So, you’re driving a car at half the speed of light. (Both hands on the wheel, please.) You turn on the headlights. How fast would you see this light traveling? What about a person standing by the road? Would they see the light beam moving at 1.5 times the speed of light? But that’s impossible, right? Nothing is faster than light.
Yes, it seems tricky. The problem is, our ideas about the world are based on our experiences, and we don’t have much experience going that fast. I mean, the speed of light is 3 x 108 meters per second, a number we represent with the letter c. That’s 670