Proper Time & Proper Length in Physics Overview & Examples

Defining time dilation with Einstein's Special Relativity | Britannica

According to Einstein’s Special Relativity, light experiences zero proper time — T = 0. For a photon, its entire journey across the universe occurs instantly. Some physicists argue this implies reality may not flow through time at all. New ideas, sometimes called a quantum platform view, suggest the universe behaves less like a movie and more like a fully deployed program — with all moments existing simultaneously. Cinematic visuals and audio generated with AI. Source: Einstein’s Special Relativ