Author : Glenn Blakeslee
Stan and I sat by the campfire in the desert night. The fire was burning low, a bed of embers surrounded by fire-blackened stones. We sipped on our beers, and I waited for Stan to start talking.
He’s one of my oldest friends, a physicist and a brilliant guy. When we camp in the desert he always has a late-night campfire lecture for me. I could tell he was ready to start talking. “Go ahead, Stan,” I said.
He smiled self-consciously. “Well…” he began, “We’ve talked about the Heisenberg Principle, right?”
“That’s where you can’t know the state of a particle until you observe it,” I said.
“Right. And by observation you collapse the wave function. But we can’t always observe, don’t always collapse the wave. There’s a natural process called vacuum fluctuation that causes that to happen without our interference. Otherwise, a particle wouldn’t reveal itself and matter, the universe, wouldn’t exist.”
Stan scratched a square in the dirt with his shoe. “Imagine that’s a cubic foot. Information theory tells us that, when the wave collapses, there’s a finite amount of physical information encoded in that cubic foot. It’s a huge amount of information, but still finite.” With his foot, Stan pushed lines out from the sides of the square. “Let’s expand this foot to a square light year.” He looked up at me and smiled. “Still a finite amount of information, right?”
“Right,” I said. I’m never sure where his conversations are leading.
“Well, the universe is infinite,” he said, and he threw a small log on the fire. “The visible edge of the universe is estimated to be four hundred thousand light years away, but that’s only the distance light has traveled. It’s still infinite.”
“A cubic foot or a cubic light year has only a finite number of possible states. Since the universe is infinite, you can map out an infinite number of cubic light years, and information theory says a good number of those cubic light years would have the same finite set of wave functions as our own cubic light year.”
Stan threw another log on the fire. “And a duplicate set of wave functions means a duplicate set of the physical properties of our own cubic light year,” he said.
“You mean…” I started, and stared at him. “There’s like… an alternate universe? One just like our own?”
“Not an alternate universe,” Stan said, “Another part of this universe that’s exactly the same as our own.”
I stared at the fire. Embers glowed red and fire licked at the underside of logs. A piece of wood popped, and a single flame twisted, curled, spat its load of carbon into the night sky. The exact same flame, somewhere else, did the same.
I looked back at Stan. In the light of the fire I could see tears welling in his eyes. I put my hand on his shoulder and said, “It’s no good, Stan. Samantha is still dead. You have to give it up.”
Stan looked at me, and he smiled. “A small variation on our finite set could make a situation where I was able to save her.”
And there was nothing, nothing in our finite set, that I could say.