String theory is what?

[The Dagda]

Reported for trolling.

[Trolldor]

[FBM]

MOD NOTE:

The Dagda has been given a 24-hr suspension.

[Tigger]

Er, BAA, can we stop now, please?

[Trolldor]

Probably. I'm thinking of writing a post in the Seminary about what trolling actually is, lots of people seem to think it's anyone who's offensive in even the slightest way.

[Pappa]

Probably. I'm thinking of writing a post in the Seminary about what trolling actually is, lots of people seem to think it's anyone who's offensive in even the slightest way.

There's a great article that's been doing the rounds since Usenet about what makes a good troll... I can't seem to find it now though. It's funny as fuck.

[lpetrich]

@Ipetrich there aren't 6 dimensions (as far as we can empirically determine) that's why its unnecessarily complicated.

That's because they are curled up into a very tiny ball -- a ball usually expected to have Planck to GUT dimensions.

I've seen speculations about extra dimensions whose effects observable at TeV energy scales, but the LHC will soon be able to test such predictions.


In any case, that kvetch about extra dimensions seems rather childish to me. In past decades and centuries, one might have felt similarly justified in objecting to the hypotheses of a variety of entities whose existence is now accepted. In fact, even more justified in many cases, because our space-time having 4 dimensions seems almost accidental.

In the late 19th and early 20th centuries, some physicists, like Ernst Mach, refused to accept the existence of atoms. Their argument was apparently that atoms were not directly observed, or at least that atomishness effects were not directly observed. One could find relative masses, sizes, and so forth, but not absolute ones, though I don't know if any of them had used that argument. But in 1905, Albert Einstein and Marian Smoluchowski independently worked out the theory of Brownian motion as a random walk caused by being struck by individual molecules, and that seemed to satisfy many such anti-atomists.

In fairness, and looking back further, I don't think that there was any strong reason to accept atomism before John Dalton's atomist explanation of Proust's recently-discovered Law of Definite Proportions. I wouldn't complain about being proved wrong, however; I'd like to see such arguments.

Likewise, in the 17th and 18th centuries, many people dismissed gravity as an "occult" force. Roger Cotes defended the gravity hypothesis by claiming that many anti-Newtonians believed in something at least as occult: mysterious vortices that the planets moved in. Newton's Philosophy (Stanford Encyclopedia of Philosophy)

[JimC]

@Ipetrich there aren't 6 dimensions (as far as we can empirically determine) that's why its unnecessarily complicated.

That's because they are curled up into a very tiny ball -- a ball usually expected to have Planck to GUT dimensions.

I've seen speculations about extra dimensions whose effects observable at TeV energy scales, but the LHC will soon be able to test such predictions.


In any case, that kvetch about extra dimensions seems rather childish to me. In past decades and centuries, one might have felt similarly justified in objecting to the hypotheses of a variety of entities whose existence is now accepted. In fact, even more justified in many cases, because our space-time having 4 dimensions seems almost accidental.

In the late 19th and early 20th centuries, some physicists, like Ernst Mach, refused to accept the existence of atoms. Their argument was apparently that atoms were not directly observed, or at least that atomishness effects were not directly observed. One could find relative masses, sizes, and so forth, but not absolute ones, though I don't know if any of them had used that argument. But in 1905, Albert Einstein and Marian Smoluchowski independently worked out the theory of Brownian motion as a random walk caused by being struck by individual molecules, and that seemed to satisfy many such anti-atomists.

In fairness, and looking back further, I don't think that there was any strong reason to accept atomism before John Dalton's atomist explanation of Proust's recently-discovered Law of Definite Proportions. I wouldn't complain about being proved wrong, however; I'd like to see such arguments.

Likewise, in the 17th and 18th centuries, many people dismissed gravity as an "occult" force. Roger Cotes defended the gravity hypothesis by claiming that many anti-Newtonians believed in something at least as occult: mysterious vortices that the planets moved in. Newton's Philosophy (Stanford Encyclopedia of Philosophy)

Good analogies, as far as I can see!

To reiterate a point I made earlier, I simply hope for some data that says something clearly about String Theory ASAP, whether for or against. Negative feelings expressed by some in this thread are not just from a tiny, crazed minority, and I suspect I know the reason. Earlier advances in the fundamental theories of physics did not involve such a lengthy delay between the elaboration of a theory and its experimental testing (think of general relativity and Eddington...) Of course, there may be perfectly legitimate reasons for the delay, but it does not engender confidence, and can give an impression of people making castles in the air...

[lpetrich]

Probably. I'm thinking of writing a post in the Seminary about what trolling actually is, lots of people seem to think it's anyone who's offensive in even the slightest way.

There's a great article that's been doing the rounds since Usenet about what makes a good troll... I can't seem to find it now though. It's funny as fuck.

Could it be the second post in The definitive guide to Trolls - Ubuntu Forums ? I've found that list in several other places also. The Vulgar Troll, the Deceptive or "Classic" Troll, the Contrarian Troll, the YerATroll, the Agenda Troll, etc.

[Tigger]

Reported for trolling.

Report was closed as the posts wasn't "trolling" enough for us. We only react to really big ugly fuck off trolls like this one:

[Nautilidae]

... What the blazes happened while I was asleep?

[Tigger]

... What the blazes happened while I was asleep?

Silly String.

[lpetrich]

To reiterate a point I made earlier, I simply hope for some data that says something clearly about String Theory ASAP, whether for or against. Negative feelings expressed by some in this thread are not just from a tiny, crazed minority, and I suspect I know the reason. Earlier advances in the fundamental theories of physics did not involve such a lengthy delay between the elaboration of a theory and its experimental testing (think of general relativity and Eddington...) Of course, there may be perfectly legitimate reasons for the delay, but it does not engender confidence, and can give an impression of people making castles in the air...

I think that that's a good point about string theory -- a LOT of theoretical work, without much that's successfully explained.

String theory handles gravity without the usual quantum-gravity troubles, and one can get the Standard Model gauge-symmetry and multiplet structure out of it, but I've yet to see anyone predict the Standard Model's parameter values from it. These parameters are:

Gauge coupling parameters: 3
Quark and charged-lepton masses: 9
Quark mixing angles: 4
Higgs parameters: 2
QCD-CP-violation phase: 1
Total: 19

Neutrinos being massive imply more parameters:
Masses: 3
Mixing angles: 4
Total: 7

The Minimal Supersymmetric Standard Model has even more -- more than 100 in the most general case. However, the non-observation of several Flavor Changing Neutral Currents places strong constraints on many of them, which make them approximately flavor-independent. But imposing flavor-independence still gives several extra parameters. Gaugino masses, sfermion masses, ...

However, with these parameters, one can test GUT hypotheses about gauge unification and mass unification. Such tests may almost qualify as tests of string theory, since GUT's are close in energy and since they have a lot of structure that must somehow come out of string theory.


Here are some additional possible particles:

• An inflaton - a particle that causes inflation, the early exponential expansion of the Universe. This expansion then causes various cosmic-scale fluctuations. This particle may emerge from GUT's, or else directly from various string effects.
• A curvaton - in some inflation scenarios, a particle that causes additional fluctuations. This particle's nature is much like the inflaton's.
• A cosmon - a particle that dynamically produces the present-day cosmological "constant", according to some "quintessence" theories. Its nature is much more obscure.

[1001.0993] Particle physics models of inflation and curvaton scenarios -- reviews inflaton and curvaton possibilities in very gory, technical detail.

I can't find anything comparable for cosmons in arxiv.org - just a few speculations.

Cosmon theories sometimes include "tracking" mechanisms, where the cosmon energy density tracks the density of the rest of the Universe's constituents in some way. Such mechanisms could avoid the problem of the fine tuning of the cosmological constant.

[Nautilidae]

I read the comments that were left last night.

The Dadga,

You have reached a dead-end. I didn't expect one to return to his usual behavior after a 24 hour suspension, but I was wrong. As a member of this board, you are expected to make coherent posts, be polite to others, and to follow the forum rules. You have insulted users, insulted moderators, and ignored the comments made by users. You do no support string theory. We understand that. However, your behavior is unacceptable. The arguments that you have made are far from coherent, and you accuse other physicists and CERN of lying (which is ironic, considering that you claimed that everyone at CERN didn't think that the LHC could prove string theory). Insulting hard working moderators as you did is completely childish. They are perfectly fair in their judgements.

I hope that a second suspension will teach you how to properly behave.

- Nautilidae.

[Nautilidae]

I think that that's a good point about string theory -- a LOT of theoretical work, without much that's successfully explained.

String theory handles gravity without the usual quantum-gravity troubles, and one can get the Standard Model gauge-symmetry and multiplet structure out of it, but I've yet to see anyone predict the Standard Model's parameter values from it. These parameters are:

Gauge coupling parameters: 3
Quark and charged-lepton masses: 9
Quark mixing angles: 4
Higgs parameters: 2
QCD-CP-violation phase: 1
Total: 19

Neutrinos being massive imply more parameters:
Masses: 3
Mixing angles: 4
Total: 7

The Minimal Supersymmetric Standard Model has even more -- more than 100 in the most general case. However, the non-observation of several Flavor Changing Neutral Currents places strong constraints on many of them, which make them approximately flavor-independent. But imposing flavor-independence still gives several extra parameters. Gaugino masses, sfermion masses, ...

However, with these parameters, one can test GUT hypotheses about gauge unification and mass unification. Such tests may almost qualify as tests of string theory, since GUT's are close in energy and since they have a lot of structure that must somehow come out of string theory.


Here are some additional possible particles:

• An inflaton - a particle that causes inflation, the early exponential expansion of the Universe. This expansion then causes various cosmic-scale fluctuations. This particle may emerge from GUT's, or else directly from various string effects.
• A curvaton - in some inflation scenarios, a particle that causes additional fluctuations. This particle's nature is much like the inflaton's.
• A cosmon - a particle that dynamically produces the present-day cosmological "constant", according to some "quintessence" theories. Its nature is much more obscure.

[1001.0993] Particle physics models of inflation and curvaton scenarios -- reviews inflaton and curvaton possibilities in very gory, technical detail.

I can't find anything comparable for cosmons in arxiv.org - just a few speculations.

Cosmon theories sometimes include "tracking" mechanisms, where the cosmon energy density tracks the density of the rest of the Universe's constituents in some way. Such mechanisms could avoid the problem of the fine tuning of the cosmological constant.

I have never heard of the cosmon. It is fortunate that we may be able to explain fine-tuning.