Re: gEDA-user: smd challenge board status

[Steve Meier <smeier@xxxxxxxxxxxxxxxxxxx>]

John has it correct.

It is facinating reading this text. A modern quantum physics book
presents the theory as cold hard fact... but back in 1930 when it was
brand new Heisenberg was presenting it in an almost appoligetic and not
quite sure manner.

Steve M.


John Doty wrote:
>
> On Oct 31, 2006, at 9:25 PM, Steve Meier wrote:
>
>> I think I will drop into this group a brief passage fom Heisenberg's
>> "Quantum Theory" translated into English in 1930.
>>
>> "Dirac has set up a wave equation which is valid for one electron 
>> and is
>> invarient under the Lorentian transformation. It fulfills all
>> requirements of the quantum theory, and is able to give a good account
>> of the phenomena of the "spinning" electron, which could previously 
>> only
>> be treated by, ad hoc assumptions. The essential difficulty which 
>> arises
>> with all relativistic quantum theories is not eliminated however. This
>> arises from the relation
>>
>> 1/c^2 = u^2C^2  + p^2 in x + p^2 in y + p^2 in z
>>
>> between the energy and the momentum of a free electron. According to
>> this equation there are two values of E which differ in sign  associated
>> with each set of P in z, P in  y and P in Z. The classical theory  could
>> eliminate this by arbitrarily excluding the one sign, but this is not
>> possible according to the  principles og quantum theory. Here
>> spontaneuos transitions may occure to the states of negative  energy; as
>> these have never been observed, the theory is certainly wrong. Under
>> these conditions it is very remarkable that the positive energy-levels
>> (at least in the case of one electron) coincide with those actually
>> observed."
>>
>> So what was wrong? What occured that proved both theories were  correct?
>>
>> Steve M.
>
> A negative energy particle with a negative charge has exactly the 
> same dynamics as a positive energy particle with positive charge. 
> Positrons were first observed in a cosmic ray experiment in 1933. The 
> "spontaneous transitions to states of negative energy" in the 
> mathematics corresponds to electron-positron annihilation in the 
> physical world. So Dirac had it right, but physicists didn't quite 
> grasp what the math *meant* in 1930.
>
> John Doty              Noqsi Aerospace, Ltd.
> jpd@xxxxxxxxx
>
>
>



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