Talk:Particle physics

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

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)

"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

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)

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)

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)

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)

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)

I think that a lot of this kind of discussion comes from the fact that people use "high-energy physics" and "particle physics" interchangeably. "High-energy physics" redirects to "Particle physics" on Wikipedia, for example. To use the example from this discussion, RHIC is undoubtedly a "high energy" machine even if it's arguable that it's a "particle physics" machine. It might not be LHC-scale, but it can collide (fully polarized) protons at a collision energy of half a TeV. Even Au ions, limited by their charge-to-mass ratios, can still be collided at 200GeV center-of-mass. To use another example: when running the heavy-ion program during pauses from the proton program, the LHC will introduce heavy-ion collisions at center-of-mass energies of several TeV.

I would go further, though, and support the idea that this kind of nuclear-collision physics can be considered as part of the diverse 'umbrella' of particle physics. Although it is funded by the (DoE) Office of Nuclear Physics, RHIC is definitely a lot more like conventional particle physics experiments than it is like conventional nuclear physics experiments. Sure, the collisions are a little messier than e+e- collisions - but so are hadron collisions (particularly in the future, at LHC energies), as we shouldn't forget that protons are themselves composite objects. Additionally, the aim of the field is not to investigate any property of actual nuclei; the nuclei involved are just tools employed in order to discover (done!) and determine the behavior (ongoing...) of the primordial matter and energy that pre-dated the existence of protons, let alone actual nuclei, in the Universe.

Finally, as regards the image itself, it is an excellent depiction of particle tracks in a solenoidal detector, albeit with rather more tracks than one would expect from an e+e- or pp collision (at current energies!) Please note, by the way, that I don't work on the STAR experiment. :)

C60 08:37, 16 May 2007 (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)

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 $-N_{F}{\frac {7}{8}}{\frac {\pi ^{2}}{90}}T^{4}$ ($N_{F}$ 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)

The counting of 24 fermions is not consistent with the counting of 12 vector bosons. There are several different ways to count particles in the Standard Model, we chose one and stick to it for both fermions and bosons. Better yet, we could provide all the different ways of counting particles and expose their different merits. I will wait at least 24 hours before making changes to the article to give people enough time to raise any concerns. —Preceding unsigned comment added by Dauto (talk • contribs) 03:42, 15 February 2009 (UTC)

Since nobody said anything, I will do it my way. For now I will just present the simplest counting method consistently. Later, when I have the time, I may introduce a new section where I will explain all the different ways o counting. Dauto (talk) 19:17, 20 February 2009 (UTC)

Timeline of particle physics

I proposed to create the article "Timeline of particle physics", as Timeline of cosmology or Timeline of particle physics technology. Lseixas 23:39, 26 December 2006 (UTC)

I created the article and linked this article with "Particle physics". Lseixas 00:06, 31 December 2006 (UTC)

Template of Particle physics

I proposed to create the "template:particle_physics". See the prototype Template:Particle physics.

Publications in partcle physics

It might be of interest to put some classics and intro level publications on the subject. --IsleScape^Talk 17:19, 8 February 2007 (UTC)

Non-accelerator physics?

This article is devoted to collider experiments, but other kinds of experiments are surely part of particle physics, too: double-beta decay, searches for dark matter, neutrino oscillation experiments, etc. Don't we need to add a section on that? SchmittM 02:14, 18 March 2007 (UTC)

evidence for physics beyond the standard model

The articles lists non-zero neutrino masses as evidence for physics beyond the standard model. How about the existence of dark matter and the baryon asymmetry? Neither of these can be explained in the Standard Model and there is absolutely no doubt about the empirical facts... SchmittM 02:14, 18 March 2007 (UTC)

Both of the issues you mention come from astronomical observations. They are evidence that we should find physics beyond the Standard Model, but particle physics hasn't been able to observe dark matter or the full cause of the baryon asymmetry yet. Josh Thompson 07:36, 21 May 2007 (UTC)

SPIRES

At the moment there's an external link to SPIRES-HEP. Should we get rid of this and make it a wikilink, since SPIRES has its own wiki article? Josh Thompson 07:45, 21 May 2007 (UTC)

Rewriting the History section

Inspired by the edit by 128.62.92.218, I starting rewriting the history section. Hopefully people are ok with what I have done. There is a lot of later history that could be added, although the section should be kept from getting too long. Josh Thompson 07:17, 26 May 2007 (UTC)

• I haven't been paying attention to the Wikipedia for a while, and I just came back to discover this edit, which bothers me greatly. The user changed the History section from what I thought was a good starting point to a bunch of stuff about the Greeks and nuclear physics. The user also removed two References. This article should have more references, not less! Does anyone have any opinions on this? Josh Thompson 17:31, 8 November 2007 (UTC)

Scale of the 'STAR explosion' image

It would be good to show a scale on the the 'STAR explosion' image. Duncan.france (talk) 07:54, 8 December 2007 (UTC)

Public policy

Do we really need the public policy section? To my knowledge, particle physics isn't very controversial. If it is a serious issue, the public policy section should be moved to Particle accelerator. I'd vote to just remove it though. --Voidxor (talk) 16:59, 24 March 2008 (UTC)

High energy particle

High energy particle redirects here but this articles does not describe a high energy particle. I see a def here of:

• high-energy particle (hī′en′ər jē)- an atomic or subatomic particle with energy greater than 100 MeV

Needs a description or maybe the redirect should be taken down in lieu of article if this is enough of an encyclopedic "thing". Fountains of Bryn Mawr (talk) 16:07, 8 June 2009 (UTC)

Heiarchy of particles or matter

Beginning with the molecule and working to elemental particles(see the standard model), there are 4 levels or states of matter:

Molecules, Atoms, Subatomic Particles, Elementary Particles

Lists correspond to each:

Molecules = List of compounds

Atoms = The Periodic Table of the Elements

Sub-Atomic Particles = Nucleons

Elementary Particles = The Standard Model

Anything larger than molecules belongs in another article, right?

The "List of particles" table of contents is confusing, it has a category of composite particles that includes all particles as well as elementary particles. Elementary particles are not composite, right?

Here is the image of the tree structure I want to include: [6]DarrenHensley (talk) 08:49, 20 June 2009 (UTC)

DarrenHensley (talk) 01:19, 10 June 2009 (UTC)

Molecule

Molecules are composed of the following: Atoms bound by Valence in Space

The molecule is listed in the category of composite particles in the "List of Particles", everything except elemental particles are composites right? It just seems wrong to have a cetegory called composite... Comments?

DarrenHensley (talk) 01:17, 10 June 2009 (UTC)

Atom

Atoms are composed of the following: Protons, Neutrons, and Electrons

There is no list of composite nucleons, why not? Protons are composites, Neutrons are composites, according to wikipedia electrons can also be composite, I do not agree, and electron is an elemental and is commonly massless, right?

DarrenHensley (talk) 01:19, 10 June 2009 (UTC)

An electron is an elementary particle with rest mass and location determinency and also unit electrostatic charge properties. It doesn't get an indeterminate property until you start messing around with the uncertainty principle related to a measurement of it's physical activities.WFPM (talk) 16:38, 13 May 2010 (UTC)

Sub-Atomic Particles

Sub-Atomic Particles (AKA Groups)are composed of elemntary particles, and they are assembled into groups as follows:

Anyons and Hadrons

Anyons are composed of families as follows:

Fermions and Bosons

Hadrons are composed of families as follows:

Baryons, Mesons, and Exotic Mesons (Tetraquark)

That's where you need a chart to organize these entities into their discrete families and subordinate entity descriptions that organizes this information. See Particle physics.WFPM (talk) 16:47, 13 May 2010 (UTC)

In the "List of particles" why not list "Atomic Nuclei" as "Sub-Atomic Particles(or Nucleons)" ?

DarrenHensley (talk) 01:17, 10 June 2009 (UTC)

Elementary Particles

Fundamental or Elementary Particles are composed of the following families:

Leptons, Quarks, Elementary Bosons, Composite Bosons(Mesons)

What's it going to be, Fundamental, or Elementary? Make up my mind, elementary particles conflicts with elementary bosons, composite bosons are mesons, so stop calling them composite bosons. Comments?

DarrenHensley (talk) 01:18, 10 June 2009 (UTC)

Families

Leptons

Electron, Tau, Muon, Electron Neutrino, Tau Neutrino, Muon Neutrino

Quarks

Up Quark, Down Quark, Top Quark, Bottom Quark, Charm Quark, Strange Quark

Bosons – Elementary

Photon, W Weak Force, Z Weak Force, Higgs Boson, Gluon, Graviton

Does anyone dispute above heiarchy? I have postulated this structure from researching wiki and trying to find a graphical representation of it. I got nowhere so I decided to make one. I'm making a graphic using Adobe Illustrator CS4, comming soon.

DarrenHensley (talk) 00:58, 10 June 2009 (UTC)

The title "Partical physics" needs to be re-examined

Yes, the title "Partical physics" needs to be seriously re-examined, because there are other kinds of particle particle physics that have to do with things other than nuclear particles, electrons, photons, etc.
One realm of study involves the placement of fine particles of a substance such as graphite (or coal dust) into rarified air (or some other gas or fluid), and then sending that mixture of particles somewhere. That mixture of particles contains graphite particles, N₂ molecules, O₂ molecules, and a few argon atoms. Sending this mixture though a system of ducts, curves, tees, valves, grills, etc., raises the question, "What is the physics of all these particles like?", and especially, "What happens when chaos sets in?"
In another field of physics, there is the area that we call "particle mechanics", where mechanics is a subdivision of physics: hence it is "particle physics". In this kind of physics, all of the objects under consideration are treated as mathematical "particles" - for example, all of the automobiles in a big city. These objects are treated as having no extent up-down, left-right, or front-back. This greatly simplifies the analysis of what is going on, because these particles, having no extent, do not have any rotational moments of inertia - because their "diameters" are so small - and hence they never have any rotational inertia or rotational energy, and they neither can they have any torques applied to them, or apply torque to any other particle.
In particle mechanics a particle is allowed to posses or experience all of the following: mass, linear inertia, velocity, acceleration, impulse, kinetic energy, and potential energy. Such particles can both exert forces onto other objects, and respond to forces appled to them, according to Newton's Third Law of Motion and the equation, F = ma. They also obey Newton's First and Second Laws.
We can visualize all of the airplanes in flight above the United States and Canada as "particles", and analyze how they move around, even though upon closer examination, and airplane is definitely NOT a particle. It all depends on the distance scale with which we visualize things.98.67.110.56 (talk) 19:12, 6 April 2010 (UTC)

Yes, but the fact remains that people don't actually refer to airplanes going around as "particle physics". This article should cover things that people actually refer to as particle physics, which means subatomic particles (very often), atomic nucleus (often), atoms (rare), and molecules (very rare). Headbomb {talk / contribs / physics / books} 19:59, 6 April 2010 (UTC)

I think that, for the vast majority of people, "particle physics" brings to mind images of big "atom smashers" or, for the slightly more educated, the Standard Model. While it may be useful to model other things as particles, I have doubts that anyone, really, would associate the term "particle physics" with that over the subject of this article. – Joe N 21:11, 6 April 2010 (UTC)

How do you know? One thing that I know for certain is that the vast majority of people know absolutely nothing about subatomic particles. They don't even know what an electron is. Billions of people worry about being around cellular telephones and high-voltage electic power lines because they do not know the difference between radio waves as electromagnetic radiation and the [[nuclear radiation[[ of alpha rays, beta rays, and gamma rays, which are dangerous because they are ionizing radiation. The only thing that they hear is the word radiation and it scares them because they think of the atomic bomb.

Ignorance is far more common than you think. So many billions of people are only interested in what has happened lately on Beverly Hills 90210, or else where their next meal is going to come from, or how half of the people in their village have AIDS.

On the other hand, I have read humorous science fiction short stories by Arthur C. Clarke. In one of them, a group of men from a British atomic energy research laboratory are sitting in a pub, sipping on beers, and telling each other tall tales. One of them is telling a story about how an uneducated technician at that laboratory has made a remarkable discovery. To emphasisize how little he knew, the teller of the story says, "He didn't even know how to integrate e to the x.

Another member of the group throws his hands up into the air and exclaims,

"Is such ignorance possible!??"

The story teller agrees, "You're right - nobody is that ignorant. He could not integrate x•(e to the x)."

The other man says, "O.K., I can believe that."

In case anyone reader does not know, the integral of the function e to the x is -- e to the x, itself. This is a unique nontrivial function for which this is true.

The point is that there are billions of people who cannot integrate x•(e to the x), or integrate e to the x, or to integrate x, or the difference between radio waves and ionizing radiation, or what a subatomic particle is.

They probably do know what a particles of talcum powder are, and particles of dust, and particles of sand, and particles of flour. To them, some science about such particles might make some sense, but something about protons, neutrons, electrons, photons, neutrinos, pions, alpha particles, and muons makes no sense at all.

"Particle physics" also means the physics of particles of talcum powder floating in the air - which is quite an interesting subject, because it leads to the subjects of Brownian motion, turbulence, the sedimentation of particles, and so forth.98.67.168.193 (talk) 03:28, 1 August 2010 (UTC)

What I'd like in particle physics is a discussion of the physics related to the physical interaction of two particles that involves a description of their interacting force relationship, similar to the way Isaac Newton made his analysis. In such a case, it seems logical that both particles would be exercising and controlling a force with properties of magnitude and direction such as to be able to explain the ensuing activity. Also, I don't see how one of these particles could exercise a force, but the other one couldn't.WFPM (talk) 17:04, 13 May 2010 (UTC)

This subject matter was discussed by James Clerk Maxwell in hie article about "Atom" in the 9th edition of the Encyclopaedia Britannica, And where he credit's Roger Joseph Boscovich as being the originator of the "noncontacting interacting force theory concept.WFPM (talk) 18:35, 13 May 2010 (UTC)

Replying on the subject of Sir Isaac Newton:
When it came to Newton's discovery concept of his Theory of Universal Gravitation, Newton set about trying to describe the gravitational force mathematically and quantatively. These were genuinely pioneering moves by Newton -- because practically nobody had ever thought to apply math to such things - and especially above the level of civil engineering. (We'll concede that some civil engineers did this.)
First Newton pictured masses strictly as point masses - in other words, as particles. Hence, Newton studied "particle phyics". Using this assumption, Newton developed the relatively-simple equation for the gravitational force between two particles,-----------F = G•m1•m2/d²

Then, to Newton, it was obvious that a spherical object with a nice distribution of its density would act, gravitationally, as if all of its mass was concentrated at its center. (I agree: it is obvious.)
However, some of his few friends with whom Newton shared his work got to this point - that the gravitational mass would be concentrated at its center - questioned this conclusion of Newton's. It seemed like an unjustified assumption of his, and actually it was. Newton told them that he would show them a mathematical proof of this idea, shortly. Then, Newton spent ten years or more working out differential and integral calculus, and especially the Fundamental Theorem of Calculus. Then, Newton could write down the proof that he needed in just a couple of pages of math.
Finally, his friend Edmund Halley recognized the deep importance of Newton's calculus, and he persuaded Newton to write a book on the subject. Newton agreed, and that was where the book Principia Mathematica Philosophiae Naturalis came from. 98.67.168.193 (talk) 04:08, 1 August 2010 (UTC)

Hey, not to be a party pooper, but I don't really see the relevance of people who don't know integration by parts or Newton's derivation of Calculus to the name of an article. While Newton was a very brilliant man and his contributions to science and math should be recognized, the name of the article should refer to what most physicists and laymen call the field, which is particle physics. I do not claim to be a physicist, but I think that I am much better educated and familiar with physics that the majority of the people who would come to read this article, and I have never heard the term used by a scientist or in a scientific work to refer to anything other than the interactions of subatomic particles. – Joe N 16:05, 1 August 2010 (UTC)

A viable title of the article would be "High energy physics" I suppose, with a redirect of particle physics to high energy physics as long as there is no disambiguation page? Aknochel (talk) 14:40, 2 August 2010 (UTC)