# What is Cancelled out When EM Waves Interfere

Through this site and others, I have learned that light waves do not have a charge, and that a light wave is a field with probabilities of where photons, are likely to be. My question is: When two coherent waves (fields) become "out of phase" what cancels to produce the dark fringes in interference patterns. There no charge to cancel. There's no physical wave to cancel. What is there to cancel? Do probabilities cancel? In my old classical view, interference made sense, but not in this new view of light. There must be some explanation as to how interference works in the quantum world.

• the probability cancels out? Is this a helpful way of thinking about it... – tom Feb 11 '17 at 1:06
• Thanks for you quick response. I guess I could just accept it, but how would that work a p=.99 next to a p=0. The average would be about p=.5 – Lambda Feb 11 '17 at 1:14
• I dont' know if it's useful to think of light waves as "where photons are likely to be". For one thing, the thing that is quantized is the vector potential, not the $E$ and $B$ fields, and for another thing, mapping quantum fields onto wavefunctions is problematic in and of itself. – Jerry Schirmer Feb 11 '17 at 1:28
• Thinking in terms of where a photon is likely to be is sketchy, IMHO. – DanielSank Feb 11 '17 at 1:56