I’m joining in on the Carl Sagan Memorial blog-a-thon, but I can’t offer unstinting praise. Sagan wrote about biology now and then, and every time he irritated me; I always felt like arguing with him about some detail that bugged me, and I think that was actually among his virtues—he was a scientist you cared enough about to want to criticize, and he also addressed questions wide and deep enough that we all felt like this curious astronomer was touching on our part of the universe.
The blueprints, detailed instructions, and job orders for building you from scratch would fill about 1,000 encyclopedia volumes if written out in English. Yet every cell in your body has a set of these encyclopedias. A quasar is so far away that the light we see from it began its intergalactic voyage before the Earth was formed. Every person on Earth is descended from the same not-quite-human ancestors in East Africa a few million years ago, making us all cousins.
Whenever I think about any of these discoveries, I feel a tingle of exhilaration. My heart races. I can’t help it. Science is an astonishment and a delight. Every time a spacecraft flies by a new world, I find myself amazed. Planetary scientists ask themselves: “Oh, is that the way it is? Why didn’t we think of that?” But nature is always more subtle, more intricate, more elegant than what we are able to imagine. Given our manifest limitations, what is surprising is that we have been able to penetrate so far into the secrets of Nature.
At the same time that I want to tear apart his annoying analogy of the genome to a set of encyclopedias, while I deplore the incessant focus on human evolution rather than, say, the beauty of a sponge or a beetle, there’s one thing he did well: he represented the joy we can find in the natural world. That’s something we don’t communicate enough, I think, that science is this wonderful, powerful, far-reaching enterprise that reaches farther into the glories of the universe than any other idea that has ever occurred to humanity. That’s something he made explicit in the title of his book, too — the way we will beat back the darkness is to illuminate it with science.