light wave/ particle duality thought

[jadibartolomeo]

so considering the wave/particle duality of light, which is just freakin' weird, it thought of this...<br /><br />let's say you took a nice, reliable source of photons and pointed it at a mirror (i'm guessing a perfect mirror) in such a way that no light was refracted in any direction except DIRECTLY back towards the source (a 180 degree turn from the mirror). if light were waves, there should be some sort of intereference pattern, right? but if light were particles, the reflected particles should collide with the particles beaming from the source and scatter all over the place, right?<br /><br />any thoughts?

 

[kyle_baron]

<font color="yellow"><br /> if light were particles, the reflected particles should collide with the particles beaming from the source and scatter all over the place, right?</font><br /><br />Nope. Photons are energy, not matter. For example, take two flashlights in a dark room and hold the beams perpendicular to each, other while each is on. I doubt you'll see any scatter at the point of intersection. <br /> <div class="Discussion_UserSignature"> <p><font size="4"><strong></strong></font></p> </div>

 

[gammarayburst]

Light acts like both particle and wave depending on if it is observed or not. See double slit experiment.

 

[venator_3000]

In many ways it’s a good thing that photons don’t collide and bounce the way you describe. If they did then using fiber optic cables might not be possible. I'm no expert but from what I've read photon-photon collisions could fall out through QED, but the probability of it happening is really, really small. And there are not too many ways to actually measure such interaction.<br /><br />Normally, photons just whiz right on past each other. According to QED photons can exchange virtual particles. These are theoretical particles that the photons can release or take in. This always seemed to me a bit like two people trying to pass a note while on 2 speeding bullet trains, but it can happen given the right conditions. Physics guys working at super-colliders have recorded the interactions of virtual photons that come about when charged particles in those colliders are smashed together. Still, no one has ever seen real photons from flash-lights simply bounce off other photons.<br /><br />v3k <div class="Discussion_UserSignature"> </div>

 

[unclefred]

You are correct. Put some type of screen in the beam and you will see the interference pattern. Put a piece of photographic film there and you will get fringes. If you do not put anything there, the light will just go past each other with no interaction. This is very similar to waves on a pond. Waves from all over can cross the pond and do not interact. Nothing unique here.<br /><br />