# Spacetime versus Spacespace

Spacetime versus Spacespace

This Demonstration shows a spacetime and a spacespace configuration of light cones. Two space stations, at distance 10 from each other, begin emitting regular transmissions at . At , a meeting is arranged halfway between the two space stations, so that representatives from many inertial reference frames can watch the first signals arrive together. Such a momentous event leads to a decision to make this the origin of all their reference frames: .

t=-5

t=0

(t,x)=(0,0)