Circumambulation ---> 1+(-)1=North

[Michael Joseph]

I have always been of the conviction that light does not travel at all.

If F=mA and light "slows down" as it goes thru a medium, then what is the Force which accelerates said light? Does not that light require a mass?

If light "slows down" then what is the nature of the drag [friction] which decelerates said light? That would require light to have mass. And if light has mass, then there must be a force to decelerate and accelerate light. That is if you accept that light has mass.