Quote Originally Posted by smoknjoe
Light waves that combine can double their amplitude or cancel it out, or anywhere in between. All electromagnetic waves are subject to interference.
I'm not sure, but I think you're wrong.

I think you're refering to the "double slit experiment".

Two EM waves (electromagnetic) can't be added together to create a greater amplitude.

By the same token, they don't "interfere" with each other, and create "interference patterns".