In the Richard Feynman's Not-So-Easy Pieces, Feynman described the spacetime diagram is made up of three different regions: 1. Space-like 2. Affective Past 3. Affective Future Feynman rised this problem If we were suddenly to become able to know things in the space-like interavals wouldn't that cause breakdown the principle of relativity? And the absolute speed of light in vacuum?