Hadronization vs. the Big Rip (Part Four--Reply to Critics)
An interesting question led to an interesting thought and another excuse to invite two of my friends from my grad school days,
BH and
DB, over for some coffee and physics.
DB: "Why do you call
this the 'I Have No Idea' post?"
Celestial Mechanic: "Because
Ken G uses that phrase or a variant of it six times in that post. Here are the quotes, with a little context left in:"
Instance #1:
Quote:
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... what would the evolution over an infinitude of time of an entire universe comprised of one single electron in an infinity of empty space? Do you think modern physics has the least idea how to answer that?
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Instances #2 and #3:
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Now, we should neither expect vacuum to undergo phase changes, nor to not undergo phase changes, if the universe expands arbitrarily -- we simply have no idea. But my point is, given that we have no idea, it is kind of silly to make particular predictions about what dark energy will or will not do.
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Instances #4 and #5:
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Carrier particles are virtual particles. We have not the least idea how virtual particles would act in a dynamical universe on that scale, nor do we have any idea that the whole "carrier particle" conceptual model would even apply.
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Instance #6:
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The question here is, which is the greater evil: to admit that which we simply don't know and likely never will, or to pretend that we do know and use it as a club with which to bludgeon others who think differently, when in fact we have not the least idea?
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CM: "Emphasis mine, of course."
DB: "Well, with that attitude, I don't expect to be getting ideas from
Ken G."
CM: "At least nothing of use for physicists. Let's look closer at some of his arguments in that post."
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Originally Posted by Ken G
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Originally Posted by Celestial Mechanic
All the "big rip" can do is dilute the most elementary particles since for all practical purposes they are point-like. [Snip!] In any event 10-1,000,000 particles per cubic gigaparsec is still not zero. That's mathematics, not pseudo-science
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On the contrary, nothing physical can happen to a single elementary particle. All of physics treats interactions between particles -- one particle cannot have an "event" occur. |
CM: "I actually agree with this. There cannot be matter without events. That is why I have to say to
BISMARCK that his hypothetical question about a universe with just a single photon in it is meaningless, sort of like trying to imagine the sound of one hand clapping."
BH: "I never understood that silly
koan."
CM: "But contemplating it sure keeps the navel-gazers engrossed for hours!"
Quote:
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Originally Posted by Ken G
So saying that there would still be "matter" at arbitrarily low density is indeed pseudo-science, ...
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CM: "Not true. Even at low densities, there would still be interactions, it would just take an unimaginable amount of time for the interactions to propagate from one particle to another."
Quote:
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Originally Posted by Ken G
... because at some point we simply have no useful definition of the word "matter"
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CM: "Well, I don't know, when does a particle of matter that finds itself in a big rip scenario stop being matter and becomes -- what? All the dictionaries may be ripped up but matter will still go on being matter."
BH: "No matter what!"
CM: "Right, no matter what. What follows is a bunch of solipsism that I will skip over, then we have this:"
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Originally Posted by Ken G
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Originally Posted by Celestial Mechanic
No pseudo-science here. In fact this property of hadrons was the inspiration for the original string theory of the late 60s.
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Again I must beg to differ. You suggest that new particles will "hadronize" and then get pulled apart, but I see no physical reason to suspect that virtual particles can become real enough to be pulled apart, in the absence of the kinds of interactions we normally need to do physics. |
BH: "There's nothing 'virtual' about any of the mesons and other particles created as the original baryons are pulled apart. They are as real as any other particle and not virtual at all."
CM: "Yes
Ken G has a fundamental misunderstanding of virtual particles and what they are, as I will comment on in a bit."
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Originally Posted by Ken G
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Originally Posted by Celestial Mechanic
Conservation of energy is rock-solid science. The energy to pull hadrons apart and form new ones has to come from somewhere. In a big rip scenario, the dark energy causing the big rip is the primary source of energy at hand. It is quite logical, maybe even Aristotelian, to suggest that dark energy be the source of the energy; it is, after all, the source of the "problem".
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Again, that is just pseudoscience. First of all, conservation of energy is simply a principle that is useful in a wide array of situations, but can be taken too seriously, just as everything else in physics can be taken too seriously. Has it ever been tested on the timescales of a Big Rip scenario? Of course not. |
DB: "Has
anything been tested in a big rip scenario? Has even the big rip scenario been tested? How
can it be tested?"
Quote:
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Originally Posted by Ken G
Should we expect it to work anyway? I hardly think so. One might expect it to work and of course we'll never know, but I think even a cursory examination of the history of science would dictate otherwise. For example, we now know that [it] is quite important for certain processes (like the hydrogen fusion that gave us life) that energy is not conserved on short enough timescales for virtual processes to occur.
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CM: "This is the place where
Ken G demonstrates his misunderstanding of energy conservation and virtual particles. He is referring to the four beta decays that occur in the process of fusing four protons into a helium-4 nucleus, whether by p-p or carbon cycle. Energy and momentum is conserved at every step: for example the total energy and momentum of the deuteron, positron and neutrino is equal to the total energy and momentum of the two protons that collided. The virtual particle in this interaction is the W
+ emitted by one of the up quarks when it changes to a down quark. Energy and momentum were conserved absolutely when it was emitted, and conserved again when the W
+ decayed into the positron and neutrino. What makes the W
+ a virtual particle is that it does not satisfy E
2-p
2=m
2, where m is the mass of the W-boson. (Units where c=1 used here.)
CM: "
Ken G's time would be better spent reading Weinberg than Wittgenstein.
Ken G continues:"
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Originally Posted by Ken G
Also, it is not clear that energy is conserved by global processes like the Big Bang itself. They are just examples of over-extrapolation of a principle, which I would classify as pseudo-science [Snip!]
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CM: "Is the Big Rip one of these 'global processes'? Is the Big Rip tearing a hadron into more hadrons a global process? Certainly not. And why is my hypothesis an 'over-extrapolation' and the Big Rip is not? There are some that would argue that our entire edifice of cosmology is one of these 'over-extrapolations'. After a bit we have:"
Quote:
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Originally Posted by Ken G
Also, there is no reason to expect "dark energy" to be able to manifest itself in the generation of particles. Dark energy might be a form of energy that can undergo no transitions of any kind without some kind of phase change happening in the vacuum. Now, we should neither expect vacuum to undergo phase changes, nor to not undergo phase changes, if the universe expands arbitrarily -- we simply have no idea. But my point is, given that we have no idea, it is kind of silly to make particular predictions about what dark energy will or will not do. [Snip!]
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BH: "Surprising that someone steeped in philosophy who claims that it gives us possibilities, has no ideas whatsoever. I see no reason why dark energy cannot generate particles. What is dark energy? What sort of particle carries it? How does it get generated without other particles generating it? As for phase changes, he gives two possibilities that seemingly exhaust the possibilities, either it changes phase or it doesn't, so we can expect one of them to occur, even if we can't figure out which one."
CM: "Good point. Next we have this:"
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Originally Posted by Ken G
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Originally Posted by Celestial Mechanic
Where can the carrier particles, once emitted, disappear to? They will still arrive at their destinations, it just may take 101,000,000 years to do so.
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Carrier particles are virtual particles. We have not the least idea how virtual particles would act in a dynamical universe on that scale, nor do we have any idea that the whole "carrier particle" conceptual model would even apply. |
DB: "Should someone with not even 'the least idea' even be discussing such things?"
CM: "More to the point brought up here though, is the fact that not all carrier particles are virtual. The photons that reach us from a distant galaxy are not virtual, the W's and Z's we've created in particle accelerators are not virtual. Another misunderstanding about the roles of real and virtual particles. And finally there is this:"
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Originally Posted by Ken G
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Originally Posted by Celestial Mechanic
Unfortunately all too often this is taken as an excuse to say, "We have no way of knowing and never will know", and that (along with the dozens of pages of arguments that usually follow) is what I take issue with.
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The question here is, which is the greater evil: to admit that which we simply don't know and likely never will, or to pretend that we do know and use it as a club with which to bludgeon others who think differently, when in fact we have not the least idea? |
BH: "If anyone here has been doing any 'bludgeoning', clearly it's been
Ken G, and
Disinfo Agent, occasionally assisted by
Len Moran and
Warren Platts. This was pointed out by
EDG_ in the
Science and Religion thread, for example. Endless nitpicks over the definitions of words, such as four definitions of 'Objective Reality', the insistence that any scientific idea be subjected to the most minute and rigorous examination while exempting the philosophical and the religious."
CM: "That's a bit harsh,
BH, even for me. I will grant that certain people here do tend to go off into philosophy and to do so in a way that is not particularly helpful to the scientific discussion at hand. We have to avoid more threads becoming YAUPTs."
DB: "But you still haven't really answered my question, and I see others are asking it too, namely, why are you posting this in the ATM section?"
CM: "Well, because
Ken G seems to think it is, and he is so well-versed in philosophy and knows exactly what science is and how it should be done that if he sees my speculations are pseudoscience, well, I've just got to believe him and take my lumps."
BH: "You don't actually
believe that, do you?"
CM: "Not a word of it. This isn't really that against the mainstream, as I'm not starting from a conviction that relativity and quantum mechanics is wrong or any of the weird misconceptions at the root of so many of the ATM theories we deconstruct here."
BH: "With enthusiasm and glee, don't forget!"
CM: "I'm not sure if I could come up with a true ATM theory, I'm more likely to consider some little side-eddy of the mainstream, and that's what this hypothesis is.
CM: "You see, that is the difference between me and
Ken G and the others: I have ideas, and they have no idea, not the least idea, and so forth. They can hold forth for page after page and edify each other with how much they don't know; I would rather add to what I know and possibly extend it to find out new things. That is my 'philosophy', make of it what you will."
To be continued...