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What is wrong with the Kalam Cosmological Argument?

Meow Mix

Chatte Féministe
@Meow Mix
And you Made similar points, so my responses to her also apply to you, (if you think I ignored a relevant point made by you please let me know


But if the universe is past eternal, it remains inexplicable why our fields decayed 13.8B years ago to produce our big bang.

If the universe is past ethernal then any field that existed would have decayed an infinite amout of time ago.

An analogy would be imagine that you are playing poker since infinite past, given this I would conclude that you got your first “full house” and infinite amount of time ago, it makes no sense that you got your first “full house” 13.8 billions years ago (nor at any point in the finite past)

If you're playing poker for an infinite amount of time, then at any time you could still get a royal flush: it doesn't matter whether the one 13.8 billion years ago was the "first" one or not.

As for your other questions, perhaps a better explanation of eternal inflation is in order. Imagine a circle (we will ignore for a moment that it is a finitely sized circle, this is just to simplify the concept enough to understand). Now imagine that this circle is expanding (ignore for now that things would have to exist in order for expansion to mean anything, again, this is just to show a particular concept. Trying to pre-empt objections to the analogy).

Now, let's say that the field causing this circle to expand spontaneously decays at one of the edges and begins to expand much more slowly. So what you're imagining now is a nearly complete circle with a little dimple. Now, because the rest of the circle is expanding so much faster than the little dimple, the circle-material wraps around the dimple-material as the circle continues to expand: now you have a circle with a smaller circle (that used to be the dimple) inside of it: a bubble.

Now, the circle continues expanding. More dimples are made, and enveloped. You end up with a very large circle with a great many bubbles inside of it. As you can see, even though parts of the circle decay to make slowly expanding bubbles (relative to the circle), there will always be more circle than bubble, and the circle will never completely decay because only parts of it decay (and the rest expands to make up for it).

Now, in the real world, energy is conserved here because the expansion is balanced against the now-existent gravitational potential of the bubbles.

vtBAB.jpg




My problem is not the claim that inflation (or even eternal inflation is true) for the sake of this discussion we can assume that such model is true.

The issue is that all the observable universe seems to have low entropy while your model of “infinite past” predicts high entropy (nearly 100% entropy) even in eternal inflation entropy on average always increases so low entropy is not expected to be seen.

Entropy is temporal, and temporality is entropic. As has been stated above, every bubble creation is a local entropic minimum (that means the arrow of time begins in the bubble). Entropy winds down from there. But can you see how the arrow of time beginning in a bubble is not an ontological beginning?

Given that our observations contradict your predictions you have to go beyond science and speculate a lot……. For example under your view our observable universe should be just a small grain of sand compared to the whole universe, such that the observed low entropy would be just a statistically insignificant exception.

But talking about the second law my biggest objection to an infinite past would be that the universe would be dominated by Boltzmann brains, Boltzmann brains would be the most typical and abundant type of observer…. So your world view forces you to conclude that you are a Boltzmann Brain. You must conclude that all your observations your memories and even this conversations are just an illusion. Paradoxically all your evidence for “inflation” would also be an illusion.

So the way I see it ether

1 you are a Boltzmann brain

2 the universe is not past eternal

Honestly I see this as a devastating objection to any godless model that includes infinite past and/or infinite (or many) worlds , any opinion on that?

The Boltzmann Brain issue is not an issue: in order for that argument to work, the universe must still be geared towards favoring the creation of such a thing; and the universe is not. It is not true that given an infinite universe and infinite time that the likelihood for all things developing is equal: we would probably smirk at the suggestion that the most likely object to exist is a green bust of Julius Caesar after all, and that's because of the physics. In order for the Boltzmann Brain objection to have any bite, Boltzmann Brains must be highly probable outcomes of the universe's physics; and they just aren't.

well quote from Guth

I might be wrong but at least as a layman it seems obvious to me that these scientists are claiming and concluding that eternal inflation can’t be “past eternal” am I missing something?

What Guth, Vilenkin, and Borde are saying is that classical methods of probing the Planck era give finite geodesics by necessity (in the same way that classical approaches to thermodynamics give us singular results like the ultraviolet catastrophe). Their phrasing is intended for colleagues that understand the context of their statements, which is that you cannot use classical physics to probe the Planck era: it is a consequence of the choice of metric. It does not mean that there was an ontological beginning, as at least Vilenkin and Guth have gone on to clarify when laypersons became interested in their papers.

In physics, sometimes you get singular results (e.g. event horizons, singularities) because of your choice of metric and assumptions. If you say "it is impossible to get past the event horizon," what your colleagues understand is that you are using the Schwarzschild metric and not Eddington-Finkelstein metric (the first is singular at event horizons, while the latter is not). It's because of the choice of metric, not because of any fact about reality. And that is what Vilenkin et al have shown: that we need quantum gravity to probe the Planck era; classical metrics won't cut it.
 

leroy

Well-Known Member
If you're playing poker for an infinite amount of time, then at any time you could still get a royal flush: it doesn't matter whether the one 13.8 billion years ago was the "first" one or not.

As for your other questions, perhaps a better explanation of eternal inflation is in order. Imagine a circle (we will ignore for a moment that it is a finitely sized circle, this is just to simplify the concept enough to understand). Now imagine that this circle is expanding (ignore for now that things would have to exist in order for expansion to mean anything, again, this is just to show a particular concept. Trying to pre-empt objections to the analogy).

Now, let's say that the field causing this circle to expand spontaneously decays at one of the edges and begins to expand much more slowly. So what you're imagining now is a nearly complete circle with a little dimple. Now, because the rest of the circle is expanding so much faster than the little dimple, the circle-material wraps around the dimple-material as the circle continues to expand: now you have a circle with a smaller circle (that used to be the dimple) inside of it: a bubble.

Now, the circle continues expanding. More dimples are made, and enveloped. You end up with a very large circle with a great many bubbles inside of it. As you can see, even though parts of the circle decay to make slowly expanding bubbles (relative to the circle), there will always be more circle than bubble, and the circle will never completely decay because only parts of it decay (and the rest expands to make up for it).

Now, in the real world, energy is conserved here because the expansion is balanced against the now-existent gravitational potential of the bubbles.

vtBAB.jpg






Entropy is temporal, and temporality is entropic. As has been stated above, every bubble creation is a local entropic minimum (that means the arrow of time begins in the bubble). Entropy winds down from there. But can you see how the arrow of time beginning in a bubble is not an ontological beginning?



The Boltzmann Brain issue is not an issue: in order for that argument to work, the universe must still be geared towards favoring the creation of such a thing; and the universe is not. It is not true that given an infinite universe and infinite time that the likelihood for all things developing is equal: we would probably smirk at the suggestion that the most likely object to exist is a green bust of Julius Caesar after all, and that's because of the physics. In order for the Boltzmann Brain objection to have any bite, Boltzmann Brains must be highly probable outcomes of the universe's physics; and they just aren't.



What Guth, Vilenkin, and Borde are saying is that classical methods of probing the Planck era give finite geodesics by necessity (in the same way that classical approaches to thermodynamics give us singular results like the ultraviolet catastrophe). Their phrasing is intended for colleagues that understand the context of their statements, which is that you cannot use classical physics to probe the Planck era: it is a consequence of the choice of metric. It does not mean that there was an ontological beginning, as at least Vilenkin and Guth have gone on to clarify when laypersons became interested in their papers.

In physics, sometimes you get singular results (e.g. event horizons, singularities) because of your choice of metric and assumptions. If you say "it is impossible to get past the event horizon," what your colleagues understand is that you are using the Schwarzschild metric and not Eddington-Finkelstein metric (the first is singular at event horizons, while the latter is not). It's because of the choice of metric, not because of any fact about reality. And that is what Vilenkin et al have shown: that we need quantum gravity to probe the Planck era; classical metrics won't cut it.


Entropy is temporal, and temporality is entropic. As has been stated above, every bubble creation is a local entropic minimum (that means the arrow of time begins in the bubble). Entropy winds down from there. But can you see how the arrow of time beginning in a bubble is not an ontological beginning?

why would the bubbles (whitle circles in your image) start with a low entropy? as far as I understand entropy is a statistical thing, some bubbles will start with high entropy and others with low entropy................am I correct?
 

leroy

Well-Known Member
I'm still waiting for a response to my points, or at least an acknowledgement that my arguments are sound.
Wow wait, you will not get a response this week, I still haven’t have the time to read the paper , and chances say that I will ask 2 or 3 more questions before answering.

For example, did all the big bangs started with a low entropy? Or where there some big bangs that started with high entropy.

BTW if you don’t have the patience of answering this type of questions or the patience of correcting my mistakes I´ll understand. You don’t have to reply to my comments if you don’t want. But I will take advantage of your free lessons for as much time as I can.
 

Meow Mix

Chatte Féministe
why would the bubbles (whitle circles in your image) start with a low entropy? as far as I understand entropy is a statistical thing, some bubbles will start with high entropy and others with low entropy................am I correct?

So, this might get complicated, but it's actually a question that's down my alley (the first paper I ever wrote was an overview on black hole thermodynamics).

With black holes, the Hawking temperature is proportional to h-bar and the entropy is 1/4 A/(l_P)^2 (with l_P being the Planck length, h-bar*G/c^3).

I'll have you note that the A here is just regular ol' area: it is the area of the horizon. The fact that entropy is related like this is actually extremely profound and leads to all sorts of important things, but I'm only bringing this up so we can draw an analogy between cosmic horizons and black hole horizons.

For an accelerating universe, we would instead associate an entropy associated with the Hubble horizon H^(-1). During stochastic inflation, the entropy associated with the horizon decreases in regions where the scalar field moves up the potential. (Entropy never decreases by more than 1 as required by the SLoT, so we have a nice sanity test there).

This process is called the "slow-roll," and it also has the consequence that /\ decreases (explaining why we haven't been in a dark energy-dominated universe this entire time until recently).

So, while you're partially correct in that different bubbles may start with different entropies, they're going to be relatively low: they start at local entropic minima (and so all have their own arrow of time within them).
 

Meow Mix

Chatte Féministe
If you imagine a curvy function (so, no cohabitation of points on the y-axis), with balls starting at the top of hills and rolling into troughs (going from entropic minima to entropic maxima), this motion of the ball is the arrow of time. This is what we call "time" and "temporality" at all in this bubble cosmos. But if you zoom out, there are all kinds of these: ours wouldn't be the only one.

This is why when we ask questions like "what was before the Planck era?" we have to answer with "the question itself is wrong." It's like asking what's higher than the peak, or what's north of the north pole.
 

leroy

Well-Known Member
All Big Bangs started with low entropy. No Big Bang started with high entropy.
Also to @Meow Mix

Why would that be the case? It seems to me that a few seconds after a Big Bang, once you have baryonic matter (say hydrogen and helium) entropy becomes and statistical thing, you can high low entropy, high entropy or anything in between. ……….. why would you always have low entropy?
 

Magical Wand

Active Member
Why would that be the case? It seems to me that a few seconds after a Big Bang, once you have baryonic matter (say hydrogen and helium) entropy becomes and statistical thing, you can high low entropy, high entropy or anything in between. ……….. why would you always have low entropy?

Because the vacuum always has low entropy. Prof. Alex Vilenkin argued "entropy is an extensive quantity; it is proportional to the volume. And the very small universe will necessarily have a very low entropy. But also it is filled with vacuum, and that is also the lowest entropy that you can have." Physicist Nikodem Poplawski made a similar point: "Entropy was small at the early universe because there was no particle production yet. Once quantum effects in the strong gravitational field start particle production, the entropy grows."

And if you ask why the vacuum always has low entropy, I can only answer that this is the way it is.
 
Last edited:

Meow Mix

Chatte Féministe
Because the vacuum always has low entropy. Prof. Alex Vilenkin argued "entropy is an extensive quantity; it is proportional to the volume. And the very small universe will necessarily have a very low entropy. But also it is filled with vacuum, and that is also the lowest entropy that you can have." Physicist Nikodem Poplawski made a similar point: "Entropy was small at the early universe because there was no particle production yet. Once quantum effects in the strong gravitational field start particle production, the entropy grows."

And if you ask why the vacuum always has low entropy, I can only answer that this is the way it is.

I answered why in #527
 

Meow Mix

Chatte Féministe
Also to @Meow Mix

Why would that be the case? It seems to me that a few seconds after a Big Bang, once you have baryonic matter (say hydrogen and helium) entropy becomes and statistical thing, you can high low entropy, high entropy or anything in between. ……….. why would you always have low entropy?

In #527 I made a comparison to black holes because of the proportionality to the area of the horizon, A: these bubbles start out very small; and you can only fit so much entropy in a finite amount of space (one of the consequences I was saying was very profound).
 

infrabenji

Active Member
If you're playing poker for an infinite amount of time, then at any time you could still get a royal flush: it doesn't matter whether the one 13.8 billion years ago was the "first" one or not.

As for your other questions, perhaps a better explanation of eternal inflation is in order. Imagine a circle (we will ignore for a moment that it is a finitely sized circle, this is just to simplify the concept enough to understand). Now imagine that this circle is expanding (ignore for now that things would have to exist in order for expansion to mean anything, again, this is just to show a particular concept. Trying to pre-empt objections to the analogy).

Now, let's say that the field causing this circle to expand spontaneously decays at one of the edges and begins to expand much more slowly. So what you're imagining now is a nearly complete circle with a little dimple. Now, because the rest of the circle is expanding so much faster than the little dimple, the circle-material wraps around the dimple-material as the circle continues to expand: now you have a circle with a smaller circle (that used to be the dimple) inside of it: a bubble.

Now, the circle continues expanding. More dimples are made, and enveloped. You end up with a very large circle with a great many bubbles inside of it. As you can see, even though parts of the circle decay to make slowly expanding bubbles (relative to the circle), there will always be more circle than bubble, and the circle will never completely decay because only parts of it decay (and the rest expands to make up for it).

Now, in the real world, energy is conserved here because the expansion is balanced against the now-existent gravitational potential of the bubbles.

vtBAB.jpg






Entropy is temporal, and temporality is entropic. As has been stated above, every bubble creation is a local entropic minimum (that means the arrow of time begins in the bubble). Entropy winds down from there. But can you see how the arrow of time beginning in a bubble is not an ontological beginning?



The Boltzmann Brain issue is not an issue: in order for that argument to work, the universe must still be geared towards favoring the creation of such a thing; and the universe is not. It is not true that given an infinite universe and infinite time that the likelihood for all things developing is equal: we would probably smirk at the suggestion that the most likely object to exist is a green bust of Julius Caesar after all, and that's because of the physics. In order for the Boltzmann Brain objection to have any bite, Boltzmann Brains must be highly probable outcomes of the universe's physics; and they just aren't.



What Guth, Vilenkin, and Borde are saying is that classical methods of probing the Planck era give finite geodesics by necessity (in the same way that classical approaches to thermodynamics give us singular results like the ultraviolet catastrophe). Their phrasing is intended for colleagues that understand the context of their statements, which is that you cannot use classical physics to probe the Planck era: it is a consequence of the choice of metric. It does not mean that there was an ontological beginning, as at least Vilenkin and Guth have gone on to clarify when laypersons became interested in their papers.

In physics, sometimes you get singular results (e.g. event horizons, singularities) because of your choice of metric and assumptions. If you say "it is impossible to get past the event horizon," what your colleagues understand is that you are using the Schwarzschild metric and not Eddington-Finkelstein metric (the first is singular at event horizons, while the latter is not). It's because of the choice of metric, not because of any fact about reality. And that is what Vilenkin et al have shown: that we need quantum gravity to probe the Planck era; classical metrics won't cut it.
Dang. You just blew my mind.
 

Magical Wand

Active Member
In #527 I made a comparison to black holes because of the proportionality to the area of the horizon, A: these bubbles start out very small; and you can only fit so much entropy in a finite amount of space (one of the consequences I was saying was very profound).

Now it is much more clear, IMO.
 

Polymath257

Think & Care
Staff member
Premium Member
If you're playing poker for an infinite amount of time, then at any time you could still get a royal flush: it doesn't matter whether the one 13.8 billion years ago was the "first" one or not.

As for your other questions, perhaps a better explanation of eternal inflation is in order. Imagine a circle (we will ignore for a moment that it is a finitely sized circle, this is just to simplify the concept enough to understand). Now imagine that this circle is expanding (ignore for now that things would have to exist in order for expansion to mean anything, again, this is just to show a particular concept. Trying to pre-empt objections to the analogy).

Now, let's say that the field causing this circle to expand spontaneously decays at one of the edges and begins to expand much more slowly. So what you're imagining now is a nearly complete circle with a little dimple. Now, because the rest of the circle is expanding so much faster than the little dimple, the circle-material wraps around the dimple-material as the circle continues to expand: now you have a circle with a smaller circle (that used to be the dimple) inside of it: a bubble.

Now, the circle continues expanding. More dimples are made, and enveloped. You end up with a very large circle with a great many bubbles inside of it. As you can see, even though parts of the circle decay to make slowly expanding bubbles (relative to the circle), there will always be more circle than bubble, and the circle will never completely decay because only parts of it decay (and the rest expands to make up for it).

Now, in the real world, energy is conserved here because the expansion is balanced against the now-existent gravitational potential of the bubbles.

vtBAB.jpg






Entropy is temporal, and temporality is entropic. As has been stated above, every bubble creation is a local entropic minimum (that means the arrow of time begins in the bubble). Entropy winds down from there. But can you see how the arrow of time beginning in a bubble is not an ontological beginning?



The Boltzmann Brain issue is not an issue: in order for that argument to work, the universe must still be geared towards favoring the creation of such a thing; and the universe is not. It is not true that given an infinite universe and infinite time that the likelihood for all things developing is equal: we would probably smirk at the suggestion that the most likely object to exist is a green bust of Julius Caesar after all, and that's because of the physics. In order for the Boltzmann Brain objection to have any bite, Boltzmann Brains must be highly probable outcomes of the universe's physics; and they just aren't.



What Guth, Vilenkin, and Borde are saying is that classical methods of probing the Planck era give finite geodesics by necessity (in the same way that classical approaches to thermodynamics give us singular results like the ultraviolet catastrophe). Their phrasing is intended for colleagues that understand the context of their statements, which is that you cannot use classical physics to probe the Planck era: it is a consequence of the choice of metric. It does not mean that there was an ontological beginning, as at least Vilenkin and Guth have gone on to clarify when laypersons became interested in their papers.

In physics, sometimes you get singular results (e.g. event horizons, singularities) because of your choice of metric and assumptions. If you say "it is impossible to get past the event horizon," what your colleagues understand is that you are using the Schwarzschild metric and not Eddington-Finkelstein metric (the first is singular at event horizons, while the latter is not). It's because of the choice of metric, not because of any fact about reality. And that is what Vilenkin et al have shown: that we need quantum gravity to probe the Planck era; classical metrics won't cut it.


VERY nice description!
 

Meow Mix

Chatte Féministe
I can't overstate how profound the relationship is.

For instance, horizons have a surface gravity (denoted by kappa): It is defined as the coefficient relating the covariant directional derivative of the horizon normal vector along itself. It may be thought of as the redshifted acceleration of a particle at the horizon -- a consequence of treating the horizon as a Killing horizon (the null horizon generators are orbits of a Killing field).

This ends up being the same as the force per unit mass that has to be applied at infinity to hold a test particle to its path. For a non-Kerr (non-rotating) black hole the surface gravity is 1/4M (another very profound thing, because for larger black holes, they have less surface gravity). This is true of cosmic horizons as well.

This is very profound because we can derive the Zeroth Law of thermodynamics by noting that the surface gravity is constant over the horizon (the Zeroth Law states effectively that temperature is uniform everywhere in a system in thermodynamic equilibrium). So somewhat counter-intuitively, surface gravity is the temperature of a horizon.

So we see when discussing the First Law for horizons, surface gravity indeed takes the role of temperature. It appears in the entropy term (kappa)dA/8piG in the formulation of the first law (normally we'd see a T there), and so heat flow can be considered by imagining a quasistatic process by which bits of mass are lowered into the horizon.

But see how this continues to be immensely profound? What happens when you add bits of mass to a black hole: if its surface gravity is inversely proportional to its mass? The surface gravity would decrease, and this would violate the Second Law of Thermodynamics! This cannot be! (And so, for horizons, the Second Law is that the horizon area can never decrease assuming a positive energy condition; this has later been called Hawking's Area Theorem, for which observations were recently made, I saved the paper to my Zotero: Phys. Rev. Lett. 127, 011103 (2021) - Testing the Black-Hole Area Law with GW150914)).

Since the area can't decrease, and it would violate thermodynamics to add mass and have the surface gravity decrease, there is only one option left: the area of the event horizon must increase. This gave me goosebumps when I fully cognized the implications. There is a relationship between the event horizon area and the entropy: you can only fit so much entropy into a finite region of space! Big holy **** moment!
 

leroy

Well-Known Member
Because the vacuum always has low entropy. Prof. Alex Vilenkin argued "entropy is an extensive quantity; it is proportional to the volume. And the very small universe will necessarily have a very low entropy. But also it is filled with vacuum, and that is also the lowest entropy that you can have." Physicist Nikodem Poplawski made a similar point: "Entropy was small at the early universe because there was no particle production yet. Once quantum effects in the strong gravitational field start particle production, the entropy grows."

And if you ask why the vacuum always has low entropy, I can only answer that this is the way it is.
@Meow Mix

sure
But once matter appears (say hydrogen and helium) entropy could be either high or low right?............. my point is that in your model there are big bangs where black holes predominated an that have few (if any stars)
 

Magical Wand

Active Member
But once matter appears (say hydrogen and helium) entropy could be either high or low right?

Matter particles don't initially appear as aggregates like hydrogen and helium (but instead, as elementary particles). But letting that aside, I would put this way: once low entropy matter appears out of the vacuum, it can start growing, but it is not initially high, as Mix pointed out in a previous comment. Quote: "while you [i.e., leroy] are partially correct in that different bubbles may start with different entropies, they're going to be relatively low: they start at local entropic minima."

my point is that in your model there are big bangs where black holes predominated an [sic] that have few (if any stars)

I don't understand anything you just wrote here. Would you mind explaining?
 

Magical Wand

Active Member

By the way, I should say that this "matter out of the vacuum" mechanism is not invoked exclusively by multiverse proponents. The same mechanism is used by those who propose a single inflationary event (a single Big Bang). And as far as I know, most cosmologists accept cosmological inflation. So, this is standard science.
 

leroy

Well-Known Member
Matter particles don't initially appear as aggregates like hydrogen and helium (but instead, as elementary particles). But letting that aside, I would put this way: once low entropy matter appears out of the vacuum, it can start growing, but it is not initially high, as Mix pointed out in a previous comment. Quote: "while you [i.e., leroy] are partially correct in that different bubbles may start with different entropies, they're going to be relatively low: they start at local entropic minima."



I don't understand anything you just wrote here. Would you mind explaining?
The reason why we have many stars and planets in this universe is because entropy started low (when matter appeared it was organized in a low entropy state)

The only point that I made is that other “bubbles” (other big bangs) would have been different, in some “bubbles” entropy was low in other entropy was high (and therefore few if any stars and planets)

With entropy I am talking about once you already have matter
 
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