Speed of Light

From Slackerpedia Galactica

The speed limit of the Universe. Do not attempt to go faster.

As things accelerate to near the Speed of Light, they get heavier, due to the Theory of Relativity. If something manages to accelerate to the Speed of Light, it becomes infinitely heavier. Since this is a silly thing for light to be, light starts out with zero mass. Light can only travel at the Speed of Light. So, it is zero times some infinite number, which turns out to be most anything it needs to be.

It's pretty fast. The Speed of Light is exactly 299,792,458 meters per second (1,079,252,848.8 km/h). That's because the meter is now defined in terms of the Speed of Light. Those of you who need English units, or furlongs per fortnight, will need to perform a conversion.

Since light moves at a finite speed, it allows Seeing The Past.