Lost in Space (parts 3 and 3.1, revised)
Section 3: Perspective (revised and updated)
Author’s note: this is a significant revision of a section I previously posted. I like the process of revision, seeing each section anew. I think it will surely undergo further perspective shifts as I come to understand its place in the overall story, but for now, I hope you find it, if nothing else, an encouragement to think about something in your life from a little different angle. This section is the third in a perhaps 5 part series. You can find the first section here, and the second section here.
Section 3: Perspective
Well done, at this point you now have two ways of getting oriented: constellations, the states of the sky, and the imaginary lines of right ascension and declination, the addresses of the sky. These two systems do pretty well, but there’s a difficulty with them that needs some thought. While these systems are fixed to the sky, we are not, which means that different constellations and different RA/Dec coordinates appear different to different people in different places and at different times. To picture it, think about ants crawling on a soccer ball. An ant on top of the ball might look straight up and see a cloud (at declination 90 degrees), and look to the side, and see a net (at declination 0). But an ant on the side of the ball sees things very differently. The cloud (at declination 90) is to his side, and straight up he’d see the net, or perhaps just an approaching foot.
On earth it might look like this: floating in my dream location on a boat in Lake Michigan, I might see the Andromeda Galaxy as a fuzzy blip 30 degrees above the horizon in the northeast. But you, from the beach in Key Largo might see it as only 13 degrees above the horizon, and your aunt in Hawai’i wouldn’t be able to see it at all until hours later, and then in a different spot on the sky.
Some of the difficulty is that the earth is quite big: it blocks half the sky from us all the time. So if you’re in Australia and I’m in Chicago we’re going to be looking at different skies: different stars, mapped by different Right Ascensions and Declinations, will be overhead. And some of it is just the hard rules of geometry: the stars might be fixed, but if I move I will view them, and the universal coordinates we’ve attached to them, from a bit of a different angle. My perspective shifts; from different places, I see differently.
I once took a three-week trip to Australia to work with some collaborators on a study concerning the impact of our galaxies’ relative locations on their properties. On that trip we took a few adventures out of town to see the kangaroos with their pouches and cute little joeys just starting to peak out their heads. I remember our host laughing at our excitement about the kangaroos, like I might laugh at someone flipping out over seeing a deer in Michigan. To us, the kangaroos were exotic. To them, they were a common nuisance, like deer in my mom’s garden. Things look a bit different from the other side of the world.
But even a little shift can make a difference. I remember a time I was scheduled to do some observing with Arecibo Observatory - a giant radio dish one kilometer around built into a sink hole in Puerto Rico. I am a heavy sleeper but I’d managed to wake up and get ready without waking my fellow grad student Greg. I think I brushed my teeth to scrub away that sleepy fog - I at least got dressed and was at the door ready to leave, quite proud of myself that I’d been so quiet. When suddenly the window panes - great heavy wooden doors made to block out even the noontime sun for sleeping astronomers - started slamming, the stilted wooden house, not updated from its use in the film Contact shaking, rocking - and Greg sat bolt upright.
Four seconds later it was over. What was that? Down in the control room, on its concrete slab, the operators on duty had hardly even felt it – a magnitude 6.2 earthquake in the fault line just off the coast. This seemed fine: our data seemed a little off that night - fewer detections and more waves in the baseline than expected, but nothing too worrisome. The next day we were scheduled for a telescope tour. The main staff don’t work on weekends, but someone was there to take us up the terrifying catwalk out to the hanging instrument platform, 2000 tons of metal suspended 400 feet above the dish below. We had a great tour. Little did we know that come Monday staff would inspect the telescope, and find that one of the cables that holds up the dish had been frayed in the earthquake, unraveling such that the platform had shifted about 6 inches. A small shift. Easy to miss. But enough to make our data from that night entirely worthless - we’d been pointing all wrong and didn’t even know it. And of course, one broken cable puts the rest under far more stress. A small fact. But one that completely changed our view of the telescope platform tour. We could have died!
Another small fact: this little fray was the beginning of the end for this iconic observatory. Though the cable was repaired, 7 years later a hurricane would snap another. And the remaining cables, already weaker from this extra stress would begin to imperceptibly stretch. Just days later, before the snapped cable could be repaired, the whole platform would come down. Amazing the impact of a 6-inch shift.
It’s worth noting that it can also be easy to miss that someone close by, even 6-inches to your right, sees things from a different angle. Pointing out star patterns at observing open houses usually requires walking over to where someone is and standing right behind them, my head aligned, as much as possible, with theirs – only then are we looking at approximately the same thing, only then does the direction I’m pointing look similar to both of us.
I wonder, how often does my opinion that others are lost or wrong stem from my unwillingness to go over to view things from their perspective? I read a book in middle school called Walk Two Moons, a story about a supposed lunatic killer that draws its title from the epigraph “Don't judge a man until you've walked two moons in his moccasins.” I end up coming back to this again and again and again. Like when I find myself driving like my mother, or taking those classic travel photos like my dad. Or my first year teaching. I remembered all those reviews I’d written of my professors, how they should have done this differently or that differently. After a few moons of teaching and my first student reviews those words came back to bit: who knew teaching was so hard! Or, the first time I worked in a maximum security prison. And met the beautiful human beings living there. It was there I saw people who knew the true meaning of justice, and pain, and hope. And there I couldn’t shake the feeling that it was me, not them, who was lost.
To do astronomy, then, I must remember that everyone is in a slightly different place. If I want to tell my collaborator Kelly where to point her telescope, I need to do some work to put things in terms we mutually understand. I have to convert between what I see now - say that a star is 44 degrees above the southern horizon - to something shared: universal coordinates or vocabulary like “star at RA = 90o and Dec =+23.5o.” Then she can convert RA 90o Dec +23.5o – perhaps determining that for her the star is 66 degrees above the horizon. Thus we both need to do some work to see what the other is seeing.
What’s more, to do astronomy I have to recognize it’s a big world out there: sometimes this conversion isn’t even fully possible. For some people, like those in Australia, the big dipper is never visible, always blocked by the earth. For others, like me in Chicago, it’s always there. There are parts of the sky they can tell me about, but which as long as I’m over here, I’ll never be able to see. I think this is part of why my mom made us read so many books. Another popular book I read in middle school was The Giver. In it Jonas lives in a world that has no color. When he experiences color for the first time, he doesn’t have any words to talk about it, saying “I wish language was more precise.” Because if you’ve never experienced color, how could you possibly understand what it means to be red, or pink, or green? And it’s not just middle school books. Thinking back, I feel like coming of age is a series of personal transformations where you can suddenly see flickers of color, maybe not the full experience, but enough to suggest the great volumes of space beyond your visible world.
Consider my experience growing up in a racially diverse church. I loved everyone I knew there, and thought I saw them too: Ardie, the gentle white haired black elder who would hug me each Sunday and say “how ya doin, grandson?” Sam, the fire-breathing Princeton-educated glasses-wearing force of nature who each Sunday “stopped by on his way to glory” to speak to us from some wise theme. I wanted so hard for everything to be equally good for everyone: I’ll treat everyone the same, I thought, I won’t see color. And yet, it’s been a long journey coming to terms with the problematic nature of my first “colorblind” ideals, learning to recognize the differences of experience that mean that it’s not “all other thing equal,” understanding my lukewarm support of some policy changes as simple complicity with a status quo that serves me. To quote Jamar Tisby, in the Color of Compromise: “Being complicit only requires a muted response in the face of injustice or uncritical support of the status quo.” Consider the steps it takes a well meaning white man to begin to recognize the size of the horizon keeping black experience invisible to him. How many more to cross it, and actually see?
It’s not just horizons that can get in the way. Astronomically speaking, there might even be factors on the ground I’m unaware of, that I can’t know without being there. Sometimes you have to be there to know there are thin high clouds blocking your view, or that the observatory dome shutter isn’t functioning properly. Or to experience other factors of environment: some people, buried in smoggy haze and bright lights, can’t even see the stars. (what sadness is this: that the byproduct of our needs often ends up creating disconnect for others; some can’t see so that others can).
Section 3.1 Perspective in Motion
Another thing to think about with all this shifting and converting talk: we all are constantly moving. Even in our stillest moments, the earth still hurries along in its great solar orbit, spinning around and around all the while. So let’s unpack this. I promise you’ll make it through: just hold on tight, and I’ll do my best to not lose you along the way.
We’ve discussed how the RA-Dec coordinate system, which we use to try to communicate, is fixed to the sky. And we’ve looked at how we look at these coordinates from different angles, so a star at RA=15 and Dec=20 will appear in different places on the sky for people standing in different places on earth. So now let’s think about what happens as we move. The main motion we need to keep track of, in addition to our own wandering around, is earth’s spin, on its axis, once every 24 hours or so. If you go outside at night in some Michigan corn field and watch carefully you’ll notice the sky doesn’t stay still. You’ll see the stars slowly circling around you: stars in the east rise up and up, crossing the sky until they are overhead, and then move down and down until they set in the west. The circling motion is especially apparent if you look north: stars there appear to circle one particular star, counterclockwise, up when they are east of that star, down when they are west of it. The whole feeling is like if you were a speck in one of those rotating snow globes, with some slowly unwinding spring moving the whole glass sky around you.
But with a little perspective shift, we can recognize that it’s us that’s spinning, not the fixed stars around us. Think again about our ants on a soccer ball, imagine a skilled player spinning it on her finger. What would our ants see? An ant on the top would see the same spot in the sky constantly overhead, but the rest of the sky spinning in a circle around it. An ant on the side, in contrast, is in for quite a ride. He’d perhaps first see the player’s face directly overhead, but as the ball spins the face would quickly be replaced by by sideline, and then the far net, and then the other sideline, and the back to the players face. Ants between the two would get a combination of these perspectives, looking toward the top, they’d see the sky rotating around that cloud overhead. Looking to the side or the bottom, they’d see the player’s head rising and setting.
If this image is confusing, try this: go stand under some light fixture, and spin around slowly, first looking up at the light, then looking at the walls, and then with your head slightly tilted back, so you can see a bit of the light, and a bit of the walls. Imagine you lived in that little pimple on your nose. The walls, the light - this would be the sky that you see. You’ll have to put this essay down for a second, but no worries, it will be here when you come back.
Now I must say, it’s not obvious that the earth is spinning. After all, wouldn’t the ants feel the flowing wind, and get a bit dizzy? I feel pretty firmly planted in my chair at the moment, no motion detected. But the key is to recognize the size of the planet. Ants aren’t actually a good analogy. If the earth was a soccer ball, you would be smaller than a microbe, as small as some of the smallest viruses. Even our tallest mountains would be no taller than the thickness of a piece of paper, smoother than the surface of a professional grade basketball. Pretty mind boggling, actually. If that’s not enough to convince you we’re moving, you can ask astronauts that have watched the rotation from space, or google these cool things called Foucault pendulums, which, detached from the earth, swing at different angles as the earth spins under them.
Stepping back, I have a love-hate relationship with the dizzying gyrations of our planet. First the hate: just when I think I’ve nailed something down in my life, I realize the world is moving too. Try as I might, I feel like I can’t catch up. We forever live between the past and the future, facing new tasks rising, leaving behind the old setting. It’s easy to get lost in these rapid changes, and never breath in the moment, look up at the sky. I’ve often worked with a small backyard telescope from Walmart my in-laws have, using it to show them Jupiter, with its beautiful stripes and moons, or Saturn, with its just discernible rings. But because of the movement of the sky overhead (well, more accurately, the earth beneath our feet), I spend most my time adjusting the telescope - sighting through the finder scope, or nudging it so that it again centers on the object in question. How easy to miss the miracle I’m witnessing through the lens.
If you take the size of the earth and the fact that it spins 24 hours in a day you can calculate how fast you would have to drive on the equator to keep the sun directly overhead. The answer is 1038 miles per hour. That’s fast. I think the lesson, or the perhaps the surrender, is that I can’t spend my whole life keeping up. Sometimes you just have to land.
I’ve moved a number of times in my life. My friend Mary Ann had a wise saying that “three moves is equal to a house fire.” A joke about the way stuff gets sold, given away, broken, and trapped away in boxes when you move. But also an allusion to the traumatic nature of uprooting and rerooting our lives. I recently had an intense discussion with my wife about moving again. We’d like to live in a place that was slightly less noisy, fewer planes flying low, destined three at a time for those parallel O’Hare run ways just few miles to the west, and maybe not right on the train tracks. Perhaps closer to church, or closer to our parents. We’d like to think about kids, or career changes and the future future future. But then we have to get the boxspring down those back stairs again. And what about our friends right now. We’re making chili for them tonight. And we’re going to have a fiddle jam tomorrow. Maybe sometimes it’s best to let the world do its thing, and be here now.
And I think this leads me to the love of the twirling of our planet. Like the stabilizing force of a spinning ballerina, the regular repeating routines of our lives allow us to dance them more fully, skirts fully extended. I feel like there’s something comforting in the daily return of the sun, the moon, the stars; I appreciate that this motion is mirrored in the motions of our home planet, marking the time of our lives.
But more, our continually changing vantage point reminds me of the wisdom of the writer of Ecclesiastes, some 3000 years ago: “There is a time for everything,/ and a season for every activity under the heavens:… a time to plant and a time to uproot,/ a time to kill and a time to heal, … a time to search and a time to give up,/ a time to keep and a time to throw away, / a time to tear and a time to mend.”
Rather than being set in stone, what is right, and what is wrong is so often best understood not as relative, but as a matter of positioning, the right place under the sun. I know these words best as a song by Pete Seeger, later made famous by the Byrds, which add three simple words as a refrain: turn, turn, turn. How else to understand the need for both tearing and mending but by the steady revolution of the earth?
The trick of course, is getting it right. Is now a time for searching, or for giving up? And once you’ve discerned the position of things, communicating your perspective in a way that accounts for the fact that each second a slightly different RA is directly overhead, that accounts for the constant shifts brought on by each interaction I have, each thought I encounter.
Thankfully you don’t have to do it alone - we’re all on this spinning ball together. For astronomers we have it comparatively easy. Astronomers much smarter than me have worked out the fine details of these shifts, and have taught computers to do much of the hard work of converting for us (though we still can easily mess it up, and so can they). And they’ve come up with tools to compensate for the motions - little motors to rotate the telescope at the same rate as the shifting sky. This is foundational to doing the rest of our astronomy – getting pointed properly. You gotta get it right. If you aren’t vigilant, with a properly set up motor to drive your telescope, your target, the light you seek, can quickly slip away.