Hello, Internet! As I take my first steps into the wonderful biome of blogging, I am reminded of the opening lines of Carl Sagan’s 1992 book Shadows of Forgotten Ancestors.
Our story begins here in the dark, pullulating, dimly illuminated disk: the story as it actually turned out, and an enormous number of other stories that would have come to be had things gone just a little differently; the story of our world and our species, but also the story of many other worlds and lifeforms destined never to be. The disk is rippling with possible futures.
Just as Sagan’s imagination stood at the threshold of the beginning of the planet, watching our world form, so do I stand at the threshold of this blog. I do not plan to be nearly as profound as Sagan—only a few minds are, and I do not count myself among their number—but the possibilities spiraling forth from my computer as we speak are as immense as can the possibilities spewed forth from the young Earth.
According to the many-worlds interpretation of quantum mechanics, all possible past, present, and future histories are real. Not real in an abstract, philosophical sense, but REAL. Real like the Sun, real like the sandwich I had for lunch, real like my boxed set of Feynman’s lectures, real like you and like me. According to the many-worlds interpretation, these worlds exist and are infinite in number. Not only is there a whole lot of world out there, but outside there’s a whole lot of worlds!
These infinite worlds are just as lush, just as diverse, and just as rich as the world you and I are experiencing right now. They have planets, stars, black holes, comets, meteors, quasars, everything that makes our universe incredible. Some fraction of these worlds have a planet we would recognize as Earth. Some fraction of these alternate Earths are populated with life, some of it like the life we know, but some of it, perhaps most of it, completely and utterly different. Some fraction of these Earths have organisms we would recognize as humans. And somewhere—actually a lot of somewheres—there is someone who looks exactly like you. And in a way, he is you. But somewhere in his world, at least one thing is different.
That difference could be incredibly huge—perhaps the Earth has no moon, or maybe the sun is purple and gold— or incredibly small—perhaps the NBC sitcom The Office had eight seasons instead of nine. It could literally be as small as a cesium atom decomposing one Planck time—the smallest unit of time measurable ever no exceptions—later there than it does here. Every decision, every quantum wave function, instead of decaying or resolving, merely shunts us into a new reality. We are surrounded by boundless, infinite realities, rushing by us like a river. And with every decision we make, every choice we confront, every photon we observe, we create a new reality.
Next week, I’ll go more deeply into explaining these infinities and examining the strangeness of our existence. Until then, keep wondering infinitely about the infinite wonder that is life.