The Old Magus Strikes Again

[sdi]

Fun fact: the first we know of to argue that light has a finite speed is our good old friend Empedocles:

Empedocles, for example, says that the Light from the Sun arrives first in the intervening space before it comes to the eye, or reaches the Earth. This might plausibly seem to be the case. For whatever is moved [in space], is moved from one place to another; hence there must be a corresponding interval of time also in which it is moved from the one place to the other. But any given time is divisible into parts; so that we should assume a time when the sun's ray was not as yet seen, but was still traveling in the middle space.

(Aristotle on Sense VI)

(Aristotle, by the way, disagreed, believing that light was a static phenomenon. Funny how much of modernity vindicates the mystics and mages and castigates the scientists.)