My son Darren learned about it at Montana State from a business professor. Three is kind of magic number, and always has been, at least since the Holy Trinity was embraced by the first Christians. For some reason, people like things in threes.
So what’s wrong with four? Studies have shown that animals, such as crows, can count to four. And a lot of research has shown that the innate human capacity to count is also four. Why do we like three so much better than four?
Triangles are inherently stronger than squares. I’m sure there’s a mathematical equation that demonstrates that. And four is basically our limit. Handling four things at once is a strain, and some people can’t manage it. And you want everybody. So you stick with three.
Then there’s the problem of three bodies. Von Braun and the Germans solved one problem in getting to the moon. Their rocket would provide the thrust. But in some ways the navigation was lot trickier than the propulsion. The mathematics involved in getting a spacecraft from the earth to the moon had been considered unsolvable. So declared the Encyclopedia Brittanica. “It would be like planning ahead of time that a tennis ball could be tossed into a coffee can from a distance of three hundred miles while the thrower, the ball and the can were all moving.” (This New Ocean).
800 mathematicians, over the course of two hundred years, had failed in attempts at it. In 1961 it was finally solved by a doctoral student at UCLA, under Doctoral adviser Shoshichi Kobayashi, named Michael Minovitch. He did it for fun on the computers at the Jet Propulsion Lab.
Somehow, with the solution of the problem of three bodies, the rule of three seems even stronger.