I think we are talking past each other? So let us regroup. We can maybe have a more pleasant discussion then last year.

>Are we in agreement then? Hawking's model may be true or false depending on what future evidence shows, and, if true it would not disprove the existence of God.

Yes we agree on this point regardless if we agree or disagree with each other on the existence of God.

>As am I. If a model with imaginary time accurately predicts what we see in reality, scientific realism implies that imaginary time does, in fact, describe something in reality.

Rather Einstein's gravity formulas with imaginary numbers plugged into them describe some mechanism in reality.

>They may be different interpretations as to what exactly it describes, but claiming that the imaginary time in the model doesn't actually exist would amount to scientific non-realism.

I guess this is the problem. How does "imaginary time" exist? Does it exist in reality? Does it exist notionally or logically? Because at best I am thinking it exists notionally because I still don't get how imaginary numbers(i.e. the radicals of negative #'s) can literally count anything real? That is all I am bitching about.

>When did I claim that it is? All I have said is that imaginary time, i.e., time that can be described by imaginary numbers, might exist.

The problem is the ambiguity of yer phrase "might exist". How does it exist? I can say Harry Potter "exists" (wait for it) "as a being of reason and imagination. But not as a real flesh and blood person". So how does "imaginary time" exist?

>We're talking about a scientific model, which should be tested based on empirical observation.

I am not against that but the ontological interpretation is what I am bitching aboot.

>Did you just mean to say "real numbers" here? If you assume that real numbers and "real world numbers" are equivalent, then you are already assuming the conclusion. And you don't have to convert back to real numbers for engineering purposes anyway. Complex valued quantities are defined for a reason.

This is what is confusing me. So if I see five cars in a lot I can just label them 5i cars? So imaginary numbers are just a trivial label interchangeable with real things? That seems absurd? But I guess the confusion I am having is yer statement "Imaginary time could be real" if we don't define "real in what sense"? Like I said Harry Potter really exists as a being of reason and imagination originating from the mind of JKR. But that is not the same as saying he literally lives down the street from me.

>Do you have an argument for this beyond "It's obvious"?

Well 2+2=4 seems obvious?

>I don't know what you mean by "only to the exclusion of real numbers", but imaginary numbers are already used all the time in quantum mechanics. The use of imaginary numbers isn't a problem in physics.

I think the problem is I don't know what you mean by "Imaginary Time" may "exist"? Like I said I cannot coherently conceive of cars literally counted with the radicals of negative numbers so I don't know what you mean either. Hopefully we will iron it out. I can say Harry Potter exist using the qualifiers I put at the end but I cannot say he lives with me.

>Any my point is that the reason you can't have a negative number of cars is because the phrase "the number of" specifically refers to cardinal numbers. So it is impossible by definition to have a negative number of cars. You are trying to use this as an analogy for something that you haven't actually shown to be incoherent - it's a false analogy.

Well it is incoherent to say you can literally have a negative number of cars or a number of cars measured in imaginary numbers because by definition "the number of" refers to Cardinal Numbers. So why can't we say the same about time? It is not a "false analogy". Notionally I might be able to use imaginary numbers in models but that doesn't mean I am literally counting a real thing.

>I think you're making a distinction without a difference here. Change does occur in spacetime. The hypersurface of the present right now is not identical to the hypersurface of the present five minutes ago.

Well it is nice to see you philosophically modeling this via Essentialism and Aristotle vs Parmenides the later is a favorite among some modern physicists. Of course when I say Change I mean some potency made act by something already in act.

>Then what's with all your claims that it's incoherent?

I guess the confusion boils down to "claiming that the imaginary time in the model doesn't actually exist would amount to scientific non-realism." How it "exists" it the question?

I say "imaginary time" at best exists as a notional concept. It doesn't describe anything coherently real.

Cheers.

I am thinking of it in terms of real world physics being the moderate realist that I am.

As am I. If a model with imaginary time accurately predicts what we see in reality, scientific realism implies that imaginary time does, in fact, describe something in reality. They may be different interpretations as to what exactly it describes, but claiming that the imaginary time in the model doesn't actually exist would amount to scientific non-realism.

If we are trying to visualize its real world applications and it is clear the concept of "imaginary time" that is time measured in imaginary numbers is clearly onto-logically incoherent.

Do you have an argument for this beyond "It's obvious"?

The model is not the thing modeled. Only a representation of it.

When did I claim that it is? All I have said is that imaginary time, i.e., time that can be described by imaginary numbers, might exist.

What does empiricism have to do with anything?

We're talking about a scientific model, which should be tested based on empirical observation.

How do you empirically measure real world things with imaginary numbers only to the exclusion of real ones?

I don't know what you mean by "only to the exclusion of real numbers", but imaginary numbers are already used all the time in quantum mechanics. The use of imaginary numbers isn't a problem in physics.

But it is still 186,282.4 mps not 1.

No, the value of the speed of light is 1 Planck speed. There is nothing special about miles per second that makes the value 186,282.4 the "real" speed of light. You can say that the speed of light isn't 1 mps, but you can't say that the speed of light isn't 1 because that depends on your units. But if all you meant to say was the former, then I don't see your point because no one pretends that the speed of light is equal to 1 mps to make their calculations easier. That would make your calculations wrong.

But they still have to convert the imaginary numbers back into real world numbers.

Did you just mean to say "real numbers" here? If you assume that real numbers and "real world numbers" are equivalent, then you are already assuming the conclusion. And you don't have to convert back to real numbers for engineering purposes anyway. Complex valued quantities are defined for a reason.

My point which you dismissed is you cannot really count how many cars are in a parking lot using negative numbers much less imaginary numbers as it is incoherent.

Any my point is that the reason you can't have a negative number of cars is because the phrase "the number of" specifically refers to cardinal numbers. So it is impossible by definition to have a negative number of cars. You are trying to use this as an analogy for something that you haven't actually shown to be incoherent - it's a false analogy.

I was referring to space time and where is the evidence of physical things that can only be measured by imaginary numbers and not by real ones?

I didn't say that there was evidence in favor of Hawking's model. All I have claimed is that we can't rule out Hawking's model (as I said in my original comment, we should be agnostic about which model of the Planck epoch is true until we actually have evidence for some theory of quantum gravity). As for things that can be measured by imaginary, complex refractive index, complex impedance, and complex current are all examples that come to mind. If you want to complain that all of these things have real-valued versions as well, the problem with your complaint is that the real-valued version don't give you the full information that the complex-valued version gives you. Another example is the wave function in quantum mechanics. You can't use a purely real value for the wave function or you will make the wrong predictions.

Metaphysical time is a necessary assumption because if there is no real change then no experiment can in principle demonstraight anything.

I think you're making a distinction without a difference here. Change does occur in spacetime. The hypersurface of the present right now is not identical to the hypersurface of the present five minutes ago.

I am not trying to "refute" it.

Then what's with all your claims that it's incoherent?

I don't dispute the true or falsehood of the model as we agree it has nothing to do with Classic Theism being true or not.

Are we in agreement then? Hawking's model may be true or false depending on what future evidence shows, and, if true it would not disprove the existence of God.

>Any interpretation of Hawking's model would include some philosophy, but Hawking's model itself is a purely mathematical model.

I am thinking of it in terms of real world physics being the moderate realist that I am. If we are trying to visualize its real world applications and it is clear the concept of "imaginary time" that is time measured in imaginary numbers is clearly onto-logically incoherent. It is an interesting mathematical model & it may tell us something but the "O"'s and "X"'s on a black board do not exhaustively explain the football game. The model is not the thing modeled. Only a representation of it.

>What do you mean by "his modelling is suspect"? Are you claiming that his model doesn't accurately represent reality? If so, on what empirical basis are you making this claim?

What does empiricism have to do with anything? How do you empirically measure real world things with imaginary numbers only to the exclusion of real ones? This is philosophical. By modelling it I mean physically as this has to do with physics and it is obviously ontologically incoherent.

As a mathematical model it is as Stephen Barr said quite elegant. But the model breaks down once you convert the imaginary numbers into real numbers and put them back into the gravity equations. The Singularity returns. The laws of physics as we know them go poof and Vilenkin has a laugh at Hawkings' expense as he is the one who called the Hartle/Hawking model an exercise in metaphysical cosmology.

> The speed of light really is 1 in the Planck system of units.

But it is still 186,282.4 mps not 1. So it doesn't tell me how fast I am really going threw the cosmos unless I make that conversion.

>What do you mean by this? Engineers use imaginary numbers for real-world applications all the time.

But they still have to convert the imaginary numbers back into real world numbers. There usefulness is not in dispute.

>Please explain to me how the fact that there are no negative cardinal numbers proves your point about a quantity that has nothing to do with cardinal numbers.

My point which you dismissed is you cannot really count how many cars are in a parking lot using negative numbers much less imaginary numbers as it is incoherent. These may be useful models but they don't tell us about anything real. Having a negative balance in my bank account means I owe a positive amount of real world money to the bank. Not that I am in fact in possession of some magical negative anti-matter money like on the old Lost in Space show.

>Incoherent? How so? It seems to me that you are making a lot of assumptions about the nature of time that are not justified by any sort of evidence.

What type of time are you referring too? Metaphysical time or space time? I was referring to space time and where is the evidence of physical things that can only be measured by imaginary numbers and not by real ones? Metaphysical time is a necessary assumption because if there is no real change then no experiment can in principle demonstraight anything. Since experiments presuppose testing for change.

>And Hawking's model is about space time, not your "measure of change from moment to moment", so if you want to use this understanding of time to refute Hawking's model, then I'm afraid you're the one equivocating here.

I am not trying to "refute" it. That is the obsession of the Intelligent Design neo Paley crowd which as a Thomist I hold in contempt. I am saying it is clearly an exercise in metaphysical cosmology not strict physics.

Nothing more.

>It seems that you're getting confused by the names "real number" and "imaginary number". Those names are historical misnomers that nearly all mathematicians now agree were a mistake.

Then I shall leave that to those learned in philosophy of mathematics.

> They say nothing about the ontology of complex numbers or things that are described by them.

But I am saying Hawking's cosmology here is metaphysical. That is what I am saying. I don't dispute the true or falsehood of the model as we agree it has nothing to do with Classic Theism being true or not. A Catholic Physicist like Barr or a Protestant Christian one like Russell can be content with a universe that comes to pass from a Hartle/Hawking model. As even Oppy argues it doesn't eliminate God. Even Hawking as said as much "Who breaths fire into the equations" Atheist that he was God rest his soul.

Cheers.

As Dennett says correctly there is no such thing as philosophy-free science

Any interpretation of Hawking's model would include some philosophy, but Hawking's model itself is a purely mathematical model. Like quantum mechanics, philosophy comes in when we need to interpret the model, because the model itself doesn't tell us how to interpret it. But I don't think that this is a valid criticism of Hawking's model.

Nobody is claiming Hawkings' science is wrong. It is his modelling that is suspect.

What do you mean by "his modelling is suspect"? Are you claiming that his model doesn't accurately represent reality? If so, on what empirical basis are you making this claim? And if his model does (or might) accurately represent reality, what exactly is "suspect" about it?

Yes and I can make C=1 & make V = % < 1 to make calculating time dilation easier

You say that as if setting c=1 is something that is only done to make calculation easier but somehow doesn't really reflect reality, but that is false. The value of c depends on your choice of units since it is not a dimensionless quantity. The speed of light really is 1 in the Planck system of units.

But real engineers have to convert their imaginary numbers back into real ones for real world applications.

What do you mean by this? Engineers use imaginary numbers for real-world applications all the time.

Which only proves my point.

Please explain to me how the fact that there are no negative cardinal numbers proves your point about a quantity that has nothing to do with cardinal numbers.

That is a metaphysical claim(& an incoherent one) not a scientific one.

Incoherent? How so? It seems to me that you are making a lot of assumptions about the nature of time that are not justified by any sort of evidence. And Hawking's model is about space time, not your "measure of change from moment to moment", so if you want to use this understanding of time to refute Hawking's model, then I'm afraid you're the one equivocating here.

Anyway if it is physical then it is ontologically real and can only be described in real terms.

It seems that you're getting confused by the names "real number" and "imaginary number". Those names are historical misnomers that nearly all mathematicians now agree were a mistake. They say nothing about the ontology of complex numbers or things that are described by them.

I do wonder why you expect an answer to an obscure post that is 8 years old?

> I am responding to a comment which falsely claims that Hawking's proposal has been ruled out and cites a paper that never even attempts to disprove it.

Fair enough.

> So this isn't a problem with the laws of nature themselves - it's a problem with our knowledge of the laws.

Actually it is our philosophical modelling of the laws. Laws of physics are merely observed regularities in the natural world. Nothing more. Many misguided physicists and skeptics treat them as Platonic entities with causal powers of their own. Hume was no better and his sophistry fails. It is not our knowledge of laws it is our knowledge of nature.
Learning about new mechanisms in nature does not answer qualitative questions about nature. It merely answers quantitative questions the later requires science and the former philosophy.

>It seems to me that the question of how to interpret imaginary time physically only exists because Hawking's model does not include any metaphysics.

As Dennett says correctly there is no such thing as philosophy-free science; there is only science whose philosophical baggage is taken on board without examination. Hawking is as his friend an Atheist Astronomer named Lord Martin Rees notes "Stephen Hawking is a remarkable person whom I've know for 40 years and for that reason any oracular statement he makes gets exaggerated publicity. I know Stephen Hawking well enough to know that he has read very little philosophy and even less theology, so I don't think we should attach any weight to his views on this topic," he said."END QUOTE.

Everybody has a metaphysics. Do you believe in Reductionist Materialism? That is a metaphysical view. Naturalism? Metaphysics. Realism? Anti-realism? Platonism? Essentialism? All metaphysics. It is just Hawkings doesn't examine his metaphysics. He takes them on board without examining them.

>Quantum mechanics is a mathematical model that has many different interpretations, and physicists can't tell us which interpretation is the correct one.

Which is why that is the providence of the Philosophers of Nature. Not physicists.

>But that doesn't mean that quantum mechanics is wrong, so why should it mean that Hawking's proposal is wrong?

Nobody is claiming Hawkings' science is wrong. It is his modelling that is suspect.

>Why not? Imaginary numbers are used all the time in physics.

Yes and I can make C=1 & make V = % I don't buy the analogy to the number of cars in a parking lot because, whenever we refer to "the number of Xs", we are talking about a cardinal number, and there are no negative cardinals.

Which only proves my point.

> But when we talk about time, we are talking about a physical thing that may very well be describable by imaginary numbers.

That is a metaphysical claim(& an incoherent one) not a scientific one. Also it is an equivocal definition. Time is not the same as space time. Time is metaphysically the measure of change from moment to moment. Space time is something else. Like Chemistry and Physics are both sciences but you cannot cause atoms to split by dissolving them in acid. Again category mistake.

Anyway if it is physical then it is ontologically real and can only be described in real terms. As I said you cannot count the number of cars using imaginary numbers and if Space Time is a physical thing (which is what it is suppose to be) then ultimately it can only be described by real numbers.

Hawking is trying to get rid of the Singularity but when he converts his imaginary numbers back into real numbers for his gravity equations the Singularity rears its ugly head.

But none of this matters to Classic Theism as you seem to agree. Cheers.

I am not trying to use the Hartle-Hawking no boundary proposal to disprove classical theism here (that would be ridiculous in principle, since the no boundary proposal is still just a proposal, not a verified fact). I am responding to a comment which falsely claims that Hawking's proposal has been ruled out and cites a paper that never even attempts to disprove it.

The Singularity presents a problem for David Hume's claims the Laws of Nature are immutable since those laws as we understand them break down at the Singularity.

The key phrase there is "as we understand them". Our current understanding of the laws of nature is incomplete. During the Planck epoch, the laws of physics as we know them break down because we don't know how quantum gravity works, but the effects of quantum gravity are too large ignore at that time. If we had an understanding of quantum gravity, the laws of physics as we know them would not break down during the Planck epoch. So this isn't a problem with the laws of nature themselves - it's a problem with our knowledge of the laws.

Hawkings model eliminates the Singularity but his model has been criticized as more metaphysics rather then physics given his ambiguous understanding of "imaginary time".

It seems to me that the question of how to interpret imaginary time physically only exists because Hawking's model does not include any metaphysics. He has a mathematical model of the Universe, but the model doesn't tell you how to interpret imaginary time. I don't really see this as a problem with his proposal though: Quantum mechanics is a mathematical model that has many different interpretations, and physicists can't tell us which interpretation is the correct one. But that doesn't mean that quantum mechanics is wrong, so why should it mean that Hawking's proposal is wrong?

Time measured using imaginary numbers has no physical ontological significance.

Why not? Imaginary numbers are used all the time in physics. I don't buy the analogy to the number of cars in a parking lot because, whenever we refer to "the number of Xs", we are talking about a cardinal number, and there are no negative cardinals. But when we talk about time, we are talking about a physical thing that may very well be describable by imaginary numbers.

A couple of problems seem evident here. Classic Cosmological philosophical arguments for the existence of God presuppose for the sake of argument a past eternal world. Also Aquinas and the bulk of Classic Theistic philosophers(with one or two exceptions) presupposed you cannot philosophically or scientifically prove creation had a beginning. So this might not be something science can show to be true or false in principle.
Also Big Bang as Fr. Lemaître said to Pope Pius XII (allegedly Dr. B disputes this) only shows our local space time had a beginning. It doesn't prove the beginning of creation or offer a "scientific" proof of creation. It seems obvious our Universe had a beginning and the Singularity presents a problem for David Hume's claims the Laws of Nature are immutable since those laws as we understand them break down at the Singularity. But Hume's philosophy was sophistry if we believe Aschombe and of course I do. Ye do what ye like.

Hawkings model eliminates the Singularity but his model has been criticized as more metaphysics rather then physics given his ambiguous understanding of "imaginary time". Time measured using imaginary numbers has no physical ontological significance. Like counting the number of cars in a parking lot using negative numbers is absurd and here he measures time using the radicals of negative numbers.

Still Christian Physicists who are knowledgeable of philosophy have no problem with Hawkings model. Stephen Barr and Robert Russell come to mind.

Atheist philosopher Graham Oppy is skeptical the Hawking model can overthrow classic Theism. In the article below he takes issue with the late great Atheist philosopher Quentin Smith.

On Some Alleged Consequences Of 'The Hartle-Hawking Cosmology' (1997)

Graham Oppy

https://infidels.org/library/modern/graham_oppy/smith1.html

Scientific Atheism is a waste of time. But then again Scientific Theism is equally vain. God is a philosophical question only. In fact to even try to claim God is a scientific question doesn't involve science. But the philosophy of science to even get started.

Cheers.

Neither of those are Hawking's model. In that paper, they argue that three simple models that in no way cover the full range of possibilities cannot be past-eternal. They aren't even trying to rule out possibilities like the no-boundary proposal, in which the Universe has a finite past but no beginning.

Currently, cosmologists do not know whether the Universe had a beginning. People who claim that modern physics proves that the Universe had a beginning are either presenting an oversimplified pop-sci version of the Big Bang theory, or they don't understand the physics. That is why the authors of the paper you cite said "probably yes", rather than "yes" - they believe the answer is most likely yes, but they know that their arguments are not conclusive and that many of their colleagues believe the opposite conclusion. Until we have a model backed up by scientific evidence of what happened during the Planck epoch and what, if anything, occurred before it, the only proper position on, "Did the Universe have a beginning?" is agnosticism.

His answer was a another question :”Well, I do. Do I think that there's some sort of master intelligence architecting all of this stuff? I think probably not because then you have to say: "Where does the master intelligence come from?" So it sort of begs the question. So I think really you can explain this with the fundamental laws of physics. You know it's complex phenomenon from simple elements”.

His answer however relates to ETERNITY.

Where did the things ( SIMPLE ELEMENTS) that are subject to the LAWS OF PHYSICS originated.?

Laws can not exist without subjects or things that are controlled by them. Laws only have regulatory powers, no creative powers. They can only influence and affect existing things. Laws can only be observed through the presence of things that do exist.

WHERE DID THESE THINGS (SIMPLE ELEMENTS) COME FROM?? OUT OF NOWHERE OR DID SOMETHING ETERNAL ALWAYS EXIST?

He, the famous person, got to the simplest, but what exist beyond the simplest? Fluctuating force fields? Still not an answer! Where do the force fields come from or are they eternal?

Does the anser given by this person really “probably exclude an timeless. Eternal Intelligence ”architecting all of this stuff”?

Allow me to explain. From every chain of events there is an "initial event" or "first cause", as some like to call it. The problem comes in the form of recognizing that "causality" dictates that every event is preceded by another event that caused it. In this scenario, "initial events" or "first causes" violate that "law", as every "initial event" is preceded by another event... in reality, meaning that those initial events aren't initial after all. And if there can't be an initial event... how then can a chain of events follow?

That said, what stands to reason, or logic, is that all things are not beholden to causality - that at some layer, our reality, the fabric of reality, just... "is". "Just is" as in eternal, infinite, without having been caused...

It's hard to imagine because we're indoctrinated to causality from birth - our minds were built on that concept. However it simply can not be. And if logic reveals to us that causality doesn't permeate all of existence, then questions of "what created X" doesn't actually need to be asked as it might not necessarily apply - thereby removing the necessity of a "creator" to explain things.

...it could very well be that the universe just... "is". An undulating field of infinite and eternal energy whose fluctuations produce everything we've ever observed.

After all, if you're willing to except that God, who is allegedly "everything", can exist without cause, then logically you should be willing to accept that lesser "things" can too exist without cause.