The universe is mostly darkness. There is very little light. Yet there are 100 billion galaxies in the universe. To picture a galaxy — well, I hope you’ve had the opportunity to look into the centre of our own, the Milky Way. When I was a kid, I saw it routinely at night; I took for granted the mass of stars that formed a band of white in the black sky that arched over the tree tops and the barn roof.
That view into the galaxy was there at night when there was no moon, and sometimes on summer nights I lay on the ground and stared into it for so long, forgetting where I was, getting to see more and more stars inside; and then it was disorienting to bring my attention back to Earth, to stand up and hear my sneakers crunch the gravel and see the dim lamp light in the windows of the farm house.
We might feel like it comes and goes, but that dense band of stars is always there. We just can’t see it when the light from our own star, the sun, brightens our sky. And if we live in Toronto, or near Toronto or any other large city, we don’t really see the Milky Way anymore. Even on a moonless night, we see only a few stars. Not enough to dazzle us, they never dominate. And most human beings alive today are living in cities. But for most of human history, people lived without electricity in small villages or campsites and they spent their nights under a sweeping canopy of stars with a view into the centre of our galaxy.
This galaxy is a disc-shaped cluster of approximately 100 billion stars. The sun that we orbit is one of those 100 billion. It’s located — we are located — near the outer edge of the galactic disc, 25,000 light years from the centre. When you hear that, what does that mean to you? 25,000 light years. It’s very hard for me to grasp. I was interested in physics when I was in high school, and I got reasonably good grades, up to a point, but I never felt like I truly understood what was going on. 25,000 light years.
A year is the time it takes our planet to travel a full circuit around our star. You might imagine that the earth is travelling slowly. Or you might imagine that it’s speeding along, finishing yet another lap around the sun, vast darkness all around. I’ve been on this planet for 39 trips around the sun. Pretty soon, the earth will cross that precise spot in its orbit where it was when I was born, and I’ll be in that location for the 40th time. Actually for the 41st time — the first time was the day I was born, when I was officially aged 0. Those 40 trips are a big deal to me. I remember about 36 of them. But the earth itself will be crossing that location in space (what I call my birthday) for the approximately 4 thousand six hundred millionth time. That is, for the 4,600,000,000th time.
Anyway, that is what we mean by a year — the time it takes for this planet to complete a full circle around this star. Now let’s try to think about the speed of light. It’s very, very fast. I’m in Toronto right now. Imagine that you’re in Australia. And somehow we’ve set up a network of mirrors that will reflect a ray of light all the way from — where would you like to be in Australia? Let’s say Melbourne, from Melbourne to Toronto. You point a flashlight at the first mirror in Melbourne and turn on the light. I’ll see the light in Toronto instantly. I mean, of course it’s not really instant, but the delay will be imperceptible. That’s how fast light travels. For you to travel from Melbourne to Toronto, you’d have to get onto a plane and fly for about 23 hours, it would require the burning of heavy amounts of fossil fuels made from ancient forests, and it would take the duration of almost a full rotation of the earth. But if you were a light beam, you’d do it in less than a second. Faster than I can say “Melbourne”. You could leave when I said “Mel” and you’d be here by the time I said, “bourne”.
So. It’s 25,000 light years to the centre of our galaxy. Now let’s imagine you can travel through space at the speed of light. Yes, yes, that’s impossible, I know. I wasn’t THAT bad in physics. There’s a law against it or something. Which is a fine topic for another story, but in this one here and now I’m sitting in a cafe thinking about life and I need you to do this for me. Maybe you’ve turned into a beam of light. Anyway, off you go. I’ll stay and finish my coffee.
As I lift up my cup, you’ve already passed the moon — one second. There’s a little girl crying, and I look up and watch her mother take her outside and bounce her up and down, and then I notice there’s a pretty woman across the street talking on her cellphone, and then I remember what I was writing, and by this time you’ve passed the planet Mars. I finish my coffee, go home, do some laundry, prepare notes for my class tomorrow, and you pass the planet Saturn. I fry a steak and make a salad for my dinner, watch an episode of Corner Gas, go to bed and sleep for 8 hours and you’ve left the solar system far behind. You’re still travelling as fast as when I said “Melbourne”. At the speed you’re going, you can’t see anything, but if you slow down for a moment to look back, our solar system looks to you now as merely a few points of light mixed in among all of the other faraway stars. I get up the next morning, shower, check the weather, decide what to wear, read the paper while eating my cereal. You fly onward through space.
Days go by. I get my new shoes waterproofed, have an argument with my girlfriend, apply for a loan, wait and worry if I’m going to get the loan. I read and mark 115 students’ journals, the leaves on the trees change colours and fall, I drive to Kingston one day listening to Keith Jarrett, winter arrives and it snows… and you’re speeding every one of those instances through outer space. I drive with my dog all the way to Halifax for Christmas, I do a jigsaw puzzle with my mother and my sister, walk on the beach, go to the pub with my dad, drive back to Toronto watching the highway for ice and blowing snow, and I stop in a remote service station in New Brunswick when it’s dark and look up and I can see the Milky Way. My dog sniffs at the snow by the side of the road, he doesn’t look at the sky; I wonder if he ever does. With every sniff my dog takes, you’ve gone another vast distance, speeding impossibly fast through outer space. Through the winter I work on a novel between my teaching tasks, day after day I go to this cafe in the morning; I ride the streetcar, I visit my girlfriend and she visits me; we break up, and we get back together again; and break up again and feel helpless. It’s not only light speed that’s impossible. I search for jobs to come after my contract, the days get longer and brighter, new leaves bud on the trees, snow melts, I get out my t-shirts and shorts and wonder if I need to go shopping for new ones, I should probably replace my sandals. There are days of sweltering heat and buzzing cicadas, when time seems to be going nowhere. And finally a whole year has passed since you left.
During all this time, you’ve been travelling at an impossible and silent speed, going further than the distance between Toronto and Melbourne in every one of those fleeting seconds when I took a sip of my coffee, or turned the page of a student’s journal, or listened as one quiet note changed to another in Keith Jarrett’s Koln Concert. The distance that you’ve just travelled during that whole year of my life is one light year. That was one light year.
And after all that, you have yet to make it to the nearest star beyond our solar system. You’re one light year from the sun, which is grand. But you’re still three light years from the nearest star.
On the galactic scale you’ve hardly gone anywhere. If we looked down at our galaxy from above — say, at a map of our galaxy — you’ve hardly moved. You’ve gone 1/25,000th of the distance from our solar system to the centre of the Milky Way. You need to keep going at this impossible speed for another 24,999 years before you will get to the centre of that band of light that I used to see above my barn roof.
Twenty-five thousand years is a long time for humans. Is it a long time since your parents were born? A long time since poor Europeans built ships out of wood and wealthier ones sent them across vast oceans? A long time since the Romans were building roads across Europe and everyone was speaking Latin and executing thousands of criminals on crosses including one who got to be counted more than all the others and in whose memory we started counting our years such that we’re now past the two-thousandth? That’s two. We’re talking here about twenty five.
Twenty-five thousand years ago there was no English, no Chinese; there were no gardens, nowhere on Earth; no agriculture. There was no such thing as a chicken. You would search in vain for what is called, on my cereal box, “ancient grain”. There was an ice age; it receded. Then there were the first plantings of corn, wheat, rice, the building of towns; then the rise of the first kings, emperors; the building of pyramids and Great Walls and the live burials of countless female concubines alongside ridiculous numbers of terracotta warriors (civilization!); then so many plagues, many wars and whippings of slaves, and through it all so many deaths, murders, many loves, many births and mothers holding and carrying their children for a fast few years. The light from a star that we might see tonight looking into the centre of the Milky Way, the light that we see now, left that star 25,000 years ago when the only light on Earth at night came from the small campfires of a human species still tiny in number, a species that was painting pictures of other animals on the walls of caves.
And at the mention of those cave paintings, let’s remember all of Earth’s other creatures across all of that time, the countless lives and deaths of dogs, whales, cicadas and willow trees.
When you finally get to the centre of our galaxy: first of all, let’s appreciate this, it’s a remarkable thing to traverse a galaxy (well, about 40% of it – you’ve gone half way through it, not from end to end). But this galaxy is just one out of 100 billion. That bears repeating. There are an estimated 100 billion galaxies in the universe. Some of them contain tens of billions of stars; others contain hundreds of billions. So, tens or hundreds of billions of stars in every galaxy, and at least 100 billion galaxies in the universe. We’ve just imagined your 25,000 year trip to the centre of our Milky Way, and that is only one galaxy among billions. On the scale of our universe, that trip at the impossible speed of light for the duration of the rise and fall of whole languages and empires has been nothing. Might as well be nothing.
And with all that, the universe is mostly darkness. There’s very little in it.
And I’m in Toronto, looking at my coffee, which – like the universe – is cooling down.
Sometimes it feels like a long time ago that I was a kid looking at the stars above the elm trees and the barn roof at night. And the truth is, not only is that time growing more distant, but so are the stars themselves. Those stars and galaxies are getting further away from us all the time.
But I’m not capable of noticing the changes in the stars. So even as time passes and I grow older and the farm is now gone, some things seem to stay the same. I don’t get to see them as often as I used to. But I know they are still the same.