(September 16, 2021 at 4:23 pm)Klorophyll Wrote: The discussion stops here. Once you're past the red line of the laws of thought, you stop being rational. Have a good day.

Ironically, says the one who believes in god.

So I think we can all agree Klor lost in every way possible 


He came in thinking he was this 



When in reality he has shown he's more like this 

(September 16, 2021 at 6:07 pm)Jehanne Wrote:

(September 16, 2021 at 5:50 pm)Klorophyll Wrote: Most physicists believed in the luminiferous aether, too. Have fun arguing from authority, if that makes you feel comfortable.

Yeah, pot meet kettle.

I admit that I might have been misquoting Griffiths earlier (it seemed to me that his proof was one of the integral of the Schrodinger equation being stationary with respect to time, which is what the Quantum Eternity Theorem seems to be saying).  While I have read Griffiths, I have not read Jackson at all (do not even own it), which is probably next on the list in trying to understand non-relativistic QM; from there, things get even worse as one ventures into the realm of QFT, with Peskin and Schroeder being the introductory text for 2nd or 3rd year PhD graduate students in physics.  In any case, Professor Griffiths did state, explicitly, in his book that to talk intelligently about QM, one must first understand the theory and mathematics behind QM.  I do not understand it; I admit that.  But, you're no physicist or cosmologist, either, and neither is WLC, and, neither am I.

You can believe, if you wish, that planets move around the Sun because there are invisible angelic beings who are pushing them along in their orbits.  Ditto for the Universe and its existence.  No physicist thiks that either of those hypotheses are necessary, though.  One thing is for sure -- neither of them are testable and neither of them are productive in terms of observing and/or explaining anything in or about our World.

Jackson is a classical E&M book, not a QM book. Peskin and Schroeder is a monster....It has the difficulty that physicists don't do math well (at least, according to mathematicians). Between Griffiths and P&S, I would suggest something like Bransden and Joachain.

I am a research mathematician and have done the PhD qualifying exams in physics but never did a dissertation.

(September 16, 2021 at 9:47 pm)polymath257 Wrote:

(September 16, 2021 at 6:07 pm)Jehanne Wrote: Yeah, pot meet kettle.

I admit that I might have been misquoting Griffiths earlier (it seemed to me that his proof was one of the integral of the Schrodinger equation being stationary with respect to time, which is what the Quantum Eternity Theorem seems to be saying).  While I have read Griffiths, I have not read Jackson at all (do not even own it), which is probably next on the list in trying to understand non-relativistic QM; from there, things get even worse as one ventures into the realm of QFT, with Peskin and Schroeder being the introductory text for 2nd or 3rd year PhD graduate students in physics.  In any case, Professor Griffiths did state, explicitly, in his book that to talk intelligently about QM, one must first understand the theory and mathematics behind QM.  I do not understand it; I admit that.  But, you're no physicist or cosmologist, either, and neither is WLC, and, neither am I.

You can believe, if you wish, that planets move around the Sun because there are invisible angelic beings who are pushing them along in their orbits.  Ditto for the Universe and its existence.  No physicist thiks that either of those hypotheses are necessary, though.  One thing is for sure -- neither of them are testable and neither of them are productive in terms of observing and/or explaining anything in or about our World.

Jackson is a classical E&M book, not a QM book. Peskin and Schroeder is a monster....It has the difficulty that physicists don't do math well (at least, according to mathematicians). Between Griffiths and P&S, I would suggest something like Bransden and Joachain.

I am a research mathematician and have done the PhD qualifying exams in physics but never did a dissertation.

I was referring to this book:

Mathematics for Quantum Mechanics: An Introductory Survey of Operators, Eigenvalues, and Linear Vector Spaces 

I have not read the other Jackson E&M book, but, have read Griffith's undergraduate E&M.  Thanks for mentioning the E&M Jackson book; I had forgotten about that one.

(September 16, 2021 at 2:44 pm)Klorophyll Wrote: polymath257
[quote pid='2061763' dateline='1631636911']
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:

(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.

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.

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.
[/quote]

@Klorophyll

“The universe either began or did not begin to exist,” is your dichotomy.

What do you mean by “begin to exist?”

(September 16, 2021 at 2:44 pm)Klorophyll Wrote: The no boundary proposal entails that the universe began to exist,

https://en.wikipedia.org/wiki/Hartle%E2%...king_state

QUOTE :However, Hawking does state "...the universe has not existed forever. Rather, the universe, and time itself, had a beginning in the Big Bang, about 15 billion years ago."

If the universe has not existed forever, it began to exist. 

Thanks for sharing Hawking's opinion, but his hypothesis, like the other hypotheses for the origin of the universe, can't be tested yet. If Hawking is right, the universe began to exist from nothing. If Hawking is wrong, a universe that has always existed in some form is still on the table. And there's no way to know if Hawking at this time is right or wrong on this matter.

Arguing from Hawking as an authority on cosmology is at least citing a relevant expert, but the problem is cosmology isn't settled and plenty of eminent cosmologists disagree with him.

(September 16, 2021 at 10:02 pm)LadyForCamus Wrote: @Klorophyll

“The universe either began or did not begin to exist,” is your dichotomy.

What do you mean by “begin to exist?”

Precisely. Usually that phrase means something along the lines of 'at one point, it did not exist, and at a later it did because of some process'.

That is manifestly NOT the case with the universe. Again, since time is part of the universe and causality depends on time, there was no *time* when the universe did not exist.

(September 17, 2021 at 9:28 am)Mister Agenda Wrote:

(September 16, 2021 at 2:44 pm)Klorophyll Wrote: The no boundary proposal entails that the universe began to exist,

https://en.wikipedia.org/wiki/Hartle%E2%...king_state

QUOTE :However, Hawking does state "...the universe has not existed forever. Rather, the universe, and time itself, had a beginning in the Big Bang, about 15 billion years ago."

If the universe has not existed forever, it began to exist. 

Thanks for sharing Hawking's opinion, but his hypothesis, like the other hypotheses for the origin of the universe, can't be tested yet. If Hawking is right, the universe began to exist from nothing. If Hawking is wrong, a universe that has always existed in some form is still on the table. And there's no way to know if Hawking at this time is right or wrong on this matter.

Arguing from Hawking as an authority on cosmology is at least citing a relevant expert, but the problem is cosmology isn't settled and plenty of eminent cosmologists disagree with him.

The no-boundary proposal is just that - a proposal.  It also seems the math may not work.

The idea is that there was "something" before the big-bang, but it wasn't a singularity, and time and space as we know it emerged smoothly as a phase transition.

There is also no causality "as we know it" in this pre-universe state.

(September 17, 2021 at 11:22 am)polymath257 Wrote: Precisely. Usually that phrase means something along the lines of 'at one point, it did not exist, and at a later it did because of some process'.

That is manifestly NOT the case with the universe. Again, since time is part of the universe and causality depends on time, there was no *time* when the universe did not exist.

And isn't the big bang just the point where the known laws of physics started working, meaning that it doesn't mean that there was nothing before the big bang, it's just that we can't know because the known laws of physics weren't working yet?

Like the center of the Black Hole, which is a place where all laws of physics completely break down so it is unknown what is going on there, but it exists, nevertheless. It's not nothing.