Imagine you're at the beach and see your friend struggling in the water. You want to go help him as quickly as possible. The shortest path to your friend would be a straight line, but you can run faster than you can swim. This means that running down the beach to minimize the distance through the water would be a better option. However, this path is longer than it needs to be. The optimal path is somewhere in between, depending on your running and swimming speeds.
This concept is also applicable to light as it passes from one medium to another. Light takes the fastest path from point A to point B, but how does it know which path to take? You might think that light just sets out in some direction and changes direction when it hits an interface. However, this is not the case. Light actually explores all possible paths at the same time. This is a fundamental concept in physics and optics.
The idea that light takes the fastest path is an illusion. It's not the actual path that light takes, but rather the path that we see as the final result. This is a mind-bending concept that challenges our understanding of the natural world.
