Is speculation in multiverses as immoral as speculation in subprime mortgages?

[D H]

The title of the thread is the same as this blog post at http://www.scientificamerican.com/blog/post.cfm?id=is-speculation-in-multiverses-as-im-2011-01-28&WT.mc_id=SA_SA_20110216 about Brian Greene's new book, The Hidden Reality: Parallel Universes and the Deep Laws of the Cosmos. A snippet:

My beef with Greene is this: He has become a cheerleader for the descent of theoretical physics into increasingly fantastical speculation, disconnected from the reality that we can access empirically.​

So, has theoretical physics (or some aspects of it) stopped being science?

 

[MathematicalPhysicist]

Who really knows?!

 

[element4]

So, has theoretical physics (or some aspects of it) stopped being science?

In the measurable set of "theoretical physics", the subset "string theory" is so tiny that it almost have measure zero! ;)

 

[marcus]

The "multiverse" vision is a graphic depiction of the defeat of physics.

It symbolizes giving up on the centuries-old program to find what constitutes the world we experience and to explain how it works. Many excellent people in theory have not given up on this endeavor---and are far from accepting defeat.

So in that sense the multiverse is a false vision: it conveys the false message that we are being forced to give up on the aim of a unique testable explanation of why the world is as it is.

The string program (as physics) may or may not have run into trouble, but I see no evidence that the rest of theoretical physics is stalled or plagued by intractable landscapes of variant theory. Be that as it may, the fate of one particular theoretical initiative is irrelevant from an historical perspective and hardly warrants a change of plans .

Overall, the signs are that progress continues.

 

[crackjack]

aim of a unique testable explanation of why the world is as it is

Given that such an explanation of the world, which is both complete and consistent, can never be found, how do we judge what is immoral - running behind one unreachable (and hence, unknowable) target OR giving up closer to the start of the game and start fantasizing about cute targets?
I would just let everyone get off and enjoy his/her own mental wa*king.

 

[marcus]

...
I would just let everyone get off and enjoy his/her own mental wa*king.

I can understand your attitude, crackjack.
But I would like to put in a good word for continuing to aim for a unique testable explanation of why the world we experience is as it is.

It is something that we can approach by successive approximations, even if we never reach a final understanding. It's the traditional goal of physics as an empirical science. And there are no indications now that it is any less practical as a goal than would have seemed back 100 or 200 years ago. It is still a good goal to strive for and remarkable progress has been made in just the past 50 years.

I don't see some temporary disappointment and frustration in one or two departments of theory as signs that the overall program is ill-conceived. Note the encouraging advance in early universe cosmology just in the past 10 or 15 years. No mere mental wanking that

 

[crackjack]

@Marcus

:D

I agree, but the counter-examples you cite are not the right ones. Just some people believing in multiverse does not mean that they think we should not study about unification or cosmo theories of our early verse etc. They are saying that, once all this is done and when we reach the question of "why such a specific bang?", they will come in with "there are all possible bangs".

 

[zaybu]

Personally, I hope that the LHC will nullify supersymmetry, by the same token, String theory. Hopefully, physicists will come to their senses, and stop this nonsense of indulging into that kind of "science fantasy".

 

[atyy]

http://arxiv.org/abs/0801.0246

I came across this from reading http://backreaction.blogspot.com/2011/01/is-universe-fine-tuned-for-life.html

 

[D H]

Personally, I hope that the LHC will nullify supersymmetry, by the same token, String theory.

I suspect most physicists hope otherwise, at least in the sense that the LHC will come up with some result that the standard model cannot explain. There haven't been enough "who ordered that" discoveries in physics for quite some time.

 

[zaybu]

I suspect most physicists hope otherwise, at least in the sense that the LHC will come up with some result that the standard model cannot explain. There haven't been enough "who ordered that" discoveries in physics for quite some time.

In a sense, I'm with you on that -- a particle that cannot be explained by the Standard Model would be cool, as long as it doesn't prove SuSy or ST.

 

[D H]

First off, what would be wrong with that?

Secondly, a new discovery won't prove string theory. A new discovery might disprove string theory (assuming string theory is falsifiable) or it might be consistent with string theory. Consistency is not the same as proof, any more than the observation of a white swan is proof that all swans are white.

 

[atyy]

The article makes a big deal about Popper. But hasn't he already been falsified by Dirac's lone monopole?

 

[zaybu]

First off, what would be wrong with that?

It's my negative attitude towards extra dimensions. Basically, I don't believe in that, and anything that utilize that concept, hopefully, will never be proved.

Secondly, a new discovery won't prove string theory. A new discovery might disprove string theory (assuming string theory is falsifiable) or it might be consistent with string theory. Consistency is not the same as proof, any more than the observation of a white swan is proof that all swans are white.

Fine, but the sooner we get off the String Theory bandwagon, the better we will be, and the more hopeful the future of science will look.

 

[D H]

It's my negative attitude towards extra dimensions. Basically, I don't believe in that, and anything that utilize that concept, hopefully, will never be proved.

Then you are no better than, and are arguably worse than, than those who talk about truly unprovable things such as non-communicating universes. You are sounding like those who argue against relativity.

The laws of physics don't care / the universe doesn't care what you think.

 

[zaybu]

Then you are no better than, and are arguably worse than, than those who talk about truly unprovable things such as non-communicating universes. You are sounding like those who argue against relativity.

The laws of physics don't care / the universe doesn't care what you think.

The difference is that there is evidence in supporting relativity, otherwise the theory would have been thrown away a long time ago. However, there no evidence supporting the idea of extra dimensions, and I don't think that can be falsifiable. To me, that smells of science fiction. At this point, I might as well believe in the supernatural, and in case you might be wondering, I don't believe in that nonsense as well.

 

[jal]

This question has comes up many times and in many form.

A search... Here is what has been presented on this forum.


https://www.physicsforums.com/showthread.php?t=31263

https://www.physicsforums.com/showthread.php?t=468837

https://www.physicsforums.com/showthread.php?t=465313

https://www.physicsforums.com/showthread.php?t=460444

AND
if you have neglected or ignored my blog go to

https://www.physicsforums.com/blog.php?u=58039
jal

 

[Fra]

The difference is that there is evidence in supporting relativity, otherwise the theory would have been thrown away a long time ago. However, there no evidence supporting the idea of extra dimensions, and I don't think that can be falsifiable. To me, that smells of science fiction. At this point, I might as well believe in the supernatural, and in case you might be wondering, I don't believe in that nonsense as well.

I do not advocate string theory, but I think it's still fair to say this:

From the point of view of a string theorist, there is certainly rational reason to believe in extra dimensions, simply because given the premises in string theory, and the conjecture that elementary particles are rather excited strings, then this together with some convenctional QFT stuff follows as consistency constraints. This logic is there, and it's a different kind of "supporting argument".

I can see that, even if I don't buy into string theory.

But my argument isn't that "I don't like" extra dimensions. My doubt is two-fold.

First of all I simply don't find the initial premises and baggage that leads to string theory, plausible or deep enough anlysis of the problems to yield my any faith in whatever that leads to by consistency. Also I see no deep conceptual reason to accept the string starting point. Apart from the original motivation of strong interaction, it seems more like a mathematical "what if" game.

The other idea is that I can accept a random speculation, if it indirectly helps the scientific process, which then indirectly, if it proves itself, is support for the originally random conjecture. However, it seems that the string conjectures doesn't help the decision process, it rather instead obscures it by suggesting a whole landscape of possible ideas. One may at some point ask how much deeper in that hole we should keep digging before reflecting upon wether something is missing, or wether something in the initial analysis that lead us here is wrong.

In that perspective I definitvely agree that all these multiverse ideas etc are steps in the wrong direction. One has to be able to distinguish between real possibilites in a decision process, each of one makes a difference, and ideas of different universes with totally different laws where we are simpyl for some reason stuck in one of them. The latter type of "possibilities" are not making any difference to the scientific process unless there is an algorithm or way of navigating/selectin between this possibilities. This is precisely as far as I know what's lacking in string theory.

I think that the supposed answer to the "what if game" is that it seems to lead us into a space of possibilities where we can not navigate. I think this alone, doesn't seem like anything that helps the scientific process.

It's the navigation process we need to understand. This is also the essence of evolution. String theory seems to paint up some gigantic space of states of laws, deduced from a what if assumption, but lacking selection principle.

Science should not try to make a list of all possible truths. That's meaningless unless there is a learning mechanism. Science IMHO should focus on the learning. Poppers abstraction is an attempt to bring order to this inductive process. I think one can critique popper without favouring string theory.

Poppers abstraction of the scientific method misses the same thing that ST does; the logic of how the generated a new hypothesis once one is shot down. This is the learning step. ST, makes a hypothesis SO complex that all resources are going into the descriptive process of defining all the possibilities. To the point where the learning process is STALLED.

If ST could replace the falsification with an efficient algorithem that with experimental feedback quickly converges in hte landscape then fine. BEcause then the "corroboration" would be convergence. If the strategy divergeces (like is certainly SEEMS to do!) then it's "wrong" (ie it doesn't work). But even that seems lacking.

/Fredrik