[chongli]

creatio ex nihilo

“At first there was nothing, then out of nothing the Big Bang happened and the universe began” is a popular misconception of the Big Bang theory. It’s completely wrong.

The Big Bang theory does not attempt to explain what things were like “before” the Big Bang. It’s not a theory of creation at all! It only offers a model starting with the inflationary epoch, when the universe was already expanding rapidly.

Prior to that, our existing theories break down and we need a different physical theory (commonly called the Grand Unified Theory or GUT). We don’t have it so we can go no further back.

The point is: back in the inflationary epoch the universe was all there, it was just much smaller. The point of the theory is to try to explain the extreme uniformity (isotropy) in the distribution of galaxies, gas, dust, and light we observe in the universe today (among other things, such as dark matter). It’s a much better model in terms of its simplicity and predictive power than any steady-state model of the universe that has been proposed.

But it’s got nothing to do with creation!

[ezion]

I don't claim to know anything before it either.

All I'm claiming is that before whatever happened, there must have been a mathematical structure that allowed it to happen following certain physical laws. That's just a fact. So these mathematical laws exist before anything. This implies a realm that's not physical. Anything that is contingent such as all material things (why is there anything at all?) must have a prior cause - and that's an assumption of science.

All theories presuppose these mathematical structures.

That is, even if the current big bang is just one in a series of several, or however else you try to explain existence, you have to presuppose the mathematical structure that forces it to follow certain physical laws.

I also don't think you fully understand inflation and why it's been proposed but I'll ignore it since it's not useful for the conversation. Also read up on the Borde-Guth-Vilenkin theorem as it basically proves that a beginning is necessary.

In addition, note that right now it seems almost certain that the universe had a beginning and any other explanation is not evidence based.

[Koshkin]

> That's just a fact.

No,

> That's, like, just your opinion man ;)

[ezion]

If the mathematics is not a priori, one must explain why it is the case particles follow particular mathematical laws instead of moving about randomly without any particular logic to them. How do these elementary particles know what to do and have always known?

[chongli]

particles follow particular mathematical laws

We don’t know that they do. We assume they do, but our laws are not their laws.

You’re like the person who sees a birdwatcher recording their observations and asking “why do birds exist?” You’re asking the wrong question to the wrong person and demanding satisfaction.

[chongli]

these mathematical laws exist before anything

You might want to study a bit of philosophy of mathematics, particularly the bit on the realism vs anti-realism debate. A great deal of people fall into the anti-realism camp, and they would disagree rather vociferously with your statement about “mathematical laws.”

[ezion]

Can you explain why it is not the case everything happens at random? Why these particles seem to follow physical laws?

Realism/Anti-Realism has no bearing to the matter. I personally think mathematics is a priori and non-causal, and not necessarily correspondent to the real world. This would imply I'm technically an anti-realist. Certain mathematics correlates to the real world, others do not and are simply (interesting) mathematical structures.

Neither viewpoints can explain why certain mathematical statements actually correlate to reality. Mathematical entities are not causal - they do not have any causal connection to the real world since they are (obviously) abstract.

Maybe a good place to start thinking about this problem would be to read Wigner's work "The Unreasonable Effectiveness of Mathematics in the Natural Sciences".

[chongli]

Can you explain why it is not the case everything happens at random? Why these particles seem to follow physical laws?

What does random mean? Are you asking why the universe appears to be consistent and intelligible at all? Where would we be if it weren’t?

The weak anthropic principle covers this nicely. Perhaps it is an unsatisfying answer, but scientists and mathematicians aren’t usually in the business of answering ontological questions.

Maybe a good place to start thinking about this problem would be to read Wigner's work "The Unreasonable Effectiveness of Mathematics in the Natural Sciences".

I have studied all of this. Wigner’s account is very important for the debates it inspired but it’s far from the last word on the topic. There have been numerous replies addressing all of Wigner’s claims. Try reading Hamming’s replies to start.

[ezion]

The anthropic principle has nothing to do with why complex numbers are necessary for doing quantum mechanics. Complex numbers are purely abstract objects and yet are necessary for giving a proper account to the real world.

"From all of this I am forced to conclude both that mathematics is unreasonably effective and that all of the explanations I have given when added together simply are not enough to explain what I set out to account for." - Hamming

[chongli]

Most of mathematics has no use whatsoever in physics. Physicists select the mathematical tools that best enable them to build their models. In other cases, the necessary tools do not exist and they are built for purpose.

In many cases, physicists are not so successful. Look at the current debates in particle physics and the grand unified theory. Progress has largely stalled.

In other cases, models are revised continually as new information comes to light. For example, the age of the universe as we know it may double [1] from 13.79 billion years to 26.7 billion years.

You might call this “unreasonable effectiveness,” I call it a process of messy refinement and rethinking over thousands of years, much of it later shown to be invalid, despite mathematical correctness.

[1] https://phys.org/news/2023-07-age-universe-billion-years-pre...