Dark Matter

I thought that dark matter was matter not illuminated by light, but I was wrong. Dark matter is not visible to us, but for other reasons besides a paucity of photons. Dark matter remains, therefore, like every other part of nature, a mystery. We think it exists because nature acts strangely. A vortex at the center spins faster than its outer parts. As a skater pulls in her arms, her rotation quickens. In some spiraling galaxies, we have not observed this same expected phenomenon. Instead, the speed of the outside of the galaxy is the same as the speed at the center. To our minds, it seems that only additional unobserved mass could account for this strange behavior; hence scientists have hypothesized dark matter - strange unobservable mass. 

So then, why not believe that some essence that animates us exists in these ideas of the mind. Plato's rings or lapis philosophorum may indeed house the weight that, en fin, produces the music of the spheres.