Everything You Know About Light is Wrong (Feynman's Path Integral)

Added: 2026-05-06

[00:00:00]Light does not travel the shortest path.

[00:00:03]It travels every path. You were taught this wrong your whole life. Every textbook, every diagram, every teacher showed you light moves in straight lines, bounces off mirrors at equal angles, picks the fastest route from A to B. That is not what happens. Richard Feynman worked this out in 1948.

[00:00:24]Every photon explores every single possible route between two points at exactly the same time. It bounces off every spot on the mirror. It detours behind your head. It loops three times around the lampshade, all at once.

[00:00:41]Nearly all those paths cancel each other out. The wave of light wiggles one way on one path, wiggles the opposite way on another, and they erase each other completely. Only one tiny cluster of paths lines up perfectly. Only those waves add up instead of destroying each other. That is the straight line you see. The light never chose that path.

[00:01:05]All the other ones just vanished.