I’d scrounged an old printer somewhere on the MIT campus and I was carrying it back to my dorm when it exploded.  It still packed a few hundred sheets of Xerox inside, and as I carried it, my hand slipped off the paper tray, and the tray fell out, and all the hundreds of sheets of shiny white printer paper fell onto the sidewalk.
            It’s windy here in Cambridge, and in the spring Vassar Street can act as a giant stream tube, a wind tunnel in two dimensions, as the gusts are forced and channeled between the rows of tall buildings.  It was this wind that seized these pages, hundreds of them, and flung them into the air, spinning and turning, dancing with each other, whirling and scattering across Vassar and up and down its sidewalks.  Pedestrians stopped, ducked, buried faces in elbows for protection.  Vehicles stopped, blinded by the eight-and-a-half-by-eleven inch snowflakes.  The world of Vassar Street was frozen in time by a blizzard of flying paper, and for a few seconds, my stupid mistake and the wind stopped traffic and life and time.
            What is time?  In physics and engineering, it’s just another variable, just another dimension.  I never saw the world as four-dimensional until I took a class on special relativity last winter; in it, the professor explained that, although his street address and office room number were effective specifications of a location in a 3-D world, if we were to come by for help at four in the morning, he would not be there.  A fourth variable is necessary, he explained, to describe most accurately an object’s location.
            But that being said, time isn’t like every other dimension.  We are free, for the most part, to travel about in any direction, at any rate of speed, in the three physical dimensions.  In time, we may only move forwards, and we may never move faster or more slowly than anyone else.  The idea of “rate of speed” is really just a ratio of change in a physical direction to change in time.  By the convention of the human mind, the change-in-time part of this is always the same.  But is it?          
            I first noticed, as a little kid, that time spent in school felt a lot longer than time spent watching Star Trek.  In fact, an hour-long class period on the proper ways to spell was a whole lot longer than an hour-long episode of Star Trek.  This was very puzzling.  I would sometimes stare at the clocks on the classroom walls, wondering why they moved so slowly.  Now and then, one would be broken, and its perpetually being held hostage to one particular place in time would infuriate me.
            I also noticed that time had a peculiar way of moving in circles.  If I were to walk in a large circle, I thought, it was pretty obvious that I would come back to where I started.  But I didn’t have to walk in a large circle.  I could walk, if I wanted, in a straight line for a mile, and never come back to where I started.  Not so with time.  Most days of the week, I was in the same place at the same time.  The mind-killing routine of elementary and middle school ensured this.  I had to travel the circle.  I had no choice.
            At the same time, I had to walk forwards as well.  When I finished the fourth grade, it was summer, and then I would be in the fifth grade, never to return to the fourth grade.  I could always go back to a physical place if I wanted to.  I could never go back in time.  At times, I wished acutely that I could.  This is still true.
            I came to realize that time is like a spiral.  I moved perpetually in circles, but I moved forwards as well.  As a middle-schooler, I learned of the double-helical structure of DNA.  I had a thought—I remember it well—of wonder at the grand symmetry of everything.  Time, a spiral.  The molecule of life, a spiral.  When I was in high school, Godsmack, a rock band I was quite fond of, had a song out called “The Spiral”, about life and death and reincarnation.  Another band, Tool, sang about “the spiral” of life and time in their epic anthem “Lateralus,” Latin for a “small brick”.  It got me thinking.
            A lot of the music I listened to, as high school drew on, centered on that sort of topic.  My perennial favorite band, Iron Maiden, sang often of life beyond death.  My mother is Catholic and I was raised in that church; it seemed that every Mass, every minute, there was talk of life after death, conquering death, resurrection, reincarnation, and so forth.  By the time I began thinking seriously about such things, I was well into my life in street emergency medicine, and the deep cynicism that comes with that was asserting dominance in my psyche.  I noted that church was always full of old people, and the priests were clearly just pandering to their constituents: giving the people what they wanted. 
            I wondered what it is like to get old.  To gradually, ever so slightly, feel the degradation of my body, the systems shutting down, one by one, the tissue going soft, sloppy, the hard muscle becoming empty soft fiber.  To wake up and be unable to get out of bed.  To take ten minutes to climb a flight of stairs.  To take a long list of pills with every meal and know that my health depends upon them. 
            Worst of all, to lose my mind.  To become the drooling zombies that populate nursing homes across America.  To be an O – EMT talk for an elderly zombie whose mouth hangs perpetually open.  To be a Q – EMT talk for an elderly zombie whose mouth hangs perpetually open with the tongue lolling out.  To ride out of the nursing homes on the Monday morning dump of sick people not noticed by the weekend staff.
            If I live to be old and decrepit, I know I’ll regale the EMTs that pick me up with stories about how I used to do their job.  They’ll smile and nod, as good EMTs do, and complete their run form, and drop me off as soon as possible, glad to be rid of the uncomfortable reminder of their own mortality. 
            The trauma calls never bothered me.  We live in a scary world and scary things happen every day, but I knew well that as long as I was seventeen I was invincible, and nothing scary would ever happen to me.  This continued to be true when I was eighteen, and then nineteen, and it’s still true today.  I am, as a matter of fact, thoroughly invincible.  For as long a time as I’m dumb enough to think so.
            That time will, one day, expire.  The old people bothered me.  Theirs was not some harsh fate of violent death that was hidden from me by teenage stupidity.  Theirs was the irrevocable fate of time.  That old spiral, the spiral I gawked at when I was younger – it still had me.  No stabbing or shooting or car accident could ever hurt me, though I drove with incredible recklessness at times.  But I knew deep down that I was helpless, tied into this spiral of time, doing the same thing every day, a little differently each time, over and over again, progressing with ever so tiny steps, inexorably toward the end.  Toward being old.  Toward being obsolete.  Useless.  A waste of everyone’s time.  Someday, this will be me, as it will be everyone else, and there’s nothing any of us can do about it. 
            And so I thought of these things, working my ambulance shifts, picking up my young patients and my old patients, all of them trapped in that spiral, hurtling toward the end, and I thought of these things, held up in church, watching and listening to the dog-and-pony show that they put on for their elderly spectators.  As my own spiral reaches an end, I hope not to be one of them.  I hope to keep my bearing, to be able to deal with my future and fate as it comes.  I hope to always have a plan for tomorrow.
            So, I’ll tell you what I’m doing tomorrow.  For one, I’m sleeping.  This doesn’t occur much at MIT.  These things may not happen; I’m no psychic.  I am a part of the spiral of time like anyone else, but I’m not going to surrender.  I’m not going to be a slave to uncertainty, or to a two thousand-year old book.  In the words of Tool,