Things you can't verify

[Philo Sofee]

Sean Carroll
Again, your practice of science is affected by the reason-ability of this multiverse scenario.

I'm going to pull an Isaac Asimov on Carroll. FIRST show me the multiverse, then we can realistically and logically talk about the ability of the reality. As such, your fantasy has no ability or reason to change anything empirically about our universe, our world, or our lives and their meanings.

Again, if that is too skeptical, show me the strings in string theory, not the mathematical speculations and philosophical possibilities of 10, or 11, or now even 15 different dimensions. This is all fart in the wind without actual evidence. That a scientist no longer grasps this, but challenges us to refute his fantasy or else it must be the only way is astounding arrogance. "Theoretical physicists used to explain what was observed. Now they try to explain why they can't explain what was not observed." (Wolfgang Smith The Vertical Ascent, Philos-Sophia Initiative Foundation, 2020: 52, quoting the particle physicist Sabine Hossenfelder, Lost in Math, Basic Books, 2018: 108).

[Philo Sofee]

Rivendale
To be fair to Carroll he supports his conclusions. He claims that the many worlds is the most parsimonious explanation.

Then he is literally out to lunch. There is no way invoking an infinite amount of universes in order to continue trying to make sense of the silly fantasies of current particle physics is "the most parsimonious explanation."

This is the singular most ludicrous thing I have read in years... YEARS. The easiest explanation from our current ignorance of astrophysics is to invoke, with no possibility of ever even seeing any evidence is our fantasy invocation can even be called real, a literal infinite amount of universe just to satisfy our desire to make the probabilities work??? I am supposed to swallow this swill???
The word parsimonious has obviously changed definition then.

[Philo Sofee]

And his defense of anti science claims.

Just to be absolutely crystal ***CLEAR*** my disagreeing with Carroll's ludicrous stance and fantasy example of utmost silliness, is not anti-science, it is anti-Carroll philosophy. He's done some great work in the past and I have enjoyed a lot of his material. This... this is idiotic to the 465,467,306,345,388,112,329 power since he is "parsiminously" invoking an infinity of universes (literally, utterly stupidly absurd) which can never be seen, heard from, or found, in order to back his claim... and then he says I am obligated to show why I disagree with it?

[Philo Sofee]

Let us remember THE glory, the CROWNING achievement of science is that it has destroyed religion because religion is based on "things you can't verify" while science is the exact opposite. That is it's glory, the verification with evidence of claims and theories being made, which religion with its multitudinous gods has failed to do for millenia.

[Res Ipsa]

Philo, I read the transcript and it seems to me that you may be strawmanning Carroll a bit. The subject of the podcast is how to think about multi-verses if we assume they exist. And he seems pretty clear that what he sees himself doing is some combination of philosophy and science, with heavy emphasis on the philosophy part. In fact, he is careful to say that there is no "multiverse theory" - that multiverses are based on predictions made by other theories. Indeed, he says that physicists were dragged kicking and screaming against their will to even have to think about multiverses.

His argument about "what is science" is, in fact, very narrow. It simply states that theorizing is part of science, as long as that theorizing is constrained by what we know. In that way, it's a defense of Einstein's attempt to visualize what it would look like to be on a trolley moving at the speed of light (something that cannot be experimentally tested).

His statements about having an obligation to provide alternative explanations are also within a specific context that I think is omitted here. He's not arguing about theoretical burdens of going forward or providing evidence or proof. He's stating a practical issue that I don't think should be controversial at all. If what I am trying to do is explain X and I reject a currently untestable theory Y as an explanation, then if I'm going to explain X, then I will have to devise a theory that will account for the things that Y explains. What's being left out of the quotes from Carroll is the conditional "If you want to explain X..." Carroll never says or implies that anyone has an obligation to accept or refute unfalsifiable explanations -- only that alternatives to existing theories still have to explain what existing theories purport to explain.

I also think your approach to what is a parsimonious explanation is off base. There is a significant difference between the assumptions of a theory and the practical effect of a theory. The simplest theory of evolution was random mutation + nonrandom natural selection. But the effect of those two assumptions was to generate an amazing and complex web of life on earth. The complexity of the result shouldn't affect our judgment of how parsimonious the assumptions are. What should count is the assumptions in inflationary theory or quantum mechanics that are made to explain what is observed in those areas and not the complexity of the results of those assumptions.

As for the crowing achievement of science, I would point to about a million things of importance that science has accomplished before I even stopped to think about its effect on religion. I still see lots of religion around, so trumpeting its destruction seems to me a little premature.

[DrStakhanovite]

So scientists propose a multiverse (there goes Occam's Razor with a vengeance!)

Like any version of the principle of parsimony, Occam’s razor is a rough heuristic that can’t really be consistently applied. Appealing to such an idea is usually a last resort.

…and then if someone else doesn't believe it, it is up to THEM to explain why and THEY must defend their reasons?!? B.S.. I am not obligated to believe something simply because someone proposes it, even if it is proposed with logic.

But that isn’t what he is doing:

0:43:46.1 SC: So that’s three different versions of physics-oriented multiverse. The cosmological multiverse, the many worlds of quantum mechanics, and an eternal fluctuating cosmology. The eternal fluctuating cosmology is a kind of a multiverse in time. It’s not like different regions of space or are different universes, but if you wait long enough, whatever kind of universe you want to think about will fluctuate into existence. So it is effectively a multiverse.

0:44:11.6 SC: One thing to emphasize, which I’ve noted all along, is that every single one of these three options is a consequence of other ideas. It is not put forward for its own sake. And it’s a consequence of other ideas that were proposed in order to account for data. In order to explain the universe that we see… So it is 100% the standard scientific process going on here. There is no sense, some diversion or distraction away from doing real science by thinking about these different multi-verses.

I don’t understand why you think he is talking fantasy when he devotes two hours trying to walk people through his thinking.

Wolfgang Smith is right, science has become a dogmatic affair and has lost it's way. It is NOT science to say, "Hey we have a proposal, without any kind of evidence whatsoever, so it is utterly pure fantasy, but you have to believe us, or else say why you don't accept our fantasy." The plain fact is, I do not have to believe one word of your fantasy, and I truly have no obligation whatever to justify me simply saying no to it.

The only thing you are really voicing here is an objection about dialectical procedure, but you still need some kind of epistemic justification as to why you think there isn’t an entailment between prevailing theories and some version of a multiverse.

I do have to say Carroll is spot on with this:

0:45:39.4 SC: The all too easy objection to the multiverse is that it’s not falsifiable. Famously Sir Karl Popper, a philosopher of science proposed the falsifiability criterion to demarcate scientific theories from non-scientific theories. Now, almost none of the physicists who bring up falsifiability have actually read when Karl Popper wrote, but they carry on their shoulder a little straw Popper that they have simplified down to this motto that says, “If you can’t falsify the theory through an experiment then it’s not science.” That’s not what Popper said. That’s certainly not what philosophers of science believe. They don’t even believe the falsifiability works at all, generally… Most of them… As a demarcation between science and non-science.

I’ve read every technical publication of Popper’s and most of his non-technical work and I will completely co-sign the above. He goes on to say:

0:48:05.2 SC: So it’s saying something definite, but you don’t know. You’re not gonna be able to test it in any simple way. So should we count it as science? Well, of course, we should. And Popper, I think would agree with me about this ’cause he had different fish to fry. The basic issue is that these scenarios could be true, and that really could be the way nature works. And that’s a difference with what Popper was worried about. There really could be other universes out there elsewhere in the wave function or in space or in time.

0:48:36.5 SC: And the reason why it matters is because whether or not there are these other universes affects how we do science here in this universe trying to explain the data that we have in our observable part of the universe. When you do cosmology or when you do these large scale scenarios to explain the universe, things are connected to each other. They’re interrelated. We talk about the multiverse and things we can’t observe. But the reason why we talk about them is because they play an explanatory role in what we do observe. And this is just science. This is not anything new.

Carroll either consulted an excellent source on Popper or did a lot of legwork reading him, because I can only agree. More to the point, the bolded part is a routine practice. I can understand why someone might dispute that a multiverse is somehow entailed by current data and explanatory models, but I don’t understand this sentiment:

Carroll cannot possibly be taken seriously that he is working with 100% science, in the multiverse, when there is precisely, and exactly NO EVIDENCE for this postulate, in any manner, nor, in theory can there be.

So now I’m curious Philo, could you walk me through the following quote and tell me why it can’ be considered science?

0:49:14.0 SC: I’m not in the camp that says, we need to think about a new paradigm for doing science because of the multiverse. It’s exactly the same paradigm we always had. We come up with a theory, we use it to account for the data. So for example, in the cosmological multiverse, we invoke the cosmological multiverse as an explanation for the observed value of the vacuum energy and possibly for the observed values of other constants of nature, like the mass of the Higgs boson and so forth. To account for the apparent mysterious numbers that we observe in physics. The fine tuning of certain parameters. That was what Steven Weinberg tried to do before we even knew the cosmological constant was not zero. And so the point is, if you are a working physicist and you say, I would like to understand why the vacuum energy has the value it does. Whether or not you think that the cosmological multiverse is a promising theory… Absolutely, indisputably affects what kind of theoretical ideas you will consider and put forward.

0:50:20.7 SC: If you don’t think that the multiverse makes sense or is there, then it is beholden on you to come up with some dynamical mechanism that explains why the cosmological constant has the value we observe. If you do think that the multi-verse is there, then arguably, you don’t need to do that, it’s just an environmental selection effect. Although you can’t have a dynamical theory that predicts with probability, one, that the cosmological constant has a certain value and think that that’s a good theory if it has other values elsewhere.

Carroll is just making an inference to the best explanation. How does favoring an interpretation of data and asking for a more viable alternative to that interpretation somehow not scientific?

[DrStakhanovite]

Philo, I read the transcript and it seems to me that you may be strawmanning Carroll a bit.

That is an understatement, Carroll does warn listeners about how some people react to it:

0:44:47.7 SC: Nevertheless, not everyone agrees. People object. There are people out there who don’t like these discussions of multi-verses. And to be honest, it gets weirdly emotional. People get very angry talking about the multi-verse on both sides. On all sides, I should say. They talk to each other about being unscientific and they get kind of ad hominem and name call-y. And it’s really kind of tiresome. And that’s kind of what I don’t want to talk about here today.

[Philo Sofee]

Yeah I have jumped the gun and commented on comments without actually getting to Carroll's materials. So, my bad. I ought to know what I am responding to before responding eh? GRIN! I've been getting over Covid, and now my wife has it, sooooo, sorry to appear to be so short tempered. I had no business posting anything yet on this. I shall have to read it or listen to it soon.

[DrStakhanovite]

Yeah I have jumped the gun and commented on comments without actually getting to Carroll's materials. So, my bad. I ought to know what I am responding to before responding eh? GRIN! I've been getting over Covid, and now my wife has it, sooooo, sorry to appear to be so short tempered. I had no business posting anything yet on this. I shall have to read it or listen to it soon

s'all good, despite my best efforts, I jump the gun on a semi-regular basis.

[dastardly stem]

Yeah I have jumped the gun and commented on comments without actually getting to Carroll's materials. So, my bad. I ought to know what I am responding to before responding eh? GRIN! I've been getting over Covid, and now my wife has it, sooooo, sorry to appear to be so short tempered. I had no business posting anything yet on this. I shall have to read it or listen to it soon.

I went hasty too. I grabbed the wrong David Deutsch quote I intended to include. Oops.