trillion miles away (roughly being the word you use when your estimate could be off by A MILLION MILES), the visible universe is a million million million million miles across, and all of the galaxies in the universe are moving away from all of the other galaxies in the universe at the same time.
This is called galactic dispersal, and it may explain why some children have a hard time sitting still.
The solar system that we live in, which fills less than a trillionth of available space, is moving at 558 thousand miles per hour. It’s part of the Milky Way galaxy, and it takes our solar system between 200 and 250 million years to orbit the Milky Way once. The Milky Way contains a number of smaller galaxies, including
the Fornax Dwarf,
the Canis Major,
the Ursa Minor,
the Draco,
the Leo I and the not-to-be-forgotten Leo II,
the Sculptor, and
the Sextans.
It’s part of a group of fifty-four galaxies creatively called the Local Group, which is a member of an even larger group called the Virgo Supercluster (which had a number of hit singles in the early eighties).
And happens to be traveling at 666 thousand miles an hour.
(So be careful out there, and look both ways before you cross the supernova.)
Back to our original question:
Expanding?
Around a hundred years ago, several astronomers, among them Edwin Hubble, he of telescope fame, and Vesto Slipher, he of awesome name fame, observed distant galaxies giving off red light. Red is the color galaxies emit when they’re moving away from you, blue when they’re moving toward you—hence the term “red shift.”
Fast-forward to 1964, to two physicists working for the Bell Telephone Company, Arno Penzias and Robert Wilson. These men were unable to locate the source of strange radio waves they were continually picking up with their highly sensitive equipment. As they searched for the source of these waves, cleaned the bird droppings (which Penzias called “white dielectric material”) off their instruments, and shared their findings with other scientists, they realized that they were picking up background radiation from a massive explosion.
An explosion, it’s commonly believed, that happened a number of years ago—13.7 billion, to be more exact.
Apparently, before everything was anything, there was a point, called a singularity, and then there was a bang involving inconceivably high temperatures, loaded with enough energy and potential and possibility to eventually create what you and I know to be life, the universe, and everything in it.
The background radiation from this explosion, by the way, is still around in small amounts as the static on your television. (And you thought it was your cable company.)
Now when we get into sizes and distances and speeds this big and far and galactic and massive, things don’t function in ways we’re familiar with. For example, gravity. Jump off the roof of your house, drop a plate on the floor in the kitchen, launch a paper airplane and you see gravity at work, pulling things toward our planet in fairly consistent and predictable ways. But in other places in the universe, gravity isn’t so reliable. There are celestial bodies called neutron stars that have such strong gravity at work within them that they collapse in on themselves. These stars can weigh more than two hundred billion tons—more than all of the continents on Earth put together . . .
and fit in a teaspoon.
And then there’s all that we don’t know. A staggering 96 percent of the universe is made up of black holes, dark matter, and dark energy. These mysterious, hard to see, and even harder to understand phenomena are a major engine of life in the universe, leaving us with 4 percent of the universe that is actually knowable.
Which leads us to a corner of this 96 percent unknowable universe, to the outer edge of an average galaxy, to a planet called Earth. Our home.
Earth weighs about six billion trillion tons, is moving around the sun at roughly sixty-six thousand miles an hour, and is doing this while rotating at the equator at a little over a thousand miles an hour. So when you feel like your head is spinning, it is. Paris is, after all, going six hundred miles an hour.
Earth’s surface is made up of about ten big plates and twenty smaller ones that never stop slipping and sliding, like Greenland, which moves half an inch a year. The general estimate is that this current configuration of continents that we know to be Africa, Asia, Europe, etc. has been like this about a tenth of 1 percent of history. The world, as we know it, is a relatively new arrangement.
Every day there are on average two earthquakes somewhere in the world that measure 2 or greater on the Richter scale, every second about one hundred lightning bolts hit the ground, and every nineteen seconds someone sitting in a restaurant somewhere hears Lionel Richie’s song “Dancing on the Ceiling” one. more. Time.
Speaking of time, here on Earth we travel around the sun every 365 days, which we call a year, and we spin once around every twenty-four hours, which we call a day. Our concepts of time, then, are shaped by large, physical, planetary objects moving around each other while turning themselves. Time is determined by physical space.
No planets, which are things,
no time.
We have calendars that divide time up into predictable, segmented, uniform units—hours and days and months and years. This organization into regular, sequential intervals that unfold with precise predictability has deeply shaped our thinking about time. These constructs are good and helpful in many ways—they help us get to our dentist appointments and remember each other’s birthdays, but they also protect us from how elastic and stretchy time actually is.
If you place a clock on the ground and then you place a second clock on a tower, the hands of the clock on the tower will move faster than on the clock on the ground, because closer to the ground gravity is stronger, slowing down the hands of the clock.
If you stand outside on a starry night, the light you see from the stars is the stars as they were when the light left them. You are not seeing how those stars are now; you in the present are seeing how those stars were years and years and years in the past.
If you stand outside on a sunny day, you are enjoying the sun as it was eight minutes ago.
If you found yourself riding on a train that was traveling at the speed of light and you looked out the window, you would not see things ahead, things beside you, and things you had just passed. You would see everything all at once. You would lose your sense of past, present, and future because linear, sequential time would collapse into one giant NOW.
Time is not consistent:
it bends and warps and curves;
it speeds up and slows down;
it shifts and changes.
Time is relative, its consistency a persistent illusion.
It’s an expanding,
shifting,
spinning,
turning,
