I’m trying to learn about the Big Bang for my study of the KCA. Here’s what I’m wondering.
The universe is expanding, so if we just extrapolate back, everything goes back to a point called a “singlularity” (apparently some are skeptical of the singlularity, but I won’t get into that now). However, all I can conclude from this is that the singularity was there and it suddenly expanded. What justifies me in saying the universe came into being, which brings up images in my mind of the singularity appearing from nothing and expanding, instead of just saying it’s always been there?
With our current theories, we can’t know much about the Planck era, the first 10−43 second of the universes expansion. So how do we know how long it is, and how can we say there was a singularity or that everything came from nothing when we currently don’t know much about this period of the universe?
I’d appreciate the help. I’d also like to know any good resources on this topic.