One of the problems with quantum physics is that we are at the edge of useful analogy.
Most of the concepts that we are familiar with break down, so trying to say "a photon is like a wave" (sometimes) is uncomfortable at best. Even ideas like time and mass start to fall to bits in terms that we find it comfortable to relate to.

Remember that evidence that the photon (as a wave) transited both slits is that the appropriate interference pattern shows. Think about how that works for a particle.

I have to admit it's been 20 years since I last took atomic and nuclear physics classes. Can't exactly remember where I picked it up.

This seems to explain it relatively simple but it also includes some links to more detailed descriptions.

http://www.newton.dep.anl.gov/askasc...5/phy05010.htm

This one's related to the single photon double slit experiment: Google cache

There is no way a high school science project using a child-safe laser, a piece of Kodak film and some glass filters is going to come anywhere close to a single-photon event. There will be stray photons bouncing around the room from some source or another.

I would also strongly doubt the accuracy of $erious $cience claiming a single-photon event. Prove that there were no other particles* involved. Explain your proof to Werner Heisenberg. If he agrees, I'm convinced.

* other photons, related bosons, quarks, leptons, hadrons, neutrinos (good luck with that one) or any other subatomic flotsam that could jigger the results.

He's been dead for almost 50 years.

I know.

OK, but the rest of the scientific community is satisifed by multiple, independently replicated peer reviewed studies, experiments, and research papers. Heisenberg himself could disagree with the result and it still be accepted as valid. Einstein, for example, didn't like the implications of Quantum Mechanics, but he still worked on research and experiments that would ultimately support it.


benwiggy's earlier comment is perfect here.

Photons / electrons / etc. at this level of observation exhibit particle and wave characteristics. This may lend itself to describing these wave characteristics as the particle being in multiple places at the same time, but that's at best a great simplification.

A quote attributed to Feynman sums this up pretty well, "If you think you understand quantum mechanics, you don't understand quantum mechanics." Or, "'It is safe to say that nobody understands quantum mechanics."

This is not uncommon in Physics. As a Mechanical Engineer, I studied Fluid Mechanics and Heat Transfer. One of the concepts there for explaining the growth of boundary layers on solid surfaces immersed in flowing fluids was Ludwig Prandl's boundary layer theory based on a concept called mixing length. Works beautifully as a predictive tool. Unfortunately, with the advent of modern computational fluid mechanics and much finer measurements than Prandl could make, it's been proven wrong. Still works, though.