Why is there a problem with wave particle duality. surely you can have a wave of particles?

Question

for example sound is a wave of air molecules. so why cant you have a wave of photons?

Answer 1

(1) there is no problem with the concept

(2) the concept refers not to "a wave of particle". But to the fact that the wave IS the particle, and the particle IS the wave. More precisely, the particle (in our everyday definition, i.e. a small bit of matter) does not really exist at a precise point in space, but it is to be found in a given region, and the probability of finding it there is proportional to the absolute value of its "wave function"

you seem to view this as little bits of matter / light undulating on top of a wave - that's wrong.


historically, what happened is that various experiments seemed to suggest that SOMETIMES it seemed that you had a wave, and other times, a particle.

The most famous one is the double slot experiment. Incoming light will go through the two slots, and lights re-emitted after having gone through each slot will interfere with each other, and on a screen you will observe an interference pattern, i.e. a series of bright and dark bands.

so then someone suggested to use light of such low intensity so that you'd literally emit one photon at a time. Hoping to not get any interference picture - since each photon could not interfere with anything.

but what happened was that the photons would arrive at various points on the screen, and little by little, their accumulation would reconstruct the interference picture

this is what caused people problems - until they invested quantum physics, which deals perfectly with this.

Answer 2

Yes waves can propogate through matter (particles). But electromagnetic waves propogate through space. Space is not made from particles. And the wave itself is not the emination of particles, travelling from point to point. It is instead, a vibration in space time itself. At least sometimes. Also, gravity travels as a wave, not particles. You should look at the light experiment involving slits on paper. It demonstrates more clearly the puzzle of wave vs. particle. To confuse you eaven more, the wave they are refering to is actually a "proboblity" wave. Look up the experiment and it's associated reading. It's really fascinating. If you take time to understand it's implications, you may look at reality in a whole new "light". Here is a link to get you started. http://www.upscale.utoronto.ca/GeneralInterest/Harrison/DoubleSlit/DoubleSlit.html

Answer 3

Yes, but how do you explain it when a single particle acts as a wave? This is what wave/particle duality means.

Answer 4

Of course you can have a wave of particles, but that is not the point in this case....here the debate is about the characteristics of light and whether it is one or the other as it shows characteristics of both whilst (don't ask me why) the physicists believe it to be one or the other!

Answer 5

This term is used to describe the characteristics of light and other electromagnetic radiation, not anything else. Some characteristics of light exhibit a wave nature and some characteristics exhibit a particle nature. That is all it means.

Answer 6

That's what they thought. However, the truth is much more complicated, and slightly disturbing. They discovered that a single photon with no others to interact with can still move like a wave.

Before you read further, go here:

http://quantumiscool1.ytmnd.com/

Others on this site already provided the hard science version, but this website is easy to understand.

Real scientists have done similar experiments to prove that the Schroedinger equations apply to objects as large as oil drops:

http://www.physorg.com/news78650511.html

Answer 7

I couldnt agree more

Answer 8

http://abyss.uoregon.edu/~js/ast123/lectures/lec06.html

Here is the answer!!