Is 299792.458 the speed of light?

Answer 1

Darkness is not an entity, so it does not travel and has no speed. In principle, a shadow or nonentity could "travel" faster than the speed of light. For example, if you pivoted a powerful laser a few degrees the point of light would travel across a screen very far away at a "speed" greater than light. Note that this is not at all faster than light motion. You could achieve a similar effect by casting shadows on things very far away. But none of this is actually a "speed."

Answer 2

299792.458 is a number. You cannot use merely a number to talk about speed, it is utterly meaningless. Speed is distance per time. This could be metres/second or kilometres/hour or miles/hour or feet/minute. You may think this is silly. But your answer might be right in some unit (maybe kilometres/second). The speed of light is about 2.997x10^8 metres/second or 671 million miles/hour. Note how the different numerical values depend on the units.

Answer 3

Actually, the speed of light in a vacuum is defined as exactly 299,792,458 meters per second. This constant value is widely recognized and used in many scientific calculations and theories.