Which of the following is true about light waves?
1. They travel at the same speed through matter and empty space.
2. They cannot travel through matter.
3. They slow down when traveling through matter.
4. They are a type of compressional wave.
According to enstiens theory of relativity, c is constant in E=mc^2 c is the speed of light. and many other physicsts all calculate it to be the same amount, 299,792, 458 meters per second.
