« Geometry is not true, it is advantageous » (Henri Poincaré)
This quote is so true when you think about a drop of water. Why is it spherical? Because it is advantageous… My point is not to give you an explanation here, but to introduce the next pictures 🙂
I let you look at your old lessons of physics if you forgot the explanation (just a clue : the highest volume embedded in the smallest surface area…).