Question

If you use an Earth-based telescope to project a laser beam onto the Moon, you can move the spot across the Moon's surface at a velocity greater than the speed of light. Does this violate modern relativity? (Note that light is being sent from the Earth to the Moon, not across the surface of the Moon.)

Short answer

This completely violates Einstein's hypothesis about the universality of the speed of light.

Step-by-step solution

Define the speed of light

The speed of light in a vacuum, commonly abbreviated as $\mathrm{c}$, is a universal physical constant that is important in many fields of physics. Its precise value is $299792458$ metres per second.

Explanation for the problem

This completely violates Einstein's assumption of universality of the speed of light, emphasizing the idea that the speed of light is constant and does not depend on the relative motion of the light source.