Do photons collide with each other?

[scotth]

*Originally posted by Whack-a-Mole *
**

Assume I manage this experiment with a single laser beam split (as both you and Cal mention it would be far easier this way) and manage to get them to destructively interfere at a given focal point. If I place a piece of paper at that focal point will the laser still burn through it (assume the lasers have more than sufficient power to put a hole in paper or whatever material we place there and assume you are capable of the precision necessary to perform this experiment)?

What I am getting at here with the energy ‘hiding’ is how much energy is actually present where the two waves cancel each other. Is it all still really there such that I still zap whatever is there or do they really zero out?

Sorry for the hijack but I’m curious. **

There is zero energy where the waves are cancelling. Putting a target up where the beams are perfectly destructively cancelling would show nothing. There would be no illumination, and certainly no damage.

BTW, getting a laser that will punch a hole in something even as slight as a piece of paper isn’t cheap.

[Ring]

*Originally posted by Whack-a-Mole *
**

What I am getting at here with the energy ‘hiding’ is how much energy is actually present where the two waves cancel each other. Is it all still really there such that I still zap whatever is there or do they really zero out?
**

It’s all still really there. For any conceivable laser and lens combination you are unable to get destructive interference without an equal amount of constructive interference.

[Ring]

Originally posted by Whack-a-Mole *
**
Is it all still really there such that I still zap whatever is there or do they really zero out?*

I missed this part. You won’t necessarily zap what’s there, because the constructive interference will probably occur away from the target.