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Post by speakertoanimals on Mar 8, 2011 18:24:12 GMT 1
I've been trying to think of a simple, hand-waving explanation for beta decay rates, but can't come up with one -- things are just too complicated, that is the point! Nuclei are complicated interacting systems of MANY particles, why they hold together at all is complicated, so why one would rather be a different nucleus is even more complicated! And exactly how fast it does it, more complications again!
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Post by Progenitor A on Mar 8, 2011 18:29:09 GMT 1
I've been trying to think of a simple, hand-waving explanation for beta decay rates, but can't come up with one -- things are just too complicated, that is the point! Nuclei are complicated interacting systems of MANY particles, why they hold together at all is complicated, so why one would rather be a different nucleus is even more complicated! And exactly how fast it does it, more complications again! You just do not know, like everyone else you rambling buffoon! Just as you do not know whether f remains constant in the idiotic 'proof' you gave where c= Lambda x f .......... proves f remains constant Science POLYMATH!
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Post by Progenitor A on Mar 8, 2011 19:04:58 GMT 1
I doubt that Principled has 'got' any coherent information at all from STA's rambling gobbldegook 'explanation' In fact he should not have done so, because no-one actually knows why these materials decay with a half-life. Like gravity we must just accept that it happens withour understanding why it does so Only a neophyte buffoon would attempt an 'explanation'. Unfortunately we have one here Anyone that might be fooled by her rambling 'scientific' 'explanations' should read this thread that shows her for what she really is a scientific half-wit! ;D radio4scienceboards.proboards.com/index.cgi?board=gensci&action=display&thread=490
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Post by abacus9900 on Mar 8, 2011 19:40:15 GMT 1
You see, the trouble with STA is that she seems incapable of giving a short summary of something without providing too many details that are inevitably going to confuse someone who just wants a clear basic description. It's a question of not being able to see the wood for the trees, in other words, by not allowing a general overview of the subject (with gaps) to be gained, which can be filled in a bit later on, the information will just be confusing. The ability to provide summaries in many areas of professions is an important one and those people who cannot do it really should not try to teach non-experts. In many cases, STA uses terms that she hasn't really defined so that all you get is a very sketchy idea of what she is on about.
Of course, the information given should ideally be tailored to the approximate level of knowledge of the questioner and this has to be a judgement on the part of the instructor. I'm afraid with STA she treats everyone as if they were undergraduates which is ridiculous.
Can you imagine STA presenting a TV documentary about physics for the general viewer? They'd all turn of after five minutes!
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Post by abacus9900 on Mar 8, 2011 19:55:59 GMT 1
Principled was TRYING to have a discussion with me, so why don't you two idiots just fuck off and go play somewhere else....................... principled said: "Thanks STA, perhaps I should row back a bit and start at the beginning. What factors affect the half life? For example why is Beryllium 11 around 14 secs and Nitrogen 16 abour half that?" This seems to me that you did not answer principled's question because he had to re-phrase it! As I said, nobody has a friggin clue what you are on about!
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Post by speakertoanimals on Mar 8, 2011 20:23:18 GMT 1
Why don't you POLYMATHS just shut the[snip] up, and let Principles answer for him/her self.............
A little common courtesy to others, or does your seemingly inexhaustible urge to try and hassle me extend to just pissing on anybody that happens to wander past.
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Post by speakertoanimals on Mar 8, 2011 20:36:26 GMT 1
The point about Beryllium 11 and Nitrogen 16, as far as I can see, is that a difference of just a factor of 2 probably isn't going to be enough!
If you were asking about a factor of several orders of magnitude, and could pick two radioisotopes with some sort of similarity, then you might have a chance of picking ONE thing that accounted for the majority of the difference.
When you look at the whole range of half-lives, you find that as a general rule, the higher the maximum emitted energy of the beta particle, the shorter the half-life. Hence when people plotted log of the decay constant against log of the energy, then found two distinct groups, which were labelled as 'allowed transitions' versus 'forbidden transitions' for that group with the longer half-life.
The rough dependance on energy isn't exactly suprising, but unfortunately I can't find an online version of the Sargent diagram at the moment....................
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Post by abacus9900 on Mar 8, 2011 20:39:32 GMT 1
In nuclear physics, beta decay is a type of radioactive decay in which a beta particle (an electron or a positron) is emitted.
That would have been enough to begin with and after a bit of thinking and further questions you could have then elaborated.
You could then perhaps gone on to say:
In the case of electron emission, it is referred to as beta minus, while in the case of a positron emission as beta plus.
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Post by speakertoanimals on Mar 8, 2011 20:43:13 GMT 1
Because that wasn't the question asked. Principled knows what isotopes are, and didn't ask what is beta decay......................
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Post by Progenitor A on Mar 8, 2011 20:47:58 GMT 1
Why don't you POLYMATHS just shut the [snip] up, and let Principles answer for him/her self............. A little common courtesy to others, or does your seemingly inexhaustible urge to try and hassle me extend to just pissing on anybody that happens to wander past. Just listen to the POLYMATH! ;D
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Post by abacus9900 on Mar 8, 2011 20:55:50 GMT 1
Because that wasn't the question asked. Principled knows what isotopes are, and didn't ask what is beta decay...................... Well ok you could have said: Basically, you need initial state (wavefunction) and final state and the transition matrix element (The interaction wich takes you from inital to final state, i.e the abstract formulation of beta decay or alpha decay etc.)
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Post by speakertoanimals on Mar 8, 2011 21:00:20 GMT 1
Go [snip] yourself. With a stick...................
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Post by Progenitor A on Mar 8, 2011 21:17:47 GMT 1
Go [snip]yourself. With a stick................... Now you know what you are talking about! ;D
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Post by abacus9900 on Mar 8, 2011 21:32:25 GMT 1
Go [SNIP]yourself. With a stick................... Now you know what you are talking about! ;D HAHAHAHAHAHAHAHAHA ;D
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Post by speakertoanimals on Mar 9, 2011 4:22:56 GMT 1
Of course the really interesting thing about beta-decay is that it was the continuous spectrum of the energies of the emitted beta-particle, that led to the idea that either energy wasn't being conserved, OR there was another particle that we couldn't see taking away the 'missing' energy. It had to be light, and electrically neutral, hence neutrino.
But damn difficult to detect them which is why you need giant tanks of fluid deep underground.............
Which then led to the solar neutrino problem, the fact that neutrinos didn't have zero mass, neutrino oscillations etc.
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