Tuesday, November 13, 2012

Foreword by Dava Sobel

I want to tell you what happens to my mind when I try to imagine the depths of space. People think this is an easy thing for me to do, because I write about the planets and chase eclipses. But the solar system is a cozy nest compared to our galaxy at large, and even this galaxy is but a dot on the seemingly infinite continuum of space-time that constitutes the universe. When pushed to visualize those extremes, my brain just stalls. Silence clogs my ears,  as though my thoughts were starved for air in the vast emptiness they are struggling to encompass. At the same time I feel I am falling, as often happens while falling asleep, when the drift into unconsciousness is interrupted by an image - part dream, part memory - that pitches me off a swing or down a staircase, and my whole body lurches to save itself.

Although these internal experiences of silence and falling seem private, even lonely, I suspect I appropriated them from movie or television special effects. Think how many sci-fi films and NASA simulations signal the moment of leaving Earth's atmosphere by letting their sound tracks go quiet. That abrupt absence of noise after the roar of the launch pad, announces our arrival in the realm of the beyond. And as for falling, well, science documentaries provide the ultimate descent scenario in the bottomless entity of the black hole. Tumble over the event horizon into one of  those monsters, and you disappear not only from light and life, but from history - from the universe itself. Or so I've been told, and shown, but the truth is, I still have no mental apparatus for penetrating such phenomena. I can no more conjure a black hole in my imagination than an ant could crawl to one.

Perhaps if I had a stronger grounding in mathematics I could better commune with the interstellar medium. I am hardly innumerate. I can calculate in my head and got through algebra, geometry, trigonometry and calculus with no trouble at all. But none of that helps me make sense of astronomical quantities - of the 100-billion-star-census of the Milky Way, say, or the two-million-light-year distance to Andromeda (which is more than twelve million trillion miles, whatever that means). In the course of my work, I routinely meet astronomers who negotiate such superlative statistics with ease, leaping by powers of ten into the grandeur that surrounds us. I make no secret of how much I envy them.

On the other hand, I also  meet people who tell me privately they feel frightened when they think about space - so frightened that they would rather not think about it. The first time I heard such a confession, I wondered whether fear of space might be a new syndrome, spreading as a traumatic effect of science news. After all, the threat of an apocalyptic asteroid impact has become as real as a terrorist attack, and some people fret over the Sun's exhaustion of its nuclear fuel as though this eventuality were imminent. But I have since become convinced that fear of space, like fear of the dark, is a primal irrational terror. Even in ancient times, it could be provoked easily enough by standing outdoors at night, under the cope of heaven, and growing sensible of one's own smallness.

Over the past five hundred years, every major advance in astronomy has made the Earth seem smaller in the context of an ever-expanding universe. Each time the home planet shrinks, some sense of human self-regard diminishes accordingly. This long lesson in humility seems complete now, given astronomers' current assessment of the cosmos. They say the entire visible universe accounts for only a fraction of reality. In other words, everything we can see on our world and within our galaxy, as all the distant galaxies revealed by the farthest-seeing space telescopes - all of that floats as a froth within a matrix of mystery. The dominant cosmic components, dubbed 'dark matter' and 'dark energy', lurk everywhere around us, but remain unobserved and unknown.

Right here, along the fuzzy border between dark matter and dark energy, you might expect someone like me to break down completely, given the  limits to my imagination and the gaps in my intelligence. Instead I find myself utterly at home in the cosmos, as in a great pasture of unsullied beauty. Pulsars and magnetars, quasars and blazars and other exotica graze all around me, sharing the same extending environment, perhaps even the same common ancestor, because surely my origins trace back beyond my parents and grandparents  to previous life forms, through previous generations of stars, to the scattered seed of supernova explosions and the binding force of gravity. What I mean is, difficulty in comprehending the universe need not deny a person the joyful sense of belonging to it.

Even dark matter and dark energy, the ultimate bogeymen, have their bright, inviting side. Their simple names     seem to stand up and defy the enormity of doubt to which they apply. Like 'the evening and the morning' of the Bible's first days, like 'Big Bang' and 'Big Chill', which are the accepted technical terms for the way the universe began and how it is most likely to end, 'dark matter' and 'dark energy' whistle into space, name the unspeakable and stake a human claim on truly limitless possibilities.

No comments: