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Working on meta-string theory December 18, 2006

Posted by dorigo in humor, mathematics, physics, science.

A comment by Alejandro made me ponder over the need for a meta-string theory.

Sure, we were blessed with two best-selling books about the failures of string theory quite recently: so, asking 2006 to bring more to the just cause of allowing non-string theoretical work in particle physics to get their due share of attention in physical departments throughout the world seems a bit over the top.

However, think about it for a second. How do you kill a theory ? By showing it is internally flawed to an irreparable level, or by showing it is utterly inconsistent with the data. They tell me that both of these avenues appear impossible with string theory these days, because of the theory’s own shortcomings: the lack of a well-defined internal structure (say a lagrangian function or a usable symmetry group as its basis), and the lack of any prediction for experimentally measurable observables. [I know, I am getting flamed for this…]

However, one could conceive a meta-string theory even in the absence of a well-defined string theory. Whatever string theory is, we can formally give it a name: S. One can then imagine to work on S with suitable operators E[] which modify S, namely E[S] = S’. What E does is to provide S with an experimental input which influences the theory in such a way to make it change form. For instance, imagine we discover a fourth generation set of particles: it is quite likely that S will change into S’ in order to accommodate -or even post-dict- the set. Easy to do, since S was not hindered by a precise pre-defined structure.

We can also imagine new mathematical developments M[]: their action on S is formally the same: M[S]=S”. For instance, maybe if M[] provided an indication of which, among the zillions of vacua of the theory, is to be preferred for some specific reason, that could make S very different from what it is right now.

Of course, all E[] and M[] are by definition idempotent. That is, E[E[S]]=E[S]. They also should commute, E[M[S]]=M[E[S]], in order for the formal system to make sense: in other words, the theory one develops should not depend on the order by which theoretical and experimental input is used in its construction. Discussing other properties would take us too far.

Given this very basic formal system, one is direly looking for an example of a suitable operator N[] which, applied to string theory in its present form, produces the null element: no theory.

So what could such a N[] be ? Would N[]== no SUSY work ? No, not enough unfortunately, as far as I understand. SUSY is generally appreciated by string theorists as a step in the right direction, but no proof – and no SUSY is therefore not a show stopper. Maybe N is the combination of several experimental and theoretical inputs ? Unlikely.

The search for N is on. But let’s make a point here: having designed our formal system of operators acting on theories, we can well say we already are half-way through: we do not need to prove anything, just saying we hypothesize the existence of a N[] such that N[S]=0 should suffice. It is now up to string theorists to demonstrate that the set of N[] is null.



1. Alejandro Rivero - December 18, 2006

Hmm at first glance it seems sociology. But in the same way that economists ask mergets for a series of axioms (rational markets, etc) we here could work out something by asuming that string theory is a “scientific market”. We could define the axioms for scientific markets in a way paralell to economists rational markets.
Not a job I would like to do. But Woit pointed out that there is already a thesis going on the sociology of string theory.

2. Alejandro Rivero - December 18, 2006

More sociology. A thinking I got while looking a crackpot/alternative theory site (Eliahu Comay; not worth the link) is that there is a coincidence between “alternatives” and stringers: they do not look at the experimental data, they argue from (they live in) the pretty world of GedankenExperiments.
In some orthodox sites, as Clifford’s, this (the stringy part) seems justified because they are looking to quantum gravity and thus string theory is a theory for cosmology etc. I could agree if then it were banned out of HEP-th.

3. Kea - December 18, 2006

Brilliant!! Yes, that’s the idea. There’s no other way to kill all the squarkions.

4. Tony Smith - December 18, 2006

Another meta-way to make string theory evolve might be to modify physical interpretations.
My favorite (very speculative) way is to give a physical interpretation of strings as world-lines of point particles, with open strings being world-line paths from distant past and/or distant future, and closed strings being virtual loops. An effort toward construction of such a thing in is on the CERN preprint server as EXT-2004-031.

Tony Smith

5. dorigo - December 19, 2006

I see Tony… Although I prefer to see string theory evolve in a string orchestra 🙂

6. dorigo - December 19, 2006

Alejandro, tsk tsk bad guy… Banning papers is never a good idea IMO. Better to ask that string theory be funded with quantum gravity money only… LOL


7. Alejandro Rivero - December 19, 2006

:-(( I humblely apologise. It was not my intention to suggest a ban out of the ArXiV, just a honest refocus of the default posting towards gr-qc. You can see a lot of “black holes” in title and abstracts of hep-th submisions.
One could counterargue that it is HEP because they are looking to the first microseconds of the big bang. But that is not ever UHEP if they are not showing intentions of running down to predict parameters in hep-ph that can be tested by the people in hep-ex and calculated in hep-lat.
If gr-qc is not fine enough, I suggest “primaeval physics”.

8. dorigo - December 19, 2006

Yes, a repositioning of string papers could be a good idea, if they complied gracefully. Maybe primaeval physics could do, or “Wild-spec/”. We should ask them politely.


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