(September 16, 2021 at 2:44 pm)Klorophyll Wrote: polymath257
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And in such a universe, there would be no causality.
Quote:There you go, dodging my request again:
I need a reference stating that causality is a physical law, as you said pages ago, and a demonstration of the assertion above: that a lawless universe could violate causality.
I can wait.
The only law of causality that I am aware of is the one in quantum field thoery that states that specetime events not in the future light cone are independent. That is a natural law.
Quote:(September 14, 2021 at 12:28 pm)polymath257 Wrote: No, the universe is NOT an element of that causal chain. The causal chain happens *within* the universe.
Um, what are you even talking about? The entire discussion was about what caused the universe, which means the universe is the last element of the causal chain.
And my claim is that this is impossible. Causes happen *within* the universe. that means the universe as a whole is uncaused.
Quote:(September 14, 2021 at 12:28 pm)polymath257 Wrote: And what makes it impossible to have an infinite sequence of events preceding something? it seems like a perfectly sensible thing to me.
What makes it impossible is that this something will never happen. In order to get to this something(S), an infinite amount of events should occur, which takes, in turn, an infinitely long amount of time to get to S. And since an infinitely long period will never elapse, S will never exist.
Again, you just state it cannot happen. But if an infinite amount of time has already elapsed at any point in time (which is what happens if there is no beginning), then your claim fails.
I agree that there cannot be an infinite amount of time between two events, but that doesn't mean the total amount of time can't be infinite.
Quote:That's why an eternal past is impossible, an eternal past is by definition an unending period in the past, and any unending period can't have a present moment occuring after it, because it takes eternity for this past to "end".
In this case, it is ending, but not beginning. it is an infinite amount of time that ends now.
There is nothing inherently illogical about an infinite past.
Quote:I agree, classical logic is enough. But that doesn't mean that quantum logic hasn't been studied and been found useful. For that mater, so have paraconsistent logics.(September 14, 2021 at 12:28 pm)polymath257 Wrote: Yes, we absolutely observe the law of excluded middle at the classical level *and* its violation at the quantum level. it is a matter of observation whether logic with the law of excluded middle is helpful or not. There are versions of logic without it and, for example, quantum logic is found to be useful.
No, you're absolutely wrong. I assume you're referring to an object's ability to be in two places at once. This is not a violation of the law of excluded middle because, under QM, objects are by definition capable of being everywhere at once, therefore, classical logic still applies to properly formulated sentences about QM.
Quote:QM only shakes up our definitions of objects and how we label reality around us, but once our labels/definitions are accurate, or say, updated, then classical logic will work wonderfully on these definitions.
Quantum logic comes from the vast topic of interpreting quantum mechanics, it eventually fell out of favor.
https://en.wikipedia.org/wiki/Quantum_logic#Criticism
Quote : "The approach of quantum logic has been generally seen as unsuccessful. The eminent philosopher of science Tim Maudlin writes, “the horse of quantum logic has been so thrashed, whipped and pummeled, and is so thoroughly deceased that...the question is not whether the horse will rise again, it is: how in the world did this horse get here in the first place? The tale of quantum logic is not the tale of a promising idea gone bad, it is rather the tale of the unrelenting pursuit of a bad idea.” The entire mathematical complex structure of quantum mechanics is perfectly well-described and clear and understood using classical logic."
Read again: The entire mathematical complex structure of quantum mechanics is perfectly well-described and clear and understood using classial logic.
Yeah , classical logic works.
And I agree. But that doens't mean non-classical logics don't exist and cannot be useful.
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