studiot Posted July 10, 2012 Posted July 10, 2012 16 elementary particles and 4(?) elementary forces to bind them all.. It's like something out of Lord of the Rings. One problem I have with this description is the question What do the particles exist in? Clearly if 'everything' is to be made of 16 or 60 elementary particles these particles must be 1) Distinguishable 2) Aggregates of such particles must be capable of assembly from these particles and disassembly into them and all the time the individual particles must be clearly distinct and identifiable, at least in a thought experiment. 3) There must be something for them to exist in. 4) This something must be distinct from the particles and must exhibit a clear boundary round each particle. Comments and discussion are invited.
mathematic Posted July 10, 2012 Posted July 10, 2012 For starters: where did get the number 16? Standard model has 6 quarks and 6 leptons, total of 12. If you include antiparticles, it goes up to 24. Force particles - photons, gluons, W and Z, gravitons are counted separately.
studiot Posted July 10, 2012 Author Posted July 10, 2012 Clearly if 'everything' is to be made of 16 or 60 elementary particles Do you want to quibble about the numbers or discuss the beef? I think my meaning is clear.
swansont Posted July 10, 2012 Posted July 10, 2012 16 elementary particles and 4(?) elementary forces to bind them all.. It's like something out of Lord of the Rings. One problem I have with this description is the question What do the particles exist in? Clearly if 'everything' is to be made of 16 or 60 elementary particles these particles must be 1) Distinguishable 2) Aggregates of such particles must be capable of assembly from these particles and disassembly into them and all the time the individual particles must be clearly distinct and identifiable, at least in a thought experiment. 3) There must be something for them to exist in. 4) This something must be distinct from the particles and must exhibit a clear boundary round each particle. Comments and discussion are invited. Reminiscent of the justification for the aether. Why must there be something for them to exist in? 1
juanrga Posted July 11, 2012 Posted July 11, 2012 (edited) 16 elementary particles and 4(?) elementary forces to bind them all.. It's like something out of Lord of the Rings. The standard model consists of 12 matter particles plus 4 force particles. Add the Higgs boson recently announced [*]. What do the particles exist in? In a 4D spacetime. Clearly if 'everything' is to be made of 16 or 60 elementary particles these particles must be 1) Distinguishable If you mean that each member of a kind is distinguishable from members of another kind, the response is "Yes". We sort particles by their properties 2) Aggregates of such particles must be capable of assembly from these particles and disassembly into them and all the time the individual particles must be clearly distinct and identifiable, at least in a thought experiment. And in practice we also assembly-disassembly composite bodies into particles. Precisely this knowledge illustrates the hierarchical structure of matter with a decomposition of one methane molecule into quarks plus electrons taking into consideration intermediate levels (atomic, nuclear, nucleon). 3) There must be something for them to exist in. See above 4) This something must be distinct from the particles and must exhibit a clear boundary round each particle. Comments and discussion are invited. Evidently spacetime is different from the particles in the above table, but I am not sure what you mean by "clear boundary round each particle". [*] The other particles are discovered, the Higgs boson has only been found. This is a technical terminology related to statistical uncertainties. Edited July 11, 2012 by juanrga 1
imatfaal Posted July 11, 2012 Posted July 11, 2012 Well there has to be something that forms the bulk of non-baryonic Dark Matter (and let's not get onto a DM/Mond debate here please) - there are also the potential super-symmetric partners. I believe the LHC has started to "clear out" the lower estimate of energy levels for the lightest super-partners with no sign of them. Can we presume that there is another gauge boson - spin 2 and chargeless the graviton? So any more fundamental theory shoud be able to also encompass hypothetical particles beyond the SM, until and unless they are ruled out.
studiot Posted July 11, 2012 Author Posted July 11, 2012 The standard model consists of 12 matter particles plus 4 force particles. Add the Higgs boson recently announced [*]. If that is all there is then what is 'spacetime' made of? Does spacetime have an existance independent of these particles? Say there are 4 particles A, B , C, D. If I compare the chunk of spacetime between A, B to the chunk of spacetime between C,D I am applying numbers to it. So how can I apply number to (measure ) nothing?
juanrga Posted July 11, 2012 Posted July 11, 2012 (edited) If that is all there is then what is 'spacetime' made of? In the Standard Model (SM) it is made of nothing, because it is not a material system. There are speculative theories where spacetime is made of something, the "something" depends of the theory. Does spacetime have an existance independent of these particles? Yes it is a prior 'structure', a kind of 'background', in the SM. However, some relational models beyond the SM claim that spacetime cannot exist without particles and I am attracted by such ideas. Say there are 4 particles A, B , C, D. If I compare the chunk of spacetime between A, B to the chunk of spacetime between C,D I am applying numbers to it. So how can I apply number to (measure ) nothing? The situation in the SM is much more complex than that. Any attempt to measure the localization in spacetime of a relativistic particle is blocked by spontaneous generation of virtual pairs. This is part of the reason for which (as I mentioned in the thread about duality) solutions to Dirac and Klein-Gordon equation cannot be interpreted as wavefunctions. Edited July 11, 2012 by juanrga
studiot Posted July 11, 2012 Author Posted July 11, 2012 Juanrga, Thank you for your answers, they provide useful information. I think you misunderstood my last point. I was not considering the particles (or their localisation or otherwise) I was trying to concentrate on the 'spacetime' between them.
Severian Posted July 12, 2012 Posted July 12, 2012 (edited) Yes it is a prior 'structure', a kind of 'background', in the SM. However, some relational models beyond the SM claim that spacetime cannot exist without particles and I am attracted by such ideas. I can't say either way, since I can never test it (since I always need particles present to make a measurement) but my gut feeling is that space and time are properties of particles (or perhaps better to say events). This would be in much the same way that energy can't exist except as a property of particles (though space and time are a bit different since they are relational between multiple particles). Of course, since it can't be tested, it isn't really a scientific question at all... Edited July 12, 2012 by Severian 1
juanrga Posted July 12, 2012 Posted July 12, 2012 (edited) I always need particles present to make a measurement This is one of reasons which I am attracted by the idea. I was not considering the particles (or their localisation or otherwise) I was trying to concentrate on the 'spacetime' between them. If you cannot localize the particles in the SM it is difficult that you can concentrate on the 'spacetime' between them. But in any case, as said above, the SM (more correctly the underlying QFT framework) does not study the properties of the spacetime, except by its basic metric and topological properties [*]. [*] There are some attempts to do QFT in more general spacetimes, but are plagued with technical/conceptual difficulties. Edited July 12, 2012 by juanrga
studiot Posted July 12, 2012 Author Posted July 12, 2012 (edited) If you cannot localize the particles in the SM it is difficult Yes I understand that. I just have this difficulty with statements of the form 'everything (in the universe) is made of XXXTheory' followed by statements of the form 'XXXtheory does not cover YYY' I have spent 60 years with the notion that the 'universe' to include quite literally everything. It has been my experience that much misunderstanding has been propagated when someone restricts that definition to less than everything. I much prefer a universe that includes matter, empty space and anything else, warts and all. Edited July 12, 2012 by studiot 1
robheus Posted July 13, 2012 Posted July 13, 2012 What else exist? Beer, ice-cream, hot tea, love, hunger, passion, war, intelect, blindness, happiness, sorrow, pi (3.14..), etc. etc. 1
studiot Posted July 13, 2012 Author Posted July 13, 2012 What else exist? Beer Make mine a double, I've already tipped you!
swansont Posted July 13, 2012 Posted July 13, 2012 I much prefer a universe that includes matter, empty space and anything else, warts and all. We don't have a theory of everything, so we have to make do with theories that have limited applicability. 1
Mynameson Posted July 24, 2012 Posted July 24, 2012 For starters: where did get the number 16? Standard model has 6 quarks and 6 leptons, total of 12. If you include antiparticles, it goes up to 24. Force particles - photons, gluons, W and Z, gravitons are counted separately. they are called force carriers
burhan hafiz Posted July 27, 2012 Posted July 27, 2012 the total elementary particles are round about 60....
Ronald Hyde Posted August 20, 2012 Posted August 20, 2012 "Great fleas have little fleas upon their backs to bite 'em,And little fleas have lesser fleas, and so ad infinitum.And the great fleas themselves, in turn, have greater fleas to go on,While these again have greater still, and greater still, and so on." This verse by the mathematician and logician Augustus de Morgan makes light of the fallacy of trying to see the world as being made up of 'things that are made up of other things'. A sort of Victorian version of Monty Pythons "The society for putting things on top of other things'. From Galileos time to the present all that experimentalists have been able to do is make measurements of experiments and report them. And all theorists have been able to do is find mathematical relations among the results and build mathematical representations of them. The fact that some of those relationships involve countable and conserved objects doesn't imply that we should view them as 'fundamental', since the objects have proved to be little changelings they themselves contradict that notion. The rules for constructing the representations might be considered as being 'fundamental', but not the representations themselves, aka 'particles'.
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