String theory is what?

[Nautilidae]

I do realise that it was the first thing to predict something that has no empirical evidence or is likely to distinguish itself now or perhaps ever, what's your point?

This is disinformation. Supersymmetry, if it exists, will lead to clear results. Supersymmetric particles are MUCH more massive than ordinary particles. If they turn up in detectors, they will be clear. Supersymmetry is one of the theories that will be tested at the LHC. It is foolish to say that it will never distinguish itself from other theories.

Smolin's theory is more testable that means it is a better hypothesis than yours

Empty claims. Present a testable prediction and an experiment used to test this prediction.

Ask yourself why Smolin left String theory? Was it because it was turning into a matter of faith or was it because of...

That's his opinion. Please give us something better than two men's opinions.

Yes Smolin's theory is faith based atm, no one would argue that.

You just said that it was testable...

The point was that string theory is no better than any other philosophical concern atm, it is hence not science as yet, although those adhering to it might be scientists.

Philosophical theories do not present testable predictions. String theory presents testable predictions. Therefore, string theory is better than a philosophical theory. A scientific theory must attempt to describe physical reality and present testable predictions. String theory presents testable predictions and attempts to describes physical reality. Therefore, string theory is science.

It's a subtle distinction and not worth getting bent out of shape on. they are not scientists doing science they are scientists doing pure maths.

See above.

I tell you what the fact that people who claim no support of it get so angry speaks volumes. Get used to it science is about destroying "theories" as much as it is making them. If it annoys you to have your beliefs challenged then why are you interested in this subject?

Do not inflate your pride. You are in no position to be telling me what science is or isn't. I present you with testable predictions. You arm-wave them. I present you with hypotheses that are considered scientific yet haven't been tested. You arm-wave them. I present you with coherent arguments. You arm-wave them. I become upset with you not because you oppose my ideas but because you are selling disinformation about a theory in order to discredit it as well as arm-waving any argument that gets in your way. Science is about formulating theories and testing them, not about arm-waving and disinformation. If it annoys you to have your beliefs changed, then why are you interested in this subject?

[Nautilidae]

No LQG predicts the same things String theory does, please take it to the other thread though. This is about a valid conference of scientists, not about whether they are right or wrong.

This thread was derailed as soon as you posted your first comment here. String theory predicts many things that LQG does not.

Seeing as the conference is over, I request that this thread be locked.

[The Dagda]

No LQG predicts the same things String theory does, please take it to the other thread though. This is about a valid conference of scientists, not about whether they are right or wrong.

This thread was derailed as soon as you posted your first comment here. String theory predicts many things that LQG does not.

Seeing as the conference is over, I request that this thread be locked.

That's not what I said, I said that St doesn't predict anything new. There's a difference, strings are atm interpretational, they have no evidence to support them and nothing to distinguish them. They are the standard model repackaged anything that happens can be explained by strings, show me one single experiment, just one that would make strings have falsifiability. If you can't I will understand Smolin and Woight have made this point as yet no one has done jack shit to challenge it. Genuinely I hope they do an experiment or something anything I would love any theory to be true, but talk is cheap. Show us the money, If you can't then you can't slam dunk and white me can't jump.

Show me a single experiment where strings could be falsifiable distinguishable from the pack? I ask again because you seem unable to do so. Strings is a piggy back theory of anything it has nothing of its own. Nothing that could be falsified at CERN, atm it isn't even a very good hypothesis like LQG it's just maths.

[The Dagda]

I do realise that it was the first thing to predict something that has no empirical evidence or is likely to distinguish itself now or perhaps ever, what's your point?

This is disinformation. Supersymmetry, if it exists, will lead to clear results. Supersymmetric particles are MUCH more massive than ordinary particles. If they turn up in detectors, they will be clear. Supersymmetry is one of the theories that will be tested at the LHC. It is foolish to say that it will never distinguish itself from other theories.

Smolin's theory is more testable that means it is a better hypothesis than yours

Empty claims. Present a testable prediction and an experiment used to test this prediction.

Ask yourself why Smolin left String theory? Was it because it was turning into a matter of faith or was it because of...

That's his opinion. Please give us something better than two men's opinions.

Yes Smolin's theory is faith based atm, no one would argue that.

You just said that it was testable...

The point was that string theory is no better than any other philosophical concern atm, it is hence not science as yet, although those adhering to it might be scientists.

Philosophical theories do not present testable predictions. String theory presents testable predictions. Therefore, string theory is better than a philosophical theory. A scientific theory must attempt to describe physical reality and present testable predictions. String theory presents testable predictions and attempts to describes physical reality. Therefore, string theory is science.

It's a subtle distinction and not worth getting bent out of shape on. they are not scientists doing science they are scientists doing pure maths.

See above.

I tell you what the fact that people who claim no support of it get so angry speaks volumes. Get used to it science is about destroying "theories" as much as it is making them. If it annoys you to have your beliefs challenged then why are you interested in this subject?

Do not inflate your pride. You are in no position to be telling me what science is or isn't. I present you with testable predictions. You arm-wave them. I present you with hypotheses that are considered scientific yet haven't been tested. You arm-wave them. I present you with coherent arguments. You arm-wave them. I become upset with you not because you oppose my ideas but because you are selling disinformation about a theory in order to discredit it as well as arm-waving any argument that gets in your way. Science is about formulating theories and testing them, not about arm-waving and disinformation. If it annoys you to have your beliefs changed, then why are you interested in this subject?

Your science is worthless, you have nothing.

My pride I don't care if string theory is proven now, all I care about is proof. Shut up and calculate.

Nothing rests on me being wrong, nothing rests on me being right, all I am trying to do is ask for evidence that will distinguish any theory. If you can't provide it then who cares, I don't win only science does. And that is a team effort, your prevarication means shit.

Talk is cheap what tests can prove strings, come on put up or shut up? Put up something that will win an award based on its evidence or kindly and I beg don't indulge your religion.

[Nautilidae]

That's not what I said, I said that St doesn't predict anything new.

I have already shown that this is disinformation.

There's a difference, strings are atm interpretational, they have no evidence to support them and nothing to distinguish them.

Ah, but LQG has no evidence to support it either.

Strings are not themselves interpretational. There are several formulations of string theory, each with defining features. All we need to do is test string theory and eliminate the theories that don't agree with the results.

As I have said, string theory has many defining features such as extra dimensions(testable), the holographic principle(testable), and AdS/CFT correspondence(allows for testing in low energy experiments)

They are the standard model repackaged

Really? Then why can't the standard model make the predictions that string theory can?

anything that happens can be explained by strings, show me one single experiment, just one that would make strings have falsifiability.

I already did that. Several times now.

If you can't I will understand Smolin and Woight have made this point as yet no one has done jack shit to challenge it. Genuinely I hope they do an experiment or something anything I would love any theory to be true, but talk is cheap.

Ditto.

Show me a single experiment where strings could be falsifiable distinguishable from the pack? I ask again because you seem unable to do so. Strings is a piggy back theory of anything it has nothing of its own. Nothing that could be falsified at CERN, atm it isn't even a very good hypothesis like LQG it's just maths.

... Your arm-waving is starting to tire me. Please review the predictions I have already given.

[Nautilidae]

Your science is worthless, you have nothing.

You keep saying that, yet you have done nothing but arm-wave the predictions listed.

My pride I don't care if string theory is proven now, all I care about is proof. Shut up and calculate.

If you seek proof, science probably isn't for you. Evidence, on the other hand, is obtainable.

Nothing rests on me being wrong, nothing rests on me being right, all I am trying to do is ask for evidence that will distinguish any theory. If you can't provide it then who cares, I don't win only science does. And that is a team effort, your prevarication means shit.

Why don't you debunk the predictions I've already given instead of arm-waving them?

Talk is cheap what tests can prove strings, come on put up or shut up?

I "put up" long ago. You simply arm-waved the predictions I listed.

Put up something that will win an award based on its evidence or kindly and I beg don't indulge your religion.

See above.

[JimC]

At the request of the OP, thread now locked.

Slight change in decision...

Unlocked, and merged with other string topic...

[The Dagda]

I do realise that it was the first thing to predict something that has no empirical evidence or is likely to distinguish itself now or perhaps ever, what's your point?

This is disinformation. Supersymmetry, if it exists, will lead to clear results. Supersymmetric particles are MUCH more massive than ordinary particles. If they turn up in detectors, they will be clear. Supersymmetry is one of the theories that will be tested at the LHC. It is foolish to say that it will never distinguish itself from other theories.

Smolin's theory is more testable that means it is a better hypothesis than yours

Empty claims. Present a testable prediction and an experiment used to test this prediction.

Ask yourself why Smolin left String theory? Was it because it was turning into a matter of faith or was it because of...

That's his opinion. Please give us something better than two men's opinions.

Yes Smolin's theory is faith based atm, no one would argue that.

The point was that string theory is no better than any other philosophical concern atm, it is hence not science as yet, although those adhering to it might be scientists.

Philosophical theories do not present testable predictions. String theory presents testable predictions. Therefore, string theory is better than a philosophical theory. A scientific theory must attempt to describe physical reality and present testable predictions. String theory presents testable predictions and attempts to describes physical reality. Therefore, string theory is science.

It's a subtle distinction and not worth getting bent out of shape on. they are not scientists doing science they are scientists doing pure maths.

See above.

I tell you what the fact that people who claim no support of it get so angry speaks volumes. Get used to it science is about destroying "theories" as much as it is making them. If it annoys you to have your beliefs challenged then why are you interested in this subject?

Do not inflate your pride. You are in no position to be telling me what science is or isn't. I present you with testable predictions. You arm-wave them. I present you with hypotheses that are considered scientific yet haven't been tested. You arm-wave them. I present you with coherent arguments. You arm-wave them. I become upset with you not because you oppose my ideas but because you are selling disinformation about a theory in order to discredit it as well as arm-waving any argument that gets in your way. Science is about formulating theories and testing them, not about arm-waving and disinformation. If it annoys you to have your beliefs changed, then why are you interested in this subject?

Laughable the standard model predicts supersymetry too, a number of theories do.

Opinion? Well it trumps yours they are theoretical physicists of great renown. That's a bit like saying Feynmans opinion doesn't matter. It's a fake science and you know it. Everyone at CERN thinks it cannot turn up any evidence and yet you persist in defying the mainstream with your self delusional Voodoo.

You just said that it was testable...

Not it isn't and it probably never will be it's a faith not a science. Honestly God exists, no one thinks it can be proven but he does!

What are your qualifications, and why does your opinion matter?

A theory must have evidence. String "theory" is a hypothesis at best and a piss poor one at that. A definition for your edification or not.

Evaluating hypotheses

According to Karl Popper's hypothetico-deductive method (also known as the method of "conjectures and refutations") demands falsifiable hypotheses, framed in such a manner that the scientific community can prove them false (usually by observation). According to this view, a hypothesis cannot be "confirmed", because there is always the possibility that a future experiment will show that it is false. Hence, failing to falsify a hypothesis does not prove that hypothesis: it remains provisional. However, a hypothesis that has been rigorously tested and not falsified can form a reasonable basis for action, i.e., we can act as if it is true, until such time as it is falsified. Just because we've never observed rain falling upward, doesn't mean that we never will—however improbable, our theory of gravity may be falsified some day.

Popper's view is not the only view on evaluating hypotheses. For example, some forms of empiricism hold that under a well-crafted, well-controlled experiment, a lack of falsification does count as verification, since such an experiment ranges over the full scope of possibilities in the problem domain. Should we ever discover some place where gravity did not function, and rain fell upward, this would not falsify our current theory of gravity (which, on this view, has been verified by innumerable well-formed experiments in the past) – it would rather suggest an expansion of our theory to encompass some new force or previously undiscovered interaction of forces. In other words, our initial theory as it stands is verified but incomplete. This situation illustrates the importance of having well-crafted, well-controlled experiments that range over the full scope of possibilities for applying the theory.

In recent years philosophers of science have tried to integrate the various approaches to evaluating hypothesis, and the scientific method in general, to form a more complete system that integrates the individual concerns of each approach. Notably, Imre Lakatos and Paul Feyerabend, both former students of Popper, have produced novel attempts at such a synthesis.

http://en.wikipedia.org/wiki/Hypothesis

In the sciences, a scientific theory (also called an empirical theory) comprises a collection of concepts, including abstractions of observable phenomena expressed as quantifiable properties, together with rules (called scientific laws) that express relationships between observations of such concepts. A scientific theory is constructed to conform to available empirical data about such observations, and is put forth as a principle or body of principles for explaining a class of phenomena.[1]

A scientific theory is a type of deductive theory, in that its content (i.e. empirical data) could be expressed within some formal system of logic whose elementary rules (i.e. scientific laws) are taken as axioms. In a deductive theory, any sentence which is a logical consequence of one or more of the axioms is also a sentence of that theory.[2]

In the humanities, one finds theories whose subject matter does not (only) concern empirical data, but rather ideas. Such theories are in the realm of philosophical theories as contrasted with scientific theories. A philosophical theory is not necessarily scientifically testable through experiment.

Sad really how a cult can indoctrinates String fanatics to the point they dispute reality. Not saying anyone here is but some people insist it is a scientific theory.

Empirical
From Wikipedia, the free encyclopedia

The word "empirical" denotes information gained by means of observation, experience, or experiment.[1] A central concept in science and the scientific method is that all evidence must be empirical, or empirically based, that is, dependent on evidence or consequences that are observable by the senses. It is usually differentiated from the philosophic usage of empiricism by the use of the adjective "empirical" or the adverb "empirically." "Empirical" refers to the use of working hypotheses that are testable using observation or experiment. In this sense of the word, scientific statements are subject to and derived from our experiences or observations. Empirical data are data that are produced by experiment or observation.

Frankly the fact that nothing on Earth can test String theory makes it philosophy rather than hypothesis atm. Just saying "it can be tested over and over and la la LA I'm not listening, with your fingers in your ears" is in dispute with every mainstream scientist on the planet, but then they are all liars aren't they? You are awaiting a Messiah simple as that. Still when have String Theorists ever had peer review except from there own priests. No one but them can understand the mathematical theory of anything.

A background independent "theory" cannot be falsified by it not meeting the requirements of other theories. Try again, sorry but no dice.

The Supersymmetric Standard Model
Main article: Minimal Supersymmetric Standard Model

Incorporating supersymmetry into the Standard Model requires doubling the number of particles since there is no way that any of the particles in the Standard Model can be superpartners of each other. With the addition of new particles, there are many possible new interactions. The simplest possible supersymmetric model consistent with the Standard Model is the Minimal Supersymmetric Standard Model (MSSM) which can include the necessary additional new particles that are able to be superpartners of those in the Standard Model.
Cancellation of the Higgs boson quadratic mass renormalization between fermionic top quark loop and scalar stop squark tadpole Feynman diagrams in a supersymmetric extension of the Standard Model

One of the main motivations for SUSY comes from the quadratically divergent contributions to the Higgs mass squared. The quantum mechanical interactions of the Higgs boson causes a large renormalization of the Higgs mass and unless there is an accidental cancellation, the natural size of the Higgs mass is the highest scale possible. This problem is known as the hierarchy problem. Supersymmetry reduces the size of the quantum corrections by having automatic cancellations between fermionic and bosonic Higgs interactions. If supersymmetry is restored at the weak scale, then the Higgs mass is related to supersymmetry breaking which can be induced from small non-perturbative effects explaining the vastly different scales in the weak interactions and gravitational interactions.

In many supersymmetric Standard Models there is a heavy stable particle (such as neutralino) which could serve as a Weakly interacting massive particle (WIMP) dark matter candidate. The existence of a supersymmetric dark matter candidate is closely tied to R-parity.

The standard paradigm for incorporating supersymmetry into a realistic theory is to have the underlying dynamics of the theory be supersymmetric, but the ground state of the theory does not respect the symmetry and supersymmetry is broken spontaneously. The supersymmetry break can not be done permanently by the particles of the MSSM as they currently appear. This means that there is a new sector of the theory that is responsible for the breaking. The only constraint on this new sector is that it must break supersymmetry permanently and must give superparticles TeV scale masses. There are many models that can do this and most of their details do not currently matter. In order to parameterize the relevant features of supersymmetry breaking, arbitrary soft SUSY breaking terms are added to the theory which temporarily break SUSY explicitly but could never arise from a complete theory of supersymmetry breaking.

Proving supersymmetry correct is beside the point, it does not distinguish Strings, only proof of its fundamental principles ie higher dimensions and strings can save it from becoming a relic. I hope they find something sincerely my dispute is not with them but their flagrant disregard for scientific method.

By the way I'm only talking about string theory as a ToE not debating its application to other fields such as weather systems.

[Nautilidae]

Laughable the standard model predicts supersymetry too, a number of theories do.

I never claimed that they didn't. However, supersymmetry is a fundamental prediction of string theory, so testing it would give string theory a push as one of it's properties would have been tested.

Opinion? Well it trumps yours they are theoretical physicists of great renown. That's a bit like saying Feynmans opinion doesn't matter.

Feynman's opinion doesn't matter any more than anyone else who is familiar with a certain topic. His "opinion" only means something because he can back it up with mathematical and experimental evidence. Smolin does neither of these. He claims that string theory is untestable, yet several examples of testable predictions have been made such as gauge-gravity duality. He, and you, ignores them all. He then goes on to study a theory that suffers the same shortcomings as string theory. Gee, and you wonder why I don't respect his opinions...

It's a fake science and you know it.

If string theory is a fake science then so is every theory that hasn't been tested:

Hawking radiation isn't science
Spontaneous symmetry breaking isn't science
Loop Quantum Gravity isn't science
Supersymmetry isn't science
Quantum gravity isn't science.
String-nets aren't science.

String theory offers testable predictions, predictions that you have failed to address several times. I'm beginning to think that you cannot debunk them.

Everyone at CERN thinks it cannot turn up any evidence and yet you persist in defying the mainstream with your self delusional Voodoo.

Bollocks. There are several CERN scientists that have hopes for string theory at the LHC, including John Ellis. In fact, a CERN scientist gave a speech on topological string theory at the conference last week. Please don't speak until you have the correct information

Not it isn't and it probably never will be it's a faith not a science. Honestly God exists, no one thinks it can be proven but he does!

I was referring to Loop Quantum Gravity. You claimed that it was testable, yet you then went on to contradict that statement. Please make your you understand what you're criticizing before you criticize it...

What are your qualifications, and why does your opinion matter?

Why does YOUR opinion matter? It doesn't. However, I don't speak from opinion. I speak from the fact that string theory offers testable predictions that you ignore. You blatantly ignore almost every prediction that I've given. I'm beginning to think that you cannot debunk these claims so you simply pretend as if they aren't there. You have reached an intellectual dead end. THAT is why my "opinion" matters: because I am willing to point to facts rather than arm-waving.

A theory must have evidence. String "theory" is a hypothesis at best and a piss poor one at that.

Both hackenslash and I have claimed that string theory is a hypothesis. Please stop using null arguments about concepts that were decided long ago. It is another intellectual dead end. Hypotheses have not been tested but have the ability to be tested. This makes string theory a scientific hypothesis. I ask you this: what are the predictions made by Loop Quantum Gravity? Since you have given none, by your logic, it isn't science.

Sad really how a cult can indoctrinates String fanatics to the point they dispute reality. Not saying anyone here is but some people insist it is a scientific theory.

It is scientific. String theory is no more cultish than Smolin and loop quantum gravity.

Frankly the fact that nothing on Earth can test String theory makes it philosophy rather than hypothesis atm.

It is official: You have reached an intellectual dead end.

String theory can be tested. You ignore every example as if it were never claimed. Stop ignoring us. Just because your arguments have reached a dead end doesn't mean that you can't make new ones. Address the predictions that we've given or stop claiming that string theory can't be tested; you are arm-waving.

Just saying "it can be tested over and over and la la LA I'm not listening, with your fingers in your ears" is in dispute with every mainstream scientist on the planet, but then they are all liars aren't they?

The irony here is thick. You accuse us of saying something over and over and ignoring reality when you yourself ignore the examples we've given. We HAVE given examples. We are waiting for you to address those examples. If anyone here is sticking their fingers in their ears, it's you. Here, let's restate the examples of testable predictions of string theory:

AdS/CFT correspondence
Holographic principle
Supersymmetry
Graviton detection at the LHC
Micro black hole production at the LHC[would verify extra dimensions, a fundamental aspect of string theory]

Let's see who sticks their fingers in their ears. I predict that it will be you.

Every mainstream scientist on the planet you say? Let's make a list of mainstream scientists that support string theory:

Steven Weinberg PhD, winner of the Nobel Prize in physics
Leonard Susskind PhD, Sakurai Prize winner
Brian Greene PhD
Stephen Hawking PhD, winner of the Albert Einstein medal.
Brian Greene PhD and Cambridge Lucasian professor of Mathematics
Ed Witten PhD, winner of the Fields Medal

These are big names in physics! Oh but I guess that since they support string theory they aren't scientists, ESPECIALLY that Nobel Prize winner.

You are awaiting a Messiah simple as that. Still when have String Theorists ever had peer review except from there own priests. No one but them can understand the mathematical theory of anything.

String theory REQUIRES peer-review in order to be accepted into academic literature. This argument is utterly facile. There aren't string theory journals JUST so that string theorists can publish their work. String theory is published in some of the world's most prestigious academic journals and peer-reviewed by those journals. Claiming bias without evidence is yet another intellectual dead end.

A background independent "theory" cannot be falsified by it not meeting the requirements of other theories. Try again, sorry but no dice.

... What the hell?

String theory is background-dependent not background-independent. It is obvious that you are ignorant on this subject

Furthermore, what is this garbage about background-independent theories being unfalsifiable? General relativity is background-independent, and it has given MANY examples tested results. Where on Earth you getting this information? Try again. Sorry, but no dice.

Proving supersymmetry correct is beside the point, it does not distinguish Strings, only proof of its fundamental principles ie higher dimensions and strings can save it from becoming a relic. I hope they find something sincerely my dispute is not with them but their flagrant disregard for scientific method.

[/quote][/quote]

Supersymmetry IS a fundamental property of most string theories, The Dadga. Please become more informed on the subject that you are criticizing.

Oh really? THEIR flagrant disregard of the scientific method? How about arm-waving testable predictions? That certainly goes against the scientific method.
I've given you several examples of testable predictions and you have arm-waved almost all of them. You are in no position to be criticizing scientists for being unscientific

You have reached an intellectual dead end, The Dadga. You have resulted to quoting articles[which give information that is already known], arm-waving testable predictions when they don't fit your arguments, and making facile and factually incorrect arguments. You have continued to do all of these things after we have informed you about them. You are recycling arguments that have been refuted SEVERAL times now. In other words, we have "torn down your arguments from the ground up". This is what happens when you use the same arguments time and time again.

Continue to sell your disinformation and facile arguments, because they are all that you have left. Your a@@ is mine, sunshine.

[The Dagda]

Continue to sell your disinformation and facile arguments, because they are all that you have left. Your a@@ is mine, sunshine.

How childish. This is another way of saying I so pwned you lulz.

Be informed? WTF?

You are saying all mainstream scientist opinions don't matter and that yours does.

String Theorists are living in their own fantasy realm, "your rules don't apply to us."

Can I get a go on your bouncy castle?

This is just saying I am right and you are wrong, and defying the criticisms of the mainstream this cannot be healthy, worse it is a form of religious advocacy. Not Even Wrong: The Problem With Physics.

Strings 2010
March 11th, 2010

Strings 2010, this year’s version of the big annual string theory conference, will be held next week in College Station, Texas. There’s a university press release about this here. Normally the conference is held in the summer at places like Rome, Madrid, Paris, Kyoto, etc. and attracts about 4-500 string theorists. This year’s time and location may keep attendance down (although College Station is a lot cheaper place to stay than Rome…).

Unlike most years, there have been no promotional public lectures arranged. It also appears that there is no summary talk scheduled. In recent years, these have often been given by David Gross (who won’t be talking this year) or by Robbert Dijkgraaf (who is busy with another project, video here, for which he might want to recruit help from fellow string theorist Lubos Motl). Many of the talk titles are now available. In the past, sometimes the hot topic was mathematical and mathematicians were in attendance, but this has no longer been true for a while now. This year the hot topic is condensed matter physics, with several talks scheduled on attempts to apply AdS/CFT techniques to superconductors.

It turns out I’m going to be relatively nearby, but a week later, giving a talk for the public the evening of March 24th at Collin College in Plano.

Starting up this week and continuing through May, the KITP is hosting a string phenomenology program entitled Strings at the LHC and in the Early Universe. The program blurb somehow neglects to mention that string theory doesn’t actually predict anything at all about LHC physics or cosmology. To get a good idea of the topics that researchers in this field are discussing, online talks are here, starting with two rather general discussion sessions, one led by Blumenhagen, the second by Ovrut. As far as connecting to real physics goes, the state of the art seems to be much like it was a quarter century ago, with people struggling to find ways to come up with string theory-motivated constructions that are not in obvious disagreement with experiment. To achieve this requires going to ever more complicated models, which often contain various particles not in the Standard Model. In terms of making LHC predictions, one has no idea if this is a good or bad thing.

Update: The Strings 2010 talks will be web-cast. There’s now a participant list. With 192 participants, this will be the smallest Strings XXXX conference in many years.

You like most string theorists need to start answering critics instead of arm waving them away with my opinion is better than there's fallacies. It's not opinion anyway its called peer review, but then they don't do that, or experiment they are a fortress unto themselves.

Furthermore, what is this garbage about background-independent theories being unfalsifiable? General relativity is background-independent, and it has given MANY examples tested results. Where on Earth you getting this information? Try again. Sorry, but no dice.

Lol you're comparing String Theory to general relativity, how trite. Precisely background independent pseudo theories must have experimental evidence for them to be falsifiable requires an experiment, only string theorists think CERN provides one, no one else does. Christ you are only lying to yourself.

Your ass is mine sunshine.

Grow up.

String theory

Although physics of string theory can in principle be background-independent , perturbative formulations of this theory do not make this independence manifest because they require starting with a particular solution and performing a perturbative expansion about this background. Non-perturbative formulations such as matrix theory and AdS/CFT resolve that issue and are fully background independent.

Well it depends on how you want to set it up doesn't it. String theory can be background dependant or not, mind you it is a theory of anything.

http://en.wikipedia.org/wiki/Background_independence

Problems and controversy

Although string theory comes from physics, some say that string theory's current untestable status means that it should be classified as more of a mathematical framework for building models as opposed to a physical theory.[26] Some go further, and say that string theory as a theory of everything is a failure.[27][28] This led to a public debate in 2007,[29][30] with one commentator expressing this opinion:

"For more than a generation, physicists have been chasing a will-o’-the-wisp called string theory. The beginning of this chase marked the end of what had been three-quarters of a century of progress. Dozens of string-theory conferences have been held, hundreds of new Ph.D.s have been minted, and thousands of papers have been written. Yet, for all this activity, not a single new testable prediction has been made, not a single theoretical puzzle has been solved. In fact, there is no theory so far—just a set of hunches and calculations suggesting that a theory might exist. And, even if it does, this theory will come in such a bewildering number of versions that it will be of no practical use: a Theory of Nothing." -- Jim Holt.[31]

[edit] Is string theory predictive?

String theory as a theory of everything has been criticized as unscientific because it is so difficult to test by experiments. The controversy concerns two properties:

1. It is widely believed that any theory of quantum gravity would require extremely high energies to probe directly, higher by orders of magnitude than those that current experiments such as the Large Hadron Collider[32] can reach.
2. String theory as it is currently understood has a huge number of equally possible solutions, called string vacua[33], and these vacua might be sufficiently diverse to explain almost any phenomena we might observe at lower energies.

If these properties are true, string theory as a theory of everything would have little or no predictive power for low energy particle physics experiments.[34][35] Because the theory is so difficult to test, some theoretical physicists have asked if it can even be called a scientific theory. Notable critics include Peter Woit, Lee Smolin, Philip Warren Anderson,[36] Sheldon Glashow,[37] Lawrence Krauss[38], and Carlo Rovelli.[39]

All string theory models are quantum mechanical, Lorentz invariant, unitary and contain Einstein's General Relativity as a low energy limit.[40] Therefore to falsify string theory, it would suffice to falsify quantum mechanics, Lorentz invariance, or general relativity.[41] Hence string theory is falsifiable and meets the definition of scientific theory according to the Popperian criterion. However to constitute a convincing potential verification of string theory, a prediction should be specific to it, not shared by any quantum field theory model or by General Relativity.

One such unique prediction is string harmonics: at sufficiently high energies—probably near the quantum gravity scale—the string-like nature of particles would become obvious. There should be heavier copies of all particles corresponding to higher vibrational states of the string. But it is not clear how high these energies are. In the most likely case, they would be 1015 times higher than those accessible in the newest particle accelerator, the LHC, making this prediction impossible to test with any particle accelerator in the foreseeable future.
[edit] Swampland

In response to these concerns, Cumrun Vafa and others have challenged the idea that string theory is compatible with anything. They propose that most possible theories of low energy physics lie in the swampland. The swampland is the collection of theories which could be true if gravity wasn't an issue, but which are not compatible with string theory. An example of a theory in the swampland is quantum electrodynamics in the limit of very small electron charge. This limit is perfectly fine in quantum field theory — in fact, in this limit, the perturbation theory becomes better and better. But in string theory, at the moment the charge of the lightest charged particle becomes less than the mass in natural units, the theory becomes inconsistent.

The reason is that two such charged massive particles will attract each other gravitationally more than they repel each other electrostatically, and could be used to form black holes. If there are no light charged particles, these black holes could not decay efficiently, barring improbable conspiracies or remnants. From the study of examples, and from the analysis of black-hole evaporation, it is now accepted that theories with a small charge quantum must come with light charged particles. This is only true within string theory—there is no such restriction in quantum field theory. This means that the discovery of a new gauge group with a small quantum of charge and only heavy charged particles would falsify string theory. Since this argument is very general—relying only on black-hole evaporation and the holographic principle, it has been suggested that this prediction would be true of any consistent holographic theory of quantum gravity, although the phrase "consistent holographic theory of quantum gravity" might very well be synonymous with "string theory".

It is notable that all the gross features of the Standard model can be embedded within String theory, so that the standard model is not in the swampland. This includes features such as non-abelian gauge groups and chiral fermions which are hard to incorporate in non-string theories of quantum gravity.[citation needed]
[edit] Background independence
Main article: Background independence

A separate and older criticism of string theory is that it is background-dependent — string theory describes perturbative expansions about fixed spacetime backgrounds. Although the theory has some background-independence — topology change is an established process in string theory, and the exchange of gravitons is equivalent to a change in the background — mathematical calculations in the theory rely on preselecting a background as a starting point. This is because, like many quantum field theories, much of string theory is still only formulated perturbatively, as a divergent series of approximations. Although nonperturbative techniques have progressed considerably — including conjectured complete definitions in spacetimes satisfying certain asymptotics — a full non-perturbative definition of the theory is still lacking. Some see background independence as a fundamental requirement of a theory of quantum gravity, particularly since general relativity is already background independent. Some hope that M-theory, or a non-perturbative treatment of string theory (string field theory was thought to be non-perturbative in the 1980s) have a background-independent formulation.
[edit] Supersymmetry breaking
Main article: Supersymmetry

A central problem for applications is that the best understood backgrounds of string theory preserve much of the supersymmetry of the underlying theory, which results in time-invariant spacetimes: currently string theory cannot deal well with time-dependent, cosmological backgrounds. However, several models have been proposed to explain supersymmetry breaking, most notably the KKLT model[33], which incorporates branes and fluxes to make a metastable compactification.

The vacuum structure of the theory, called the string theory landscape, is not well understood. String theory contains an infinite number of distinct meta-stable vacua, and perhaps 10500 of these or more correspond to a universe roughly similar to ours — with four dimensions, a high planck scale, gauge groups, and chiral fermions. Each of these corresponds to a different possible universe, with a different collection of particles and forces.[33] What principle, if any, can be used to select among these vacua is an open issue. While there are no continuous parameters in the theory, there is a very large set of possible universes, which may be radically different from each other.

Some physicists believe this is a good thing, because it may allow a natural anthropic explanation of the observed values of physical constants, in particular the small value of the cosmological constant.[42][43] The argument is that most universes contain values for physical constants which do not lead to habitable universes (at least for humans), and so we happen to live in the most "friendly" universe. This principle is already employed to explain the existence of life on earth as the result of a life-friendly orbit around the medium-sized sun among an infinite number of possible orbits (as well as a relatively stable location in the galaxy). However, the cosmological version of the anthropic principle remains highly controversial because it would be difficult if not impossible to Popper falsify; so many do not accept it as scientific.
[edit] Other testability criteria

Many physicists strongly oppose the idea that string theory is not falsifiable, among them Sylvester James Gates: "So, the next time someone tells you that string theory is not testable, remind them of the AdS/CFT connection ..."[44] AdS/CFT relates string theory to gauge theory, and allows contact with low energy experiments in quantum chromodynamics. This type of string theory, which only describes the strong interactions, is much less controversial today than string theories of everything (although two decades ago, it was the other way around).

In addition, Gates points out that the grand unification natural in string theories of everything requires that the coupling constants of the four forces meet at one point under renormalization group rescaling. This is also a falsifiable statement, but it is not restricted to string theory, but is shared by grand unified theories.[45] The LHC will be used both for testing AdS/CFT, and to check if the electroweakstrong unification does happen as predicted.[46]

More "opinion".

I'm just going by the current claims that it is background independent according to x. If that's not true it doesn't change anything. You still need an experimental setup in theory at least before you even claim a rigid hypothesis.

Do strings exist?

http://en.wikipedia.org/wiki/String_theory

You aren't answering the critics you are just saying I am right and they are wrong if that's handing it to me then I'm a laugh long and loud. Unless you are an eminent scientist in the field instead of some cult groupie then your opinion matters less than mine. But then as I've made clear its not my opinion that matters.

If you were unbiased would you ask a String Worshiper to convince you their god exists, or even there religion has a foundation? Or would you look at the empirical facts, realise there are none and wont be for the foreseeable future if ever and relegate this to a curiosity for the time being.

By the way I'm only talking about string theory as a ToE not debating its application to other fields such as weather systems. Its utility is not at issue only its fundamental concerns are, and they are not addressed at CERN. No matter how many times you say they are you will fail to convince the mainstream. A resort to authority is pretty much all science has that differentiates it from philosophy, that and scientific method, neither of which you accept as valid.

[Nautilidae]

Alright, buddy. Since you can't address anyone's points in any way other than ignoring them, I'm going to do what you have done to hackenslash and I; ignore you.

Goodbye.

[The Dagda]

Alright, buddy. Since you can't address anyone's points in any way other than ignoring them, I'm going to do what you have done to hackenslash and I; ignore you.

Goodbye.

Did you read that post it addresses them all.FFS, yeah bye you got nothing.

Read the wiki. Blue shift is not currently testable nor does it distinguish string theory. Red shift maybe testable at least overall red shift, we know such effects occur. Done, done and done.

Pound–Rebka experiment
From Wikipedia, the free encyclopedia
Jump to: navigation, search
Jefferson laboratory at Harvard University. The experiment occurred in the left "tower". The attic was later extended in 2004.

The Pound–Rebka experiment is a well known experiment to test Albert Einstein's theory of general relativity. It was proposed by Robert Pound and G. A. Rebka Jr. in 1959,[1] and was the last of the classical tests of general relativity to be verified (in the same year). It is a gravitational redshift experiment, which measures the redshift of light moving in a gravitational field, or, equivalently, a test of the general relativity prediction that clocks should run at different rates at different places in a gravitational field. It is considered to be the experiment that ushered in an era of precision tests of general relativity.

The test is based on the following principle: When an atom transits from an excited state to a base state, it emits a photon with a specific frequency and energy. When the same atom in its base state encounters a photon with that same frequency and energy, it will absorb that photon and transit to the excited state. If the photon's frequency and energy is different by even a little, the atom cannot absorb it (this is the basis of quantum theory). When the photon travels through a gravitational field, its frequency and therefore its energy will change due to the gravitational redshift. As a result the receiving atom can no longer absorb it. But if the emitting atom moves with just the right speed relative to the receiving atom the resulting doppler shift will cancel out the gravitational shift and the receiving atom will be able to absorb the photon. The "right" relative speed of the atoms is therefore a measure of the gravitational shift. The frequency of the photon "falling" towards the bottom of the tower is blueshifted. Pound and Rebka countered the gravitional blueshift by moving the emittor away from the receiver, thus generating a relativistic Doppler redshift:

Special Relativity predicts a Doppler redshift of :

f_r=\frac{1-v/c}{1+v/c}f_e.

On the other hand, General Relativity predicts a gravitational blueshift of:

f_r=\frac{1-\dfrac{2GM}{(R+h)c^2}}{1-\dfrac{2GM}{Rc^2}}f_e.

The detector at the bottom sees a superposition of the two effects. The emitter dish was placed in an elevator and the speed was varied until the two effects cancelled each other, a phenomenon detected by reaching resonance. Mathematically:

\frac{1-v/c}{1+v/c}\cdot\frac{1-\dfrac{2GM}{(R+h)c^2}}{1-\dfrac{2GM}{Rc^2}}=1.

In the case of the Pound–Rebka experiment h\ll R. Therefore:

v \approx \frac {gh}{c} = 7.5×10−7 m/s

In the more general case when h ≈ R the above is no longer true. The energy associated with gravitational redshift over a distance of 22.5 meters is very small. The fractional change in energy is given by δE/E, is equal to gh/c2 = 2.5×10−15. Therefore short wavelength high energy photons are required to detect such minute differences. The 14 keV gamma rays emitted by iron-57 when it transitions to its base state proved to be sufficient for this experiment.

Normally, when an atom emits or absorbs a photon, it also moves (recoils) a little, which takes away some energy from the photon due to the principle of conservation of momentum.

The Doppler shift required to compensate for this recoil effect would be much larger (about 5 orders of magnitude) than the Doppler shift required to offset the gravitational redshift. But in 1958 Mossbauer reported that all atoms in a solid lattice absorb the recoil energy when a single atom in the lattice emits a gamma ray. Therefore the emitting atom will move very little (just like a cannon doesn't recoil much when you put a lot of sandbags behind it).

This allowed Pound and Rebka to set up their experiment as a variation of Mössbauer spectroscopy.

The test was carried out at Harvard University's Jefferson laboratory. A solid sample containing iron (57Fe) emitting gamma rays was placed in the center of a loudspeaker cone which was placed near the roof of the building. Another sample containing 57Fe was placed in the basement. The distance between this source and absorber was 22.5 meters (73.8 ft). The gamma rays traveled through a Mylar bag filled with helium to minimize scattering of the gamma rays. A scintillation counter was placed below the receiving 57Fe sample to detect the gamma rays that were not absorbed by the receiving sample. By vibrating the speaker cone the gamma ray source moved with varying speed, thus creating varying Doppler shifts. When the Doppler shift canceled out the gravitational blueshift, the receiving sample absorbed gamma rays and the number of gamma rays detected by the scintillation counter dropped accordingly. The variation in absorption could be correlated with the phase of the speaker vibration, hence with the speed of the emitting sample and therefore the doppler shift. To compensate for possible systematic errors, Pound and Rebka varied the speaker frequency between 10 Hz and 50 Hz, interchanged the source and absorber-detector, and used different speakers (ferroelectric and moving coil magnetic transducer).[2]. The reason for exchanging the positions of the absorber and the detector is doubling the effect. Pound subtracted two experimental results:

(1) the frequency shift with the source at the top of the tower

(2) the frequency shift with the source at the bottom of the tower

The frequency shift for the two cases has the same magnitude but opposing signs. When subtracting the results, Pound and Rebka obtained a result twice as big as for the one-way experiment.

The result confirmed that the predictions of general relativity were borne out at the 10% level.[3] This was later improved to better than the 1% level by Pound and Snider.[4]

Another test involving a space-borne hydrogen maser increased the accuracy of the measurement to about 10−4.[5]

So how is it discreetly measured and how does it differ from more standard models?

http://en.wikipedia.org/wiki/Pound%E2%8 ... experiment

[hackenslash]

Way to miss the fucking point by light-years. The experiment you have described deals with the red shift of light travelling in a gravitational field, and has nothing to do with the shift of gravitational waves toward the blue end of the spectrum. You do understand, do you not, that gravity is not light? The predictions of the brane-worlds hypothesis are that the gravity itself will be shifted toward the blue end of the energy spectrum, not the fucking light travelling through it.

Now, you were saying?

[Nautilidae]

Way to miss the fucking point by light-years. The experiment you have described deals with the red shift of light travelling in a gravitational field, and has nothing to do with the shift of gravitational waves toward the blue end of the spectrum. You do understand, do you not, that gravity is not light? The predictions of the brane-worlds hypothesis are that the gravity itself will be shifted toward the blue end of the energy spectrum, not the fucking light travelling through it.

Now, you were saying?

Do not even attempt to present acceptable arguments, Hack. He will simply pretend as of they aren't there. He has failed to address 90% of the points raised, yet he claims that we have nothing. Do not waste your effort.

[The Dagda]

Way to miss the fucking point by light-years. The experiment you have described deals with the red shift of light travelling in a gravitational field, and has nothing to do with the shift of gravitational waves toward the blue end of the spectrum. You do understand, do you not, that gravity is not light? The predictions of the brane-worlds hypothesis are that the gravity itself will be shifted toward the blue end of the energy spectrum, not the fucking light travelling through it.

Now, you were saying?

I was saying that gravitational shift is predicted by many models and observing it will not distinguish it from many. You guys are labouring under the delusion that those who have the most to lose by defending string theory are the most likely to be correct about their fanciful ideas. I was trying to show you an experimental set up, I know scary isn't it evidence, experiments woooo boogey men! Now where is blue shift being tested for and how do they propose to do so. This is not a hard question, I think you may even be able to answer it. Give it a whurl, hell there's a first time for everything.

"Don't worry faceless fanatic of a failing theory they will not explain x."

Ad hominem.

Basically I already have explained everything and its all tied up in those posts. If you don't like it then tell me what experiment shows blue shift, or can test for it and where is it based? And is it distinguishable from other shift theories?

So why is Feynman, Rovelli, Woight, Smolin etc's points ignored by you then.

Remove the beam from thy brothers eye before you seek to remove the mote from mine own.

I'm going to guess that nautilidae has a GCSE at best and the other guy is a graduate, what makes your opinion any better than scientific peer review by real professionals and those educated to the standard of Professor in string theory such as Smolin? Who died and made you two chancers kings of science?