One.
The question is, does this refer to types or count?
How Many Elementary Particles Are There, Really?
101–110 of 160 posts
Re: How Many Elementary Particles Are There, Really?
#102[flagged]
Re: How Many Elementary Particles Are There, Really?
#103Stopped reading after "Yet in the mathematical equations that define the Standard Model, the eight gluons are distinct from one another in the same way that the W and Z bosons differ." W and Z bosons, photons, etc have fixed masses, charges, interaction strengths with other particles. These properties can exactly be listed and looked up in a table of elementary particles with discrete rows. Gluon color is continuous…
It’s how gauge theories work:
- fermions (charges) are in the fundamental representation of the gauge group, here SU(3) so 3 Colors
- bosons are in the adjoint représentation, for SU(3) that 8 dimensions
Re: How Many Elementary Particles Are There, Really?
#104Earlier quoted context omitted.
You've said that "37 fields" at least twice. It doesn't seem to come from the arxiv article you linked, though. And it seems rather high to me. (Of course, 118 seems ridiculously high...) Anyway: Would you list them? Or supply a link to somewhere that does?
First, just to clarify - there are different ways to count the quantum fields, just as there are different ways to count particles, as the article points out. You really need to specify the premises you're using to count them. But either 17 or 37 are natural counts. 17 is a somewhat simplified version, which ignores quark color charges and groups the W and Z bosons together. Here's how the list of 37 typically breaks…
I'm a bit surprised that the weightier generations of fermions are categorized as fundamentally different fields. Is this a crutch/temporary classification that we expect to be resolved with further research, or are there real indications that the apparent similarities between e.g. up/charm/top are fully independent manifestations?
Re: How Many Elementary Particles Are There, Really?
#105Earlier quoted context omitted.
Well, why would there be fewer than N? There is no general principle that we can impose on the world, it just is, we can only discover what the laws and components of the world are (hopefully). I'm not claiming it's impossible for there to be fewer fields than we think right now. But there is no reason to believe there should be.
I'm not saying fewer fields, but perhaps a more fundamental substrate to reality than fields that fields emerge from. Maybe the N fields are just vibrational modes or attractor dynamics of something simpler. It seems there has to be a reason WHY there are exactly N fields, and WHY they interact in the ways they do. Edit: As I noted in another comment, the best explanation may come down to "there are only 100 viable t…
I think it's very obvious no such answer is even possible in principle. Mathematics has no limits, you can describe anything you like by picking some axioms. Do you want to make sense of the expression 1+1=3? I can find axioms in which this is true.
So, there is no way to start from mathematics and find something that must exist in some way, such as "there can only be 100 types of universe". Any such discovery is contingent upon some arbitrary choice of axioms. You can choose axioms that appeal to some ultimately esthetic sense of elegance or simplicity, and that can explain our universe more or less uniquely, but this doesn't mean that they are right to any extent more than the SM is.
Re: How Many Elementary Particles Are There, Really?
#106Earlier quoted context omitted.
In QFT every particle type has its own field.
...and a field is just a value that behaves in a particular way. An example outside QFT: phonons [1] behave like particles, but there is no "palpable" sound field, there's only local distribution of implulses of the molecules of air (or whatever medium) where the sound propagates. Other fields can be seen as attributes of the space itself , and "elementary particles" as wrinkles on it. Gravity is special because it b…
> Gravity is special because it bends the very geometry of space.
It's important to remember that this is not true in QFT, and QFT is not true in GR. That is, the math of QFT does not work if spacetime can become curved (at least, if it can become significantly curved).
Re: How Many Elementary Particles Are There, Really?
#107Earlier quoted context omitted.
> I am no mathematician, but the math needs to start with that fundamental principle. This is a weird sort of hubris. “I’m not qualified to do this job but I can certainly tell you how it needs to be done.” > And if everything is a wave there are no discrete quantities beyond our definition of what constitutes the end, or borders, of the wave. This is not true in multiple ways. First, it’s known that these particles…
> This is a weird sort of hubris. “I’m not qualified to do this job but I can certainly tell you how it needs to be done.” A quantum state is a mathematical entity that represents a physical system. Since waves are not physical can you see where I can assume that the math needs to start from a different place? If it is even useful at all? > it’s known that these particles exhibit quantum behavior. Many measures are i…
> To measure is to quantize, so this is circular reasoning.
This is a fundamental misunderstanding. Measurement (which is a precisely defined mathematical concept) is not the same thing as quantization. For a very basic example, in all known physics theories, including QFT, SR, and GR, space and time can be measured, and they are not quantized. In fact, there is no theory compatible with SR in which space and time can be quantized, given the nature of the Lorenz transform: SR predicts continuous length contraction from the PoV of observers moving at any velocity relative to each other; for any distance of length 1, some other observer can exist for which the length would be 1/x, with x as a real number.
Re: How Many Elementary Particles Are There, Really?
#108Earlier quoted context omitted.
Chirality is a real property of (most) elementary particles. For example the electron with left chirality has a weak hypercharge of -1, but the electron with right chirality has a weak hypercharge of 0. https://en.wikipedia.org/wiki/Weak_hypercharge#Definition In some sense, they are very different particles. Also, only the left version interact with the weak interaction.
Ah, then I was thinking about helicity
I expected the article to explain "helicity" and then say "and chirality is almost the same (for fast particles)", that is good enough for not specialist. There are a few graphics here and there that show helicity, but that paragraph in the text is totally unintelligible and the only conclusion is that there is something with right and left.
Re: How Many Elementary Particles Are There, Really?
#109Earlier quoted context omitted.
planck scale is the theoretical limit to disassembly.
If something cannot be reduced, does it exist as an entity?
something that cant be reduced would be the only entity, all other things are assemblages of that entity, the problem of variability occurs, if you can observe at the scale of absolute fundamental structure, how can difference occur?
Re: How Many Elementary Particles Are There, Really?
#110Earlier quoted context omitted.
Very interesting. I imagine though that the 17 model is reasonably consistent. I wonder what parallels there are with other areas of mathematics.
Something like " 17 different values of mass "[1][2][3][4][5][6][7] is a good simple model, if you allow me to put enough footnotes at the end. Different particles have different mass, and we can use the mass to classify them and call it a day and so we get 17. [1] Actually the photons and the gluons have mass=0, but nobody would confuse them. So, let's count them as different particles. (If it exist, the graviton al…
What’s the best introductory book for this sort of thing?