Light as a particle or wave?

thecatspjs

What can be explained assuming light is a wave and what can be explained assuming it's a particle (photon)?

My understanding is that diffraction, refraction and interference all exhibit a wave nature. Can these things be explained if light is a particle?

I haven't started studying duality in college yet so I'm not entirely clear on the issue.

FISMA

Reflection can be explained in terms of particles OR waves.

Refraction can be explained in terms of particles OR waves.

Interference, diffraction, and polarization can be explained in terms of waves. Some arguments could be made for particles, but it's a bit of a stretch.

The photoelectric effect cannot be explained by waves, only particles. That's why Einstein received the Nobel prize.

Give this link a read.
http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html

Morbert

I never liked the "wave-particle" duality picture, and it isn't really a paradox in the modern formalism of quantum mechanics.

FISMA

If light were considered to be little particles, then you could argue that when a stream of these particles go through a diffraction grating, then it could be possible for the particles to have a glancing or offset collisions with the grating that could cause an interference pattern

It's a weak argument, granted. That's why scientists used single electrons in the double slit experiment to ensure that a particle would not interfere with itself.

However, even with the single shot, an interference pattern is observed - welcome to Quantum world!

I do not see how you could make an analogy to a particle bending around something - diffraction. You can hear a noise on a city street around a building's corner because the wave can bend around the corner. How that's explained with a particle is beyond me.

With the polarization filter, you may again make, an albeit weak, argument as I did with the double slit experiment that there were glancing collisions that were responsible for the polarizing effect.

In both cases it's totally wrong. Kind of like - you can do it that way, but you'll be wrong!

thecatspjs

ok, that all makes sense.
Also, would light have mass if it is a particle? Or if it's a wave?

Professor_Fink

thecatspjs wrote: »

Also, would light have mass if it is a particle? Or if it's a wave?

No, photons have no mass.