Why light is faster and smarter than us
by Nibil Krishna, founder of Ovitalab Space Research and Development Corporation
Today I want to ask you all something that has always stuck in my head.
Imagine you are on a beach and suddenly someone is drowning in the sea. You are standing on sand and can run fast on sand but slow in water. So, the question is: which path would you choose to save the person — straight line into the water or run sideways and then enter the water? Obviously, the fastest path, right?
Now here comes the crazy part: light also behaves the same way when it goes from one medium to another, like air to water. But we are humans; we know where to go, whereas light does not have a brain. So, how does light always know the fastest path?
The Law of Least Time
This was explained by the scientist Fermat. He said light always chooses the path that takes the least time. This is called Fermat’s Principle of Least Time. From this rule, we can even derive Snell’s Law that we study in physics (n1sinθ1 = n2sinθ2).
It’s similar to the drowning person problem:
- Fast on sand = light fast in air
- Slow in water = light slow in water
Double Slit Experiment
Another experiment is the double slit experiment. When we shine light through two small slits, we see an interference pattern of bright and dark fringes. This shows light acts like a wave, and waves can interfere with each other.
In a way, light is not “choosing” a path. It is trying all possible paths as waves, and only the path that matches the least time and creates constructive interference survives. The others cancel out.
Feynman Path Idea
Later, Richard Feynman explained even more astonishingly. He said that in quantum mechanics, light and particles go through all possible paths at the same time. Most paths cancel each other out, and only the one that gives stationary time or least action becomes visible.
This is why it looks like light is always choosing the smartest way, but actually, it is just physics at work.
Experiments Proving This
- Newton’s prism experiment showed light bends when entering glass, but he didn’t know why.
- Young’s double slit experiment showed the wave nature of light.
- Michelson and Morley experiment showed light speed is constant.
- Quantum experiments show that all paths exist until interference cancels them.
My Conclusion
So, the final answer from my perspective: light is not thinking. The universe itself is built on rules like least time and least action. Light just follows that naturally, like water flows downhill.
To me, this is very inspiring because it feels like nature already knows mathematics before us humans. We are just discovering it slowly.
And maybe one day Ovitalab will use this idea in space research as well, because the fastest path is not only about light — it can be about rockets, spacecrafts, and even our own life.
