What Mathematical Equation Is Hidden in Our Hands?
When you hold a sphere, your fingertips always end up in a single plane. Behind this everyday gesture lies a specific geometric figure: a family of spherical caps.
Do We Really Know Our Hands?
"I know it like the back of my hand" is a very common expression. We use it to say we know something perfectly. But it is worth asking whether we really know our hands.
There is a mathematical equation written in them. You do not need any instrument to discover it. All it takes is watching how your fingers position themselves when you grip an object.
The Experiment: Holding a Sphere
Pick up a sphere and look at your fingertips. They always end up in the same plane. This is the most stable way to hold an object.
With a small sphere, the little finger curls in on itself. This closes the hand and stops the sphere from slipping out. The same thing happens with a larger sphere: the fingertips form another plane and another circle. With an even bigger sphere, the result is the same.
The Hand Traces the Plane Even Without an Object
The test also works with an empty hand. Open it and close it slowly. Your fingers once again trace that same plane.
This shows that it is not just a matter of bones. Muscles and nerves work in coordination so that the hand takes the shape of a sphere.
What Mathematics Says: Spherical Caps
In mathematics, when a plane cuts through a sphere, it leaves a circle. It also separates a portion of the sphere called a spherical cap.
If the size of the sphere changes, the cap changes too. Together, all of these caps make up a family of spherical caps. That is the equation written in the hand.
A Hand Designed to Grip Spheres?
Óscar Melchor, who created the images in the video, proposes that the human hand is designed to grip spheres.
He also suggests that we are the only primate with this feature. According to his proposal, the way our fingers close would serve that purpose.
Frequently asked questions
What equation is hidden in the human hand?
That of a family of spherical caps. This is the figure the fingers form when gripping spheres of different sizes.
Why do the fingertips end up in the same plane?
Because it is the most stable way to hold an object. It happens with spheres of different sizes and even when opening and closing the hand with nothing in it.
What is a spherical cap?
It is the portion of a sphere separated off when a plane cuts through it. That cut also leaves a circle.
Who proposes that the hand is designed to grip spheres?
Óscar Melchor, who created the images in the video. He also proposes that we are the only primate with this feature.
Informative article written with the help of AI tools from the verified script of the video. The video is in Spanish.