The LHC will go on-line later this year and hopefully will be gathering useful data before the end of the year.
A lot of hopes are resting on the LHC to begin answering some fundamental questions - not least among String Theorists.
As yet there is no experimental evidence that string theory is in any way valid - in fact it is not even a theory, and its many forms are contradictory and at odds with Standard Model experiment results. It introduces more questions than answers - instead of the 11 unknowns the Standard Model leaves unanswered, String Theory introduces a myriad of unknowns and unknowables that can never be answered by experiment. Maybe the LHC results will give an indication wether it is a valid science.

As you've probably gathered I am not a proponent of String Theory or its many variations, so I will state my bias against it now. One of the few areas where I think it might be relevant is Loop Quantum Gravity which is usually scorned by most String Theorists.

I am predicting that the LHC does not find evidence of a Graviton or of micro black holes. However String Theorists have a habit of making excuses and I am sure that failure to find any experimental evidence for their "theory" will not deter them from their current path. To paraphrase one of the greatest minds of the last century "String theorists do not make predictions - they make excuses" Richard Feynman.

The big problem with an alternative to the Standard Model is that at the moment String Theory is the only game in town and most of todays most prominent physicists (those in charge) have invested fruitless decades in it. They are unlikely to lay it down due to lack of evidence. I am with Peter Woit on this one - String Theory is "Not Even Wrong".

The LHC therefore will not help String Theorists, but I do believe we will see them making even more excuses about why we see no experimental results that might agree with their "Theory". I would love to have to eat my words on this - science progresses when experiment throws up new unexpected results, however I'm not getting out the salt and pepper yet.

I'm off to fill myself with Beer after reading all that rubbish.

Why does Science not say :

"Dunno, but I would love to know."

Both Art and Science share one thing in common: Arrogance.

Not at all meant for you John.

I was ranting and raving.

I apologise if you took my view of the state of Science personally.

Both Art and Science share one thing in common: Arrogance.

No - thats just me.

Are there no defenders of string theory here? - Superstrings, supersymmetry, M-Theory, etc. etc. etc.? I know enough about each to describe its principles but not a definition of the theory.
Can any proponents give me a definition of any of the theories, of what they predict and the experimental results that confirm them?

I think we'll find that there is no theory (only a hope that there may be a theory), that no predictions have been made, and that no experiments have been done (you can't do an experiment unless you can make a prediction). And it has taken well over 3 decades to get here (nowhere).

So when you read an article in Astronomy Now about the possibility of the LHC finding Gravitons, and micro black holes just remember where these fictitious ideas have come from (NOT the successful Standard Model - which has nothing to say about them - 'cause they don't exist).

It is time for physicists to wake up and reject String Theory. Take the sexy mathematics that has been developed and put it in your tool bag and move on. Unfortunately String Theorists now run most of the top jobs in physics - are they going to admit they were wrong after wasting 30 years on it? I hope the LHC results will hasten the demise of all things String.

So when you read an article in Astronomy Now about the possibility of the LHC finding Gravitons, and micro black holes just remember where these fictitious ideas have come from (NOT the successful Standard Model - which has nothing to say about them - 'cause they don't exist).

I'm more interested in seeing whether the LHC finds the Higgs Boson and what the properties turn out to be.

I'd love to debate string theory but I'm sitting on the fence about it. I've studied it a bit but I don;t understand it enough to debate it with you!

Albert,
I think we'll see some indication of the Higgs if not some hard evidence. At least it might confirm the energy range of the LHC may not be high enough to give positive confirmation which in itself tells us more about the mass of the boson. If the LHC does nothing else other than give data on the Higgs then it will have been worthwhile, but there is so much more to come from this behemoth. I am so looking forward to the data that will result after October Imagine finally being able to understand why matter has mass - and as a result understanding why mass/energy curves spacetime. Gravity can then finally go in the bin and future generations may be taught the correct laws of nature.

BTW: before you get immersed in studying string theory, read Peter Woits book "Not Even Wrong - the failure of string theory and the continuing challenge to unify the laws of physics". Its useful, though not necessary, to have a grounding in all flavours of things String. Without Witten - undoubtably a mathematical genius, but not necessarily a physicist - I don't think String Theory would be around today.

BTW: before you get immersed in studying string theory, read Peter Woits book "Not Even Wrong - the failure of string theory and the continuing challenge to unify the laws of physics". Its useful, though not necessary, to have a grounding in all flavours of things String. Without Witten - undoubtably a mathematical genius, but not necessarily a physicist - I don't think String Theory would be around today.

Sounds like an interesting companion to a re-read of the Elegant Universe!

Albert,

Yes a very interesting read - no doubt about it.

You could add a few more to that:
1. The Elegant Universe (as you point out) - Brian Greene - good book for a grounding in all things string.
2. Our Superstring Universe - L.E.Lewis.
3. The Search for Superstrings, Symmetry and the Theory of everything - John Gribbin.
4. Lucifers Legacy - the meaning of Asymmetry (not really all that relevant here but a good read all the same) - Frank Close.

I haven't read the Elegant Universe, but I have Brian Greene's "The Fabric of the Cosmos" which I quite enjoyed. I also found "Not Even Wrong" to be a good read.

One short (if somewhat oblique) defense: string theorists certainly didn't invent making excuses. One of the founding principals of quantum mechanics was that two particles in the same system couldn't have the same quantum state (the Pauli exclusion principle). When particle physicists found that quarks often did had the same charge and spin, they said "ahh... they must be different colors". And when not even that sufficed, they invented new flavors -- first "charm" and "strange", and later "top" and "bottom".

Cheers,
-- Jeff.

One short (if somewhat oblique) defense: string theorists certainly didn't invent making excuses. One of the founding principals of quantum mechanics was that two particles in the same system couldn't have the same quantum state (the Pauli exclusion principle). When particle physicists found that quarks often did had the same charge and spin, they said "ahh... they must be different colors". And when not even that sufficed, they invented new flavors -- first "charm" and "strange", and later "top" and "bottom".

I agree with you in principle - the difference though is that quantum theory has been re-defined based on what has been seen in experiments - so flavours, colours etc were deemed necessary to refine the theory of what was actually happening. Whereas in String Theory no experiments are performed - at all.
An analogy might be a refernce text book vs "alice in wonderland".

And for those who would rather watch the program than read the book here it is!

The Elegant Universe (3 hours)
www.pbs.org/wgbh/nova/elegant/program.html

Are there no defenders of string theory here? - Superstrings, supersymmetry, M-Theory, etc. etc. etc.?

It is time for physicists to wake up and reject String Theory. Take the sexy mathematics that has been developed and put it in your tool bag and move on. Unfortunately String Theorists now run most of the top jobs in physics - are they going to admit they were wrong after wasting 30 years on it? I hope the LHC results will hasten the demise of all things String.

I always find it a bit sad that physicists seem to invest so much of their personal responsibility and credibility into their theories. Fred Hoyle springs to mind with the steady state theory, to the point where he became a bit blinkered and eventually a bit discredited trying to make a moribund theory work, instead of taking a more objective standpoint. Even Einstein lost some objectivity talking about QM.

So what, if string theory as it stands turns out not to be 100% verifiable? If its proponents say, OK, let's see whether it needs to be completely discarded, or more likely modified, then at least they will have made an effort to describe something which had hitherto been incomprehensible. And so far as "waking up and rejecting" string theory, isn't this something you do when you see actual experimental evidence which contradicts it rather than the absence (so far) of evidence? This seems to be just the kind of thing you are criticising the stringers for.

So what, if string theory as it stands turns out not to be 100% verifiable?

But you see that is the problem. None of it is verifiable - you cannot do experiments to prove it one way or the other. So even if 1% was verifiable I would be happy to endorse its continuation.
The standard model experiments that do apply results are totally at odds with the numbers that String does comes up with - by many orders of magnitude.

All I'm saying is that after 30 years hard work by thousands of physicists, you would at least expect to see the definition of the theory (none yet) and some indication that they are on the right track (a single experimental result maybe - none yet). Draw your own conclusions.....

So what, if string theory as it stands turns out not to be 100% verifiable?

But you see that is the problem. None of it is verifiable - you cannot do experiments to prove it one way or the other.

Are you sure, or just that we can't do them at present? You can't discard a theory just because of the limitations of our current technology. No experiment or observation is proof of any entire theory anyway, just that particular prediction. How about keeping an open mind until we know one way or the other?

Hi John,
I have to say you have grabbed my attention.
Can you give us a number of examples where string theory is simply wrong ?
convince me! (BTW, I dont have time to read books on the subject)

Hi John,
I have to say you have grabbed my attention.
Can you give us a number of examples where string theory is simply wrong ?
convince me! (BTW, I dont have time to read books on the subject)

Dave,
Let me answer this with a question of my own. Can you show me a single example of where String Theory has been proven correct. With experimentally verifiable results.
There are numerous examples of where it has been experimentally shown to be at odds with Standard Model experimental results.
I can't prove String Theory is wrong just like I can't say for sure there is no God. However after thirty years you would imagine some experimental result or even a written definition/Theory would have emerged. What we have though is no Theory and no predictions, and therefore no experimental results - isn't it time to find a new game?

Hi John,.
What you're saying sounds really surprising from a scientific point of view, surely they must have some reasoning to think string theory is good, as for example I cant giver any as I know little about it.

You make it sound like they came up with a theory for something, that doesn't do anything, that solves no problems, so what is its use ??
Usually a theory is there to solve an encountered problem, so is what the problem its trying to solve ?

You make it sound like they came up with a theory for something, that doesn't do anything, that solves no problems, so what is its use ??
Usually a theory is there to solve an encountered problem, so is what the problem its trying to solve ?

Exactly my point Dave. There is in fact no defined Theory, no predictions, no experiments and no results. (The most important part of the above is - "no predictions" - think of the implications of this, if my theory doesn't predict anything then it can never be proved right or wrong).

The initial problem they were trying to address was the 11 unanswered questions left by the Standard Model - however they introduced billions of unknowns by trying to do this - in other words they made things worse. Secondly they are proposing this as a Grand Unified Theory (GUT), however this has not been forthcoming either. There isn't even a definable Theory - there are lots of different strands of thought, often contradictory of each other which they somehow hope to tie together to give us the answer to life, the universe and everything - sounds a bit like a religion doesn't it? - it's certainly not Physics as we know it. The emperor is naked as the day he was born. I can say this because I'm not defending a position in physics and have nothing to lose. I wonder how many physicists would love to have the freedom to speak out against String.

It sounds like another spin off of the "worm holes and baby universes" theories again. Sure, if some great minds can think it up, then surely it must exist... "um, we just don't have any proof, mathematics, or evidence to the contrary, so we must be correct!"

Know what I mean?

The day is rapidly approaching when the limits of human understanding will be reached.

Our brains may not be up to the task of deeply understanding nature.

We wil not be able to understand the "proofs" delivered to us by computers.

The "real" HAL is probably only a short distance into the future.

We won't have the brains to understand the "reasonings" of HAL.

I know what your doing Mark .... Mark .... Mark...................Don't plug me out..............

Just sing "Daisy Daisy" and you won't feel a thing John.

(Trust me, I am programmed to be incapable of error on this point.)

Exactly my point Dave. There is in fact no defined Theory, no predictions, no experiments and no results. (The most important part of the above is - "no predictions" - think of the implications of this, if my theory doesn't predict anything then it can never be proved right or wrong)

Even if what you say is true are you suggesting that the theorists should just stop working on it? You can't erase this stuff from history, the idea will still be out there. Yes you can say you think it's wrong, and until they come up with some way of testing it experimentally its status is clear, but I don't really know what you're saying here.

There is perhaps a little bit of a distorted perspective on String Theory here. First of all String Theory is currently the dominant approach in quantum gravitational research. It is certainly not dominant in physics in general hence String Theorists certainly do not "run most of the top jobs". For instance the condensed matter community outnumbers the quantum gravity community by over 15 to 1. So let's be clear that string theory is currently dominant only in a niche area of physics. Secondly it is only dominant in that niche area in American universities, not British, French, e.t.c.

Secondly Supersymmetry is a completely seperate idea that merely String Theory incorporates. It is not a part of String Theory. SuperSymmetry may or may not be true, however it does make explicit experimental predictions.

Finally:

Even Einstein lost some objectivity talking about QM.

This is an often repeated statement that reflects unfairly on Einstein. Einstein thought QM was a wonderful theory and certainly didn't think it was wrong, he simply disagreed with the old Copenhagen Interpretation. At the time he lived all his objections were valid. Remember he was the one who found that QM predicted entanglement, so he certainly didn't dismiss the theory.