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Old 24-06-2011, 03:12 PM
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CraigS
Unpredictable

CraigS is offline
 
Join Date: Jul 2010
Location: Australia
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Quote:
Originally Posted by sjastro View Post
The reference to real and imaginary components in this context is mathematical.

A wavefunction is complex valued.
A complex number is in the form a+bi. "a" is the real part of the complex number, "b" is the imaginary part of the complex number. i=sqrt(-1)
Similarly a wavefunction is composed of real and imaginary components.

Mathematically the complex number is the measurement.

Regards

Steven
Thanks Steven (& Carl) ..

Steven ..
They say the real part is provided by the shift in the 'pointer' related to the position of the photon, and the imaginary part is the shift in the pointer related to the momentum of the photon.

But somehow, they then jump to making the statement that the position is weakly measured but the momentum is strongly measured (implying that there is no overlap in the initial and final values in the momentum part, but there must be some overlap in the same for the position part).

Presumably, (recollecting from my days gone by), all sorts of things can be derived if the real and imaginary parts of the complex number are known. Why the real and imaginary parts are associated with position and momentum in the first place … I'll have a guess and say its something to do with the complex function describing the generalised wavefunction ? (Its a wild guess, though .. probably wrong ..)

Cheers
PS: I notice the square of of a wave function's absolute value is interpreted as a three dimensional probability density function. The wave function itself, returns the probability amplitude of a position or momentum for a particle. All possible states of a systems are considered to be the whole number set, (hence the inclusion of the imaginary component). I think that answers my own question. Cool. Cheers.

Last edited by CraigS; 24-06-2011 at 03:47 PM. Reason: Added the 'PS'
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