April 6, 2009

Dimensions, Time and Separate Universes

After his longtime confidante, Michele Besso, passed away, Albert Einstein sent a letter of condolence to his friend’s family, in which he wrote:

He (Besso) has departed from this strange world a little ahead of me. That means nothing. For us believing physicists, the distinction between past, present and future is only a stubborn illusion.
Einstein’s point was rooted in his own scientific theories, an implication of which is that time is a fa├žade disguising a deeper reality. He likened our understanding of that reality to the limitations a child experiences upon entering a library. The library is filled with books written in various languages, and though the volumes have their authors and appear to have been placed in some order, the nature of that arrangement is beyond the child’s grasp.

Our world, according to Einstein’s letter, is strange in that it hides the true nature of time as a physical property inextricably linked to space. If we could perceive the past, present and future as they truly are, we would see them as differing locations, rather than events that occurred or will occur. Time, in this way, is an illusion that humans comprehend imperfectly, because we’re three-dimensional beings who are incapable of perceiving that illusive fourth dimension of space time.

The idea of life in a world of limited dimension is not new with Einstein. In the book Flatland, which first appeared in 1884, Edwin A. Abbott tells a story set in a two-dimensional world without height. In this world any object—a circle on its side, for instance—is perceived by its inhabitants as a straight line across the horizon. The book is an interesting treatise on the conditions of such a universe and describes the difficulty one would have in perceiving other dimensions beyond it. After reading the book as a young man, I became fascinated with the idea of worlds with dimensional constraints and began to see physical corollaries all around me.

For example, let’s say you notice a wasp in your car as you travel 65 MPH down the freeway. Afraid of getting stung, you crack open your window and shoo the insect outside. That’s good for you, but think of what has happened to the wasp. Suddenly it has been whisked away from a world of limited space into one that seems upwardly and outwardly unbounded. The temperature, too, is probably different and because of the speed of the car, the wasp feels the effects of friction that quickly slows it down. The turbulence is so great, the poor insect offers up some wasp puke. For an instant, it must believe it has been sucked through a vortex into a very different universe.

I could go on and on with such examples, but here is my favorite. I took a bush flight into the Bristol Bay watershed one day, when we happened over a section of the Nushugak River. The Nushugak is known for many things, but it’s especially famous for large runs of king salmon and the bears that come to feed on them. As we flew over, the river didn’t disappoint. We spotted salmon—as numerous as maggots on a carcass—and a brown bear sow with two cubs.

What happened next, I will never forget. The sow leaped into the water in a manner that seemed without stealth or forethought and raised a commotion that scattered the salmon upstream toward an oxbow bend in the river. At first I thought the bear had clumsily missed her chance for a meal, but by her next actions it was apparent she’d been employing a stratagem, all along. The sow simply crossed to the opposite bank, ran up an incline through scrub willows, then back down to an upstream section of water, where she waited until the fish came to her. When they did—believe me—her reaction was swift and effective. She came out of the water with a salmon in her mouth and immediately fed it to her cubs.

The scene made me think about the separate worlds all around us. The fish—if they’re capable of such thoughts—may have believed due to the river’s undeviating flow that they were in a universe that stretched in a single unwavering direction. Moreover, unaware of the wormhole that crossed a fold in their universe, the fish may have assumed they’d encountered two different bears. The sow, on the other hand, had a different perspective of the salmons’ world and understood the twists and turns of it. That knowledge she used to great advantage.

This is my hope: If there’s really a future part of the universe and if a wiser and better me resides there, it would be nice if he could send a kind thought or two through the twists and turns of my universe in this direction. After all, there has to be a few wormholes he can use along life’s way.

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