Does Higgs boson discovery mean String Theory is dead?

I was up late last night with the heady knowledge that I now have the power to post on ATS (!), weighing what question I should ask the members first. It turned out to be a tie between the expansion (acceleration) of the universe and the recent discovery of the Higgs boson. The second seems to be a bit more recent and contentious, so here goes...

My understanding of quantum physics is fairly limited but there are few things I believe I've picked up (please correct me if I've gotten anything wrong).

For starters, bosons are particles of force rather than particles of matter (fermions). In other words, bosons are what impart energy onto fermions and set the whole subatomic soup we swim in into motion. In the case of the Higgs, it's what gives particles their symmetry (or mass) -- what determines why, and how many, electrons are stuck to a nucleus, for example.

Once the discovery of the Higgs was made at the LHC, and the peer reviews seemed to support it, scientific publications exploded with the news: the Standard Model is now complete! (oh, and String Theory is dead)

This left me scratching my head because this is not how I understood the relationship of the two theories. The Standard Model, if I understand it correctly, predicts the existence of all of the elementary particles such as fermions, bosons, leptons, gluons, etc., and does a pretty good job of showing how they all interact too. To me this seems like a description of our solar system -- we can tell both through mathematical models and observation how the earth (for example), rotates around the sun, how it would rotate if the sun was half its size, or if the earth was twice as big, are a third of the distance farther, etc. But it doesn't seem to explain what the earth and the sun are really composed of, it just describes their physical properties and interactions.

String Theory, from what I've read, seeks to explain these elementary particles at a lower level, essentially claiming that they're composed of tiny vibrating strings of energy. The theory predicted (in fact, it required), the existence of a Higgs boson, and unless I'm completely getting it wrong, it doesn't seem like the Standard Model and String Theory in any way contradict each other.

In other words, the Standard Model does seem to have been fully proven, but it doesn't go any farther than the quantum limit denoted by Planck's constant. String Theory takes over after that and seems to be poised to become the next frontier of quantum physics, basically digging deeper into the particles that make up the universe.

So ... am I completely off course with this, or is String Theory really dead?

Many thanks for your feedback!

If String Theory was really "dead" it'd be published and boasted about everywhere.

reply to post by Philosophile


When I was flipping through various articles online, that's kind of the impression that I got.

Originally posted by transmundane
So ... am I completely off course with this, or is String Theory really dead?

Many thanks for your feedback!

I explained why string theory is unlikely to be proven or disproven anytime soon here, unless we develop some radically different views on string theory, and since string theorists don't even know what string theory is (I'm not making that up, a leading string theorist actually said that), it's possible ideas about it can change.

I dont think the higgs boson/higgs field is real....

Its funny you describe string theory as ... tiny vibrating strings of energy.... these areas of science are attempting at comprehending the fundamental constituents of the universe... is there any way to further simplify or comprehend what the energy part of "vibrational strings of energy" means or is?.... this is all related to the same problem... why is matter matter,,, why is it exactly as it is,, and why does it have the attributes it does.... what actually are the fundamental quanta of matter that all physical things of the universe are built of... why are they the way they are and why do/can they do the things they do?

is the higgs field the bottem turtle?

if it is admited that energy is something rather then nothing.... and the universe has an exact potential of postive energy/matter ( potential amount of physical material that can be created with whatever and why ever there was matter at the beginning of the universe) ..... then there is no reason to bring about a flying spaghetti monster.. or higgs field... to describe why this energy can be said to have what is known as mass.... its simply that the energy/matter that is a placeholder in objective reality as a part of an atom, or star, or planet, or person... is actually something.... and this something has physical qualities that can be compared to other comparable constituents... you know... we compare the subatomic particles.... we compare what the subatomic particles can create; atoms... we can compare what the atoms can create with each other; chemistry....

String theory became unnecessarily popular. It was just a theory, and one that wasn't widely accepted by the scientific community.

Originally posted by Arbitrageur

Originally posted by transmundane
So ... am I completely off course with this, or is String Theory really dead?

Many thanks for your feedback!

I explained why string theory is unlikely to be proven or disproven anytime soon here, unless we develop some radically different views on string theory, and since string theorists don't even know what string theory is (I'm not making that up, a leading string theorist actually said that), it's possible ideas about it can change.

edit on 13-12-2012 by Arbitrageur because: clarification

If I understood your linked post, your claim (based on the Wikipedia article), is that the power consumption required to prove String Theory is so high that it's not likely to happen any time soon. Is that correct?

I think I've come across this as well and it seems to be in keeping with quantum mechanics and how we measure them. It's why previous particle accelerators weren't nearly enough to measure things like the Higgs boson ... the energy required to split up these particles is immense (teravolts at this point). I'm not sure how useful the comparison to the explosive power of TNT is though.

These experiments are accelerating particles and creating massive differences in electrical potential (the volts part). The "explosions" are so minuscule that, at most, we'd see a flash of light as photons are tossed out. I also don't think it would do them much good to just throw arbitrary matter in there and collide it, and it would really be the amount of matter in the accelerator that would create any sort of destruction. There are also all those fiddly little detectors in there they probably wouldn't want to wreck

Regardless, I think you may be correct -- the energies that are calculated are immense and would require new methods of particle acceleration. But considering the advances humanity has made in just the last 100 years alone, I'm not convinced that it's either impossible or that it may even take outrageously long.

Originally posted by nixie_nox
String theory became unnecessarily popular. It was just a theory, and one that wasn't widely accepted by the scientific community.

Most currently accepted scientific theories were rejected and derided when first proposed. The established scientific community seems very unwilling to accept new ideas, even if such ideas appear to be based on solid mathematical and theoretical footing (as String Theory is). In fact, Einstein's own work was shunned for roughly 40 years before physicists decided to give it a second look.

But String Theory IS a theory, that much is certainly true. Einstein's General Relativity was (and still is) a theory too, though empirical evidence has shown it to be mostly true. Prior to that, it existed only in the mind of the diminutive German (and for a while afterwards, only on paper). The missing bits of Einstein's ideas (especially surrounding quantum gravity), are where String Theory jumps in. In this case, String Theory also seems to be one of the strongest contenders in explaining these gaps in Einstein's work.

With the Higgs discovery, the Standard Model now looks complete, but I wonder if physicists are high-fiveing each other and basically saying, "now we know everything!", or if this just completes one level of understanding and if the next level is where String Theory comes in.

Originally posted by transmundane
For starters, bosons are particles of force rather than particles of matter (fermions). In other words, bosons are what impart energy onto fermions and set the whole subatomic soup we swim in into motion.

Ehh, sort of. The particles which are force carriers, and are associated with "ordinary symmetries" in them are bosons. But being a boson doesn't imply you're a force carrier.

The "imparting energy" sentence doesn't make sense, so I won't try to correct it....

In the case of the Higgs, it's what gives particles their symmetry (or mass)

The word "symmetry" doesn't make sense here, but it is what gives some particles (e.g., quarks and electrons) their mass. It's not "where" all mass comes from, though. Most of the mass of a proton, for example, does not come from the masses of the constituent quarks, but from the total energy.

what determines why, and how many, electrons are stuck to a nucleus, for example.

There are no electrons in a nucleus, and the Higgs doesn't directly determine anything about nuclear structure. But it is part of the description of electroweak interactions.

Once the discovery of the Higgs was made at the LHC, and the peer reviews seemed to support it, scientific publications exploded with the news: the Standard Model is now complete! (oh, and String Theory is dead)

That's because the media almost never actually listens to what scientists tell them, and somehow manages to find the crackpot ones in the unlikely event that it does... The Higgs discovery has absolutely nothing to do with String Theory.

The Standard Model, if I understand it correctly, predicts the existence of all of the elementary particles such as fermions, bosons, leptons, gluons, etc., and does a pretty good job of showing how they all interact too.

Well, it depends on how you arrange things, but a more correct description (although still sloppy from a technical point of view) is that it "describes" them, but doesn't "predict" (most of) them. The Standard Model is a particular example of a Quantum Field Theory where some particles and interactions have been inserted by hand, and some others are a consequence of the theory.

It doesn't explain, e.g., why there are three identical generations of particles (and not one or four or zero of infinity or whatever else), or why there are no additional light elementary particles (there may be heavier ones that haven't been detected).

To me this seems like a description of our solar system -- we can tell both through mathematical models and observation how the earth (for example), rotates around the sun, how it would rotate if the sun was half its size, or if the earth was twice as big, are a third of the distance farther, etc. But it doesn't seem to explain what the earth and the sun are really composed of, it just describes their physical properties and interactions.

Sort of... That's really going too far in the "ad hoc" direction, though.

it doesn't seem like the Standard Model and String Theory in any way contradict each other.

That is correct, that is definitely true.

In other words, the Standard Model does seem to have been fully proven

Well, sort of. It's "proven" in the sense that it is a complete description of low-energy particle physics (where "low" means "ridiculously high compared to every day things"), but it's not known how well it holds up at just-slightly-higher energies.

It's likely there could be, for example, multiple Higgs particles, or other fundamental particles, that will be discovered by the LHC, that would not strictly speaking be included in the Standard Model (but through slight modifications could easily be included).

Originally posted by transmundane
If I understood your linked post, your claim (based on the Wikipedia article), is that the power consumption required to prove String Theory is so high that it's not likely to happen any time soon. Is that correct?

That's a common claim, but it's quite wrong. Like most things in the popular science media (which includes Wikipedia, sadly), it's based off of a misunderstanding of an idea that's decades out of date .

It's a bit complicated to go into the details of why, but String Theory provides a more strict mathematical framework than the Standard Model. Claiming you need ridiculously high energies to "prove" String Theory correct is like saying that you need ridiculously big numbers to prove algebra is correct, because if all you know is arithmetic, you have to check solutions one-at-a-time.

String Theory is, by design, a framework which includes the Standard Model, and the framework it is built out of--Quantum Field Theory--as special cases. In the same way that algebra includes the statement "2*3" as well as the framework it is built in--arithmetic

It is known to be the case that String Theory extends and includes the Standard Model in that sense. That was never really a question (at least, after the 1970s-ish). The question is if it is a complete description, or if more is needed. There are examples of Quantum Field Theories described by String Theory where it is known that no more is needed, but that statement is not quite proven for the Standard Model.

Specifically, we know, as a theorem, that Standard-Model-like theories do exist in String Theory, but the theorems that tell us that don't tell us how to actually construct any of these models. On the other hand, we know some models explicitly that have each of the pieces of the Standard Model separately, but there is not a known model that has all the pieces together. It turns out to be very technically difficult to do that!

At any rate, finding such a model explicitly would certainly prove Sting Theory correct, as it would provide a concrete mathematical example from which the Standard Model could be derived as a particular case. It would also provide many non-trivial relationships that couldn't, even in principle, be explained by the Standard Model.

Originally posted by transmundane
If I understood your linked post, your claim (based on the Wikipedia article), is that the power consumption required to prove String Theory is so high that it's not likely to happen any time soon. Is that correct?

Since the post started with: "there may be a few predictions of string theory which can be tested in the LHC" I wouldn't say that interpretation is completely accurate. Obviously that points to some capabilities of testing limited aspects of string theory in the LHC.

It's not the power consumption that's the key issue, it's the energy levels that are created, as explained by this Harvard professor/particle physicist who also works with string theorists ideas as she explains:

Lisa Randall: String Theory

Note that just before 2 minutes in the video she states we don't have near the energy levels needed to test string theory. The post I linked to previously conveyed a thought experiment about the scales which would be needed to create higher energy levels, if we just scaled up the LHC design. In reality, we can only scale it up so far, and we would need to come up with more innovative designs to get higher energy levels. An example of a new technology that might help would be room temperature superconductors, for example.

Modulii is free to disagree with the Harvard professor, and with Wikipedia, and with many other sources, but I find Harvard professor Randall's explanation more credible than modulii's explanation.

Here's another professor saying more or less the same thing, and he puts the LHC experiments in perspective relative to the above quote from my linked post, regarding what they may or may not accomplish:

Can We Prove String Theory?


And here's the screenshot of the string theorist explaining how string theorists are still not sure what string theory is, so that's a problem; how do you test it if you don't know what it is?



David Gross: The Coming Revolutions in Theoretical Physics

There's also the problem of string theory making too many predictions, that aren't unique.
That's a pretty good video if you want more than the dumbed down explanations for the masses.

Someone said that they do not believe that the Higgs and its attendant feild actually exist. Others have said in this thread, that no one understands string theory.

The reality is that there has been a massive drive to discover the veracity of the Higgs boson, which has attained results which, according to those who actually worked at the project, and have reveiwed the raw data from the experiment, show the Higgs to be the real deal.

Where string theory is concerned, there has never been an experiment performed which showed any of its assumptions to be unassailable. Of the two then, I am more inclined to favour the Higgs because there is actual evidence for its existence.

One of the things that I love about science in general, but physics in particular, is that a premise which is posited, is only validated by evidence. String theory, interesting a concept as it may be, and educational in some areas as it most certainly is, has not been validated, nor indeed has any widely understood effort been made to do so, probably because the very essence of these strings is so intangible and mysterious, that the mind cannot begin to see how one might go about isolating and examining such a thing.

Sometimes theoretical physics, and those who are involved with it, become so caught up by an elegant idea, or an entertaining and exciting chain of thought. Like old time gold miners, they can get locked onto what looks like a seam leading to a motherlode, only to come up holding iron pyrite. Now, given the complexity of the subject that they deal with, one can understand them having the occassional flight of fancy, but the real sticking point for any idea is when it comes to the point that engineering skills, materials, and manpower come together, to allow a person to TEST these theories. When that happens, a theory can have itself, or its elements properly examined.

If string theory has any value what so ever, then mankind is currently unable, for one reason or another, to test for the presence of these strings, so to know for certain that string theory is dead we may have to wait a while. In the mean time, we have the Higgs boson, and all the possibilities that working with a particle which imparts mass on others, presents for the human race. I think thats more than enough for one species to be getting on with for the moment! Dont you?

Originally posted by TrueBrit
Someone said that they do not believe that the Higgs and its attendant feild actually exist. Others have said in this thread, that no one understands string theory.

While you were writing your post, I was writing my post which included the screenshot illustrating blind people touching an unknown creature trying to figure out what it is. This was done by a string theorist so I appreciate his candor.

String theory, interesting a concept as it may be, and educational in some areas as it most certainly is, has not been validated, nor indeed has any widely understood effort been made to do so, probably because the very essence of these strings is so intangible and mysterious, that the mind cannot begin to see how one might go about isolating and examining such a thing.

As both professors said in the videos in my previous post, we can conceive of higher energy levels that might demonstrate string properties. The problem is, we don't know how to achieve those energy levels, since the LHC doesn't come close.

Originally posted by Arbitrageur
Note that just before 2 minutes in the video she states we don't have near the energy levels needed to test string theory.

No, she doesn't say that, she says you'd have to do that for it to become obvious you were looking at strings instead of point-like particles. That statement is completely true, but has nothing to do with "proving string theory correct." It has to do with directly probing string-length scales, which, no surprise, takes a lot of energy.

But that has nothing to do with testing string theory. Do you need to literally have a billion dollars to really make sure you know how to do a budget? No, you need to know basic algebra.

It's the same with string theory. But with more complicated algebra.

Modulii is free to disagree with the Harvard professor

I don't disagree with her; you don't understand her. There's a difference. Also, I have a degree in string theory, I do know what I'm talking about. Also also, it's not "modulii," it's "moduli," as in, the things that show up in string theory.

And here's the screenshot of the string theorist explaining how string theorists are still not sure what string theory is, so that's a problem; how do you test it if you don't know what it is?

Statements like that are just sloppy speaking, it's like an engineer saying "we don't understand everything about combustion engines." We do, we understand a lot about them, and when we say things like that we just mean that we'd like to understand more about them. Hardly a shock.

Originally posted by Moduli

The word "symmetry" doesn't make sense here, but it is what gives some particles (e.g., quarks and electrons) their mass. It's not "where" all mass comes from, though. Most of the mass of a proton, for example, does not come from the masses of the constituent quarks, but from the total energy.

Where does the "other" mass come from besides the higgs giving mass to quarks and electrons? what is the other mechanism which imparts mass onto non quark and electron particles?

What about the concept of a "string", the physical aesthetic of that idea,, became so appealing? why was it chosen? what about that "shape" or quality do they believe is cutting closer to the true nature of matter/energy? even to go on and say that the strings most likely appear as particles to us... but they are.. strings.....
did the idea of oscillating strings come about to relate to the concept of waves? or tiny fields even?

how is it thought these strings we formed.. and what from? ( related to the beginning of the universe) I think ive heard theories saying string theory is best explained if the universe did not begin in a big band but were two branes colliding or something...?

Originally posted by Arbitrageur
There's also the problem of string theory making too many predictions, that aren't unique.
That's a pretty good video if you want more than the dumbed down explanations for the masses.

This is another complete misunderstanding BTW (well, combined with more unfortunately lazy explanations that are just asking to be misunderstood...). It's like complaining you can build too many things with LEGOs, and no one that's built things with them has built exactly the thing you wanted.

The point of string theory isn't make only one prediction. It would be a pretty stupid theory if it did! The point of string theory, like quantum mechanics, or quantum field theory, is that it is a framework for building theories. That's really what any modern (as in, past century) theory is.

It's not the framework's job to do all the work for you, it's your job! Sometimes it's hard, but whatever, it's not the theory's responsibility to do that (in the same way it's not algebra's job to do your budget for you automatically!).

It is, however, the theory's responsibility to be proven mathematically correct and shown to be an extension of previous theories, and string theory has done this in a large number of ways. Just as you can be sure a budget done correctly with algebra is indeed correct.

Originally posted by ImaFungi
Where does the "other" mass come from besides the higgs giving mass to quarks and electrons? what is the other mechanism which imparts mass onto non quark and electron particles?

There's no "mechanism" it's just the usual relationship between mass and energy (the Higgs mechanism is actually doing the same kind of thing, too, just in a sort-of different way).

What about the concept of a "string", the physical aesthetic of that idea,, became so appealing? why was it chosen?

There's nothing "aesthetic" about it, and it was not "chosen." It's the result of math. And, additionally, it's not all about strings either. "String theory" is about the dynamics of point-like, string-like, plane-like, etc. things. Not just "strings." But all of these different objects are related to each other in complicated ways.

Why they show up is technical, and it's not really something you can understand without a lot of math background. But in a vague sense, string theory is the most general thing you can write down, so you're obligated to start with that theory, and then ask how you can specialize it to other cases.

A similar example is that quantum field theory is the most general theory of quantum mechanics without gravity you can write down, and the Standard Model, ordinary quantum mechanics, and special relativity are specializations of that general framework. But it can also be specialized to specific things, too, like the theory that describes the properties of the liquid crystals in your computer's monitor. Using the general theory first, to describe something like your monitor, lets you use the mathematical sophistication of the general theory to make problems in the specific theory easy.

This isn't any different than how you can use geometry to prove things like the Pythagorean theorem, when without geometry you wouldn't be able to prove that, it would just look like a weird coincidence. And of course, using geometry, you can derive simple statements about shapes that you never would have been able to guess were true without it.

reply to post by Moduli


You definitely seem very well informed on the topic and your answer was cogent and insightful. I'll be sure to do a bit more digging into the topics you've brought up. Thank you!

Originally posted by Arbitrageur

Originally posted by transmundane
If I understood your linked post, your claim (based on the Wikipedia article), is that the power consumption required to prove String Theory is so high that it's not likely to happen any time soon. Is that correct?

Since the post started with: "there may be a few predictions of string theory which can be tested in the LHC" I wouldn't say that interpretation is completely accurate. Obviously that points to some capabilities of testing limited aspects of string theory in the LHC.

It's not the power consumption that's the key issue, it's the energy levels that are created, as explained by this Harvard professor/particle physicist who also works with string theorists ideas as she explains:

Lisa Randall: String Theory
...
Note that just before 2 minutes in the video she states we don't have near the energy levels needed to test string theory. The post I linked to previously conveyed a thought experiment about the scales which would be needed to create higher energy levels, if we just scaled up the LHC design. In reality, we can only scale it up so far, and we would need to come up with more innovative designs to get higher energy levels. An example of a new technology that might help would be room temperature superconductors, for example.

Modulii is free to disagree with the Harvard professor, and with Wikipedia, and with many other sources, but I find Harvard professor Randall's explanation more credible than modulii's explanation.

Here's another professor saying more or less the same thing, and he puts the LHC experiments in perspective relative to the above quote from my linked post, regarding what they may or may not accomplish:

...

And here's the screenshot of the string theorist explaining how string theorists are still not sure what string theory is, so that's a problem; how do you test it if you don't know what it is?

...

David Gross: The Coming Revolutions in Theoretical Physics

There's also the problem of string theory making too many predictions, that aren't unique.
That's a pretty good video if you want more than the dumbed down explanations for the masses.

Regarding the power levels, your answer certainly makes sense and just from an instinctive, what-I-know-now level, I'm inclined to agree. And yes, you're absolutely right -- that is how I started this whole thread so fair enough.

But having said all that, and moving forward, do you think it's feasible that:

a) Just because we don't know how to test the theory at this time doesn't mean we won't be able to do so in the future?
b) Just because the energy levels seem astronomical by today's standards, this doesn't mean we won't figure out how to harness either alternative power sources, or find other ways to test the theory in the future?

I don't know if it's apocryphal or not but I recall hearing about a White House science adviser (presumably considered top in his field), making a pronouncement just prior to man's first space flight, that the power level required to get a rocket into space would be completely unreasonable. I'm sure I can dig up the reference if you're curious, but I'm sure there are other examples of scientists making faulty assumptions based on the best of their knowledge at the time.

Personally, I would like to believe we're not at the pinnacle of our scientific knowledge just yet.

Higgs boson is a theory, they will only be able to see its footprint, in reality, it is infinity.