1 Does our universe owe its form to the properties that were inherent in the ‘primeval atom’? — Jacob-B

Someone with a better background in physics can probably answer this with more certainty than I can, but so far as I am aware the answer for empirical reality is yes.

2. Could there have been other ‘inputs’ post the Big Bang and unconnected to it that shaped the
universe? — Jacob-B

It would beg the question where those inputs are supposedly from. In any event, this wouldn't make the universe any less deterministic.

The Big Bang is just one model for how the universe came into existence, there are others.

I think since probability exists hard determinism is incorrect. Current physics uses the Schrodinger cat experiment to make this apparent. The cat is either alive or dead, there is no certainty, no hard determinism, no omnipresent observer making all things certain and predetermined. This of course is just theory too.

This morning I decided to drink a cup of tea with my breakfast, it was departing from my habit of drinking coffee. It seems to me that I arrived at this momentous decision freely being under no duress whatsoever to do so, I even had a rationale for that decision having read somewhere about the health benefits of drinking tea. However, that is not the way a determinist would look at my decision — Jacob-B

Why?

I am not asserting determinism, but just want to point out that nothing that you said is in any tension with determinism.

. The cat is either alive or dead, there is no certainty, no hard determinism, no omnipresent observer making all things certain and predetermined. — Josh Alfred

I've always questioned why the cat isn't dead or alive just because we don't know if it is. Just because we don't know a true/false value doesn't mean one doesn't exist. We have no evidence that the universe doesn't exist without an observer. I think that in our mind the variable is unknown, but there is a correct answer, us knowing it or not doesn't change that.

I've always questioned why the cat isn't dead or alive just because we don't know if it is. Just because we don't know a true/false value doesn't mean one doesn't exist. We have no evidence that the universe doesn't exist without an observer. I think that in our mind the variable is unknown, but there is a correct answer, us knowing it or not doesn't change that. — TogetherTurtle

You may think that, but there is no evidence for it. And when we talk about the physical reality, evidence is all that ultimately matters. Schrödinger's Cat is a thought experiment, but there have been plenty of experiments that all confirm the notion. Including experiments that specifically tested whether you can trick photons to reveal the hidden variable that determines their state, but you can't. Either the universe looks into the future and sabotages our attempts to find this hidden truth by telling the particles to act differently, or it really is a probability distribution.

And by "it really is" I of course mean "in reality as observed by humans".

I think since probability exists hard determinism is incorrect. Current physics uses the Schrodinger cat experiment to make this apparent. The cat is either alive or dead, there is no certainty, no hard determinism, no omnipresent observer making all things certain and predetermined. This of course is just theory too. — Josh Alfred

Just because there is a range of possible outcomes with certain probabilities, the outcome is not indeterminate. You can still fully describe the state of the universe in quantum mechanics, and hence also future states (in theory, anyways).

According to hard determinism, the universe as it is, down to its most minute and trivial events (like my decision to drink tea rather than coffee) is the result - and the ONLY possible result - of an inevitable chain of a causational event originating at the Big Bang. To my thinking, that implies that somehow the shape of our universe with all its incredible complexity was inherent in the structure of the infinitesimal small sized primaeval atom. That, in turn, implies some sort of DNA- like plan. That, in turn, makes hard determinism uncomfortably resembles ‘creationism’. If the shape of our universe was indeed inherent in the primaeval atom, the determinists need to provide a physics theory of supporting that assumption. I tend to think that the causal chain of the primaeval atom did break down at a certain level of complexity and was replaced by a not strictly causal evolutionary process that doesn't rule out Free Will.

According to hard determinism, the universe as it is, down to its most minute and trivial events (like my decision to drink tea rather than coffee) is the result - and the ONLY possible result - of an inevitable chain of a causational event originating at the Big Bang. To my thinking, that implies that somehow the shape of our universe with all its incredible complexity was inherent in the structure of the infinitesimal small sized primaeval atom. — Jacob-B

Well it implies that all information was always present in some form, yes. Conservation of energy and conservation of information. I don't think the big bang theory assumes a "very small atom", it assumes that space itself was created. It's not a small particle, it's a state without spatial dimensions.

That, in turn, implies some sort of DNA- like plan. That, in turn, makes hard determinism uncomfortably resembles ‘creationism’. If the shape of our universe was indeed inherent in the primaeval atom, the determinists need to provide a physics theory of supporting that assumption. — Jacob-B

All the laws of physics are based on that assumption.

I tend to think that the causal chain of the primaeval atom did break down at a certain level of complexity and was replaced by a not strictly causal evolutionary process that doesn't rule out Free Will. — Jacob-B

How does this not strictly causal process interact with the strictly causal processes we observe?

You may think that, but there is no evidence for it. And when we talk about the physical reality, evidence is all that ultimately matters. Schrödinger's Cat is a thought experiment, but there have been plenty of experiments that all confirm the notion. Including experiments that specifically tested whether you can trick photons to reveal the hidden variable that determines their state, but you can't. Either the universe looks into the future and sabotages our attempts to find this hidden truth by telling the particles to act differently, or it really is a probability distribution. — Echarmion

I think that probability has a say in it, but I don't think it has to be observed or at the very least just by a human. Generally, most things happen the same way whether we look at them or not. I'm aware that in quantum physics that can be very different. I'm more partial to believe that things are determined but we just don't know why, because that's always how it's been before. When we didn't know why certain planets didn't obey predictions based off of the theory of gravity we genuinely didn't know why, and while that was troubling, further study led to the creation of the theory of relativity and most of those problems went away. Of course, I'm no professional historian or scientist (at least not yet) so there's a good chance that I am missing something, but to me, that seems like the general pattern.

As for my thoughts on probability, I think it is a reflection of how little we really know about the world. If we knew everything, including hidden variables, we wouldn't need probability because we could speak in absolutes. Maybe this could be a way to test if we really know everything about a subject, keep testing it and see if it does anything strange.

The only way to know anything for sure is to find these hidden variables that seem to be so stubborn. I think that someday we will find out what these are. More abstract things have been found by less well-equipped scientists. Until then, maybe the cat is in a superposition. I just hope that hurts less than death, for the cat's sake. But then again, I would assume you know more than me. It's generally good to assume you are going to learn when talking to others rather than assuming you will be teaching.