Quantcast
  • Register
PhysicsOverflow is a next-generation academic platform for physicists and astronomers, including a community peer review system and a postgraduate-level discussion forum analogous to MathOverflow.

Welcome to PhysicsOverflow! PhysicsOverflow is an open platform for community peer review and graduate-level Physics discussion.

Please help promote PhysicsOverflow ads elsewhere if you like it.

News

PO is now at the Physics Department of Bielefeld University!

New printer friendly PO pages!

Migration to Bielefeld University was successful!

Please vote for this year's PhysicsOverflow ads!

Please do help out in categorising submissions. Submit a paper to PhysicsOverflow!

... see more

Tools for paper authors

Submit paper
Claim Paper Authorship

Tools for SE users

Search User
Reclaim SE Account
Request Account Merger
Nativise imported posts
Claim post (deleted users)
Import SE post

Users whose questions have been imported from Physics Stack Exchange, Theoretical Physics Stack Exchange, or any other Stack Exchange site are kindly requested to reclaim their account and not to register as a new user.

Public \(\beta\) tools

Report a bug with a feature
Request a new functionality
404 page design
Send feedback

Attributions

(propose a free ad)

Site Statistics

205 submissions , 163 unreviewed
5,047 questions , 2,200 unanswered
5,345 answers , 22,709 comments
1,470 users with positive rep
816 active unimported users
More ...

  Is there a maximum number of types of elementary particles?

+ 6 like - 0 dislike
2224 views

Doing a Google search i found a paper called The maximum number of elementary particles in a super symmetric extension of the standard model.

It claims in the abstract that the upper bound is 84 (i don't have access to the article)

My question is: Is there a max number of types of elementary particles predicted in advanced physics theories such as string theory? What are the reasons for this?Are the arguments purely mathematical?

This post imported from StackExchange Physics at 2014-03-12 15:53 (UCT), posted by SE-user Mark
asked Apr 13, 2011 in Theoretical Physics by Mark (60 points) [ no revision ]
Hi Mark, I suggest you go read the blog El Naschie Watch. I find it amazing that Elsevier kept Chaos, Solitons and Fractals going instead of letting it rest in peace.

This post imported from StackExchange Physics at 2014-03-12 15:53 (UCT), posted by SE-user Simon

3 Answers

+ 7 like - 0 dislike

The paper you cite employs Mohammed El Naschie's "E-infinity theory" of physics, which is one big exercise in what physicists call "numerology". Numerology is where you match up numbers - e.g. the three generations of particles in the standard model, and the three dimensions of space - and then you state or insinuate that there is a connection; but you cannot justify the connection logically (deductively). Another common example is where people find formulae for particle masses and other unexplained quantities, using combinations of transcendental numbers, other particle masses, and so on.

This "numerology" sometimes does work in physics and mathematics. That is, the search for quantitative coincidences sometimes does stumble upon relationships which have a deeper origin. Balmer's formula for the emissions of the hydrogen atom was explained by quantum mechanics; the coincidence in mathematics known as "monstrous moonshine" was proven to be true by Richard Borcherds; there are many other examples. But it is also possible to make extremely contrived relationships - e.g. you can approximate any real number arbitrarily closely, using combinations of e and $\pi$, if you use enough of them. You can also pile up lots of deductively unjustified "connections", and claim to have a theory of everything. "E-infinity theory" is in the latter category. These papers don't contain even the moderately difficult sorts of calculation that you see in real particle physics papers - I mean scattering amplitudes, particle lifetimes, and all the other detailed quantities which come from employing a theory with a proper equation of motion. Instead, these papers are full of basic algebra equations in which various known quantities are "explained" in a meaningless way. But these papers don't actually explain anything, nor do they predict anything, and the journal which publishes most of them is considered low-quality for this reason.

This post imported from StackExchange Physics at 2014-03-12 15:53 (UCT), posted by SE-user Mitchell Porter
answered Apr 13, 2011 by Mitchell Porter (1,950 points) [ no revision ]
I just read the paper. Sadly its not just "low quality", but pure garbage! I cannot understand how these "E-infinity" papers were able to get published for so many years.

This post imported from StackExchange Physics at 2014-03-12 15:53 (UCT), posted by SE-user Heidar
good way to make money though, a little more cool than motivation speeches :)

This post imported from StackExchange Physics at 2014-03-12 15:53 (UCT), posted by SE-user jokoon
@4tnemele, google for El Nashie You will find reason for this publications in the fact that he was editor of that "paper". The "case" El Nashie is setteled meanwhile.

This post imported from StackExchange Physics at 2014-03-12 15:53 (UCT), posted by SE-user Georg
Sommerfeld was blamed for doing "Zahlenmystik" (number mystics)

This post imported from StackExchange Physics at 2014-03-12 15:53 (UCT), posted by SE-user Georg
@Gokoon at least with a motivational speech you know you're getting fed BS.

This post imported from StackExchange Physics at 2014-03-12 15:53 (UCT), posted by SE-user corsiKa
@glowcoder yes of course, but if research starts spending money on that kind of bullshit, I guess there's nothing fixable: people with graduates just gets lazy and starts masturbating with pseudo-science because they know they will never get out of a job. Those guys have been given gold education but are just too stupid to make something worthy. Sometimes I wonder if there's truly nothing else important to find in physics, or rather if we just educate and give degrees to the wrong people.

This post imported from StackExchange Physics at 2014-03-12 15:53 (UCT), posted by SE-user jokoon
Do you think it's possible to get El Nashie's papers (and most of the garbage published in "his" journal) withdrawn and removed from reputable search engines? I got tricked by his BS during a summer project a while back (before he became infamous) and wasted a fair chunk of time trying to understand what he was doing. As evidenced by this question, I'm not the only one whose been fooled. Elsevier should really made to be held accountable for packaging up CS&F and basically forcing libraries to buy it. And yes, I know that Baez et al have already tried...

This post imported from StackExchange Physics at 2014-03-12 15:53 (UCT), posted by SE-user Simon
+ 1 like - 0 dislike

The number of particles depends on the theory assumed. Symmetries, such as super symmetry impose limits, but who knows what the theory of everything is?

Yes, the arguments are purely mathematical, until some experiment at a future date will chose among the multiplicity of theoretical models.

This post imported from StackExchange Physics at 2014-03-12 15:53 (UCT), posted by SE-user anna v
answered Apr 13, 2011 by anna v (2,005 points) [ no revision ]
In the case of string theory,particles are understood as tiny vibrating strings with certain frequencies,so there is a finite number of possible frequencies?Are these frequencies quantized?

This post imported from StackExchange Physics at 2014-03-12 15:53 (UCT), posted by SE-user Mark
Also,the electromagnetic spectrum is related to the photon's energy.Does it imply that at the string level the string is vibrating faster?

This post imported from StackExchange Physics at 2014-03-12 15:53 (UCT), posted by SE-user Mark
@Mark: The frequencies are quantised, but there are an infinite number of modes.

This post imported from StackExchange Physics at 2014-03-12 15:53 (UCT), posted by SE-user Dimensio1n0
+ 0 like - 0 dislike

My question is: Is there a max number of types of elementary particles predicted in advanced physics theories such as string theory? What are the reasons for this?Are the arguments purely mathematical?

Definitely, at least in String theory, there is no such finite number. In string theory, the closed string mass spectrum is given (in unnatural units, although it would work in natural units, too) by:

$$m=\frac{2\pi T\ell_s}{c_0^2}\sqrt{N+\tilde N-a-\tilde a}$$

Where $a,\tilde a$ are the left- and right- moving normal ordering constant. Here, the number operators $N,\tilde N$ can be ANY integer or half-integer. So, they vary from 0 to $\infty$ and thus, so does the mass $m$. In other words, the mass spectrum is infintely large.

And since each mass correponds to a different particle, there is an infinite "particle spectrum"...

answered Jun 20, 2013 by dimension10 (1,985 points) [ revision history ]
This is true, but the "particles" we see in accelerators are just the massless particles, and there are a finite number of these. This is probably the best interpretation of the question.

This post imported from StackExchange Physics at 2014-03-12 15:53 (UCT), posted by SE-user Ron Maimon

Your answer

Please use answers only to (at least partly) answer questions. To comment, discuss, or ask for clarification, leave a comment instead.
To mask links under text, please type your text, highlight it, and click the "link" button. You can then enter your link URL.
Please consult the FAQ for as to how to format your post.
This is the answer box; if you want to write a comment instead, please use the 'add comment' button.
Live preview (may slow down editor)   Preview
Your name to display (optional):
Privacy: Your email address will only be used for sending these notifications.
Anti-spam verification:
If you are a human please identify the position of the character covered by the symbol $\varnothing$ in the following word:
p$\hbar$ysicsOverfl$\varnothing$w
Then drag the red bullet below over the corresponding character of our banner. When you drop it there, the bullet changes to green (on slow internet connections after a few seconds).
Please complete the anti-spam verification




user contributions licensed under cc by-sa 3.0 with attribution required

Your rights
...