A question about Superstrings

[MolotovCocktail]

One question I have about Superstrings is this: What, exactly, would one look like? Or more specifically, what would be considered as evidence that they actually exist? I've been searching in the books that I have, such as a Brief History of Time and Elegant Universe, and they never really talk in great detail about what would be considered as evidence of their physical existence. Its the same with multiple dimensions that they are supposed to exist in (both 11 and 26 dimensions)

 

I would imagine that if we did actually find solid evidence, I'd imagine that we would measure effects associated with gravity, and it would probably crank out some exotic particles that we have never seen (maybe even turn particles of one class into another since all particles are presumed to be vibrations of a string).

[ajb]

I am sure we have a thread on this already. Try a search.

[lakmilis]

ya, but for the record....I hate this notion people use that a dimension çurls' up infintely small. Is completely bananas to think of dimensions as that.

[Meir Achuz]

"I've been searching in the books that I have, such as a Brief History of Time and Elegant Universe, and they never really talk in great detail".

That's how they sell so well.

[ajb]

ya, but for the record....I hate this notion people use that a dimension çurls' up infintely small.

 

Who says that?

 

They have finite radius, just small.

[MolotovCocktail]

"I've been searching in the books that I have, such as a Brief History of Time and Elegant Universe, and they never really talk in great detail".

That's how they sell so well.

 

 

Yeah, no kidding, but it is not answering my question.

[lakmilis]

Who says that?

 

They have finite radius, just small.

 

Think most layman's literature says that....

 

not to mention a singularity .... (I mean, can you argue for it to *not* be a dimension? )

 

[merlin wood]

One question I have about Superstrings is this: What, exactly, would one look like? Or more specifically, what would be considered as evidence that they actually exist? I've been searching in the books that I have, such as a Brief History of Time and Elegant Universe, and they never really talk in great detail about what would be considered as evidence of their physical existence. Its the same with multiple dimensions that they are supposed to exist in (both 11 and 26 dimensions)

 

I would imagine that if we did actually find solid evidence, I'd imagine that we would measure effects associated with gravity, and it would probably crank out some exotic particles that we have never seen (maybe even turn particles of one class into another since all particles are presumed to be vibrations of a string).

 

Here's a couple of other questions you could ask, MolotovCocktail: Why should anyone believe that superstring theory is anything more than a piece of elaborate mathematical trickery dressed up as science? Or in other words: Why should this theory be regarded as anything more than modern numerology?

[BenTheMan]

Here's a couple of other questions you could ask, MolotovCocktail: Why should anyone believe that superstring theory is anything more than a piece of elaborate mathematical trickery dressed up as science? Or in other words: Why should this theory be regarded as anything more than modern numerology?

 

This is where those who know very little about string theory do one (or both) of two things:

1.) Pimp their own ideas about ``quantum reality'', or

2.) Preform intellectual fellatio on Lee Smolin and ``The Trouble with Physics''.

 

Let us make wagers about merlin. My money is on 1 AND 2. (Apologies, of course merlin, if you are an actual physicist studying LQG or Euclidean Quantum Gravity.)

 

What, exactly, would one look like? Or more specifically, what would be considered as evidence that they actually exist?

 

What, exactly, does this question mean? One cannot ``look'' at a string. Well, if string theory is right, I take that back. You're looking at strings right now---they look like photons:)

 

Evidence that strings actually exist may be hard to come by, and if string theory is ever proven, it may be a whole bunch of circumstancial evidence that eventually convinces us that string theory has to be right. For example, if we discover a tower of Kaluza Klein gravitons, as predicted by string theory, we would be relatively convinced that we were right. However, as in all of physics, we can only be convinced that we are right inasmuch as we are confident that we have imagined all of the other possibilities.

 

And it might be a process of elimination---we may end up trying everything else, and finding out that quantum gravity is ONLY consistent if we quantize things as strings. This is, of course, barring a catastrophic breakdown of the strings research programme, or a fantastic breakthrough in the LQG or EQG research.

[GutZ]

This is where those who know very little about string theory do one (or both) of two things:

1.) Pimp their own ideas about ``quantum reality'', or

2.) Preform intellectual fellatio on Lee Smolin and ``The Trouble with Physics''.

 

Let us make wagers about merlin. My money is on 1 AND 2. (Apologies, of course merlin, if you are an actual physicist studying LQG or Euclidean Quantum Gravity.)

 

What does that have anything to do with anything? Can string theory be proven at this very moment? no! You don't have to be a physicist to understand that. Whether it's right or not doesn't concern me, I am not trying to discredit it in anyway, but instead of insulting people, why not try actually proving them wrong.

[Severian]

Superstrings look like wriggly eels (without the eyes of course). I though everyone knew that!

[merlin wood]

What does that have anything to do with anything? Can string theory be proven at this very moment? no! You don't have to be a physicist to understand that. Whether it's right or not doesn't concern me, I am not trying to discredit it in anyway, but instead of insulting people, why not try actually proving them wrong.

 

But then that's the whole problem, given the standard model of quantum and particle physics, you just can't prove string theory wrong in any case. So, as string theorists themselves admit, whatever the results of the forthcoming Large Hadron Collider experiments, these wouldn't be sufficient to prove the theory right or wrong.

 

Then if you read an argument for string theory, like in Brian Greene's The Elegant Universe, you find it relies quite heavily on a certain interpretation of Heisenberg's Uncertainty Principle and how this can be thought to apply to what occurs at the Planck length, and which itself cannot be proven.

 

So it seems to me that you get just back to the fundamental problem of how you interpret quantum mechanics and where there is no account that you can prove right or wrong since you're dealing with description of object behaviour that cannot be directly observed or detected by any means.

 

I say the only way of disproving string theory is by developing a quite different kind of general theory that is based on the evidence of quantum physics but is supported by much more observable evidence than is string theory or the existing standard model of quantum theory for that matter.

 

Although that really is a quite a different matter...

[JackMuChabas]

Euclidean quantuum gravity effect given it's sub coherance in space time flux and manners given the up cycle of two difacted and abraviated sub love bends.

[Severian]

Euclidean quantuum gravity effect given it's sub coherance in space time flux and manners given the up cycle of two difacted and abraviated sub love bends.

 

lol. How can anyone make that up! 'sub love bends', awesome!

[Reaper]

I don't know if string theory even suggests evidence for such. Seems too convenient for it to require a particle accelerator with the energy output of the sun to be able to detect one. Seems much more like numerology to me.

 

Superstrings look like wriggly eels (without the eyes of course). I though everyone knew that!

 

 

I thought they looked more like spaghetti .

[BenTheMan]

Lockheed---have YOU done any of the calculations?

[Reaper]

I've not actually done them, but what I don't like about it is the number of solutions for them.

[BenTheMan]

That's fair. It may be a long time before anyone figures out what string theory is, exactly, if it's not a framework for understanding how to quantize gravity. But it certainly isn't numerology.

[JackMuChabas]

I think string theory is just a theory and will not make it past the litmus test.

[BenTheMan]

Great. I'm glad that we can have such well-informed and expert opinions as yours, jack.

[ajb]

Great. I'm glad that we can have such well-informed and expert opinions as yours, jack.

 

LOL, makes you want to cry somtimes, doesn't it Ben?

[BenTheMan]

Especially when I read things like what Jack said in the New York Times, by a ``science'' reporter who reads blogs to stay on top of trends in science. So it goes I guess.

 

Maybe I'll take one for the team and go into science journalism. There's so much bad reporting going on that it should make people sick. But they don't even realize it.

[Reaper]

Especially when I read things like what Jack said in the New York Times, by a ``science'' reporter who reads blogs to stay on top of trends in science. So it goes I guess.

 

Maybe I'll take one for the team and go into science journalism. There's so much bad reporting going on that it should make people sick. But they don't even realize it.

 

 

The thing is, all topics, especially physics and psychology, are all so badly reported that there really is no way you can fix it. If you go into media outlet such as CNN or ABC they will probably fire you for reporting the science correctly.

 

The best way is to simply make sure that the newspapers and magazines responsible for reporting it do it right. Even organizations such as Scientific American are guilty of bad scientific reporting.

[webplodder]

One question I have about Superstrings is this: What, exactly, would one look like? Or more specifically, what would be considered as evidence that they actually exist? I've been searching in the books that I have, such as a Brief History of Time and Elegant Universe, and they never really talk in great detail about what would be considered as evidence of their physical existence. Its the same with multiple dimensions that they are supposed to exist in (both 11 and 26 dimensions)

 

I would imagine that if we did actually find solid evidence, I'd imagine that we would measure effects associated with gravity, and it would probably crank out some exotic particles that we have never seen (maybe even turn particles of one class into another since all particles are presumed to be vibrations of a string).

 

 

String theory attempts to merge quantum mechanics with general relativity and the name string theory comes from the modeling of subatomic particles as tiny one-dimensional “stringlike” entities. The concept of a string vibrating is supposed to represent a particle with a certain mass and charge. We're told that string theory has the potential to incorporate all four of nature's forces, i.e. gravity, electromagnetism, strong force, and weak force and all types of matter in a single quantum mechanical framework, suggesting that it might be the long-sought unified field theory. Although, to the best of my knowledge, string theory is still being persued it remains a purely mathematical construct because it has yet to be experimentally verified. So I guess the short answer to your question is that strings are, at least at the moment, purely conceptual ideas and can't really be visualized and may even be dropped in favour of some other model in the future, who knows? You'd need to have a knowledge of very advanced mathematics to follow the reasoning behind them!

[Martin]

String theory attempts to merge quantum mechanics with general relativity and the name string theory comes from the modeling of subatomic particles as tiny one-dimensional “stringlike” entities. The concept of a string vibrating is supposed to represent a particle with a certain mass and charge. We're told that string theory has the potential to incorporate all four of nature's forces, i.e. gravity, electromagnetism, strong force, and weak force and all types of matter in a single quantum mechanical framework, suggesting that it might be the long-sought unified field theory. Although, to the best of my knowledge, string theory is still being persued it remains a purely mathematical construct because it has yet to be experimentally verified. So I guess the short answer to your question is that strings are, at least at the moment, purely conceptual ideas and can't really be visualized and may even be dropped in favour of some other model in the future, who knows? You'd need to have a knowledge of very advanced mathematics to follow the reasoning behind them!

 

That seems to me to be a legitimate viewpoint. My primary interest is that we allow different views peaceful expression. I would say that WE CAN'T TELL if the string framework will eventually produce a testable (i.e. falsifiable) theory going beyond the standard model, or whether it will or will not be much pursued 10 or 15 years from now.

 

What we can say is that string research output has declined since 2002 in terms of objective quality measured by citations and in terms of objective quantity measured by publication rate. Although I wouldn't, it certainly could be argued that subjective measures are superior to the usual objective ones. But the academic committees that decide on hiring and tenure typically DO look at objective measures such as how many citations a candidate's work has received as a measure of how much it is valued by his/her colleagues in the research community.

 

And we can ask WHY there has been the decline in research output and quality, to the extent that these indicators are valid. And will the decline since 2002 turn around?

 

Another objective measure is the planned cutback in string faculty positions that was discovered in a recent study which inquired of US college and university physics departments concerning plans for 2007-2012, and added up the results. For US institutions overall it came to around a 10 percent cutback as I recall.

 

I do not know the reason for this perceived decline since 2002 (which seems to have occurred in several categories) but it seems significant that it COINCIDES with the publication of a January 2003 paper by a Stanford group that put the spotlight on the STRING LANDSCAPE. This was the paper by Kachru, Kallosh, Linde, and Trivedi----the famous "KKLT" paper which led to a belief that the string framework offers some 10⁵⁰⁰ separate versions of physics. Later that year Leonard Susskind wrote a paper with a title like "The Anthropic Landscape of String Theory"---Susskind also reported a decline in morale among those of his colleagues that did not like the Anthropic answer to the Landscape dilemma.

 

Now we cannot say that the KKLT paper caused the decline in string research or that the Susskind-led movement towards a resort the the Anthropic Principle did (which David Gross has called "giving up"). All we can say is there has been a lot of obvious turmoil and controversy within the string community since 2002 and that the objective indicators have dropped.

 

This is not necessarily bad. Maybe the cutbacks will be healthy. Maybe new ideas will show up next year. Maybe the overall picture will rebound. An outsider like myself simply does not, or CAN not predict the future.