Max Tegmark's infinite universes

[sol invictus]

A universe that we can't EVEN IN PRINCIPLE conceive or perceive without contradiction is arguably nonexistent.

As Roboramma says, that's obviously not what we're discussing. Discussing something like that would be rather difficult, in fact.

Back to reality, how can we evade the Count Chocula problem? One way, as I mentioned, is if the universe simply isn't spatially infinite. Cosmologists tend to assume it is because the part of it we can see is consistent with the universe being homogeneous, isotropic, and with zero spatial curvature. Those three together imply that the space is infinite, and that - together with the standard rules of quantum mechanics plus a little knowledge about the early universe - seems to lead us inevitably there. But of course since we can only ever see a finite part of the space, we can't ever know for sure that something doesn't change outside the region we can see.

So, is the existence of Count Chocula regions sufficiently disturbing that one can use them to argue that the universe cannot be homogeneous, isotropic, and with zero (or negative) spatial curvature? I find that difficult to accept. Science generally proceeds by finding the simplest possible theory that's consistent with data. In this case, that's a homogeneous and isotropic universe with zero spatial curvature.

Can we accept Count Chocula instead? I also find that difficult to accept... but if there's one thing the history of science has taught us it's that human intuitions about what is reasonable are very rarely trustworthy, particularly when it comes to situations far different from the environment we evolved in.

 

[fuelair]

Then he's wrong.

Which isn't surprising, since his infinite universe theory is a nutcase theory that no sensible physicist takes at all seriously.



No way to tell.

My bet is that it almost certainly has not, because there is less experimental evidence for Tegmark's infinite universes than there is for the Fundamentalist Christian God who created the universe in about 4000 BCE.

Not including the phrase nutcake, my first hit on disagreement with T. by physicists: http://physicsworld.com/cws/article/news/39306

Took 2 minutes to locate one. It is polite, but.

 

[sol invictus]

Not including the phrase nutcake, my first hit on disagreement with T. by physicists: http://physicsworld.com/cws/article/news/39306

Took 2 minutes to locate one. It is polite, but.

I skimmed the article. I don't see anything in it that's particularly relevant to the topic of this thread. He only mentions Tegmark once, in passing and in a different context than the one at issue here. And all the discussion of "timeless multiverses" is a little strange. I don't agree with his assertions about time and timelessness, nor does he provide any support for them.

 

[fuelair]

I skimmed the article. I don't see anything in it that's particularly relevant to the topic of this thread. He only mentions Tegmark once, in passing and in a different context than the one at issue here. And all the discussion of "timeless multiverses" is a little strange. I don't agree with his assertions about time and timelessness, nor does he provide any support for them.

I don't either, but above my "paygrade "- and he mentioned him to diss him so....

 

[Norm Breyfogle]

First of all, I'd like to apologize to you, drkitten, for my emotional reaction in referring to you (in my last post on this thread) as hostile. Your arguments are generally very valid (as far as I can tell, from my limited understanding), and I resolve to fully set aside any emotions which might get in the way of communication from here on.

This discussion is far "above my pay grade," too, and concerns some entirely different areas of expertise than anything I've mastered (math, for one, and QM, for another). However, this thread's OT and responses do indeed impinge on philosophy in a way in which I don't think some of you are fully acknowledging.

As far as I know (and over the last few days I've researched the subject some to make sure I haven't missed a new and complete formulation of any final GUT), the measurement problem in QM, and which of various interpretations of QM is most valid, hasn't been finally resolved. Although a general research approach assuming a kind of traditional scientific objectivity is taken, this hasn't formally or finally resolved the issues involved. Therefore, to say that a Count Chocula universe without humans in it could exist (or that it could even be described without contradiction) is to beg the unresolved questions of QM, isn't it? I'm willing to be educated on this point, but I feel quite certain that there is presently no way to resolve these issues in the way that drkitten (for instance) has implied that there is. What I think you're referring to instead, drkitten, is the fact that a majority of western philosophers and almost all scientists prefer a traditional sense of objectivity as a workable background assumption for laboratory research. However, this isn't the same thing as having the issue actually resolved. In fact, we can't really resolve it short of a final GUT.

 

[drkitten]

As far as I know (and over the last few days I've researched the subject some to make sure I haven't missed a new and complete formulation of any final GUT), the measurement problem in QM, and which of various interpretations of QM is most valid, hasn't been finally resolved. Although a general research approach assuming a kind of traditional scientific objectivity is taken, this hasn't formally or finally resolved the issues involved. Therefore, to say that a Count Chocula universe without humans in it could exist (or that it could even be described without contradiction) is to beg the unresolved questions of QM, isn't it?

Only in the sense that to make any definitive statement is to beg the unresolved questions of QM.

You're confusing the technical term "observer" in QM with the idea that there must be an actual intelligent, human observer.That's a common mistake among laymen but considered to be quite wrong among physicists; instead you get "observation" anywhere you get interaction with an observing instrument, which need not be conscious, and, really, need only be sufficiently complex and give macro-scale results.

Eugene Wigner is the only significant physicist who holds otherwise. And there's a reason that this particular theory is not taken seriously. Are you (or he) seriously suggesting that the sun had not been shining until the first Homo erectus noticed it? And why are you drawing the line at Homo erectus?

 

[Norm Breyfogle]

Your points are well made, and well received. I can see that you and I will continue to return to this point of discussion often, until we both recognize that we're really arguing semantics.

Obviously, it can be clearly demonstrated that any individual consciousness is separate from the objects in existence in the universe, but you can never do that for yourself in any *ultimate* sense, because you can't be aware of something and unaware of it at the same time, and we don't yet have an exhaustive GUT.

As far as I can tell, in your last post you're referring to an assumption of objectivity which is highly useful and verifiable in any or most particular situations we've encountered, but *might* not be true for existence as a whole. For instance, you could indeed be a butterfly dreaming this entire life of yours, including everything in it, or we could all be a computer simulation, etc. It's not useful reasoning for conducting science (about which I'm a strict scientific realist/objectivist, too), but it's a semantic backdrop of which we should be aware, it's not been disproved, and it couldn't be exhaustively disproved short of the formulation of a final, all-encompassing GUT.

This reasoning is relevant to this thread because, when it comes to either alternate universes, a multiverse, Tegmark's speculations, or in fact any overarching cosmology or philosophical speculation, we are in a similar situation: until we have an exhaustive GUT, we can't be absolutely certain that such radically imaginative speculations (like Tegmark's) are untrue or possible or self-contradictory.

 

[drkitten]

Obviously, it can be clearly demonstrated that any individual consciousness is separate from the objects in existence in the universe, but you can never do that for yourself in any *ultimate* sense, because you can't be aware of something and unaware of it at the same time, and we don't yet have an exhaustive GUT.

Sure I can. My lab assistant tells me "there's something in the box, and you don't know what it is."

Obviously, the objects in existence are separate from the objects of which I'm conscious.

For instance, you could indeed be a butterfly dreaming this entire life of yours, including everything in it, or we could all be a computer simulation, etc.

Right. We're back to newage claptrap.

we can't be absolutely certain that such radically imaginative speculations (like Tegmark's) are untrue or possible or self-contradictory.

Really? You were pretty damn certain a few posts ago that the Count Chocula universe was self-contradictory and therefore impossible:

if a universe existed in which there was ONLY Count Chocula, would anyone know it? No, because by definition no one could perceive it in any way, even in principle, and so it would be meaningless to say it existed at all. Therefore, the actually existent non-contradictory universes must be ones much like ours in which humans exist.

Now that we've shown that this statement is completely baseless and without foundation, you're back to the standard newage claptrap of "oh, but science might be completely wrong about everything, and therefore you should take this completely unsupported belief of mine as seriously as the stuff we've got actual evidence for."

No. We shouldn't.

 

[sol invictus]

As far as I know (and over the last few days I've researched the subject some to make sure I haven't missed a new and complete formulation of any final GUT), the measurement problem in QM, and which of various interpretations of QM is most valid, hasn't been finally resolved.

That's true (although you're confused about what a GUT is - having a successful GUT wouldn't help in the slightest).

Therefore, to say that a Count Chocula universe without humans in it could exist (or that it could even be described without contradiction) is to beg the unresolved questions of QM, isn't it?

No.

I'm willing to be educated on this point, but I feel quite certain that there is presently no way to resolve these issues in the way that drkitten (for instance) has implied that there is.

You're wrong.

What I think you're referring to instead, drkitten, is the fact that a majority of western philosophers and almost all scientists prefer a traditional sense of objectivity as a workable background assumption for laboratory research. However, this isn't the same thing as having the issue actually resolved. In fact, we can't really resolve it short of a final GUT.

There is no remotely mainstream interpretation of QM in which a falling tree makes no sound if there's no one there to hear it. Human perception, and humans in general, play no special role whatsoever. A human absorbing some sound waves and experiencing them mentally is not different in any way relevant to this discussion from a rock absorbing them.

 

[Norm Breyfogle]

Kinda cute how you guys feel the need to assume as true that which is clearly not proven or even falisfiable (i.e., any final hypothesis re the ultimate nature of consciousness and its relationship to the objects of consciousness). All the assuming in the world won't resolve the issue, just as all the assuming in the world won't definitively falsify Tegmark's speculations, or the speculative Many Worlds hypothesis re QM.

Such speculations aren't "New Age claptrap"; they're merely speculations. They would indeed be New Age claptrap if any of them were assumed to be proven true (which I'm definitely not doing).

 

[drkitten]

Kinda cute how you guys feel the need to assume as true that which is clearly not proven or even falisfiable (i.e., any final hypothesis re the ultimate nature of consciousness and its relationship to the objects of consciousness). All the assuming in the world won't resolve the issue, just as all the assuming in the world won't definitively falsify Tegmark's speculations, or the speculative Many Worlds hypothesis re QM.

Nor will all the assuming in the world falsify Sagan's invisible dragon in the garage.

Such speculations aren't "New Age claptrap"; they're merely speculations.

No, they are precisely newage claptrap.

One of the key marks of newage claptrap is the use of unfalsifiable and unsupportable speculation to reject scientific consensus based on large amounts of actual evidence.

We have, for example, evidence that objects can exist without a specific human being being conscious of them. We recreate such situations routinely in the lab. We have evidence that objects can exist without any living human being being aware of them. The recent Anglo-Saxon (or earlier, the Sutton Hoo) illustrate that. We even have evidence that objects can exist without any human being, living or dead, being aware of them. For example, we've found old photographs that clearly show celestial objects that would not be "discovered" for some time.

And yet, on the basis of a speculative, unprovable, and even unsupportable theory of mind, you reject the possibility that the Count Chocula universe could exist, claiming it to be self-contradictory.

That, sir, is newage claptrap.

They would indeed be New Age claptrap if any of them were assumed to be proven true (which I'm definitely not doing).

No, you're definitely doing it. You're just embarassed to be caught with your hand in the cookie jar, so to speak.

 

[Norm Breyfogle]

"No, you're definitely doing it. You're just embarassed to be caught with your hand in the cookie jar, so to speak."

- drkitten

---------------

No, I'm definitely not doing it. You're just embarrassed by the fact that you've misunderstood what I've expressed, and now can't admit it.

I'll even own some blame for that confusion, due to my not making myself more clear (though I'm really trying to do so).

Once again, has the measurement problem in QM been resolved? Don't many cosmologists - in increasing numbers - recognize the value of the Many Worlds hypothesis re QM? And, is there no value at all to Tegmark's speculations? Isn't subjectivity one intractable aspect of a definition of consciousness? Aren't you assuming, without final proof, that consciousness can be absolutely separated from the objects of consciousness on the ontological level? Aren't you continuing to confuse my ontological speculations with ontic beliefs?

 

[sol invictus]

Once again, has the measurement problem in QM been resolved?

Not definitively, no. But with every post of yours I grow more convinced that you don't know what the "measurement problem in QM" actually is.

Don't many cosmologists - in increasing numbers - recognize the value of the Many Worlds hypothesis re QM?

It's my impression that most physicists that bother to think carefully about it regard the MW interpretation as the one most likely to be correct. Everything I've said in this thread is true in MW (as it is in all the other reasonable interpretations). Human consciousness has absolutely nothing to do with it.

And, is there no value at all to Tegmark's speculations?

I would say there is, if only as a reductio ad absurdum. You were the one asserting that the Count Chocula universe is impossible even in principle.

Isn't subjectivity one intractable aspect of a definition of consciousness? Aren't you assuming, without final proof, that consciousness can be absolutely separated from the objects of consciousness on the ontological level? Aren't you continuing to confuse my ontological speculations with ontic beliefs?

You made a bunch of absolute, and absolutely false, assertions. Then you attempted to back them up with vague mumblings about interpretations of QM. Unfortunately for that style of argument, I'm rather knowledgeable about that particular topic. I can call BS.

The Count Chocula universe with no humans in it isn't just possible in the MW interpretation, it is predicted by it (at least under the assumption that the universe has infinite volume plus some minimal information about its early stages). That's basically Tegmark's point, although it's not contingent on MWs being correct.

 

[Roboramma]

Kinda cute how you guys feel the need to assume as true that which is clearly not proven or even falisfiable (i.e., any final hypothesis re the ultimate nature of consciousness and its relationship to the objects of consciousness). All the assuming in the world won't resolve the issue, just as all the assuming in the world won't definitively falsify Tegmark's speculations, or the speculative Many Worlds hypothesis re QM.

Such speculations aren't "New Age claptrap"; they're merely speculations. They would indeed be New Age claptrap if any of them were assumed to be proven true (which I'm definitely not doing).

Similarly I find it kinda cute how you feel the need to assume as true the idea that there is no teacup orbiting Pluto.

This speculation that there is a teacup orbiting pluto is not "New Age claptrap", it's merely a speculation. It would indeed be New Age claptrap if it were assumed to be proven true (which I'm definitely not doing).

 

[Roboramma]

"No, you're definitely doing it. You're just embarassed to be caught with your hand in the cookie jar, so to speak."

- drkitten

---------------

No, I'm definitely not doing it. You're just embarrassed by the fact that you've misunderstood what I've expressed, and now can't admit it.

Um...

Therefore, the actually existent non-contradictory universes must be ones much like ours in which humans exist.

That's a pretty definitive statement, which you either hold or don't. I'm happy if you don't consider it true any more, but you haven't said as much yet.

Once again, has the measurement problem in QM been resolved? Don't many cosmologists - in increasing numbers - recognize the value of the Many Worlds hypothesis re QM?

I don't think you understand the implications of quantum mechanics. As sol said, they do not support your position.
But to stay fair and clear: What, specifically, about the many worlds interpretation shows that the Count Chocula universe is impossible, or that things don't exist without human (or conscious) observers?