Hello, I am trying to understand how light would interact with a shockwave, but for that I need to make sure my understanding of the physics of light is correct. It is my understanding that light travels independent of a medium because of the electromagnetic waves it produces. A wave, such as a shockwave, requires a medium to travel through. Particles must bump into other particles to transmit the energy of the wave. If these two things travel in different medium how do they interact? They obviously must because we can see a shockwave when it forms. Does light simply slow down when it reaches the area of more dense particles that is the shockwave then speed back up, upon exit? Do they influence each other at all? Thanks for you input!