Gravata General Relativistic Universe (with curved grid)

Several Concepts of general relativity are illustrated in the tie. Red and green apples represents the concept of local flatness in general relativity. The design of Buckets means the famous thought experiment by Newton, and reconsidered by Mach several hundred years later, arguing whether rotational motions are absolute or not. The design of light cones means that the speed of matters never exceeds that of light. The curved grid represents the curvature of the space-time. The geodesic equations are illustrated on the back of the tie.