The Spacetime of Fine Art

This article is part of Nautilus’ month-long exploration of the science and art of time. Read the introduction here.

I recently came across this diagram of time and space:

It puts the observer at the intersection of two converging cones of light, one representing the past and the other the future. Physicists use the diagram to think about relativity and spacetime, and to decide whether two events or objects can ever have interacted (they can’t if they’re not in each other’s cone).