Parity

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by EBTX</i>
<br />How could MM handle parity non-conservation in the weak interaction? ... It would seem that the only way out would be to posit a chance left-right asymmetry in this volume of the universe.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">Perhaps I'm missing something in your question, but I'm not aware of any such problem. Earth's biosphere has a chirality preference, probably a product of local biology. But insofar as we can now tell, it extends no further than that. Specifically, organic molecules in meteorites show up as left-handed or right-handed in equal numbers. What observation (as contrasted with theory) leads you to suggest that "this volume of the universe" has any preference? -|Tom|-

I'm refering to the particle physics experiments with the weak interaction showing a handed preference (starting with the well known Wu cobalt experiment in '56 for which Lee & Yang received the Nobel prize).

This would be impossible to explain by any mechanical reasoning as it clearly shows that nature can distinguish between left and right and demonstrate a preference for one over the other ... balanced out only by the opposite preference in anti-matter which is nowhere to be found in any large quantities in the observable universe. Hence, parity non-conservation is regarded as one of the biggest discoveries in physics in the 20th century. If MM accepts these experiments, it is in a theoretical bind for which the only way out is an unreasonable "patch".

For instance:
MM could postulate another section of the universe with the opposite handedness which was at one time in contact with our section and which somehow "twisted off" of our section resulting in an overall handed preference.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by EBTX</i>
<br />I'm refering to the particle physics experiments with the weak interaction showing a handed preference (starting with the well known Wu cobalt experiment in '56 for which Lee & Yang received the Nobel prize). ... If MM accepts these experiments, it is in a theoretical bind for which the only way out is an unreasonable "patch".<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">I have no idea why you say this. MM has not yet been extended significantly into the quantum domain. The new article just appearing in the December MRB (to be mailed tomorrow) makes a start by suggesting a physical model for protons and electrons. That is a long way from pi mesons and parity violations.

Moreover, it is obvious from the crude model for protons that potential reasons exist for spin and decay asymmetries. So I'm sure that, if the model is any good, it will have a ready, <i>a priori</i> explanation for all natural phenomena when it gets there. But I'm not a quantum physicist, and don't know the experiments well enough to carry it there on my own. The trick is to know what the experiments really mean, as opposed to the standard-model-dependent interpretations normally placed on them.

BTW, parity violation was obviously not predicted or expected by the standard model. What is its explanation therein, and why doesn't that need for a "patch" disqualify the standard model? -|Tom|-

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">What is its explanation therein, and why doesn't that need for a "patch" disqualify the standard model?<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
SM has no explanation. The theoretical response is "duh, hmmmm ... OK ...spontaneous symmetry breaking" which is just naming the thing.

Standard modelers may potentially give some kind of an explanation because they are not bound by a mechanistic model, i.e. they may give an explanation founded purely in logic (as I have). It is not possible to deal with this issue from a purely mechanistic point of view. You will most definitely have to expand your model to accomodate this at some point. What I mean is that you will be forced to return to fundamentals and ask "What am I missing here?". When this occurs, I offer my condolences. It is a tough nut to crack.

Basically the problem is to show two views of the same picture (one left handed and the other right handed) ... and ... reveal some difference which is not left-right related so that you could logically show a "preference" for one picture over the other. For instance, if you could show that the left hand picture of a man had a beard while the right hand one didn't ... that would qualify as a solution ;o)

I don't agree that one or two patches disqualifies any wide ranging theory (including yours). However, the more patches there are, the more suspicious one should be that there is something fundamentally wrong with the model. We are in agreement here.