No I mean he has to receive photons to measure the speed with his radar gun, unless he has found something (tachyons) that is faster than light speed. ... Oh never mind. I never was much good at puns and jokes.
I was in a job interview and I opened a book and started reading. Then I said to the guy, "Let me ask you a question. If you are in a car that is traveling at the speed of light, and you turn on the headlights, would they do anything?" He said, "I don't know." I said, "Never mind, I don't want to work for you."
It's one of my favorite "Wrightisms", geek that I am!