In article <7Fkdu*...@alturia.abq.nm.us> anew...@alturia.abq.nm.us writes:This is certainly understood in principle. For the case of alpha
><Stephen F. Schaffner (ssch...@roc.SLAC.Stanford.EDU)> wrote:
>> [...] could you explain just what is unknown about such
>> decays that casts doubt about their reliability for dating purposes?
>The cause of the randomness of the event, for one thing. That is, what
>determines the magnitude of a given element's half-life
decay, as a number of others have noted in previous postings,
the simple underlying mechanism is quantum mechanical tunneling
through a potential barrier. You will find a simple explanation in
any elementary quantum mechanics textbook; for example, Ohanion's
_Principles of Quantum Mechanics_ has a nice example of alpha decay
on page 89. The fact that the process is probabilistic, and the
exponential dependence on time, are straightforward consequences of
quantum mechanics. (The time dependence is a case of "Fermi's
golden rule" --- see, for example, page 292 of Ohanion.)
An exact computation of decay rates is, of course, much more
For beta decay, the underlying fundamental theory is different; one
>and what determinesWhy? Your intuition about cause and effect is based on experience
>that a given atom will undergo that decay at a certain point in time?
>Although the process is "truly random", as I've heard posited, SOMEthing's
>gotta cause it!
at certain physical scales, much larger than atomic scales. What
makes you so sure that individual events at the subatomic level must
have individual "causes"? It's certainly *possible* that we will find
some kind of underlying causal theory that "explains" quantum mechanics,
but I don't see any reason to believe that such a theory *must* exist.
Are you really ready to throw out modern physics on the basis of a
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