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Lincoln » March 8th, 2017, 7:30 am wrote:Models are good in a reason of applicability. Those ball and stick models of organic molecules have value. They are wrong in detail, mind you; but they have value.
The solar system atom has value. Again, wrong. But there's a reason we teach it.
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Mind you, those of us on the hairy edge of knowledge know that these models are themselves imperfect. What seem to be the smallest particles are actually probably a composite of smaller vibrations of constituent fields. And it may be that we will get to a size scale where we have to chuck these ideas for something else. Current thinking (and don't believe this) is that we will eventually find that the universe consists of quanta of space or time.
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Lincoln » March 7th, 2017, 10:30 pm wrote:What seem to be the smallest particles are actually probably a composite of smaller vibrations of constituent fields.
Lincoln » March 7th, 2017, 10:30 pm wrote:Current thinking (and don't believe this) is that we will eventually find that the universe consists of quanta of space or time.
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Lincoln » November 23rd, 2017, 11:33 pm wrote:We don't know how many levels of structure there are below quarks. There may be but one, or there may be many. I'd bet on many, but I wouldn't bet much. The short answer is nobody knows and anybody who makes confident assertions on this topic is either a fool or a liar.
Lincoln » November 23rd, 2017, 11:33 pm wrote:The characteristic scale of superstrings is of order 10-35 meters, while the smallest thing we can currently resolve is of order 5 x 10-20 meters. Round numbers, that's 15 orders of magnitude. That's the difference between the size of a proton and you. Think about how many different structures occur over that particular range of scales. It seems highly improbable that nothing happens between the minimum current size measurement and the Planck/string scale.
Lincoln » November 23rd, 2017, 11:33 pm wrote:This isn't to say that we know that strings aren't the final answer.
Lincoln » November 23rd, 2017, 11:33 pm wrote: We actually know precisely zero about this, but it might be true.
Lincoln » November 23rd, 2017, 11:33 pm wrote: But I would bet that there are a few levels of matter between quarks and strings.
Lincoln » November 23rd, 2017, 11:33 pm wrote:And the issue with the energy of removing two mutually-interacting quarks is a red herring. This is a consequence of the nature of the binding force and not sizes. QCD is an abelian (e.g. self interaction) theory/force, while non-abelian theories (e.g. electromagnetism) don't experience this phenomenon.
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Lincoln » November 24th, 2017, 9:16 am wrote:Quarks are real. I discovered one of them in 1995. (Well, me and 800 of my closest friends.) And there is really no doubt about the existence of quarks. Although the person who proposed them (Gell Man) thought of them as a mathematical constructs, the experimental community established that they exist in the 1970s. The fact that protons consisted of something predates that by at least a decade. And the discovery of the gluon in 1979 bolstered the theory of QCD to the point where it is not argued by any expert.
Lincoln » November 24th, 2017, 9:16 am wrote:There absolutely IS reason to presuppose a substructure to quarks and leptons and that is called the flavor problem or generation problem. Hell, even the idea of superstrings presupposes a substructure, at least in a manner of speaking. In any event, the experimental community thinks the substructure hypothesis to be of sufficient merit as to explore it. Hundreds of papers have been published using Tevatron and LHC data on the hypothesis, including many dozens which I co-authored. These are in respected journals such as Physical Review Letters and Physics Letters B. I even wrote a cover article in Scientific American on the subject in 2012. The preon idea is not well regarded by the community, but it is a credible one.
Lincoln » November 24th, 2017, 9:16 am wrote:Nobody...even me...should believe that quarks and leptons have substructure. There is zero experimental evidence for that hypothesis to be correct. However, the Standard Model is sufficiently robust that there is very little experimental evidence for any extension. That's why the research community is rummaging around in the data looking for clues. The one possible real clue is in the g-2 data and we'll get a better handle on that in 2020 when it starts taking data for real. And, at least for me, the clues inherent in the existence of three generations of matter is compelling enough for me to spend my research time looking into that, rather than other attractive questions.
Lincoln » November 24th, 2017, 9:16 am wrote:I looked you up...the internet is good for that sort of thing. Congratulations on your book. Have you considered using a publisher for future efforts rather than self-publishing?
Lincoln » November 24th, 2017, 9:16 am wrote:Your paper of 2000 seemed reasonable. I presume that this was your MA work? Your coauthor continues to generate an ongoing body of work. I was unable to find any additional published work of yours to better evaluate your credentials.
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Lincoln » November 24th, 2017, 5:16 pm wrote:There are plenty of ongoing mysteries, from dark matter and energy to the matter/antimatter asymmetry to something as mundane as the quadratic divergences in the Higgs mass. I predict that all of them will eventually manifest solutions at energy scales far below the Planck scale. In fact, we hope that they will be solved at energy scales only one or two orders of magnitude beyond current state of the art.
Lincoln » November 24th, 2017, 5:16 pm wrote:Detar's work on lattice QCD is known and perfectly reasonable. Can't say I know him personally, although I did see his plenary back at the January APS meeting this year. Of the UT profs, I knew Lynn Higgs best, but he's been gone for two years now.
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Lincoln » Thu Nov 23, 2017 11:33 pm wrote:Hi guys...
We don't know how many levels of structure there are below quarks. There may be but one, or there may be many. I'd bet on many, but I wouldn't bet much. The short answer is nobody knows and anybody who makes confident assertions on this topic is either a fool or a liar.
This isn't to say that we know that strings aren't the final answer. We actually know precisely zero about this, but it might be true. But I would bet that there are a few levels of matter between quarks and strings.
And the issue with the energy of removing two mutually-interacting quarks is a red herring. This is a consequence of the nature of the binding force and not sizes. QCD is an abelian (e.g. self interaction) theory/force, while non-abelian theories (e.g. electromagnetism) don't experience this phenomenon.
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