Monday, February 17, 2014

Alan Lightman on seeking permanence in our universe (or in other universes)

by Salman Hameed

Alan Lightman is one of my favorite writers. He used to be an accomplished astrophysicist and now he is an outstanding writer. His new book is titled The Accidental Universe: The World You Thought You Knew. It is a collection of his essays and I haven't had a chance to read it yet. But he is a thoughtful writer and it is always a pleasure to read him. Here is a taste of it in the Wall Street Journal where Lightman ponders the search for meaning in an ephemeral universe:
I don’t know why we long so for permanence, why the fleeting nature of things so disturbs. With futility, we cling to the old wallet long after it has fallen apart. We visit and
revisit the old neighborhood where we grew up, searching for the remembered grove of trees and the little fence. We clutch our old photographs. In our churches and synagogues and mosques, we pray to the everlasting and eternal. Yet, in every nook and cranny, nature screams at the top of her lungs that nothing lasts, that it is all passing away. All that we see around us, including our own bodies, is shifting and evaporating and one day will be gone. Where are the one billion people who lived and breathed in the year 1800, only two short centuries ago? 
The evidence seems overly clear. In the summer months, mayflies drop by the billions within 24 hours of birth. Drone ants perish in two weeks. Daylilies bloom and then wilt, leaving dead, papery stalks. Forests burn down, replenish themselves, then disappear again. Ancient stone temples and spires flake in the salty air, fracture and fragment, dwindle to spindly nubs, and eventually dissolve into nothing. Coastlines erode and crumble. Glaciers slowly but surely grind down the land. 
What about our sun and other stars? Shakespeare’s Caesar says to Cassius: “But I am constant as the northern star, of whose true-fix’d and resting quality there is no fellow in the firmament.” But Caesar was not up on modern astrophysics. The North Star and all stars, including our sun, are consuming their nuclear fuel. After which they will fade into cold embers floating in space or, if massive enough, bow out in a final explosion. Our sun, for example, will last another five billion years before spending its fuel. Then it will expand enormously into a red gaseous sphere, enveloping the earth, go through a serious of convulsions, and finally settle down to a cold lifeless ball. One by one, the stars in the sky will wink out. In the distant future, space will be black.
Ultimately, he finds permanence in the idea of multiverses:
For the religious, there is God and the immortal soul. But for those of us who, like me, do not believe in any divine substance lying outside the material universe, there is one last possibility for something eternal. Recent ideas in physics suggest that our universe may be only one of a staggering number of universes, constantly emerging out of the hazy probabilities of quantum mechanics, existing for a limited period of time like our universe and then passing away. After which new universes would be born, in an endless cycle of birth and demise. Most of these other universes would be very different from ours. Some would have 17 dimensions of space. Some would have planets and stars, like our universe, while some might contain only a diffuse cloud of energy. Some few might harbor life, while most would not be endowed with the special conditions needed for life. Even though we in our universe could have no contact with these other universes, we might consider ourselves part of a super family of universes, a vast cosmic chain of being stretching back into the infinite past and forward to the infinite future. In this way, the tiny flash of our individual lives, the passing of the human generations and the millennia, the fading of our sun, and finally the demise of our entire universe could be given a much larger meaning, a place in an infinite and eternal tapestry of unfolding worlds.
I'm a bit surprised that he so quickly excluded our own universe from permanence. All evidence so far suggests that our universe will expand forever, and even if all the stars turn into white dwarfs, neutron stars or black holes - well - you will still have all these stellar remnants part of the universe - forever! Not to mention that even after all the stars are dead in the universe and there are no new stars forming (don't worry, that will not happen for a very very very long time), there will still be unused low density gas clouds, orphaned planets and moons, and comets and astroids, floating in such an inert universe. I think it is quite permanent.

This is just fun nit-picking. The essay is wonderful and you can read the full article here


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