Big Stuff, Deep Stuff, Heavy Stuff
Jerome Shea November 25, 2011 Weekend Wonk
We live among immensities of time and space. Sometimes the question is not so much how we manage to grasp those immensities, but how we entertain that knowledge without just blanking out, clicking off, like a spaniel trying to understand quadratic equations (woof?).
What started me thinking about this was a couple of recent science articles guaranteed to titillate us laymen. In one, astronomers think they have discovered a galaxy—make that “evidence of a galaxy”—that is the earliest, which is to say oldest, that has been seen so far. This cluster of stars is estimated to date back to 13.1 billion years ago. Bear in mind that astronomers currently place the age of the universe, starting with the Big Bang, at about 13.6 billion years. I am reading a good book about Galileo right now (Galileo’s Daughter, by Dava Sobel) and I have to wonder what he would make of all this, and of the Hubble Telescope, were he to come back today. I can tell you that my inner spaniel is seriously flummoxed. And what moves me from flummoxed to discombobulated is that what astronomers are seeing is not what exists right now! That’s why I said “evidence of a galaxy,” and I hope that’s a fair way to put it. In other words, and this is Cosmology 101 stuff, what shows up in the Hubble photo is not the galaxy as it exists right now, but simply the light that has finally arrived after traveling unfathomable distances.
I can understand that, because I know that the sun that we see shining down on us right this second is really the sun that existed about eight minutes ago, which is how long it takes the sun’s light to reach us. And compared to that distant galaxy, the sun is practically invading our private space. To be more dramatic, were the sun to suddenly shut down—don’t worry; it’s supposed to last another billion years or so—we would have time to empty the dishwasher and maybe shine our shoes before the cold blackness extinguished us. So it is not just space but time that’s implicated. (Of course, Einstein made that connection more than a hundred years ago.) I have to wonder, though, just what it is that showed up on the photo plate. If it is not “really” that distant and unimaginably ancient star cluster (which may not even exist anymore) exactly what can we call it? A chimera, a cosmic will-o-the-wisp? A smudge of un-reality, obsolete reality?
We all knew that the universe is a big place and that it contains, in Carl Sagan’s unforgettable words, “billions and billions” of galaxies. He estimated—his PBS show, Cosmos, seems light years away from us now, and almost quaint—a hundred billion galaxies, each with a hundred billion stars. So multiply a hundred billion by a hundred billion and call it Sagan’s estimate. You have probably exhausted your allotment of zeros, eh? But a new study by a couple of Ivy League astronomers suggests that the universe may contain three times that many stars. That’s three hundred sextillion, or 300 followed by 21 zeros! And does that mean that the universe may be three times bigger than we had thought? But how do we define the universe, anyway? Is it characterized by the stars and other matter, which reach only so far? Why should this be the defining characteristic? I have heard it said that the universe has no center and no edge. Does that mean it’s infinite? Well, that’s a concept that scared the togas off the Greeks and scares the pants off me.
And if you’ve got a minute, can we talk about time? Someone said that time is eternity living dangerously. That someone was probably a poet, not a physicist or philosopher, but for that reason it has always stuck with me. Some physicists now tell us that there really is no such thing as past or future, just the present. But the present is not just fleeting but infinitesimally fleeting, so how can it exist in any meaningful way? Perhaps that’s why David Park, a retired physics professor, can say, “You get into an awful lot of trouble if you say that time exists.” Easy for him to say. I’ve been living with time, immersed in time, for almost seventy years. Haven’t I?
And we haven’t even begun to talk about eternity. Does eternity amount to just gobs and gobs and gobs of time? Is eternity just never-ending time, MacBeth’s “tomorrow and tomorrow and tomorrow”? Good God, I hope not! That would make any heaven a hell, and a much more hellish place than the traditional one. So eternity must be, uh, the absence of time?
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