smaller than subatomic particles

Discussion in 'Physics & Math' started by Lexi, Jan 30, 2010.

1. prometheusviva voce!Moderator

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You seem to be implying that quarks in bound states don't have a well defined mass. This is not true - they certainly do have a well defined and fixed mass. The problem is that in a strongly bound state much of the mass comes from interactions with the glue, and we can never see a single quark because of colour confinement. The problem of the mass of the light quarks is one of measurement, not theory.

3. Walter L. WagnerCosmic Truth SeekerValued Senior Member

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No, I wasn't implying that. I was saying we don't know what those masses are separately - not that they don't have a set mass; if that is even a meaningful assertions, since they can't be separated, nor the mass measured.

I suppose you could say I was implying that the Chart depicted above is wrong to have set particular values if we don't know that those are the values; particularly when it was to two decimal places, implying relatively well-measured values. It should have given the broad error-bars of rpenner.

5. AlphaNumericFully ionizedModerator

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And I'm sure the Wikipedia article covers the current uncertainties but I don't think that diagram is anything more than a quick illustration of particular trends. Anyone who really needs to know quark masses is likely to know enough physics that they know things aren't so clear cut. Things are simplified and caveats and details stripped away when explaining it to people who don't need to know the details. I'm sure you've heard a great many stripped down layman explanations in your time Walter, when people patiently explain high school physics to you.

7. BenTheManDr. of Physics, Prof. of LoveValued Senior Member

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I agree. The quark masses are not known exactly. It is not really a meaningful question (in my opinion), and it is certainly one that doesn't seem to be experimentally verifiable.

Now can we move the discussion forward please?

8. Lawson's CriterionRegistered Senior Member

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Dear Lexi:

Sub-quark events have been observed.

LC, Ph.D., Los Alamos National Laboratory.
Los Alamos, New Mexico.

9. prometheusviva voce!Moderator

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[citation needed]

10. AlphaNumericFully ionizedModerator

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I doubt the troll masquerading as a member of the LANL is going to provide one. I must admit I thought of precisely the same reply before I scrolled down to your post

11. prometheusviva voce!Moderator

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I almost went to xkcd when I posted that. I feel I should remedy that now.

12. CptBorkRobbing the Shalebridge CradleValued Senior Member

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Just to point out as far as quark masses and uncertainties go... Even the electron's true mass is uncertain, because in any experiment you do, you'll be measuring the effects of the electron + its cloud of virtual particles. The "masses" of the fundamental particles are nothing but abstract mathematical creations, which we can use to predict what happens in reality when you add in the effects of virtual particles, bound states, etc.

13. BenTheManDr. of Physics, Prof. of LoveValued Senior Member

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You can at least isolate electrons, though.

14. CptBorkRobbing the Shalebridge CradleValued Senior Member

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You can isolate them from bound states, sure, but I don't see how that eliminates the virtual particles they're constantly emitting. I don't pretend to be an expert though- I've only just been learning the mathematical details about renormalization over the past 2 weeks.

15. AlphaNumericFully ionizedModerator

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This is exactly something I was talking with office mates about yesterday. Electrons are fundamentally electroweak while quarks are mostly gluonic in their interactions (mostly). We only know of the electron so many years before the quark because we can supply enough energy to rip apart electromagnetic bound states and the electroweak corrections to the electron mass are tiny. In the same way that the top quark is actually easier to 'weigh' than the up quark due to having less, proportionally, effects due to gluonic interference the electron is not quite free of corrections from electroweak fuzz around it but its small enough not to be anything more than a correction in a late decimal place. If we had the same problem with electrons we have with light quarks basic electromagnetism might have taken another 100 years to find! Not to mention anything based on charged particles (like the computers you and I are staring at) would be impossible.

16. BenTheManDr. of Physics, Prof. of LoveValued Senior Member

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Sure---I wasn't arguing this. You still have to specify a renormalization scheme (eg MSbar). You're completely right that there is not real meaning to the quantity of mass'', as there's no good way to define it in quantum field theory. In that sense ALL masses quoted are ambiguous.

Hmmm....

Suppose electromagnetism was strongly coupled.

Could life exist?

17. CptBorkRobbing the Shalebridge CradleValued Senior Member

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Depends on your definition of "life"

18. Fraggle RockerStaff Member

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Minimalist definition: a sustained, increasing, self-managing local reversal of entropy.

19. CptBorkRobbing the Shalebridge CradleValued Senior Member

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Such lifeforms have yet to be discovered even in our own universe

20. BenTheManDr. of Physics, Prof. of LoveValued Senior Member

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The normal one

My guess is no, probably, because you wouldn't be able to ionize hydrogen. There are anthropic arguments about changing $\alpha_{em}$, but I can't remember what they are.

Anyway, just an interesting question...

21. EnergySaverRegistered Member

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I have really enjoyed reading this information. The collaborative approach you all take is soooo refreshing. I'm working on vetting some very old asian theories on existence and energy and would like to find out about the normal energy discharge of these particles both common and rare. Also what is the general thinking around time, space and mass from both the linear and non-linear aspects?

22. eramSciengineerValued Senior Member

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Very old Asian theories? What?

23. ZMacZRegistered Senior Member

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Fyi..

Umm..because after all this it still might be unclear for you, the following:

Science is based on the principle that all information is infinite..which leads to conclude that all we actually KNOW of science (not speculation) is NOT what all there is out there..
Since we actually don't KNOW everything we can also conclude that we have yet to find more..

So..simply put...WE DON'T KNOW...but simply because we don't know, does not mean it does not exist..

And to other guys in this column that actually stated stuff going either one way or the other...get a life...don't practice science..you suck at it...
You don't know (and I KNOW that you don't), and no proof is given either way, therefore..speculation...and that falls in the same column as assumption..
(and as we all know, or most of us maybe, assumption is the mother of all (scientific) fuck-ups..)

If you disagree..get a life also..you seem to have skipped science 101...

To all who agree with my statement..thanx...at least you know what I'm talking about..

Last edited: Apr 16, 2014