Of course I am not qualified to have an opinion about whether the landscape is of value or not. That there are people on two sides that have differing opinions, and based on what they have as proof to the contrary, of one or another, is whether the issue is ready for a forgone conclusion? Whether the person in association is a forgone conclusion.
7. dorigo – October 8, 2007
I will take your word for it – I must admit I was not aware of the breadth of his works. However, Nima’s position on the anthropic landscape of ST is enough for me to warn any student about his views.
My research concerns string theory. At present I am interested in finding an explicit expression for the n-loop superstring amplitude and proving that it is finite. My field of research is particle theory, more specifically string theory. I am also interested in the recent results of Seiberg and Witten in supersymmetric field theories.
So by looking at a statement of a person, I wondered, has such a conclusion been reached and support by documentation that will help me decide?
There’s an article in this week’s Nature by Geoff Brumfiel entitled Outrageous Fortune about the anthropic Landscape debate. The particle physicists quoted are ones whose views are well-known: Susskind, Weinberg, Polchinski, Arkani-Hamed and Maldacena all line up in favor of the anthropic Landscape (with a caveat from Maldacena: “I really hope we have a better idea in the future”). Lisa Randall thinks accepting it is premature, that a better understanding of string theory will get rid of the Landscape, saying “You really need to explore alternatives before taking such radical leaps of faith.” All in all, Brumfiel finds “… in the overlapping circles of cosmology and string theory, the concept of a landscape of universes is becoming the dominant view.”
The only physicist quoted who recognizes that the Landscape is pseudo-science is David Gross. “It’s impossible to disprove” he says, and notes that because we can’t falsify the idea it’s not science. He sees the origin of this nonsense in string theorist’s inability to predict anything despite huge efforts over more than 20 years: “‘People in string theory are very frustrated, as am I, by our inability to be more predictive after all these years,’ he says. But that’s no excuse for using such ‘bizarre science’, he warns. ‘It is a dangerous business.’”
I continue to find it shocking that the many journalists who have been writing stories like this don’t seem to be able to locate any leading particle theorist other than Gross willing to publicly say that this is just not science.
For more about this controversy, take a look at the talks by Nima Arkani-Hamed given today at the Jerusalem Winter School on the topic of “The Landscape and the LHC”. The first of these was nearly an hour and a half of general anthropic landscape philosophy without any real content. It was repeatedly interrupted by challenges from a couple people in the audience, I think David Gross and Nati Seiberg. Unfortunately one couldn’t really hear the questions they were asking, just Arkani-Hamed’s responses. I only had time today to look at the beginning part of the second talk, which was about the idea of split supersymmetry.
Update: One of the more unusual aspects of this story is that, while much of the particle theory establishment is giving in to irrationality, Lubos Motl is here the voice of reason. I completely agree with his recent comments on this article. For some discussion of the relation of this to the Intelligent Design debate, see remarks by David Heddle and by Jonathan Witt of the Discovery Institute.
Jacques Distler :
This is false. The proof of finiteness, to all orders, is in quite solid shape. Explicit formulæ are currently known only up to 3-loop order, and the methods used to write down those formulæ clearly don’t generalize beyond 3 loops.
What’s certainly not clear (since you asked a very technical question, you will forgive me if my response is rather technical) is that, beyond 3 loops, the superstring measure over supermoduli space can be “pushed forward” to a measure over the moduli space of ordinary Riemann surfaces. It was a nontrivial (and, to many of us, somewhat surprising) result of d’Hoker and Phong that this does hold true at genus-2 and -3.
So by following the conversation I meet up with was offered as evidence, this then, leads me to follow up in even greater depth. How can one give a person such a title of “in question,” based on what another posts, as to their characrter of study?
The equations of string theory specify the arrangement of the manifold configuration, along with their associated branes (green) and lines of force known as flux lines (orange). The physics that is observed in the three large dimensions depends on the size and the structure of the manifold: how many doughnut-like “handles” it has, the length and circumference of each handle, the number and locations of its branes, and the number of flux lines wrapped around each doughnut.
11. Plato – October 9, 2007
Tammaso:However, Nima’s position on the anthropic landscape of ST is enough for me to warn any student about his views.
So is this support for what you think is relevant. I have followed the discussions between Lee Smolin, Jacques Distler, Clifford of Asymptotia and Peter Woit of “Not Event Wrong.”
I wonder if you had “more information,” if this might change your statement above, and conclusion, you may have drawn from seeing another view? One you might not of seen before?
Is mathematical consistency of value to you when it is developing?
So with a certain knowledge already gain from following other discussions I am quick to ask if such a link to another is good enough for assigning credibility to another person. Especially one who holds a “view point” other then one held by Peter Woit. After all is Peter Woit not a mathematics man? I am really asking.
So based on this assumption(what I ask others not to do) about Peter Woit or string theorist while having a basis in mathematics. I am asking, that if such a development that is, “current and consistent in mathematics” why would this contradict and qualify any individual “to other then” what mathematics requires to move forward. To try and attempt too, “connect to reality” in a phenomenological way?
The basis of my insight is in fact current collider technologies, and the relationship I see to bulk production gravitons. If Gr is an outcome of String theory then, any pocket universe that demonstrates some mathematical consistency should, be of relevances in one’s decision?
It is always a work in progress that such questions continue to push me forward. In that process I “vaguely recall” that Jacques did not think the association to modular form in terms of the genus figure could ever be related to that pocket universe?
I must say to you that in my case I am asking of Calabi Yau’s, can have some predictability to how universe selection is accomplished and thus any steady development in mathematics pushing that landscape to credibility?