Hmm, I know it’s a joke, but it must be the same as the speed of light... Let’s say you switch off A laser beam. The tail end of the beam continues to travel outward at the speed of light, followed by dark, which cannot overtake it. Therefore, it’s traveling at the same speed. Doncha just LOVE physics?!!
In the old days I would turn off the tube tv and watch the light shrink to a dot then disappear slowly.
I am also baffled by the new laws of physics. Such as - If Joe Biden, a communist, a pedophile, and a pervert enter a bar for the duration and only one comes out at closing time - How can this be?
We don’t really exist-We are only perturbations in the higgs field.