I think you're not grasping the concept. We don't know that math and physics were the same. The universe following the BB was extremely different for millions of years. BB shows that it was. So, why would anybody think that math and physics operated the same back then, since the rest of the universe didn't. It's right in the BB Theory.
Our knowledge hasn't changed about BB. We still don't know if it existed or if it didn't.
Let me explain it like this. Imagine that our universe started, say, 5 million years ago. How did it start? Let's call the method XXXXX Beginning. And let's say that math and physics, and XXXXX, were extremely different. But they rolled along according to whatever path they were taking, all of them gradually changing.
Today we have our math and physics... which was very different than the math and physics of XXXXX beginning times.
We use our math and physics to try to determine what the beginning of the universe was like. We come up with BB, 13.5 billion years ago. We don't know any different, because we don't have a clue for a method for determining the what changes that naturally, slowly, came about in math and physics really were. There is no way to tell what math and physics changes might have been.
BB is a nice science fiction dream. Even if BB were completely true and real, we don't have any way of knowing. And BB Theory suggests that BB math and physics were different from today, just as the BB universe is different from today's universe.
Because the laws of physics don't change. I have no idea what math has to do with anything.
It's borderline stupid to think 'we don't know' physics don't change when there's not a slightest indication it could be true.
That's untrue, it was always the same. We can only discover new laws that we didn't know before and that make things possible that were possible all along but we didn't know about it.
Time dialation for example.
Just because we discover new laws doesn't mean they didn't apply before. We just didn't know about them.
There were no changes.
We do.
All the planets&systems are expanding in a certain direction at a certain speed.
If we reverse the direction they're heading all the planets and all matter that we know off originate to 1 spot. To 1 singularity. From where all of them were propelled in their directions.
That's why it's called the big bang.
Where did you get that idea from?
Ah! At last I found a scientist who knows math and physics, and who took a time machine back a million years, and did all the tests necessary to determine math and physics were the same back then... NOT.
Where did I get that idea from? Read my post you quoted. It tells you right in there. Things were different back at the time of the BB. Why would you believe math and physics weren't different? How can you know? Maybe it's not even a good guess to say that math and physics were the same back then... considering that BB Theory, itself, acknowledges that the whole universe was so extremely different within at least the first 3 million years.