I am doing a presentation on the big bang theory in my religious moral and philisophical studies class at school. We are looking into the arguements of the big bang theory, the strengths and the weaknesses.

One arguement I would like to look at is the red shift, but i don't completly understand it. Am I right in saying it is to do with the differences in frequency of red light to blue?

It is to do with genreal relativity isn't it?

I would like to know a bit about it, and also i would love to know its weaknesses.