Often Maxwellâ€™s equations are described as linear except in some materials. To me that is not fundamental enough. I suggest that ultimately the wave equation of the Universe (if there are such things) absolutely must be nonlinear. If light was linear then it could never be observed. Nonlinearity and interaction are the same thing. Linear equations have zero interaction. We can see light and therefore its behaviour is nonlinear. All of our senses depend on nonlinearities for detection. Only with nonlinearity does the Universe become interesting.
Of course in most cases that we observe light it is at far below the intensity at which nonlinearities begin to manifest. But intense lasers can achieve interactions.
There are a number of people who, like me, think that matter is just a special case of electromagnetic waves. Particles are spherical standing waves of e/m which means that as the centre is approached the intensity of waves gets very high and so therefore do the nonlinear effects. And as a result there are no infinities.
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doliii

This topic was modified 2 years, 8 months ago by dolii45.