Properties of Light

[rayray17]

Hi, there was a question regarding the properties of light. Where we have to list 2 properties based on whether they are explained by the wave, particle or both theories.

I have for wave: diffraction, refraction
I have for particle: photoelectric effect, dispersion
For both: reflection,

I'm don't know the last one for both theories, and also im not 100% confident about refraction or dispersion.
I'm hoping some of you guys have some more info on this.

Thanks

[Lasercookie]

For both:
Another one that both does is all that mirror/lenses stuff from Unit 2. You could also explain something like inverse square law for intensity with both models too. Or maybe something really obvious like light travels in straight lines in a uniform medium.

Another one for waves only:
- Light can cross paths without disturbing each other (shine two torches at each other)
If you were thinking of light as some kind of particle, you would assume that they would collide and go in some other direction.

For the wave explanation of refraction, I'll give you this link which has a fairly simple analogy which might get your head around the idea: http://www.physicsclassroom.com/class/refrn/u14l1c.cfm

You can also look at the particle explanation of refraction, and see that it gives incorrect predictions. It's fairly odd and has something to do with some other force in play. I think this link explains it quite well and I think it's worth giving the whole thing a read: http://galileo.phys.virginia.edu/classes/609.ral5q.fall04/LecturePDF/L20-LIGHTII.pdf

[rayray17]

Thanks for that really helpful, i didn't think about the straight line thing one bit.
Is the dispersion thing being particle theory correct? because thinking about it now, i refraction can only be fully explained by waves, isn't dispersion similar to refraction?

[Lasercookie]

Is the dispersion thing being particle theory correct? because thinking about it now, i refraction can only be fully explained by waves, isn't dispersion similar to refraction?

Yeah, dispersion is a wave property, due to the different refractive indices for each colour etc.