Talk:Particle physics

From Wikipedia, the free encyclopedia

	This article is within the scope of WikiProject Physics, which collaborates on articles related to physics.	Physics Portal
B	This article has been rated as B-Class on the assessment scale.
Top	This article is on a subject of top-importance within physics.
This article has been rated but has no comments. If appropriate, please review the article and leave comments here to identify the strengths and weaknesses of the article and what work it will need.

WikiProject Featured articles in other languages has identified Particle physics as a foreign language featured article. You may be able to improve this article with information from the Slovenian language Wikipedia.

Old talk (prior to April 2004) archived in Talk:Particle physics/archive 1.

Contents 1 Chart 2 "Particle physics" or "Particle Physics" 3 Reductionism 4 Removal of links to new physics theory 5 Links to website wrong? 6 Alphabetical list of collaborations? 7 Do we have to use a STAR event display as first picture? 8 45 fermions?

[edit] Chart

Does wiki already have a chart like this [1]? I think it would make a nice addition to this (and other) articles.--Deglr6328 07:38, 18 Mar 2005 (UTC)

[edit] "Particle physics" or "Particle Physics"

Should this article be redirected from "Particle physics" to "Particle Physics"? Irpen 23:05, May 23, 2005 (UTC)

Please don't redirect. "Particle physics" is in line with Wikipedia's policies on capitalization of article names. -- CYD

I sure won't if you say so. I just asked. Irpen

[edit] Reductionism

Hi. I imagine there may have been some discussion of the "Particle physics and reductionism" section already, but I have to ask: what is it doing here? It's somebody's POV, and it's written using the "some people say..." type argumentation. The criticism it mentions is not really relevant to an article on particle physics (which after all has as its goal to reveal the fundamental laws of nature...). --RE 07:17, 25 September 2005 (UTC)

I'd never noticed it before, but it is a little but POV-y, and not very clear on what it's trying to say. If you rewrite/delete it, I certainly won't object. -- SCZenz 14:24, 25 September 2005 (UTC)

If you're looking for a reference on this subject, check out [2] and Anderson's "More is Different" article: Science, 177, 393-396. -- CYD

That is a good reference. The valid objection of RE to the section is that it is of the form "some people say" without saying who "some people" are, so-called weasel words, so if you want to keep the section's contents, perhaps you could edit it using those references to make it more concrete who says these things. --DannyWilde 03:42, 26 September 2005 (UTC)

OK, I'll edit it a bit with references. I'll also add something about defense of reductionism, e.g. by Steven Weinberg. --RE 04:03, 26 September 2005 (UTC)

==Is a proton a physics particle?== Scott 00:18, 30 September 2005 (UTC)

A proton is definitely a particle in physics. Do you mean something else by the question? --physicsdavid 00:22, 30 September 2005 (UTC)

Well yes Doctor Dave, Please see [3] Thank-You Scott 00:30, 30 September 2005 (UTC) I thought it was a good reference. Just my opinion, as it is a proton beam they have. Does that relate to particle physics? It's not like its a nuclear reactor Thanks, Scott 00:30, 30 September 2005 (UTC)

Ahhh... This is about the deletion of the Spallation Neutron Source..? That's a bit more complicated. An experiment done with particles need not be particle physics, and the line between nuclear physics and particle physics is notoriously hard to draw. (Even for funding agencies! The United States Department of Energy inexplicably counts neutrino experiments as nuclear, and requires them to be funded from a different source!) I think the SNS is probably more nuclear than particle, because it has no applications to investigating fundamental physics. -- SCZenz 00:36, 30 September 2005 (UTC)

By the way, the United States Department of Energy does fund neutrino physics, including at Fermilab --physicsdavid 01:33, 30 September 2005 (UTC)

Yes, yes. But it comes from their nuclear division, rather than their particle division, or something like that. Ask the people I work for, not me..!  :P -- SCZenz 01:40, 30 September 2005 (UTC)

Neutrino physics is funded through the DOE Office of Science in both their High Energy Physics (HEP) program and their Nuclear Physics (NP) program. (I work in the HEP part.) I think this just reinforces your earlier point that the line between nuclear and particle physics is "notoriously hard to draw." -- physicsdavid 17:21, 30 September 2005 (UTC)

Your word is good enough for me! You know that. I think you know who, is sleeping now. Really pisses me off, It's called staulking. Just so you know I'm out in the open, and referenced #40 Not that it will do any good..... Takes up too much unconstructive time from me. Anyway, getting late here. Isn't this the truth: [4] Catch up with you tomorrow! Caio Scott 00:47, 30 September 2005 (UTC)

Um, I didn't understand that last entry... Anyway. I removed the SNS link because it's more like nuclear physics what they're going to do there. It has more to do with the energies than with the type of particles, and there are nuclear physics experiments that have electron beams for example. At higher energy one looks at smaller things. SNS has lower energy and is designed to look at the nuclear forces (between nuclei/nucleons). But maybe there should be something about this in the article... --RE 01:01, 30 September 2005 (UTC)

The difference between particle and nuclear would probably be a good thing to add, yes. -- SCZenz 01:07, 30 September 2005 (UTC)

[edit] Removal of links to new physics theory

Sorry, in my comment for that removal I should have written see Wikipedia:Reliable sources. You might also look at Wikipedia:No original research. -- SCZenz 22:42, 23 December 2005 (UTC)

[edit] Links to website wrong?

when someone clicks on the "particle adventure" link it takes one to the credits page (????!!!!!!!) Hopefully someone could fix that 69.22.224.249 23:55, 28 December 2005 (UTC)

Done. Thanks for pointing it out. - mako 00:06, 29 December 2005 (UTC)

[edit] Alphabetical list of collaborations?

Should the list of collaborations be alphabetical? If so, Fermilab should be somewhere in the middle. Masud 20:16, 12 March 2006 (UTC)

On a related note--shouldn't the list of "collaborations" really use the word "laboratories" instead of "collaborations". e.g. CERN is a lab, LEP is a facility, and L3 is a collaboration/experiment. Josh Thompson 01:12, 19 November 2006 (UTC)

[edit] Do we have to use a STAR event display as first picture?

Heavy ion physics is not really particle physics proper i would say. Also, i am not really aware of any ground breaking scientific results from STAR, or even RHIC in particle physics. i propose to replace the image with a more famous event display, such as a classic bubble chamber picture like the discovery of Omega++ or neutral currents. A W from UA1 is also possible, or some LEP image. gbrandt 11:00, 3 April 2006 (UTC)

No, we don't have to. Feel free to change it if you can find another good picture. -- SCZenz 20:50, 3 April 2006 (UTC)

I found something but i have trouble with licensing. Does anyone have an idea of how to proceed correctly when putting research results (in this case event displays, but i can think of using illustrative plots) from DESY, CERN or other labs not in the U.S. into Wikipedia? With the US all research results seem to be PD, but what about Europe? gbrandt 10:46, 20 April 2006 (UTC)

[edit] 45 fermions?

Can someone explain how there are 45 fermions? I count 6 quarks, 3 leptons, 3 neutrinos. Plus antiparticles making at most 24.Jameskeates 09:47, 17 August 2006 (UTC)

Hmm - looks like 24 to me as well. See here:[5] --MichaelMaggs 10:19, 17 August 2006 (UTC)

Yeah I edited it. I thought I'd see if anyone objected but to be honest if they object they are wrongJameskeates 11:38, 17 August 2006 (UTC)

Particle counting is, at some level, a silly business. I can think how to get 48 (also count left- and right-handed separately) or 42 (but neglect right-handed neutrinos), but not 45. I can also get more than this by counting the quark colors separately, which gives 3*6 + 3 + 3 = 24. Then if I count handedness, but don't count antiparticles, I get 48... So now if I neglect the right-handed neutrinos, I get 45. Whoever did that count had taken a field theory course too recently, and is thinking in terms of theoretical fields rather than what anyone would actually refer to as distinct particles. Anyway, the right handed neutrinos are rather likely to exist, now that we know neutrinos are massive but very light, so I don't think excluding them is a good idea.

The point is, there isn't really a right way to count particles. Wikipedia should not be in the business of doing it. -- SCZenz 19:15, 17 August 2006 (UTC)

3 colours of 3 left handed up quarks, 3 colours of 3 left handed down quarks, 3 colours of 3 right handed up quarks, 3 colours of 3 right handed down quarks, left handed electron, right handed charged lepton, left handed neutrino = 15. Times 3 generations = 45. jay 21:38, 26 August 2006 (UTC)

As I said above... That's a count of the degrees of freedom in the Standard Model; for most purposes, however, it is not a sensible way to count particles. For example, left-handed and right-handed electrons turn into each other by interacting with the Higgs Field (or whatever spontaneous symmetry breaking mechanism that actually exists) so often, that us poor experimentalists tend to think of the "electron" as a single kind of particle. This counting method, as is clear from the confusion above, will be obscure to anyone with less than a year of graduate-level coursework specializing in particle physics. So I don't think Wikipedia should count particles this way. -- SCZenz 21:07, 7 September 2006 (UTC)

This is slightly more than semantics and actually has physical meaning. For instance if you consider the Universe at a high enough temperature, then the free energy contains a term (N_F is the number of fermions). This has important consequences for early universe cosmology. 15 fermions per generation is also an important number for grand unified theories because each of the 15 fermions are placed on equal footing. jay 17:50, 26 September 2006 (UTC)