Standard Model

[Little Bang]

I don't think they will ever discard it because there will always be an excuse for why it can't be united with gravity and charge. There are to many big name scientist who have spent their entire lives attempting to prove it is the only choice and teaching all of their students the same.

[joekgamer]

I don't think they will ever discard it because there will always be an excuse for why it can't be united with gravity and charge.

 

How so? What is an 'excuse' is this context? Does it mean something along the lines of "We don't have enough money" or is it closer to "We have found something new to research in it"? Your wording is vague. Could you clarify?

[Rade]

Not looking good for Standard Model at this time.

 

1. In April, 2011, FermiLab reported a new boson within protons and antiprotons (not the Higgs) outside the predictions of the Standard Model. If confirmed by additional experiment, the new FermiLab boson predicts a force fifth force in nucleus of the proton, completely not predicted by Standard Model.

 

http://www.sciencenews.org/view/generic/id/72095/title/Remodeling_the_standard_model

 

2. Results of round one using lower energy experiments in from CERN--no Higgs found (March, 2011 report).

 

http://arxiv.org/abs/1102.5429

[Jay-qu]

This isn't a very complete poll.. we know the Standard Model does not explain everything, but it does do a tremendous job of describing physics within its domain of validity. The current results collected by the LHC have not done much more than the Tevatron has already, but by the end of the year the LHC will have charted some new territory.

 

The 'Standard' Standard Model has a simple form of the Higgs, but it is likely that the Higgs mechanism will be effected by or be part of physics beyond the Standard Model. Unfortunately our current experiments don't give us much to go by, but hopefully in the next 10 years the LHC will give us something new - and even better, give us something completely unexpected.

[CraigD]

I don't think they will ever discard it because there will always be an excuse for why it can't be united with gravity and charge.

Despite much effort by theorists to do so, the Standard Model of particle physics hasn't been successfully expanded to describe gravity, so I'd say it's accurate to say that "excuses" have been offered for this failure, all roughly of the form "I tried this approach, but couldn't get it to work".

 

However, the earliest formulations of the SM (ca. 1960) included quantum electrodynamics, which describes all charged particle interactions. So I think your claim that the SM can't be united with charge is inaccurate, about as badly as saying classical mechanics can't be united with mass.

 

Can you explain what you mean, LB? And if so, can you support it with something other than your own opinion?

 

As for the thread's main question, in my opinion the SM is only a intermediate, working theory. It's of great practical use, but fundamentally empirical, conforming to observed reality rather than explaining its deep "whys". Such theories are not "thrown out", because they're not, in a practical sense, wrong. They are expanded. Doing this is the big challenge in physics of the last 50 years, and I think will likely remains so for at least another 10.

 

PS: You've misspelled "throw" as "though" in the poll question. You should correct it, and be careful to spell correctly when posting at hypography.

 

Also, when creating polls, you should try to include all likely responses, if necessary by including a "none of the above" response. Otherwise, it's likely nobody but you will answer the poll, which is what's happened to date with this one.

[watcher]

garret lisi's e8 lie group is a promising theory derived from standard model

 

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

[Little Bang]

Craig, give me the description where sm tells us why a particle has charge.

[CraigD]

Sorry to take so long replying, LB.

 

Craig, give me the description where sm tells us why a particle has charge.

The Standard Model is a scientific theory, not a philosophical ontology. It doesn’t answer the question of why observed physical reality is as it is, only supplies a model for explaining and predicting how physical phenomena.

 

Epistemology question dealt with, the SM describes 6 fundamental particles – Quarks, and leptons, which are fermions, and photons, gluons, W bosons, and Z bosons, which are bosons - with various quantum numbers (called flavors when applied to the fundamental particles), and how these particles interact. Electric charge (or just charge or short) is one of these quantum numbers. Quantum electrodynamics – which can be considered part of the SM – describes how particles with non-zero charge (all quarks, some leptons, and none of the bosons except the W have non-zero charge) interact. Simply put, they do so by exchanging photons.

 

The rest of QED is detail.

 

There are more textbooks and webpages about the SM and QED than I can begin to count. The ones at wikipedia to which I’m so fond of linking are pretty good references, though like most encyclopedia articles, not very good as textbooks.

[CarlNGraham]

How sure are physicists that the fundamental particles are fundamental?

If we went to even higher energies could there be an underlying set of more fundamental particles?

Will the next advance come from the theory/understanding or from finding more detail?

 

It does seem to be a fairly fundamental rule of this universe that the closer you look the more you see.

(The uncertainty principle being the exception to the rule)

[CraigD]

How sure are physicists that the fundamental particles are fundamental?

This question depends heavily on what’s meant by fundamental (more conventionally called “elementary”, though I prefer using “fundamental” as a synonym). I’ll assume we mean “not entirely composed of other particles”, in which case, for example, best present theory considers the electron to be fundamental, but the proton to be composite, consisting of 3 quarks and many gluons. The fundamental/composite distinction is somewhat blurry, because if we consider quarks to be constituent particles in protons, an argument can be made that the electron should be considered composed of itself and photons, as photons have a similar force-carrying role between electrons as gluons do between protons – but let’s exorcise this blurriness by defining that the composite particle require all its constituents – even if this requirement is automatically met by the existence of other constituents, not needing to be supplied from outside, as is the case when doing nuclear chemistry or making an omelet. :)

 

This defined, I believe the answer is, “since the early 1980s, pretty sure.” There were a proliferation of theories attempting to define the 17 fundamental particles of the Standard Model as composite particles of a smaller number (as few as 2, in the case of this model) of more fundamental particles – the catch-all name for such a particle is “prion” – but these theories didn’t have much success. However, as most prion theories predict no higgs boson, if soon-to-be-done experiments to detect the higgs don’t find it, this “pretty sure” may change – though not as far as to “pretty sure not”, and the search for prions be rejoined.

 

If we went to even higher energies could there be an underlying set of more fundamental particles?

As a consequence of the “pretty sure” consensus above, the best guess answer to this question is “no”.

 

Will the next advance come from the theory/understanding or from finding more detail?

My hope is that a future theory like the fictional “quantum graph theory” published by Sarumpaet 2035-2038 will map the standard model and general relativity to a vast and complex, but essentially discrete mathematical formalism – but my hope is, at present, literally science fiction. ;)

 

It does seem to be a fairly fundamental rule of this universe that the closer you look the more you see.

(The uncertainty principle being the exception to the rule)

I agree, but another empirical rule seems to be that the closer you look, the fewer entities you see. The macroscopic biological world contains millions of species, but biochemistry reveals them to be made of a few of about 100 chemical elements. Early particle physics revealed a “zoo” of particles, albeit most short-lived, that the SM reduced to an even dozen fundimental particles. A far future physics may reduce everything to a single gigantic integer.

[Rade]

...A far future physics may reduce everything to a single gigantic integer.

I predict that integer will be the dialectic outcome of matter interacting with antimatter to form a stable coexistence...you read it here first.

[CraigD]

I predict that integer will be the dialectic outcome of matter interacting with antimatter to form a stable coexistence...you read it here first.

I don't understand what you mean by "the dialectic outcome of matter interacting with antimatter to form a stable coexistence", Rade.

 

In most of the contexts I seen it, a "dialectic outcome" is the result of an argument between two (or sometimes more) people with initially disagreeing opinions, who though the "dialectic process" reach a common, agreed upon opinion. Antimatter is rare and usually short-lived, so not able to "argue" the way a person can, so I can't understand how it can be said to have a dialectic interaction with anything.

 

Can you explain what you mean?