- #316
MTd2
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If the LHC applies only to the particle side, what motivation is left to study strings (not counting xyz/CFT stuff) ? Anything else is just too convoluted and complicated.
MTd2 said:If the LHC applies only to the particle side, what motivation is left to study strings (not counting xyz/CFT stuff) ? Anything else is just too convoluted and complicated.
MTd2 said:You mention "imply", "suggest", but what really decides is the experimental evidence of this kind of thing,
arivero said:Well, just from the definition, it seems clear that string theory is to riemannian geometry as homotopy is to topology, so it seems reasonable to have it in the basic toolbox...
...a basic tool. Of course, same could be said of Connes Spectral Action.
period 1999-2001 2002-2004 2005-2007 2008-2010 2011
annual HEP theory hires 18 24 23 13 11
annual string hires 9 8 6 2 1
year (some omitted for brev.) 2001 2003 2005 2007 2009 2010
recent work highly cited in year 12 6 2 1 1 0
negru said:Doing field theory is the same as doing string theory. You can't expect to make any progress on M theory without understanding stuff like ABJM or (2,0) theory.
negru said:And there is any empirical evidence to favor other speculative fields of quantum gravity?
negru said:People are usually happier knowing that what they're spending time on is making maximum use of their abilities.
arivero said:Hmm, MTd2, I think that you have misread Aidyan question. He asks for heavy involvement, no results during a long period, and then suddenly it happens to be right. I doubt you are claiming that Aristotle biology happened to be right at the end, nor even a huge involvement of resources (by biologists, aka veterinaries and doctors, not by teologists).
Aidyan said:In fact. As everyone knows the aristotelian cosmogony turned out to be dead wrong (and no, between Ptolemy and Copernicus almost nobody was working on it).
Aidyan said:I could mention several technical reasons why SS theory leaves me cold, but am still a layman in QFT and don't dare to go into technical details I'm still learning. But from a simple historical perspective, I'm wondering if there is a single example in the history of physics where hundreds, if not thousands, of top physicists worked on for more than three decades without producing a concrete result, and then turned out to be a correct theory? I can't think of any. People are slowly realizing that if a theory, despite all the efforts, does not produce tangible results after say 15, max. 20 years, then it must be wrong. And I'm afraid that this holds for LQG too.
MTd2 said:No! Thousands of people indeed researched the Ptolomaic model! It indeed achieved a great accuracy during the Islamic period. In fact, the accuracy was so great, that the muslim astronomers came up first with the heliocentric model, or close to it...
negru said:The history of things is irrelevant here. String theory and its alternatives have a minimal amount of external data to work with. This was usually not the case before. People were observing various phenomena then trying to explain them. They were guided by data. Now we're not observing anything new, we're just trying to make the theory we have prettier. Any new predictions we could make will very likely be at unobservable energies anyway (unless we're extremely lucky and there is low energy susy, or dark matter detection says anything). So even if string theory somehow made a prediction around i don't know say 100-1000 Tev, no one would take it seriously anyway for another 50 years or so. Almost everyone working on string theory now would be dead by then.
Hmm perhaps we could have a better example here, with the theory of indivisibles/fluxions... it is a whole lifespan of development, the initial players, such as Kepler or Cavalieri, never see the final physical results (Newtonian Dynamics). Kepler himself -whose treatise is mostly numerical- was never considered a player, except perhaps by Cavalieri, who insisted on showing his work to Galileo (and failing to attract attention). Cavalieri atoms run into all kinds of problems, until Newton and Leibnitz got the final formulation.Aidyan said:Kepler
Of course not, but the relevant data was already used to give precisely QM, GR and the SM. if you want a bigger theory, you need more data than was already used, that was my point. Just like Newton used all the data he knew to get classical gravity. Even if he saw hints of things beyond classical gravity, the data he had wouldn't have been anywhere near of helping him.Aidyan said:I wouldn't call QM, GR, the SM and all the modern particle physics and astrophysical observations "minimal amount of external data to work with".
Yes, and the data they had was enough to produce what they did. A bunch of yearly measurements is all that's needed to derive Kepler's laws. A bunch of particles is all that's needed to derive the SM. To derive a TOE, you need data comparable to the scope of that goal.You might that the combination of all of GR and SM data should be enough. Not necessarily. If Kepler only had data from one of whatever he was measuring, it's very possible that wouldn't have been enough. Or if we had only detected half the particles we did before i don't know EW unification, maybe that wouldn't have happened either. Sure with hindsight a minimal amount of data seems required to derive a new theory, but it doesn't work that way. Same with string theory. Perhaps all that's needed is one low energy susy particle, or missing energy, or who knows, to guide us towards the correct formulation.And what "data" had three guys as Copernicus, Kepler or Tycho Brahe to work with? Only those of the extremely limited human senses, and yet they produced something.
Aidyan said:Modern organized science in the form we know exists only since three max. four centuries. And since then I can't think of another theory in physics that was so revered, cherished and honored for a so long time without producing concrete results.
period 1999-2001 2002-2004 2005-2007 2008-2010 2011
annual HEP theory hires 18 24 23 13 11
annual string hires 9 8 6 2 1
year (some omitted for brev.) 2001 2003 2005 2007 2009 2010
recent work highly cited in year 12 6 2 1 1 0
marcus said:Or it could simply be that newer approaches to QG and explaining the SM have arisen, and that researchers have some natural tendency to spread out seeking fresh ideas and new areas to work on.
What is your opinion of grand unified theories and supersymmetric field theories?Aidyan said:But from a simple historical perspective, I'm wondering if there is a single example in the history of physics where hundreds, if not thousands, of top physicists worked on for more than three decades without producing a concrete result, and then turned out to be a correct theory? I can't think of any.
negru said:A bunch of yearly measurements is all that's needed to derive Kepler's laws. A bunch of particles is all that's needed to derive the SM. To derive a TOE, you need data comparable to the scope of that goal.
MTd2 said:The scientific method, as we now it was first used by al Haytham, in the X century.
http://en.wikipedia.org/wiki/History_of_scientific_method#Ibn_al-Haytham
Anyway, I think you are not considering the quantity of data and the works that was not preserved.There was no printing and paper was hard to acquire. So, even important texts were erased, when not destroyed, for random uses...
mitchell porter said:What is your opinion of grand unified theories and supersymmetric field theories?
This is why I asked your opinion of GUTs and supersymmetric QFT - to see if you thought that they differ from string theory in this regard.Aidyan said:there is nothing in history like the effort in terms of people, research and money set behind a single project like string theory *AND* with no concrete results.
Aidyan said:You can't compare with the actual state of affairs the exceptional individual cases of some people who showed up from time to time throughout a centuries long period and that otherwise had almost no scientific progress.
mitchell porter said:We know that string theory can get close to reality in various ways. One has every reason to hope it can go all the way.
Aidyan said:Organized science began with Galilei, Newton, perhaps even later. And since then, and also before that, there is nothing in history like the effort in terms of people, research and money set behind a single project like string theory *AND* with no concrete results.
mitchell porter said:When you say string theory has "no concrete results", I can't agree.
mitchell porter said:What it has given us is a very large number of models which incorporate and complete the field theories that non-string theoretical physicists were already using, and which have the potential to explain the quantities which are just input parameters for something like the standard model. We know that string theory can get close to reality in various ways. One has every reason to hope it can go all the way.
arivero said:If you are happy with 50 years without concrete results, then my previous example, the quest for quadratures of areas and cubatures of volumes, holds.
arivero said:Note that Kepler http://www.matematicasvisuales.com/english/html/history/kepler/doliometry.html Nova Stereometria doliorum vinariorum is from 1615, Cavalieri atoms, "Geometría indivisibilibus continuorum quadam nova ratione promota" are from 1635 and the final "concrete" results, Newton' "Analysis per aequationes número terminorum infinitos" and then the Principia, are from from 1669 and 1687. During this time, most of the Natural Philosophers (ie MathPhys), from Glasgow to Rome, were putting a lot of resources on this, and before Newton all they got was to confirm the Greek results and to add some extra examples.
Now I agree, that String Theory is near to break this record (and we will see if it gets something "concrete" out of it).
Aidyan said:I believe that string theoreticians should refrain from pointing at such examples, that doesn't make them look well...