The thrill of the scientific hunt is to have an idea whose truth is hitched to predictions that take us to… — Neil Shubin

For thousands of years, mankind considered itself the pinnacle of life’s creation on a planet sitting in the center of the universe. Science changed that perception. Leavitt, Hubble, and others helped us see that we live near the margin of a vast galaxy, in a universe of galaxies, with our planet one of many worlds. Darwin and the biologists had their say too. Our entire species is but one little twig on an enormous tree of life filled with all life on earth. But each discovery that moves us from the center of creation to some obscure corner brings an entirely new relation between us, other species, and the entire universe.

Humans are a timekeeping species, and much of our history can be traced to the ways we parse the moments of our lives.