Monday, April 18, 2016

Are elementary particles extended simples?

This argument is valid and every premise is plausible:

  1. An elementary particle is located at every point where its wavefunction is non-zero.
  2. An elementary particle is simple.
  3. A simple located at every point of a region with non-zero volume is an extended simple.
  4. Typical elementary particles have a wavefunction that is non-zero at every point of a region with non-zero volume.
  5. So, typical elementary particles are extended simples.


William said...

I think you reveal a bind for Aquinas' substance concept here, if that matters.

Because physics says that such particle waveforms can and generally do overlap, overlapping composition in space is then genuine. So one can use this to show that a given region contains more than one substance, so that there is no reason not to allow substances like a body to have composition and contain other substances.

Alternatively, the waveform and the extension are not genuine, and only the just-measured single point position of the particle is real.

Alexander R Pruss said...

I don't see the move from a region containing more than one substances to substances being composed of other substances. It doesn't seem at all problematic for Aquinas to suppose that there could be ghosts that could interpenetrate.

We never measure a single point position, though. Our particle detectors are not that precise. What we measure is whether the particle is within some region of non-zero volume. Perhaps, though, you were referring to something like Bohm's theory.

Alexander R Pruss said...

Another option is to say that elementary particles are vaguely located (basically, at every location at which the wavefunction is non-zero).