big Bang Nucleosynthesis, the creation of the first primordial chemical elements, takes place over the course of minutes. I think most would agree that once recombination happened and atoms were formed, the big bang as such is over, but that's 400 000 years after the mathematical singularity!