The Earth as Porridge
On Chestnut trees, gum balls, and Goldilocks and the Three Bears.
In the book The Overstory, by Richard Powers several generations of the Hoel family create a photo book of a transplanted chestnut tree by taking a picture from the same spot once a month, rain or shine. The tree and tradition carry on beyond the great plague that killed the eastern chestnuts, and the many smaller plagues that permanently end many Hoel’s best laid plans. The picture book, thousands of pictures collected over the better part of a century, contains a certain appeal that none of the Hoels can fully explain. Yet one Hoel, a farmer of few words, said it this way: “Makes you think different about things, don’t it?” To which the other characters agree: yes it did.
I don’t have a photo book with a picture a month of this majestic growing tree. But I have been thinking a lot about our planet earth: it’s girth, weight, and size. It’s certainly enough to shift my vision around a little. So today, three ways to think about the size of our planet.
1. Really big. 24,901 miles around at the equator. That’s a substantial drive: about the number of miles I might put on my car in two years, or, if I’m feeling ambitious, a hectic month of road trips. If you don’t like driving, consider walking. My fitbit says I average 8,423 steps, or about 4 miles, per day in my walk heavy life here in Chicago. At that pace it takes 17 years to circle the planet, suggesting in my mid-late 30s I’m just completing my second lap! And apparently that’s a high daily average. Mayo clinic says the average American walks more like 2 miles each day, or about a loop of Earth every 34 years. I’ll slow, I suppose, with age, and if I’m lucky get another lap or two or three, another turn on this planet to learn a little more of its majesty, its sweat, and its tears.
But just circling the planet doesn’t give you the whole picture, since there’s a whole other dimension to explore. Here’s another way to consider the bigness: there are about 8 billion people on the planet. For you to say hi to all of them you’d have to say hi to 2.5 people every second, hi-hi-hi, even assuming you lived to 100 and forgetting lots of new babies yet to be born. That’s a lot of people. And yet, there’s so much area on the planet that if we evenly spaced out all 8 billion people each person would have an area equivalent to about 12 football fields. So much separation you’d never hear me shouting.[1]
The earth is so big, in fact, that there are situations I struggle to comprehend. Like when I read the sign at the hotel: “Do not enter the pool if you are ill with diarrhea.” Or on the back of the toilet stall door: “don’t flush notebooks.” Notebooks? The world is big enough that this occurs? The world, from my experience, seems big enough to contain some of heaven, some of hell, and everything in between.
2. Really small. There’s a famous story where Carl Sagan had the Voyager satellite turn back and take a picture of Earth from just beyond Saturn’s orbit. From this distance earth is just a tiny “pale blue dot” on the screen. Sagan famously writes “That's here. That's home. That's us. On it, everyone you ever heard of, every human being who ever lived, lived out their lives. The aggregate of all our joys and sufferings, … every hopeful child, every mother and father, … every saint and sinner in the history of our species,… on a mote of dust, suspended in a sunbeam. … Our planet is a lonely speck in the great enveloping cosmic dark.”
Indeed, try comparing our planet to the size of the sun, just a modest size star. Imagine dropping earths in it like pennies in a big jar, or better, like gum balls in a gum ball machine. One each second would take about 12 days to fill the machine, which, if the earth was the size of a gum ball, would be a little over 100 inches across, that’s over 8 feet. Chew on that, for a while.
I did once see a giant gum ball machine, nearly that size in my inflated memory of it, I think in an airport somewhere. Which reminds me of the time I randomly met my cousin in the Albuquerque airport just months after we’d randomly run into each other at a rest area in Georgia at 4am. Or that, riding in a jumbo jet 15 hours from LAX I can get to Australia, nearly the other side of the world, where Kookaburras actually sit in gum trees, like in that strange old nursery rhyme that somehow we all just know. Like that Disney song they play at Epcot: “it’s a small world after all.”
3. Really impressively about right. Astronomers are just beginning to learn about the distribution of planetary sizes across the galaxy – there are certainly lots of planets bigger than earth, but most of these have giant gaseous atmospheres, not places we’d want to live unless if we were happy spending our lives in flying machines. There likely are lots of planets smaller than earth too, but it’s unclear how many of these smaller rocks might be able to hold onto their atmospheres. What we do know is that earth is about right, at least for us. Sure, sometimes it’s too hot, sometimes too cold, sometimes just plane rude. Sometimes it’s unclear if there’s space for me, or whether my cries are just lost in the lonely wind. Yet it still remains true that I can live on this planet, and make a go of it.
Astronomers spend a lot of time considering the so called “Goldilocks zone” around stars, a region where it’s not too hot, not too cold, where there’s a chance life could exist. Somehow this dot of ours still exists in the middle of the sun’s goldilocks zone – our oceans apparently a porridge that was just right. Goldilocks zone: a funny name, when you think about it. Goldilocks was quite the character, stealing a little warm food, and perhaps some solace in a bear’s home. Is life in the Goldilocks zone just the quick nap we steal before the bears’ return?
Smart people argue about how likely it is that we exist at all, how perfectly the universe is fine tuned for our species to emerge, and whether that’s evidence for anything – philosophical nonsense, or a glimpse of God. Is the earth unique to life, or insignificant prototype? Does it matter, and what will become of it all? I might suggest that it’s interesting to think about, but worry if these debates might just be our adult version of the fairy tale. After the bears return home and Goldilocks jumps through the window, we’re told of her fate simply that “no one can say.”
Any yet, at some deeper level, I wonder if this perhaps points to a fourth way to consider the size of our planet: a mystery. Like the mystery of me getting out of bed each day, the solaces I steal, the bears I await. Mystery in the sense of wonder. Mystery, like that suggested by the apostle Paul: “Behold, I tell you a mystery: We shall not all sleep, but we shall all be changed.”
[1] It’s worth noting that this does not mean that human population growth is not a problem. If you consider only reasonable livable land (e.g., not ocean, desert, glacier, etc.), this area is much less, 1 or 2 football fields, and on that land you have to include room to produce all your food, energy, entertainment, and other life needs. This also doesn’t account for the impact that humans have on the planet, or the millions of other species that also need space to live, move, and have their being.