Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

How can a particle be a combination of other particles?

  1. Sep 26, 2015 #21

    PeterDonis

    Staff: Mentor

    What this means is that, if we tried to detect such particles in our current universe, those are the masses we would have to be able to detect--which means we would have to be able to run experiments that involved particles with energies of that order of magnitude. We are many orders of magnitude short of being able to do that.

    As I understand it, in grand unified theories, the Higgs field that is involved in electroweak symmetry breaking is not the "entire" Higgs field; it's only a piece of it. There is another piece of the Higgs field that is involved in grand unified symmetry breaking, and gives mass to the GUT bosons after that symmetry breaking event, and leaves behind what we usually call the Higgs field, the one that's involved in electroweak symmetry breaking.

    However, we haven't observed any of the GUT bosons, and, for the reason I gave above, we don't expect to any time soon. So we don't really have any experimental test of the GUT Higgs mechanism, whereas we do have experimental tests of the electroweak Higgs mechanism. So we don't really know for sure how the GUT bosons acquire mass, the way we know how the weak bosons acquire mass. We don't even know for sure which GUT, if any, is the right one; there are multiple possible GUT's that are consistent with what we currently know.
     
  2. Sep 26, 2015 #22

    Buzz Bloom

    User Avatar
    Gold Member

    Hi Peter:

    Thank you for clarifying what the Wikipedia article's language meant, and that the Wikipedia text (technically) was not in error. It just used the Physicsese dialect in a different way than other uses, e.g., your excellent and clear exposition in your post #15.

    I get that there seems to be a very extensive reluctance to "fix" Wikipedia text when is is not tecnically wrong, just only misleading and confiusing to non-experts. My own feeling about this is that it's a sad shame.

    Regards,
    Buzz
     
  3. Sep 26, 2015 #23

    PeterDonis

    Staff: Mentor

    I think the reluctance is due to the fact that one does not have to be an expert in the subject to edit a Wikipedia article, so even if an expert makes a change, a non-expert can come along and undo it, or make another change that negates it. So there's a limit to how much time and effort experts are willing to put in.
     
  4. Sep 26, 2015 #24

    Buzz Bloom

    User Avatar
    Gold Member

    Hi @PeterDonis:

    Thanks for your insight into the psychology about "fixing" Wikiedia. I understand from multiple personal expeiences the frustration of trying to correct Wikipedia text when there is someone with more patience and stamina for unfixing than I have for fixing.

    Here is the entire Wikipedia paragraph with the misleading and confusing text.
    The novel particles predicted by GUT models are expected to have masses around the GUT scale—just a few orders of magnitude below the Planck scale—and so will be well beyond the reach of any foreseen particle collider experiments. Therefore, the particles predicted by GUT models will be unable to be observed directly and instead the effects of grand unification might be detected through indirect observations such as proton decay, electric dipole moments of elementary particles, or the properties of neutrinos. Some grand unified theories predict the existence of magnetic monopoles.​
    I underlined "masses", the single word that I believe causes "the problem". Do you think changing "masses" to "energies" would fix "the problem"? Do you think making this change would be controversial?

    Regards,
    Buzz
     
    Last edited: Sep 26, 2015
  5. Nov 3, 2015 #25

    Buzz Bloom

    User Avatar
    Gold Member

    About a month ago I changed "masses" to"energies " in the Wikipedia article
    The change is still there, so maybe it is worthwhile sometimes to make the effort to make a change and then hope for the best.
     
  6. Nov 3, 2015 #26

    Orodruin

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member
    2017 Award

    Your change is misleading and should be reverted. That nobody has done so yet just shows that people with sufficient knowledge are not paying attention.

    I do not get why you keep wanting to change Wikipedia on subjects you do not fully understand. I would call this vandalism.
     
  7. Nov 3, 2015 #27

    Buzz Bloom

    User Avatar
    Gold Member

    Hi Orodruin:

    Thanks for your post. From your comment that my edit is "misleading", I get that you looked at the edit and formed this conclusion. I would very much appreciate understanding your reason for this conclusion.

    The reason I try to improve Wikipedia, even though I am not an expert, is because Wikipedia says they want people like myself to help improve the quality of their physics articles. Please see:
    I frequently find text which as a non-expert I find confusing. I would be very happy if experts did the improving by making the text clearer for non-experts to understand, but if they don't, I feel invited to do the best I can.

    Regards,
    Buzz
     
  8. Nov 3, 2015 #28

    PeterDonis

    Staff: Mentor

    I suspect it's because "mass" in particle physics means "rest mass", which is not the same as "energy". The Wikipedia article before you edited it was correct: it said the rest masses of the novel particles predicted by GUT models were around the GUT scale. After your edit, the article is wrong: the energies of such particles can be anything higher than their rest masses, depending on the situation, and those energies are not what is predicted by the GUT models--they can't be, because, as I said, the energy of any given particle depends on the situation, so no physical model will predict a single energy for a particle.

    This kind of attitude is a big reason why many experts don't want to spend time and effort to edit Wikipedia articles. What seems clearer to you, a non-expert, is very likely to be wrong, but as a non-expert, you won't know it. So what you think are helpful changes are really destroying the work of experts. As you did with the article discussed above.

    The fact that no expert has undone your change doesn't mean it was a good change. It just means that experts don't see the point of trying to correct it, since some other non-expert could come along tomorrow and destroy their work. Again.
     
  9. Nov 3, 2015 #29

    Orodruin

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member
    2017 Award

    You really should not edit unless you are certain. What do you think is worse, that someone finds an article confusing or that someone reads it, think they understand it, and got the completely wrong expression? Many people tend to (unfortunately) take Wikipedia as their standard reference. A physics student doing that will spend time and effort learning things which are not true. Then they come to the exam and fail and the argument "Wikipedia said" does not work as an excuse on most university teachers.
     
  10. Nov 3, 2015 #30

    Orodruin

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member
    2017 Award

    Said and done. Please stop vandalising the work of actual experts. This is the second time I have had to revert one of your "improvements". As I remember, also the last time you were unwilling to revert your change even after being told repeatedly that it was not correct.
     
  11. Nov 3, 2015 #31

    Buzz Bloom

    User Avatar
    Gold Member

    Hi Orodruin and Peter:

    Congratulations. I confess you are succeeding in discouraging me from efforts to make Wikipedia physics articles less confusing and misleading to non-experts.

    I understand Orodruin's dislike for my mistakes when I try to make improvements. What I don't understand is why with less effort than that required to undo my poor efforts, he doesn't instead just do it right in the first place, or help me understand what the right fix should be. Do either of you disagree that the current language written by experts is misleading or confusing to a non-expert? Do either of you accept that this is so, but feel that it is unnecessary to make it better?

    From time to time I discover texts that I misunderstand. I believe the reasons I misunderstand them is that the text includes specialized expert usages of language that are confusing and misleading to non-experts. What I try to do is get clarification from discussions on the forums. I feel that there is, or should be, an opportunity on these forums to get experts to suggest language to fix confusing or misleading Wikipedia text. Why is that a bad idea?

    In the last few posts it has become clear to me that "masses" is still confusing and misleading to non-experts in particle physics. While "energies" made it worse, why wouldn't adding "rest" make it better?

    The previous post on this thread before today's was dated September 26th. That post includes the following question:
    If someone since September 26th had posted that "rest" would fix the text, and that "energies" would make it worse, then I would certainly have used "rest" in my change. Would that have been such a terrible thing to do?

    Regards,
    Buzz
     
  12. Nov 3, 2015 #32

    Orodruin

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member
    2017 Award

    No. I do not agree that it is misleading or confusing. What was wrong here was your interpretation of Peter's posts.

    Because it was right already, until you changed it.

    Peter tried, that resulted in you misunderstanding his post and doing the wrong edit.

    Because as a non-expert, you are likely to miss crucial information and certain details. In order to make relevant contributions, just hanging around and asking people who know is not going to make you qualified to write about it. Unfortunately, this is also true of many journalists who try to write about science.

    No, it would make other things worse. In particular, it would counteract efforts of getting the idea of "relativistic mass" out of the mind of the general public. In high-energy physics, we only talk about "mass", never-never-never-never "relativistic mass".
     
  13. Nov 3, 2015 #33

    Buzz Bloom

    User Avatar
    Gold Member

    Hi Orodruin:

    Thanks for your post answering my questions.

    I accept as true all of your comments. I confess I find them discouraging. The conclusion I reach is that the language dialects of physicsese for various branches of physics are so precise that any attempts to "improve" text would be counter to the intended nuances of meaning. Therefore it is impossible for a non-professional in a particular branch to avoid being confused and misled by reading specialized text. It seems to me that physics is thus enduring a tower of Babel condition.

    Regards,
    Buzz
     
  14. Nov 3, 2015 #34

    Orodruin

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member
    2017 Award

    I would argue against this as well. Given the inclination, you can go to a university where you can study the language of physics and other natural sciences. As with any language, it takes time and effort to master.
     
  15. Nov 3, 2015 #35
    It's a physics article. That is the correct language to write it in. In Wikipedia, the straight article is not intended for didactical purposes (there was a simplified edition of Wikipedia for that, iirc).

    Also, even for didactical purposes, "mass" would still be a better term: you misunderstood PeterDonis' post when he said you need higher energies to access the phenomena concerning particles having such masses, and you somehow conflated the two concepts. Thus, rather than Babel's tower condition, there's a Chinese whispers condition to which you are contributing ;)
     
  16. Nov 3, 2015 #36

    PeterDonis

    Staff: Mentor

    You're missing the point. Somebody already did it right in the first place. Then you changed it to something wrong. If Orodruin, or anybody else, changes it back, what guarantee is there that some other non-expert won't come along tomorrow and change it to something wrong again? Answer: none.

    In other words, if you're an expert, trying to keep a Wikipedia article's text correct ends up being an endless game of whack-a-mole. Experts have better things to do with their time. Yes, that means Wikipedia is often not a good source. That, quite frankly, is Wikipedia's problem.
     
  17. Nov 3, 2015 #37

    Orodruin

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member
    2017 Award

    Just to elaborate on this: I did not correct it because I want Wikipedia to be correct - as Peter says, that is a Herculean task and there is no guarantee it will not be changed to something wrong tomorrow. I reverted the change because these things could have a detrimental effect on the reputation of Physics Forums. Imagine someone sees your edit and realises it is wrong - they go to the talk page, get your user name, search for it, and this thread will pop up. All of a sudden, Physics Forums is the place where you got your ideas from and vandalised the Wikipedia article.
     
  18. Nov 3, 2015 #38

    Buzz Bloom

    User Avatar
    Gold Member

    Hi ddd:

    Thanks for your post:

    This is what I understood from Peter's and Orodruin' post.
    (1) In particle physicsese, "mass" means "rest mass" as opposed to M = E/c2 mass.
    (2) GUT models predict the rest mass of particles.
    (3) The particular predicted rest mass for a GUT predicted particle requires an extremely high amount of energy to produce such a a particle, either experimentally or naturally. This level of energy is called the GUT scale. This is the scale of energy that was naturally present during the stage of the universe before the strong force separated from the week-EM force.

    What did I misunderstand?

    Regards,
    Buzz
     
  19. Nov 3, 2015 #39
    You probably should ask that yourself since you ended up editing the article with "energy" which can't be correct, since energy can vary a lot from the rest mass portion (e.g. ultrarelativistic regimes). Your "rest mass" objection is a different one from the first, which you came up with after you figured out you were wrong in the first place: that's a first misunderstanding. The second misunderstanding, different from the first, is the fact that the concept of rest mass really is useless on both fronts:

    1) technically, it's just redundant: mass is already rest mass, because relativistic mass is just a flawed concept of old.
    2) didactically, relativistic mass only confuses people more (as you are an example), since parallel or perpendicular forces have different results from such a mass: so it's not really what you think about concerning "mass" anyway - your "Babel" problem, in a reductio ad absurdum scenario, is still present and exacerbated if you just start editing all particle physics articles writing "rest mass" instead of "mass".
     
  20. Nov 3, 2015 #40

    Buzz Bloom

    User Avatar
    Gold Member

    Hi Orodruin:

    Thank you for your post. I get and accept your point.

    There is one more Wikipedia physics article I have edited. (There are many others for which I have only edited the Talk page.) It is
    I tell you this so if you want to you can take a look at it and let me know if you think I should undo it, and why.

    Regards,
    Buzz
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook