Well... the start of the universe is a very difficult thing to study.

Science has ideas for how the universe started, but they are simply our best ideas for how it might’ve happened given the evidence we can collect.

It really, REALLY helps that the farther away something is from us in the cosmos, the longer it takes its light to reach us. So if something is 5 light years away, the light we are receiving from it now (at the current moment) is a snapshot of how that object was 5 years ago.

This means we can look at the sky and look “back in history” by looking at things that are farther or closer to us.

The farthest we can look is at the “background” of the sky, which is called the cosmic microwave background, and which contains the faintest light from the longest time ago. The different aspects of this imprint—how the energy is distributed, whether it’s uniform or not, etc.—gives us lots of clues.

We also get clues from observations like the expansion of the universe, the formation of stars, fundamental physics, and so on.

The biggest limitation right now is that we do not have a good model of quantum gravity. All the other forces have been united at the quantum scale and we know how they interact at different energies. We just haven’t yet been able to figure out gravity.

A big discovery was finding evidence of gravitational waves. We now have to wonder whether there exists a particle that mediates the force of gravity much like the photon mediates the electromagnetic force (plus the other gauge bosons; the gluons for the strong force that “glues” nuclei together, and the W and Z bosons for the weak force... these are some stupid names for sure, but hell, it’s what we’ve got).

Our theories for fundamental physics work pretty well, so it’s a clue that we are on the right track. If your buddy had a model for how he thought quarterbacks could be rated, that would be all fine and dandy... but the moment he was able to start predicting the scores of entire football seasons in advance, you’d think, well maybe it isn’t PERFECTLY accurate but at least it’s pretty damned close!

It is undebatable that using theory alone, we have been able to predict with incredible accuracy the existence of new particles, like the Higgs boson. Technologies like GPS also depend on very complex topics like relativity, so we know that our models are at least “pretty good” if they are able to be predictive and not just descriptive.

This isn’t anything against religion at all. The two are not mutually exclusive, and are not in competition.

social accountability, in real time, not evolution. Everyone can see if someone cheats and would not do business with him after.

the second, yes, except it does not mean any specific personal moral god did it.