While we’re getting the multiverse out of our system, let me point to this interview with Leonard Susskind by Amanda Gefter over at New Scientist (also noted at Not Even Wrong). I’ve talked with Amanda before, about testing general relativity among other things, and she was nice enough to forward the introduction to the interview, which appears in the print edition but was omitted online.
Ever since Albert Einstein wondered whether the world might have been different, physicists have been searching for a “theory of everything” to explain why the universe is exactly the way it is. But one of today’s leading candidates, string theory, is in trouble. A growing number of physicists claim it is ill-defined, based on crude assumptions and hasn’t got us any closer to a theory of everything. Something fundamental is missing, they say (see New Scientist, 10 December, p 5).
The main complaint is that rather than describing one universe, the theory describes some 10500, each with different kinds of particles, different constants of nature, even different laws of physics. But physicist Leonard Susskind, who invented string theory, sees this huge “landscape” of universes not as a problem, but as a solution.
If all these universes actually exist, forming a huge “multiverse,” then maybe physicists can explain the way things are after all. According to Susskind, the existence of a multiverse could answer the most perplexing question in physics: why the value of the cosmological constant, which describes how rapidly the expansion of the universe is accelerating, appears improbably fine-tuned to allow life to exist. A little bigger and the universe would have expanded too fast for galaxies to form; a little smaller and it would have collapsed into a black hole. With an infinite number of universes, says Susskind, there is bound to be one with a cosmological constant like ours.
The idea is controversial, because it changes how physics is done, and it means that the basic features of our universe are just a random luck of the draw. He explains to Amanda Gefter why he’s defending it, and why it’s a possibility we simply can’t ignore.
Right on Aaron! You know, what’s just amazing to me is how the arguments can seem to go on forever about the consequences of GR and cosmic inflation, and yet apparently very few are willing to think that it just might be that the concepts of GR, inflation, and the whole cosmological model are the real problem. Given the constants of G, c, and h, we are fixated on interpreting them in only one way, even though it leads to confusion and desperation. Just because GR works does not mean that we understand the nature of space and time correctly, and just because QM works does not mean we understand the nature of space and time correctly.
In fact, Gross’s continual insistence that we are missing something fundamental about space and time should be the focus of the intense discussion, instead of Susskind’s multiverses. You can be assured that this “period of utter confusion” is caused by our current theories, not by nature. The contradiction in the space and time concepts of GR and QM are certainly a challenge to finding a T.O.E., but stubbornly assuming that they can be reconciled, that they must be reconciled, that they are not both wrong in some respect, is as an unscientific position to take as any ever taken in the past.
But what’s worse is that when these two theories are employed to devise a cosmological model, knowing that they are fundamentally contradictory, and the result requires an ad hoc invention like cosmic inflation to avoid disaster, the whole thing leading to the absurd conclusions now being seriously entertained, no one is willing to tell the emperor that he has no clothes on. It’s time someone stood up and recognized that the contradiction of GR and QM means that maybe what we think is space is not space, and what we think is time is not time.
The vacuua, the vacuua, my kingdom for a doggone vacuua. Crap, we think we know, we are absolutely convinced, that there is a suitable vacuum energy out there that can be uniquely determined either by a “deep and inevitable” principle, or, heaven forbid, an environmental “selection principle.” Meanwhile, it’s just too iconoclastic, even for the most daring rebels among us, to think that finding a suitable vacuum energy has nothing to do with how nature is put together. Oh my gosh, we have G, and we have c, and h, and by golly, they give us a Planck length and a Planck mass, so we’re not going back — the answer has to be down there, somewhere way, way down there, in the vacuum.
Sorry, guys. All indications are that we’re barking up the wrong tree, or walking the plank (pun intended).
If you want to get some idea of the damage to the public perception and understanding of science that the pseudo-science promoted by Susskind and followers is about to cause, take a look at
http://www.helives.blogspot.com/2005_12_01_helives_archive.html#113465921781166371
which concludes:
“Susskind has presented the physics community with what is, for some (not this writer), a Sophie’s Choice: a hidious, complictated, unfalsifiable String-Theory Landscape, or Intelligent Design.
Susskind rocks.”
It’s utterly appalling that virtually no prominent particle theorist besides David Gross is willing to publicly take on Susskind. And not just on the question of whether or not he is the “father of string theory”.
Well, I like to think that I invented the concept of gourmet ketchup, and this feeling is not dampened by learning that someone else invented it first without telling me. Although, to be fair, I won’t be including that on any book jackets.
Imagine “superfluids” as ketchup? Hardly? 🙂
Bubble nucleation is interesting and why wouldn’t it be?
I like Moshe’s point of view better, that indeed perspecive change can initiated “other ideas” about the physics, and the way we do things ( maybe he didn’t say that exactly). Who might have known that Dirac’s sea would not have been a supefluid?
Of course, I speculate, yet vision is driven down to enormous potentials. Some cannot “fathom” standing at the edge? Heretics the whole works? They should be burned for insighting ID?
Come on 🙂
I knew the ID people would pick up on string theory eventually.
I’m curious to see the way it’s explained how string “theory” is a valid scientific theory while intelligent design is not?
I am a product of “M” What can I say:) I try to understand the “negative expression” as much as I can. It does not mean I am evil:) I’m just learning.
You just had to know where the hole was to make it flip? I don’t.
Grue and Bleen?
Why the Anthropic Principle, anyway? Why not the “Quarter-Pounder-With-Cheese Principle” ? Since humans pre-exist hamburgers the universe that produces hamburgers is even more specific (fine-tuned) than the universe that produces humans. Does Susskind have hamburgers covered? With all the fixin’s? Then I’d be impressed.
Modern theoretical physics looks like philosophy-by-numbers, but that’s ok – philosophy and science are fraternal twins; every few centuries they have a reunion.
In any case, it seems to me that the multiverse idea is no harder to swallow than the notion of a single universe; both are inexplicable by our best current theories.
Doug: For sure – we’re missing something fundamental about space and time; you’ve gotta know that in your gut. I doubt that we can understand time and space without being able to answer the ‘hard question’ of consciousness.
sisyphus:
Hamburgers are an essential ingredient of the modern universe; they explain why we have entered a new inflationary epoch see here.
🙂
Suppose GR was a perturbatively renormalizable QFT. Would you be any happier right now?
I would have been just as guilty of comparing aromatic smells, to the values of sound froma fifth dimenisonal perspectve, as having choosen “M” for Macs?
Well, Robert Laughlin would have been glad for you choosing what ever building blocks you choose 🙂
Cycle of Birth, Life, and Death-Origin, Indentity, and Destiny by Gabriele Veneziano
These were not simple questions that were unprepared for on how we saw the cosmos giving it disrespect? But the true father is certainly dealt his share? 🙁
Would life be possible in a universe with a single generation of quarks and leptons of the standard model, instead of three generations? If yes, then doesn’t that put paid to the anthropic principle?
While I am not capable of answering your question and maybe someone will, nonetheless, it becomes a interesting journey, looking, to find an answer.
Why this universe?
http://www.nap.edu/books/0309074061/html/10.html
This is a wonderful blog—I am glad to have found it via my site log.
I want to comment on what Peter wrote in #29, where he refers to “the damage to the public perception and understanding of science that the pseudo-science promoted by Susskind and followers” with the evidence he provides being a excerpt and a link to a post of mine.
Susskind is not the darling of this (cosmological) IDer. After all, he is out to destroy the fine-tuning. But even that is OK with me, if done with old fashioned, testable physics. The only comfort, if that’s the right word, that cosmological IDers get out of this is that Susskind’s landscape is just as metaphysical as ID. There aren’t many criticisms about cosmological ID that do not equally apply to the Landscape. (Sorry I keep adding the adjective cosmological, but I am not an IDer in the Behe-Dembski sense.) And for the same reasons that Cosmological ID should not be published in journals such as PRL, neither should Landscape speculations, in my opinion.
Susskind’s conclusion really is, as I pointed out, a Sophie’s choice; but, even as an IDer, I find that disturbing rather than a cause for celebration. I think most of us who are professional physicists, but yet have cosmological ID leanings, want physics to continue as it always has, with a search for testable elegance. Nothing would be more depressing to both the IDer and physicist within than for Susskind to influence a large segment of the HEP community.
I think Peter’s worry is misplaced. It is not the damage Susskind’s book does to public perception that is the issue, but rather the damage it might do to physics itself. Because at the heart of it, what Susskind is really saying is that HEP physics is dead. If we have just annealed into our habitable universe, any further search for truth and beauty is a fool’s errand.
I seem to be the lone voice here, and not the expert one at that.
How can one not carefully think that such progressions were not considered?
Yes, it is under the wide “sweeping gaze” of a question, but it still retains the values of science.Nor do I think Susskind by defintion a ID’er.
Is this the consensus of the whole fraternity of science’s brothers? Maybe that is the easier question? 🙂
Plato,
Based on my limited reading of the book so far… (I had actually planned to read the book before commenting…) I tend to agree that Susskind is not an IDer.
I am a layperson as well. I think the more provocative threat that arises is the challenge to the traditional scientific process. Not so apparent so far in the book but clearly apparent in other writings by Susskind.
Elliot
Elliot,
It has been much consternation to me why the very institution that would support one another would go out to seek and destroy same?
It is to much for me to understand why such questions would not of been of value?
You have “this choir” of responsiveness? Is it’s uselfulness(string theory) at a end, like the choir predicts? I don’t know? I think one had to understand the motivation and the concept of “disgruntled employees?”:)This did not lesson the things that we can learn “given the right atmosphere” from the sounds that are emitted in harmony? 🙂 Dedication to research and enlightenment.
I have not read Susskinds book either or completed Krauss’s, but I have read enough staying close to the front of research, to see the divison created because someone said, “hey, let’s look to the origins of the cosmos” and instituted the expression of same, from the physics of approach.
I mentioned Moshe earlier becuase this is what happens when you present models to the ways we have always done things?
THis does not lesson the impact of our methods to percieve into the intracies of the nature of the cosmos does it? It does not lesson our perception to assumptions of such a model, to points of Equilibirum(landscape) does it?
Thanks Elliot
david,
Why don’t you say what you mean, you believe a god made the laws of nature. There is no need to couch, what you yourself consider to be a belief outside of science, in the discovery institutes invented terminology that was designed to confuse the issue of its scientificness.
Scott,
I wouldn’t know about terminology invented by the DI, and anyone who visits my blog would know that I (like many scientists) indeed believe that the ultimate source of the laws of nature is God. That doesn’t affect how I do science. I have no idea what your point is, and don’t know what the word “scientificness” means. I wasn’t even sure your comment was meant for me, but I seem to be the only “David” who has posted.
Folks, just to be clear: environmental selection in the multiverse is not a close relative of ID in any way — it’s the opposite of ID. It proposes a completely mechanistic and non-teleological explanation for the apparent fine-tunings we observe in nature, without relying on any supernatural intervention.
Susskind’s mistake, in his enthusiasm for the multiverse, is to suggest that without a multiverse, ID might make sense as an explanation for such fine-tunings. He unfortunately ignores the fact that ID doesn’t make sense under any circumstances. It doesn’t provide any description of the “designer” (including, of course, who designed the designer), any mechanism through which the designer goes about designing things, any criterion for deciding whether something is designed or not, and so on. It’s just empty posturing by people who want to sneak religion into high-school education.
If there is no multiverse, then we just got lucky that the uniquely-determined laws of nature allow for us to be here. That statement, all by itself, is much simpler and straightforward than the invocation of a mysterious supernatural force with no role other than to fix the laws in their specific configuration.
environmental selection in the multiverse is not a close relative of ID in any way — it’s the opposite of ID
It’s about time. It needed to be said.
Especially, for those of us on the periphery of this debate about string theory that has been reduced to all the kinds of “the wrong speculation” that that we hear of. The heart and soul of science blemished, towards continued research and developement of M theory.
If you did not see this in context of the universe, then how would you not know about the physics and cosmological approach, brought together?
Should we succumb to the leaders who would instigate “ID classification,” to have those who follow this rule of thumb, sing such praises?
I would defintiely be asking for more clarity. Is there no bubble nucleations initiated in cyclical cosmological variations, hence no return to the very beginnings we saw in the beginning of our own??
Thanks Sean
#36: Arun, until the past summer I guess I couldn’t have come up with a single way that the second and third generations of matter might have been relevant for life. All known chemistry, hence biology, is essentially the physics of the electron shells surrounding nuclei made of protons and neutrons, which in turn are made of up and down quarks. Only the first generation is involved.
Then, in June, we were told that strange quarks actually have a significant, measurable effect on the magnetic and electric properties of protons:
http://www.jlab.org/div_dept/dir_off/public_affairs/news_releases/2005/gzero.html
So at least in principle I can now imagine that removing the higher generations of matter could have a measurable effect on the electron shells surrounding nuclei, hence chemistry, hence biology. But prevent life from arising? That still looks like a really long shot.
Sean,
The fine tuning is only “apparent” if you have a mechanistic explanation for it. In the absence of an explanation, merely designating it as apparent is begging the question. At least Susskind offers a possible explanation, which sort of gives him the right to call it “apparent.”
You wrote:
That’s a gross generalization. I and other IDers I work with have no interest in getting religion into public schools. This is no better than generalizing about an atheist “agenda” for non IDers. What’s to be gained by painting with an infinitely broad brush?
That is merely opinion, not an incontrovertible fact. If there is no multiverse, then some may decide that Occam’s razor comes down in the favor of design rather than blind luck. In that, Susskind is correct.
Dear David Heddle
In your post #38 of this thread you say:
Susskind’s conclusion really is, as I pointed out, a Sophie’s choice; but, even as an IDer, I find that disturbing rather than a cause for celebration.
On the other hand saying “Susskind rocks” at the end of your blog of 15 December titled “Susskind’s Sophie’s Choice”
http://www.helives.blogspot.com/2005_12_01_helives_archive.html#113465921781166371
you appear to be celebrating. If it was meant ironically, a chance visitor to your site might well miss that.
I merely note the apparent inconsistency, but do not object. I wish the message in your blog was more clearly in line with what you say in this context, but don’t feel I’ve the right to criticize.
Setting that aside, I’d like to quote your post #38 because I find a lot in it:
—David #38—
This is a wonderful blog—I am glad to have found it via my site log.
I want to comment on what Peter wrote in #29, where he refers to “the damage to the public perception and understanding of science that the pseudo-science promoted by Susskind and followers” with the evidence he provides being a excerpt and a link to a post of mine.
Susskind is not the darling of this (cosmological) IDer. After all, he is out to destroy the fine-tuning. But even that is OK with me, if done with old fashioned, testable physics. The only comfort, if that’s the right word, that cosmological IDers get out of this is that Susskind’s landscape is just as metaphysical as ID. There aren’t many criticisms about cosmological ID that do not equally apply to the Landscape. (Sorry I keep adding the adjective cosmological, but I am not an IDer in the Behe-Dembski sense.) And for the same reasons that Cosmological ID should not be published in journals such as PRL, neither should Landscape speculations, in my opinion.
Susskind’s conclusion really is, as I pointed out, a Sophie’s choice; but, even as an IDer, I find that disturbing rather than a cause for celebration. I think most of us who are professional physicists, but yet have cosmological ID leanings, want physics to continue as it always has, with a search for testable elegance. Nothing would be more depressing to both the IDer and physicist within than for Susskind to influence a large segment of the HEP community.
I think Peter’s worry is misplaced. It is not the damage Susskind’s book does to public perception that is the issue, but rather the damage it might do to physics itself. Because at the heart of it, what Susskind is really saying is that HEP physics is dead. If we have just annealed into our habitable universe, any further search for truth and beauty is a fool’s errand.
—endquote—
David, if you don’t want to be unfairly generalized, then don’t call what you are doing “Intelligent Design.” Call it “natural theology” or “the God hypothesis” or whatever you like. But “Intelligent Design” has a very specific referent, namely a certain form of cleaned-up creationism with no scientific content and an explicit agenda of getting religion into schools. If that’s not you, then don’t associate yourself with them.
David, our posts crossed.
In #37 you say
“If there is no multiverse, then some may decide that Occam’s razor comes down in the favor of design rather than blind luck. In that, Susskind is correct.”
I am very interested in getting your reaction to a testable multiverse model (very different from the eternal inflation or string vacua landscape pictures) called cosmological natural selection and described in
http://arxiv.org/abs/hep-th/0407213
Scientific alternatives to the anthropic principle
Lee Smolin
Contribution to “Universe or Multiverse”, ed. by Bernard Carr et. al., to be published by Cambridge University Press.
Susskind’s multiverse might conceivably be discarded, if it is found to have no observable consequences, and yet the choice not YET come down to blind luck versus design. As far as the determination of fundamental constants, I mean.
You might wish to consider a further possibility.