Thursday, May 11, 2017

Sagan's Dust Mote: An Evening Reflection

Tonight I sat on my couch just as the evening sun was streaming through my west window, and I noticed a few dust particles glowing and dancing in the light. It made me think of Carl Sagan's famous reflection comparing the Earth to "a mote of dust, suspended in a sunbeam."

His comparison was inspired by a photo of the Earth taken by the Voyager 1 space probe in 1990, just as it was leaving the solar system. That's it, in the image I've posted here. That little dot in the band of light at the top is Earth, as it looks from beyond the orbit of Neptune. The "sunbeams" are actually bands of refracted sunlight created by the camera's optics, but that's a justifiable bit of poetic license. After all, Earth really is suspended in sunlight.

As I watched the dust motes in my living room swirling in that same sunlight, I thought about Sagan's comparison, and wondered how accurate it was. Is our whole world--the home of every known living thing--really that tiny? To find out, I did some figuring. I'll spare you the math and skip to the results--I think you'll find them impressive.

Imagine the Earth really were the size of one of those dust particles floating in my living room--a big one; about 30 millionths of a meter across. That speck of dust would be about 15 inches from the sun, which would be about the size of a BB. Neptune would be orbiting that BB at a distance of about 37 feet.

And the nearest star? It would be 63 miles away.

That's about the average distance between all the 100 billion or so stars in the Milky Way galaxy. If Earth were a speck of dust, the Milky Way would still be over a million miles across. And that's just one galaxy, in a universe filled with uncountable galaxies.

It seems, then, that Carl Sagan wasn't exaggerating at all. If anything, he was being too generous. On the scale of the stars, our planet is unimaginably tiny--a little speck of nothing. And yet, it's not nothing; not to us. But don't listen to me. Listen to Dr. Sagan, because he said it better than I ever could:
Consider again that dot. That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every "superstar", every "supreme leader", every saint and sinner in the history of our species lived there — on a mote of dust suspended in a sunbeam. 
The Earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become the momentary masters of a fraction of a dot. Think of the endless cruelties visited by the inhabitants of one corner of this pixel on the scarcely distinguishable inhabitants of some other corner, how frequent their misunderstandings, how eager they are to kill one another, how fervent their hatreds. 
Our posturings, our imagined self-importance, the delusion that we have some privileged position in the Universe, are challenged by this point of pale light. Our planet is a lonely speck in the great enveloping cosmic dark. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves. 
The Earth is the only world known so far to harbor life. There is nowhere else, at least in the near future, to which our species could migrate. Visit, yes. Settle, not yet. Like it or not, for the moment the Earth is where we make our stand. 
It has been said that astronomy is a humbling and character-building experience. There is perhaps no better demonstration of the folly of human conceits than this distant image of our tiny world. To me, it underscores our responsibility to deal more kindly with one another, and to preserve and cherish the pale blue dot, the only home we've ever known.

Saturday, May 6, 2017

Darkness, Light, and Prairie Dogs

This past Thursday I was off work on a beautiful day in Colorado, and I was depressed. It was the National Day of Prayer, and Donald Trump was using it to sign an executive order promoting "religious freedom", which all too often these days means using religion as an excuse to discriminate. Meanwhile, the House of Representatives was using the day to vote for a bill that--if it passes the Senate and gets signed--will result in millions of people losing meaningful health insurance. And then there as a tweet by a former Republican congressman named Joe Walsh, saying "Your sad story doesn't obligate me or anybody else to pay for somebody else's health care." I figured that was a good summary of the way many Republican politicians think, and that was depressing.

So, I did what I always do when I get depressed and cynical about the human race, and took a hike. Getting out in nature always restores me. But this time, it was taking a while. I was walking along, stewing about the news and human cruelty, when I saw a litter of prairie dog pups playing, while their mother watched over them from their burrow. Every once in a while one would run back and nuzzle its mama, and then go play again. They were having a blast, and my dark mood vanished instantly. 

I thought, "However ugly humans can be, there's still all this joy and beauty in the world" Prairie dog pups have been spilling out of their burrows to play in the spring sun for millions of years. It's an ancient, rhythmic cycle of happiness that's older than humanity. And that's a beautiful, awe-inspiring thing.

So nature did its trick, and I was soothed. And I stayed that way, but my thoughts soon grew darker and more realistic. And here I need you to bear with my for a while, because I'm going to sound really cynical, but my ultimate point is not cynical at all. So buckle up--it gets ugly for a second. As I kept walking, I realized I shouldn't romanticize the prairie dog pups too much. I'm convinced they were feeling real joy as they romped, but their lives are hard. Coyotes, rattlesnakes, and hawks are out there hunting them, and not all the pups are likely to make it to adulthood. Plus, prairie dogs are plagued with disease. Literally--they get bubonic plague. And they're no angels themselves--they often kill smaller rodents who compete with them for food. 

So I kept walking, still soothed but more sober. As I came around a small hill, I heard a strange snorting sound. I started looking in the bushes, hoping to see a badger (for some reason I was imagining badgers sound like that). But it turned out to be a deer. There was a group of mule deer browsing on the hillside, and one of them was snorting, shaking its head, and pawing at its face. And here was another reminder not to romanticize nature. Most likely, the deer had been attacked by a deer bot fly. While it was grazing on bushes, the fly--which mimics a bumblebee almost perfectly--had flown up and sprayed its eggs into the deer's nose, and its young had grown into bullet-shaped worms in a cavity in the deer's head. Now the deer was slowly snorting and coughing them out, so they could go on with their horrid little life cycle. The deer will probably be fine, but it's safe to say its life is no bowl of rose petals. That's why I always scoff when I see products that say they're safe because they're "all natural". Have people SEEN what nature is capable of?

But please stay with me, and don't get me wrong. Nature is beautiful and endlessly awe-inspiring, and I love it as much as anyone I know. But it isn't benevolent. It's not malevolent, either. It just IS. Organisms in nature evolve because they find a niche that's stable. That niche may be the "playful, lovable otter" niche, or it may be the deer bot fly niche (or the bubonic plague bacterium niche, for that matter.) Evolution doesn't have a preference, because it doesn't feel empathy. It doesn't say, "I can't make a fly that does that to a deer!" Nature as a whole does not feel compassion. What happens just happens, and sometimes it's pretty awful. 

And I think many Republicans with a social-Darwinist outlook, like Joe Walsh of the Mean Tweet, think that's something humans should emulate. While some liberals romanticize nature by seeing it as benevolent, there's a subset of conservatives who look to the callousness of nature for an ethical example. And both are committing that most common of fallacies, the appeal to nature fallacy. The fact that nature does something doesn't mean we should. Mammals often commit infanticide. Male ducks practice what's euphemistically called "forced copulation". These things are absolutely natural, because they happen in nature all the time. Does that mean we should do them, too?

Hell no.

And that's my non-cynical point, if you've stayed with me this long: even if nature as a whole is pitiless, compassion and empathy do exist, and they can be cultivated. It doesn't just exist in humans. I believe a mother prairie dog feels compassion (and maybe even joy) as she watches her babies play. Many animals seem to be compassionate toward their close relatives. A few of the more brainy mammals and birds form friendships with non-relatives, occasionally even from other species. There's a whole theory of why this happens, called reciprocal altruism, but the point is that they've widened the circle of care beyond family. Humans have widened it even further. We, or at least most of us, are capable of looking at other sentient beings and realizing they are capable of joy and suffering, just like we are. If nothing else, sheer, cold logic should tell us that other people's hopes, desires, fears, and pains are just as real and intense to them as ours are to us. Why wouldn't they be? 

Even if other animals are capable of this sort of realization (and I bet some are) there's not much they can do about it. We're different. We can look at nature's dearth of kindness and compassion and say, "That's not good enough." Once I came upon a dog stranded on a pillar of rock. Its owner told me later it had been missing for a week. Nature would have let that dog die, but I didn't. I got it off that rock and got it some food and water. And you would have too. And that is an amazing thing. Think about it: we are a part of nature that is actually capable of seeing suffering in the world, and deciding to do something about it. We are, at least in this part of the universe, nature's conscience. 

Or we could be. We have that potential. But history has shown that we sharpen nature's hardest edges as often as we smooth them. The worst of us have invented cruelties nature could never match, because nature isn't cruel. It may be mostly compassionless, but it doesn't revel in the pain of others. Some people unfortunately do. So, cruelty, like kindness, is also a rare element in the universe, and I think most of us are capable of both under the right circumstances. There's a darkness in us darker than anything in nature, but there's a light in us, too. That light is composed of things like compassion, kindness, and the ability to make the world a better place; to make life in it more worth living. Maybe it's a divine light, I don't know. Maybe it's the light in the Jewish idea of the broken vessels, and gathering and cultivating that light is the act of tikkun olam--repairing the world. Maybe that light is what Jesus meant when he said the kingdom of heaven is within. And maybe it's a happy accident? I don't know the answer, and I don't know that it matters. But I am pretty sure that humans have a choice between the darkness and the light inside of us. And I know which one we had better choose.

Saturday, February 25, 2017

Hidden Beauty

At times when science is questioned and threatened, as it is currently, its defenders remind us of the many reasons science is vital: Science cures diseases and improves our quality of life. Science education and funding helps the US stay competitive in an increasingly technology-driven global economy. Science helps us understand how the world works; uncovering nature's deepest laws. All these things are true and crucial, but I think there's another gift science gives us that's widely underappreciated, even by many scientists. Science shows us the hidden beauty and wonder of nature. Science can make the mundane awe-inspiring.

Consider, for example, the rock in the picture above. It doesn't look like much, does it? It sits in a parking lot at a trailhead near Boulder, Colorado, and people walk by every day without ever noticing it. But that rock has a story to tell.

It comes from a layer of rock in the canyons above Boulder known as the Coal Creek Formation. If you look at it closely, you see that it's made of smaller rocks--it's a type of rock called conglomerate. The constituent rocks are slightly rounded, like river rocks, because that's exactly what they once were. Long ago, they were part of a rocky riverbank a few miles from a mountain range. But no animals roamed that bank, and no trees shaded it. Animals and trees didn't exist yet, because that riverbank existed 1700 million years ago.

Even then, the pebbles inside that rock were ancient by our standards. They had eroded out of rocks formed millions of years before, when the ancient core of North America colliding with a line of volcanic islands, which slowly smashed together to create the first land that would become Colorado. Mountains rose in the collision, and then began to erode away, as mountains constantly do. The riverbank was eventually buried, and the pebbles and sand solidified into a layer of conglomerate. Then it was buried deeper and deeper, until eventually it was miles underground, where the heat and pressure fused the pebbles and sand together into a metamorphic rock called quartzite. The conglomerate had become a metaconglomerate. In some places where this rock appears today, you can see where the original river pebbles were warped and stretched in its journey through the depths.

A billion and a half years ago, then, our boulder was part of a layer of rock buried deep in the earth. And there it stayed, for hundreds of millions of years. Up above, single-celled life slowly evolved into complex organisms like early plants and animals. Some of the fish came onto the land and became amphibians, and some of the amphibians evolved into early reptiles. Finally, after 1400 million years, our rock began to rise again. Far-off tectonic forces were lifting a new mountain range, called the Ancestral Rocky Mountains. The Coal Creek formation rose to the surface, and was then hoisted into the air as a part of the mountains. Once again, erosion set in, and parts of the formation eroded into pebbles in mountain streams. Aprons of rocky debris spread out of the dwindling mountains onto the flatlands. One day, they would become the soaring red cliffs of Red Rocks Amphitheater and the Boulder Flatirons. Finally, the Ancestral Rockies crumbled into a sea of sand dunes (which would one day form the rocks at Garden of the Gods), which was in turn covered by an actual, shallow sea.

Elsewhere, dinosaurs evolved and grew into giants, who eventually migrated across the Jurassic coast of Colorado, leaving their huge footprints and bones in the sand. The seas rose again, and giant reptiles patrolled the waters, while pterosaurs soared above the waves like scaly pelicans. Then the sea retreated again around 67 million years ago, as a third set of mountains--called the Laramide Rockies--started to rise. Triceratops and T rex roamed the rainforests below, leaving more bones and footprints along the Front Range, before they were killed by an asteroid that firebombed North America. All the while, the Coal Creek formation kept rising with the mountains.

The Laramide Rockies began eroding as soon as they started to rise, and parts of the Coal Creek Formation again fell into mountain streams, creating a new generation of river rocks. Giant boulders southwest of Denver tell us that enormous floods once roared out of the mountains, powerful enough to carry refrigerator-sized rocks for nearly fifty miles. Eventually, all the erosion nearly buried the Laramide Rockies in their own debris. The high plains rose nearly to the tops of the mountains in a smooth incline, as they still do in southern Wyoming. The surface of the plain was high above the current sites of the cities along the Front Range. Our boulder was still part of a larger rock, which was (probably) buried once again.

Finally, around 5 million years ago, the land began to rise again (or perhaps the climate grew wetter) and rivers began carving up the landscape once again. The hard rock in the buried mountains resisted erosion, and the mountains began to emerge from their debris. These were the modern Rockies--the fourth mountain range our rock has seen. Earth entered one of its periodic ice ages, and glaciers began to descend from the mountains. They would stick around for 100,000 years or so, carving the high peaks into their current dramatic form, and then retreat for a few millennia during a brief, warm recess. Human civilization has arisen during the latest recess.

Down lower, when the ground around Boulder was still a few hundred feet higher than it is today, our rock finally eroded out a cliff and fell into Coal Creek. Its rounded shape tells us that floods knocked it against other rocks and ground away its edges, and its large size tells us these were powerful floods--only a flood can carry a rock that big. One of these floods finally carried it out of the mountains and deposited it on a flat plain. That plain was left standing by erosion around it, and now it's a mesa (technically a pediment) known as Rocky Flats. Rocky Flats is now notorious for being radioactive, due to careless handling of nuclear waste by some recently-evolved primates. At some point, those primates built a parking lot, and put our boulder there as a decoration. And there it sits. For now.

Will it still be sitting there when we are gone? It certainly could be--we are ephemeral things by its standards--but how long we last will depend on how wise and lucky we turn out to be. In any case, in the short time we've been here, we've discovered science. And science has allowed us to look at that nondescript rock in a parking lot and see beyond its initial appearance, to the amazing, eons-long story it can tell. The rock can't appreciate the grandeur of its own story, but we can. That's a major reason science is so important--it gives us the knowledge we need to appreciate the hidden beauty of nature.

Of course, some people don't see science this way. They think science kills the wonder of nature by reducing it to equations and theories; by "unweaving the rainbow" as Keats put it. And science can be dry and boring, when it isn't communicated well. But it doesn't have to be. When it is communicated well, science can show us the astounding majesty of nature. I think the physicist Walter Lewin put this best (in a lecture on the beauty of rainbows): "Knowledge always adds. Knowledge never subtracts. Knowledge is hidden beauty." That nondescript rock in a parking lot is full of hidden beauty, once you know how to see it.


Geology Underfoot Along Colorado's Front Range / Lon Abbott and Terri Cook  I learned about this rock, and the Coal Creek formation, from this excellent book. My copy is falling apart, because I've tromped all over the Front Range with it in my backpack.

The Hidden Beauty of Rainbows / Walter Lewin