Warning: if you follow this blog, you’ve heard this many times before, so can move on to something more interesting now.
There’s a video conversation between Brian Greene and Lenny Susskind from last week here. At 44:02, Susskind has this to say:
One of the chief critics is a colleague of yours, I believe. And he is rather forcefully maintaining that string theory, until it can produce a success of the kind where you actually can produce a number and that number can be checked with experiment, that it doesn’t have any value.
The main reason for this post is just to reiterate that this is not what I think. The problem with string theory as a unified theory is not that it hasn’t made a tested prediction, but that it has made no predictions, of any kind. It’s very clear now that, as a theory of the real world it’s a speculative idea that just doesn’t work. As to whether it has “any value”, you have to first define what “string theory” is. Under some definitions there are things of value, under others not.
Susskind goes on to accurately explain that any well-defined version of string theory (which he calls “String theory”, capital S) definitely doesn’t correspond to the real world. But, he argues, maybe some new, unknown variant of String theory will work. According to him “It’s the only game in town” and “you have to see it through”.
Brian later asks him “Is there anything that you could imagine happening in the field that would convince you that this is time to put it away?” “Finding it mathematically inconsistent” comes up, but he has already said that this is about an unknown new idea that would make things work. “I don’t know the answer to that” is then his answer: nothing would convince him. About other approaches doing better: “I think both you and I probably don’t put a lot of stock in there.”
In case you haven’t seen this, something from a Kurt Vonnegut magazine piece:
A guy with the gambling sickness loses his shirt every night in a poker game. Somebody tells him that the game is crooked, rigged to send him to the poorhouse. And he says, haggardly, “I know, I know. But it’s the only game in town.”
Update: For another think regular followers here won’t find new at all, see this interview with Neil Turok, who shares a lot of my point of view on the state of theoretical physics. I’m also quite sympathetic to the general idea that right-handed neutrinos are behind the dark matter mystery, although don’t know enough about cosmology to know whether the proposal he mentions is promising.
Hi Peter,
What I find interesting is how much String Theory still carries a mystique for the general public.
Recently, I was in a conversation with a colleague who was telling me about this “great guy” -according to him, almost a genius – because he had developed a new electronics data acquisition system that was supposedly brilliant. Not really my cup of tea, so fine, who knows.
Then he continued: “The guy is a real genius – he does not only electronics, he can also tell you all about String Theory.” And I remember thinking: “OK… now I don’t believe in this circuit anymore….”
To some extent, I think this is also why people keep publishing these BS papers and press releases.
Perhaps there’s no actual contradiction, but these statements surprise me . I watched Suskind’s interview with Curt Jaimungal with great interest, and in that discussion he espoused the need for novel approaches to make progress in fundamental physics. He even went so far as to exhort young researchers to find the bravery to strike out into uncharted territory, irrespective of his generation’s approval or lack thereof. It’s not odd to hear him reiterate the view that string theory (capitalized or not) is still the best framework for model-building. But to hear him seemingly revert to the notion that only string theory (no caps) holds promise, and is therefore the compulsory basis for a realistic TOE is disappointing.
LMMI,
I think the difference between the two interviews was the interviewers. Brian has built his career on the idea that string theory is the way forward, and took the discussion in that direction. Curt is devoted to looking at alternatives and was quite intent on confronting Susskind about the issue of alternatives to string theory. From what I remember, it was Curt’s line of questioning made Susskind realize that he shouldn’t dismiss the search for alternatives. So, yes, it’s kind of discouraging to see him and Brian back at it.
Peter,
The video of the colloquium that Turok gave about his proposal, which preceded the interview, has now been posted: https://www.youtube.com/watch?v=VlP-12yc2f8
LMMI,
” I watched Suskind’s interview with Curt Jaimungal with great interest, and in that discussion he espoused the need for novel approaches to make progress in fundamental physics.”
Maybe Suskind for “novel approaches” is meaning a “new version of String Theory”.
😛