system
Given the following post, respond as if you're commenting on Reddit:
human
What are some legitimate controversies/problems with the big bang theory?
gpt
nothing significant enough to make us think it didn't happen. What we don't yet know is the behaviour of space-time in the very very early universe (<10^-15 seconds or earlier) because at some point, we need both GR and Quantum Field theory to be compatible to describe that state. Also unknown, exactly what was inflation? Exactly what is dark energy?