7 ms·

Data hint at 'five God particles'

41 points by mebassett 16y ago

jarin 16y ago
The growing number of elementary particles reminds me of the epicycles-upon-epicycles in the Ptolemaic system of astronomy. The question is when are we going to have our "Newton moment" and figure out that they're all just manifestations of one elementary particle or string or something else?
- Luc 16y ago
  That would be nice, but isn't that metaphysics? The thought that there is something simple underneath it all appeals to our aesthetics, but it needn't be that way...
  - jarin 16y ago
    No you're totally right, there's nothing that says it has to be that way. But since it seems that all of the elementary particles coalesced out of a relatively homogenous energy field after the Big Bang, it doesn't seem unlikely that all of the particles could be explained by tiny permutations in an underlying universal field.
  - jessriedel 16y ago
    If that's metaphysics, then every famous physicist--Newton to Einstein to Feynmann--has been a strong believer in the power of metaphysics.
    - Luc 16y ago
      Well, I agree with that, it's been a fruitful heuristic, but it doesn't need to hold in every case.
    - aswanson 16y ago
      Fine, but that doesn't make the "power " any more or less valid, only that it seems to be useful thus far.
      - jessriedel 16y ago
        Well, then this just basically becomes a philosophical argument about the justification for empiricism/inductive-reasoning. Can we axiomatically prove that just because the sun has risen in the morning for the last 10,000 mornings that it will do so tomorrow? No. Neither can be sure that just because every single major advance in physics has come because of simplification/beauty that the next one will come the same way. But you'd be a fool to bet otherwise.
        Luc 16y ago
        Well, I certainly wouldn't want to be a fool. I might be of course, especially compared to the many people I know who are smarter than myself. I think though that your argument is basically an 'appeal to ridicule' fallacy. You are making it sound like my statement is the philosophical equivalent of 'we can't be sure the sun will rise tomorrow'. It isn't, it is simple the statement that the current zoo of particles may well all be fundamental, with no 'simpler' theory underlying them. Secondly, I think your statement that 'every single major advance in physics' has been a simplification is debatable. Thirdly, extrapolating from that that every new advance will be found using the same heuristic is also debatable. If there really is to be a scientific breakthrough of the magnitude of a Newton, it seems likely (almost by definition) that it will be from an unexpected avenue of thought - seeing that the expected ones have been well researched and haven't been all that productive. I guess it makes sense to bet on a unifying theory if you are a career particle physicist. There's a Nobel prize in it. It doesn't make sense to bet on the opposite notion, since there are probably no breakthroughs that way.
        jessriedel 16y ago
        I do think your statement is the philosophical equivalent of 'we can't be sure the sun will rise tomorrow', except that it differs by degree. (The sun has risen thousands of times in my personal experience, and bazillions of times in the experience of humans, while only a handful of fundamental physics discoveries have been made.) In either case, it's a question of justifying the claim that "In situations of type A, X has always been true in the past. Therefore, in situations of type A in the future, X will be true". Likewise your simple statement that "the current zoo of particles may well all be fundamental, with no 'simpler' theory underlying them." is analogous to "the sun will collapse into a black hole tomorrow". Again, just a difference of degree. [I should stress here that the justification for empiricism is an age-old philosophical problem which isn't easy to understand, much less solve. However, I think that a proper understanding of the history of physics gives very convincing (though maybe not the-sun-will-rise convincing) evidence that simplicity and beauty will be found at the bottom of the particle zoo.] I don't understand what the true statement >If there really is to be a scientific breakthrough of the magnitude of a Newton, it seems likely (almost by definition) that it will be from an unexpected avenue of thought - seeing that the expected ones have been well researched and haven't been all that productive. has to do with our current discussion. Lastly, (basically) no career particle physicist think that any Nobel prizes will be awarded for a unifying theory in their lifetime. (See, for instance, http://www.math.columbia.edu/~woit/wordpress/?p=2998 http://www.math.columbia.edu/~woit/wordpress/?p=2998). Perhaps, if we're lucky, there will be a somewhat simplifying theory (which gets a Nobel prize) but that certainly couldn't come from the dominant research avenue, string theory.
    - tel 16y ago
      It's not just metaphysics though, right? More complex models have more moving parts and require more energy and information to specify. I feel like, in a wholly qualitative but empirically guided fashion, there is a natural savings to simplicity.
- seanstickle 16y ago
  Ptolemy, and his intellectual descendants, didn't actually use epicycles-on-epicycles. Just a single epicycle on a deferent. Although "epicycles-on-epicycles" might be traditionally emblematic of "incorrectly formulated over-complicated theories", it has no sound basis in the history of astronomy. The Ptolemaic model, while ineffective at meeting the measurements of planetary movement, was a fairly simple, and elegant, mathematical model.
- pfedor 16y ago
  Where have you seen a growing number of elementary particles? The number hasn't changed since the formulation of the Standard Model some thirty years ago.
- fhars 16y ago
  That has already happend in the 70ies when the unexplained zoo of hundreds of elemenary particles has been reduced to a handful of more elementary particles (12, called quarsks and leptons) and a set of dynamic theories that use even fewer bosons to describe the interactions between them. This post-copernican model of elementary particle physics is the standard model. Particle physicist have been expecting the next copernican revolution that replaces this model really soon now with the next accelerator upgrade since at least 1980 (look for example for conference talks by Haim Hariri from that time), but fundamental shifts don't happen that often.
rauljara 16y ago
The hunt for the higg's boson reminds me of the attempts to measure the speed of the earth using light beams. Everything we thought we knew about physics told us that we should be able to measure the speed the earth was orbiting by measuring the difference in speed between two beams of light. When the experiments failed, the response was develop more precise measuring techniques, and more perfect mirrors. It wasn't until Einstein that people realized these failed experiments were not failures at all, but evidence that the universe doesn't work quite how we thought. The hunt for the Higg's Boson, and the "failure" to find it after all these years just seems like a reminder that empirical evidence > theoretical models. Just because the math seems elegant doesn't mean it necessarily applies to the universe we are living in. Of course, they may find the Higg's boson tomorrow, and then my little theory about them being wrong would be proved wrong, but that's science for you.
- jessriedel 16y ago
  While it would be very surprising if the Higgs turned out to be a boring, Standard-Model Higgs, there are very good reasons to believe that something Higgs-like has to happen at the multi-TeV scale. Basically, without a Higgs the Standard Model yields non-physical predictions (e.g. probabilities for certain processes exceed unity). In other words, the Standard Model isn't even consistent above a TeV or so without the Higgs. Something has to give. Edit: to make contact with your example, everyone knew that if you didn't find evidence for the ether, than the model of electromagnetism was very wrong. In fact, that was great justification for carrying out Michelson-Morely type experiments.
- avar 16y ago
  The two aren't really comparable. With Newtonian physics there were clear signs decades before Einstein that something wasn't right, the clearest example being the perihelion precession of Mercury: http://en.wikipedia.org/wiki/Kepler_problem_in_general_relativity#Historical_context_and_intuitive_understanding http://en.wikipedia.org/wiki/Kepler_problem_in_general_relat... In modern particle physics the main limitation is lack of experimental data. To get that data we have to build giant and expensive experiments like the LHC. Even if the LHC is completely successful we're still going to need bigger colliders to test other things at even higher energies. Another problem is that the current theories make predictions about things that we probably won't ever be able to measure directly due to the microscopic scales involved. To name an example. We think that gluons exist inside atomic nuclei, but we can't observe them unless we break the nuclei apart, thus destroying the gluon's habitat. We think it's there because we see what looks like the energy of a gluon falling apart, and because mathematical models back it up.
td 16y ago
Can anybody explain how they get the number of five Higgs particles? If they count one doublet as 4 particles, two doublets would be 8 particles, right?
- mootothemax 16y ago
  From the news story: Bogdan Dobrescu, Adam Martin and Patrick J Fox from Fermilab say this large asymmetry effect can be accounted for by the existence of multiple Higgs bosons. They say the data points to five Higgs bosons with similar masses but different electric charges. Three would have a neutral charge and one each would have a negative and positive electric charge. This is known as the two-Higgs doublet model. And: The Standard Model only has one Higgs "doublet". Although we tend to think of the Higgs boson as one particle, it actually comes in a package of four, explained Dr Martin. "In the Standard Model, you only see one of them because the other three are absorbed into [other parts of the scheme] such as the W and the Z bosons. There's only one left," he told BBC News. "So if you want to add another Higgs doublet - you actually have to add four more particles."
- sp332 16y ago
  FTA: > The Standard Model only has one Higgs "doublet". Although we tend to think of the Higgs boson as one particle, it actually comes in a package of four, explained Dr Martin. > "In the Standard Model, you only see one of them because the other three are absorbed into [other parts of the scheme] such as the W and the Z bosons. There's only one left," he told BBC News. > "So if you want to add another Higgs doublet - you actually have to add four more particles."
gahahaha 16y ago
"""The Higgs boson's nickname comes from its importance to the Standard Model; it is the sub-atomic particle which explains why all other particles have mass.""" That's not the story I heard: Leon Lederman named the hypothesized Higgs boson the "God particle" as a joke, because its effects were everywhere yet nobody had ever seen it in the flesh--not because it was in any way powerful or dangerous or numinous or terrifying.
AaronM 16y ago
This theory would tend to suggest that there are indeed several undiscovered particles http://www.dailygalaxy.com/my_weblog/2007/11/how-a-surfer--1.html http://www.dailygalaxy.com/my_weblog/2007/11/how-a-surfer--1...

41 points by mebassett 16y ago

jarin 16y ago

The growing number of elementary particles reminds me of the epicycles-upon-epicycles in the Ptolemaic system of astronomy. The question is when are we going to have our "Newton moment" and figure out that they're all just manifestations of one elementary particle or string or something else?

Luc 16y ago
That would be nice, but isn't that metaphysics? The thought that there is something simple underneath it all appeals to our aesthetics, but it needn't be that way...
- jarin 16y ago
  No you're totally right, there's nothing that says it has to be that way. But since it seems that all of the elementary particles coalesced out of a relatively homogenous energy field after the Big Bang, it doesn't seem unlikely that all of the particles could be explained by tiny permutations in an underlying universal field.
- jessriedel 16y ago
  If that's metaphysics, then every famous physicist--Newton to Einstein to Feynmann--has been a strong believer in the power of metaphysics.
  - Luc 16y ago
    Well, I agree with that, it's been a fruitful heuristic, but it doesn't need to hold in every case.
  - aswanson 16y ago
    Fine, but that doesn't make the "power " any more or less valid, only that it seems to be useful thus far.
    - jessriedel 16y ago
      Well, then this just basically becomes a philosophical argument about the justification for empiricism/inductive-reasoning. Can we axiomatically prove that just because the sun has risen in the morning for the last 10,000 mornings that it will do so tomorrow? No. Neither can be sure that just because every single major advance in physics has come because of simplification/beauty that the next one will come the same way. But you'd be a fool to bet otherwise.
      - Luc 16y ago
        Well, I certainly wouldn't want to be a fool. I might be of course, especially compared to the many people I know who are smarter than myself. I think though that your argument is basically an 'appeal to ridicule' fallacy. You are making it sound like my statement is the philosophical equivalent of 'we can't be sure the sun will rise tomorrow'. It isn't, it is simple the statement that the current zoo of particles may well all be fundamental, with no 'simpler' theory underlying them. Secondly, I think your statement that 'every single major advance in physics' has been a simplification is debatable. Thirdly, extrapolating from that that every new advance will be found using the same heuristic is also debatable. If there really is to be a scientific breakthrough of the magnitude of a Newton, it seems likely (almost by definition) that it will be from an unexpected avenue of thought - seeing that the expected ones have been well researched and haven't been all that productive. I guess it makes sense to bet on a unifying theory if you are a career particle physicist. There's a Nobel prize in it. It doesn't make sense to bet on the opposite notion, since there are probably no breakthroughs that way.
        jessriedel 16y ago
        I do think your statement is the philosophical equivalent of 'we can't be sure the sun will rise tomorrow', except that it differs by degree. (The sun has risen thousands of times in my personal experience, and bazillions of times in the experience of humans, while only a handful of fundamental physics discoveries have been made.) In either case, it's a question of justifying the claim that "In situations of type A, X has always been true in the past. Therefore, in situations of type A in the future, X will be true". Likewise your simple statement that "the current zoo of particles may well all be fundamental, with no 'simpler' theory underlying them." is analogous to "the sun will collapse into a black hole tomorrow". Again, just a difference of degree. [I should stress here that the justification for empiricism is an age-old philosophical problem which isn't easy to understand, much less solve. However, I think that a proper understanding of the history of physics gives very convincing (though maybe not the-sun-will-rise convincing) evidence that simplicity and beauty will be found at the bottom of the particle zoo.] I don't understand what the true statement >If there really is to be a scientific breakthrough of the magnitude of a Newton, it seems likely (almost by definition) that it will be from an unexpected avenue of thought - seeing that the expected ones have been well researched and haven't been all that productive. has to do with our current discussion. Lastly, (basically) no career particle physicist think that any Nobel prizes will be awarded for a unifying theory in their lifetime. (See, for instance, http://www.math.columbia.edu/~woit/wordpress/?p=2998 http://www.math.columbia.edu/~woit/wordpress/?p=2998). Perhaps, if we're lucky, there will be a somewhat simplifying theory (which gets a Nobel prize) but that certainly couldn't come from the dominant research avenue, string theory.
  - tel 16y ago
    It's not just metaphysics though, right? More complex models have more moving parts and require more energy and information to specify. I feel like, in a wholly qualitative but empirically guided fashion, there is a natural savings to simplicity.
seanstickle 16y ago
Ptolemy, and his intellectual descendants, didn't actually use epicycles-on-epicycles. Just a single epicycle on a deferent. Although "epicycles-on-epicycles" might be traditionally emblematic of "incorrectly formulated over-complicated theories", it has no sound basis in the history of astronomy. The Ptolemaic model, while ineffective at meeting the measurements of planetary movement, was a fairly simple, and elegant, mathematical model.
pfedor 16y ago
Where have you seen a growing number of elementary particles? The number hasn't changed since the formulation of the Standard Model some thirty years ago.
fhars 16y ago
That has already happend in the 70ies when the unexplained zoo of hundreds of elemenary particles has been reduced to a handful of more elementary particles (12, called quarsks and leptons) and a set of dynamic theories that use even fewer bosons to describe the interactions between them. This post-copernican model of elementary particle physics is the standard model. Particle physicist have been expecting the next copernican revolution that replaces this model really soon now with the next accelerator upgrade since at least 1980 (look for example for conference talks by Haim Hariri from that time), but fundamental shifts don't happen that often.

rauljara 16y ago

The hunt for the higg's boson reminds me of the attempts to measure the speed of the earth using light beams. Everything we thought we knew about physics told us that we should be able to measure the speed the earth was orbiting by measuring the difference in speed between two beams of light. When the experiments failed, the response was develop more precise measuring techniques, and more perfect mirrors. It wasn't until Einstein that people realized these failed experiments were not failures at all, but evidence that the universe doesn't work quite how we thought. The hunt for the Higg's Boson, and the "failure" to find it after all these years just seems like a reminder that empirical evidence > theoretical models. Just because the math seems elegant doesn't mean it necessarily applies to the universe we are living in. Of course, they may find the Higg's boson tomorrow, and then my little theory about them being wrong would be proved wrong, but that's science for you.

jessriedel 16y ago
While it would be very surprising if the Higgs turned out to be a boring, Standard-Model Higgs, there are very good reasons to believe that something Higgs-like has to happen at the multi-TeV scale. Basically, without a Higgs the Standard Model yields non-physical predictions (e.g. probabilities for certain processes exceed unity). In other words, the Standard Model isn't even consistent above a TeV or so without the Higgs. Something has to give. Edit: to make contact with your example, everyone knew that if you didn't find evidence for the ether, than the model of electromagnetism was very wrong. In fact, that was great justification for carrying out Michelson-Morely type experiments.
avar 16y ago
The two aren't really comparable. With Newtonian physics there were clear signs decades before Einstein that something wasn't right, the clearest example being the perihelion precession of Mercury: http://en.wikipedia.org/wiki/Kepler_problem_in_general_relativity#Historical_context_and_intuitive_understanding http://en.wikipedia.org/wiki/Kepler_problem_in_general_relat... In modern particle physics the main limitation is lack of experimental data. To get that data we have to build giant and expensive experiments like the LHC. Even if the LHC is completely successful we're still going to need bigger colliders to test other things at even higher energies. Another problem is that the current theories make predictions about things that we probably won't ever be able to measure directly due to the microscopic scales involved. To name an example. We think that gluons exist inside atomic nuclei, but we can't observe them unless we break the nuclei apart, thus destroying the gluon's habitat. We think it's there because we see what looks like the energy of a gluon falling apart, and because mathematical models back it up.

td 16y ago

Can anybody explain how they get the number of five Higgs particles? If they count one doublet as 4 particles, two doublets would be 8 particles, right?

mootothemax 16y ago
From the news story: Bogdan Dobrescu, Adam Martin and Patrick J Fox from Fermilab say this large asymmetry effect can be accounted for by the existence of multiple Higgs bosons. They say the data points to five Higgs bosons with similar masses but different electric charges. Three would have a neutral charge and one each would have a negative and positive electric charge. This is known as the two-Higgs doublet model. And: The Standard Model only has one Higgs "doublet". Although we tend to think of the Higgs boson as one particle, it actually comes in a package of four, explained Dr Martin. "In the Standard Model, you only see one of them because the other three are absorbed into [other parts of the scheme] such as the W and the Z bosons. There's only one left," he told BBC News. "So if you want to add another Higgs doublet - you actually have to add four more particles."
sp332 16y ago
FTA: > The Standard Model only has one Higgs "doublet". Although we tend to think of the Higgs boson as one particle, it actually comes in a package of four, explained Dr Martin. > "In the Standard Model, you only see one of them because the other three are absorbed into [other parts of the scheme] such as the W and the Z bosons. There's only one left," he told BBC News. > "So if you want to add another Higgs doublet - you actually have to add four more particles."

gahahaha 16y ago

"""The Higgs boson's nickname comes from its importance to the Standard Model; it is the sub-atomic particle which explains why all other particles have mass.""" That's not the story I heard: Leon Lederman named the hypothesized Higgs boson the "God particle" as a joke, because its effects were everywhere yet nobody had ever seen it in the flesh--not because it was in any way powerful or dangerous or numinous or terrifying.

AaronM 16y ago

This theory would tend to suggest that there are indeed several undiscovered particles http://www.dailygalaxy.com/my_weblog/2007/11/how-a-surfer--1.html http://www.dailygalaxy.com/my_weblog/2007/11/how-a-surfer--1...