The earth and moon are locked in a gravitational embrace. The moon, strictly speaking, does not orbit the earth. Rather, the earth and the moon each orbit around a common point. That point is called the barycenter (‘bary’ is Greek for ‘heavy’) because it is the center of mass of the two-body system. The moon’s mass is about 1/80 of the earth’s and it is about 30 earth-diameters away. The barycenter of the earth-moon system, it turns out, is located about 1000 miles beneath the earth’s surface.

Here’s a .gif I found on Wikipedia that illustrates the dance:


That’s how it goes for us and our lunar partner. Round and round and round. Our moon is quite large for a planetary satellite. It is in fact bigger than the dwarf planet Pluto! The Sun is much more massive than the Earth, about 333,000 times bigger, so the barycenter of the earth-sun system is much closer to the center of the sun itself even though the sun is almost 12,000 earth-diameters away. The sun accounts for about 99% of all the mass in our solar system. Jupiter, interestingly, is massive enough and far enough away that its barycenter is about half a million miles above the sun’s surface. That’s not much when you figure Jupiter is nearly half a billion miles away.

This odd dance we do only shows us one side of the moon. We know the earth rotates on its axis once a day. The moon rotates on its axis once a month. The earth revolves around the sun in one year. The moon revolves around the earth in one month. That synchronicity of the moon’s rotation with its revolution means we see the same face all the time. The moon is said to be tidally locked to the earth. The so-called dark side of the moon is not really dark at all, we just don’t get to see it illuminated like we do the near side. So it’s best to call it the far side of the moon as it is always further from us than the side we see.

The moon disappears from our view once a month as it travels between us and the sun and the near side is no longer sunlit. That means the far side would be in a full moon phase if we could see it. No humans saw the far side of the moon until a Soviet spacecraft sent back pictures in 1959. We actually do see a little more than half of the moon’s surface from earth because the moon’s orbit is not a perfect circle. Its slightly elliptical shape causes a little more of one side and then the other to appear in our view now and again. The moon appears to wobble east-west. This is called libration and is something you can observe yourself. Get a moon map and a pair of binoculars and watch the Mare Crisium and note how far from the edge it appears. Watch carefully for several days and you will be able to see it ‘wobble.’ A full moon, I should note, is very bright, so if you look at it with binoculars wear your sunglasses. Waxing crescent and first quarter phases are good times to find the Sea of Crises, just west (from our perspective) of the famous Apollo 11 landing site at Tranquility Base in the Mare Tranquillitatis.


The moon also has a nodding north-south libration but that is due to its inclined orbit. The moon does not lie in the same plane as the sun and the earth but is tilted about five degrees. This is the reason we don’t have eclipses every month. But that’s the subject of my next post.


Our trip covered almost 1000 miles or one kilomile. At roughly 0.75 kmi the VW turned on the dreaded check-engine light and then the motor coughed and quit. It restarted, but lurched its way around and was obviously in distress. Fortunately we had made it to our lodging and were merely driving downtown to get some food and drink. I found a local mechanic the next morning and they hooked up their computer-code gizmo and told me I needed a new mass-air-flow (MAF) sensor. Naturally they had to order the part and we had to wait another day for it to arrive. It took all of 15 minutes to fix after that. Being a Volkswagen engine the part was twice as expensive as most: $235! It’s about the size of a stick of deodorant but if it fails you can’t do much driving.

Starting for home the next day the check-engine light came on again. I went straight back to the shop and they ran the diagnostic again and it found no issue with the MAF and no other problems. We then drove to the VW dealer in Bend and tried to get them to check it out but they insisted they were too busy and could not see us on a drop-in basis until the next day. Well, fuck those assholes. All I wanted was five minutes to check the code output! The guy told as that as long as the engine was running fine not to worry about the light unless it was flashing. Thanks pal, that’s reassuring. Why have the damn light if it is meaningless? Suffice to say we made it home just fine, but it was not without its white-knuckle moments, worrying that some problem would manifest itself in the middle of US-97.

We covered a lot of ground in the state of Oregon but had no rain until we returned to California. There were thundershowers in Butte Valley and believe it or not snow on the summit of Mt. Hebron. By Grass Lake the rain was coming down so fast it was pooling on the highway. Once we made it to A12 the normal summer weather was back in full force—lots of scary-looking clouds but no precipitation.

Today and tomorrow we are cleaning and organizing. We both need a break from all the driving, and as much as we love camping it’s nice to be in a real bed and take hot showers! The eclipse is on the 21st of August, so we have some time before we take off again. Now if I can only get that goddamn check-engine light to turn off!


They told us we got the last room at the inn (and only because of a cancellation). It’s that busy time of year—summer vacation—here in recreation-happy central Oregon. After some excellent camping and some arduous driving we found an oasis in Prineville, namely the Ochoco Brewing Company. They make a fine pilsener, I must say.  The bad news is the VW crapped out and we have to stay an extra night while we wait for a part. The good news is we get to keep our motel room. Road trips have their own crazy logic, it seems.

I was pleasantly surprised to discover beautiful mountains and forests emerging from the vast arid volcanic wastelands that characterize much of the eastern part of the state. I suppose that’s a bit harsh, the river valleys are filled with irrigated fields and pastures and quite a number of prosperous-looking farms and ranches. And I don’t think I’ve been anywhere with a higher percentage of four-door, four-wheel drive F-250s. Those aren’t cheap, man.

As far as the eclipse goes, I think we’ve got a couple of good spots pegged. I feel like a fisherman who has a secret fishing hole and is loath to tell anyone about it. So I won’t—yet. My notion of a good spot is someplace isolated, in the woods, with water nearby. Key word: isolated. I can see the appeal of the wide-open spaces along highway 26, the moon’s shadow racing across the tablelands and prairies would be quite dramatic. Some of the landscape, especially around John Day, is freakishly bizarre. The flat-topped buttes are ringed with dark basalt columns that look like a monk’s tonsure. Goofy formations of blocky lava chunks like a kindergartner’s art project are pasted capriciously on the cliff sides. Throw in the sweeping vistas, a hundred or more miles in every direction, and I can see the appeal. A forested site would lack those broad views but I’m in the mood for isolation, like I said.

A staff person in the USFS station in Prairie City which is very close to the centerline said they were expecting “50,000 people” for the event. There can’t be more than a thousand residents! There are a lot of ranches and farms in the surrounding area and several are renting out their fields to campers. We spoke to a clerk in a grocery store in town and she said her husband was planning to “stay inside and close his eyes!” That was my favorite reaction to all this eclipse hype. I’m wondering if the numbers are exaggerated. On the one hand, an eclipse is pretty cool, and gas is cheap, and if the filled motels are any indication people are on the road in big numbers this summer. On the other hand, it’s a bit of a nerd-fest, don’t you think? Are there really that many nerds and nerd-wannabes in this great land of ours?

It’s bloody hot here today. We took the vehicle this morning to a shop in town a little less than a mile from the motel and we were soaked in sweat on the walk back. This was before ten o’clock! I think I’ll enjoy the air-conditioning in the room for a while and then go for a swim in the pool. Yes, they have a pool. Thank goodness for the little things. I want to go back to the Ochoco Brewing Company and try that unusual pale ale again, they seem to have a creative brewer. But it will be REALLY hot by this afternoon. Fresh brew, though. Sacrifices may have to be made.


Actually we are in Hines, Oregon which is just a stone’s throw from Burns. In fact it is hard to tell where Hines ends and Burns begins. No matter, we had a good steak and some local brew at The Pine Room Restaurant and now we are kicking back in our motel room. On the way here (via US-97 and Klamath Falls) we had lunch in the mini-burg of Dairy on 140 on the way to Lakeview. The place was called O’Connor’s Bar & Grill! From Lakeview it is US-395 to Burns. Talk about wide-open country. Lots of sagebrush and juniper and some imposing volcanic buttes. Lake Abert is huge but singularly uninviting as it’s alkaline. Figures. You are out in the high desert and you get to a 60-square mile body of water and it is undrinkable and can’t be used for irrigation.

I kept thinking about the pioneers who came this way. “Well Jethro, I think this looks like a good place to graze us some cattle!” Seriously? Of all the places to pick, these characters decided the prime real estate was bone-dry and hot as hell. I suppose if you are the first people to settle a place it might look good. But my goodness it’s some seriously bleak country. And it’s huge. The distances are staggering. It’s one thing in the age of the automobile and the interstate system, it’s another in the age of the covered wagon. Those folks were either nuts or totally hard-core. Most likely both.

Tomorrow we head out to the forested regions to look for camping spots. We are scouting potential locations for our eclipse trip. It’s a month from the event and we need to get some boots on the ground so we’ll have a workable plan of attack for then. I have a feeling that this part of Oregon will not experience the crush of travelers that are expected for the more accessible areas like the coast and the I-5 corridor. Madras, just north of Bend, is sort of eclipse central, and we are far from there. I’m hoping the famously clear and dry summer weather that bakes the arid wastelands to a crispy golden brown will mean good viewing for those of us prepared to swelter for science.

So what’s the allure? Why drive hundreds of miles out to the middle of some godforsaken scab-land for a two-minute event? I don’t know. Maybe I’m the one that’s nuts. I have air-conditioning and hot showers. I’m choosing to forgo them. I suppose it’s the scale of the thing. After all we are talking about the sun and the moon. They are really big things and really far away. The moon is about ten earth-circumferences away from us. To travel a quarter of a million miles you’d have to circumnavigate the globe ten times. That’s a long way. It’s miniscule compared to the sun’s distance—over 90 million miles away. Forty trips around the equator will get you a million miles. To get to 90 million that’s 3600 trips!

Astronomical distances are of course on a much larger scale. The nearest star other than the sun is over four light-years away, that’s about two dozen trillion miles. So this solar system stuff is pretty damn small by comparison. But on a human scale it is pretty damn big. The deep space stuff is so massive (there are stars so large that if placed where our sun is they would fill the space all the way to Jupiter) and so distant that our feeble mammalian brains can barely grasp the numbers. So a solar eclipse is a local phenomenon. It’s happening in our own celestial neighborhood.

That makes it more dramatic. The moon will actually cast it’s shadow upon the earth and I intend to stand in the middle of it. I’ve looked through ‘scopes at deep-sky objects like galaxies and whatnot and it’s pretty cool shit. Now that we have the Hubble up there peeking into the void we get great pictures of amazing and bizarre structures, and with X-ray imaging and other magical technologies we can “see” things that we never knew existed. All of that is pretty damn groovy.

Maybe that’s it. Eclipses have been experienced by humans since they could look up. For many they were of great cosmic and cultural significance. Predicting—not just observing—eclipses goes back to antiquity. In fact eclipse data are still predictions. The measurements of the actual events are necessary to check and fine-tune the models used to describe these heavenly motions. It only seems like the NASA geniuses have this stuff all figured out. More like they are always figuring. Things are complicated out there and they are always tweaking the formulae. Eclipses, particularly total solar eclipses, are something humans have looked on with awe and reverence for a long time. In our fast-moving special-effects 24/7 info-tainment world an eclipse may no longer have that cachet. I know I’ll be missing a few baseball games and Law & Order re-runs. Guess I’ll just have to suck it up!

I’ll report back in a few days when we are on the return leg.


Us and Them

Science upends the world. That’s what makes it different. Philosophy and religion can stick with the old questions as they are unanswerable. Were the old sages wise? Do they still teach us? That’s enough material to keep anyone going. It’s good stuff, but it’s not new. Science alone does that—it finds out new things.

Here’s one:

There are more bacteria in your gut alone than cells in your entire body.

Our parents and grandparents didn’t know this. They might not have cared. But it would have upended their world. After all this is what that bit up there means: there is more of them than you.

If that doesn’t mess with your head consider a check-up. Seriously. There is more of them than you. What is our most sacred and treasured thing? Our autonomy. Our sense of self. Our individual identity. Our uniqueness. It should be said that unless you are a twin or somesuch you do indeed have a unique arrangement of alleles on your genes. This notion of apart-ness is powerful and important, especially in a capitalist society. But now we know that there are more of them (tiny critters) than there are of us (folks).

I think we ought to shout that from the rooftops. I have a lot of rooftops, and it’s hot. But think about all the foaming at the mouth we do over stuff like immigration. We as a body politic worry about whether there are more of them than there are of us. That’s nothing. We are already there. There’s more of them than us.

We aren’t who we think we are. Science has shown us that our idea of race is a fallacy. We all have the same genes. Some of us have different characteristics, but we are all united by common ancestry. We’ve all got the same DNA. Now we’ve found out that our very notion of individuality is a joke.

You’ve got a monkey on your back. Me, too. All of us. It’s inside, and microscopic, but it’s there and it’s as much you as you. More, in fact. Imagine the genetic possibilities, all the many, many non-human genes living within you. That blows my mind. Think about the diversity of creatures. It’s like your own wilderness area. A private ecosystem. Well, except for the stuff you excrete. Thanks for sharing, by the way. Nothing is truly private in nature, it all has to go somewhere. Closed systems are temporary things; the Second Law cannot be violated.

I’m not an “I” anymore I’m a “We.” Me and my flora. There’s more of my flora than there is of me. And before you get upset about these alien invaders it turns out they are the older ones. I’m the newcomer. These living things came first. It may be that they made me come about, that their role in the evolution of hominids was a crucial one. After all without them I can’t digest my food or void my wastes or fight infection or any of a host of things. We live within an intricate metabolic energy balance, whizzing and pasting and pooting through the day. We have to have air, fuel, and water to keep things pretty close to 98.6 Fahrenheit. We are constantly on, we have only a shutdown button and there’s no reset. Our very lives are flux as we live inside this permeable membrane that continually exchanges stuff, like air and other chemicals—the stuff of life—with the outside world. If it stops, we stop.

And now it turns out a whole bunch of other things are in there with the me I thought was just me. I’m in this bag of skin and bones with armies of them and only one of us. I mean me. Here’s some science-speak:

The gut harbors trillions of bacteria that modulates the host homeostasis within and outside the intestinal tract.

Good thing! I like homeostasis. You should, too. So these trillions of fellow travelers with me are keeping the me alive. I can’t kick ’em out. I’m stuck with them. They make it all go and I suppose I ought to take a more neighborly outlook. Hey, I eat live-culture yogurt! I drink homebrewed beer! I’m very pro-biotic, man. My bacteria ought to be happy with me. I’m thinking it’s smart to keep them that way.

Science is a human endeavor. It’s filled with all that’s good as well as all that’s bad about people, just like any other human endeavor. But this new stuff that pops up is truly new. People may have guessed some of the things about nature back in the day. The Greeks came up with the idea of atoms, for example. But those were just ideas then. They are tangible now. Not literally, you can’t touch them. But they are real. Ideas in science are all fine and dandy, but repeatable results matter more. And when the facts come, we have to be ready to see the world anew.

We are not what we think we are. Our social conditioning and mental outlook are holdovers from more ignorant times. We know more now than we did then when we constructed these schemes about individuals and societies. Science has out-stripped cultural norms. We aren’t autonomous beings. We are ecologies. That’s a very different thing. So different we don’t know what to make of it. We aren’t mentally evolved enough. I predict that will change, and sooner rather than later. The accumulation of such revelatory ideas will reach a crticial mass and we’ll be forced to adapt, as a species. Note the physical words, mass and force. See how hampered I am by the language of Newtonian mechanics? Surely these happenings will not be governed by Newton’s Laws. They aren’t billiard balls or rocket ships.

In the meantime I’ll try to be me and you try to be you and we’ll all be us together. But we better start thinking more about them. They aren’t going anywhere.

Umbral dreams

I’ve got this notion about going up to Oregon to see the eclipse next month. They say a million people will converge in the Beaver State for this event, that will increase the roughly four million population by twenty-five percent. All for two minutes of totality. The entire eclipse will be over two hours, but the shadow will be complete for only a fraction of that time. I’m chasing that shadow nonetheless. Looks like a scouting trip up to the eastern part of the state is the first order of business. I’d like to find some dispersed camping spots out in the woods somewhere near the centerline. If I can come back with a list of three or four likely places that will make the actual journey more relaxing. It’s only a day’s drive from here, but I plan to stay away from the key highway corridors, especially US-97 and I-5, and I want to be up there before the weekend as the eclipse is a Monday morning.

We took a trip to Mexico in 1991 to see a total eclipse predicted to nearly last seven minutes. We were on the beach at Mazatlan and as totality approached the temperature dropped dramatically. What happens when moist air gets cold? Bay Area people know all about marine fog. That’s what happened. A fog layer formed and obscured the eclipse from view! But I remembered something a colleague told me before I left, which was to ‘turn my back on the sun’ and watch what was happening to the earth. Sure enough we did and we saw the moon’s shadow racing across the Sea of Cortez. I did not expect that to be such a startling sight, but it was. Eclipses create two shadows, one while the sun is partially covered (called the penumbra) and one when the sun is totally covered (called the umbra). As you can imagine, the umbra is much darker, noticeably so, and to see a shadow on that scale was mind-bending. I’m a big fan of mind-bending. That particular eclipse cast a shadow about 150 miles wide! The path this summer in Oregon will less than half that.

Nocturnal fishes leapt from the waters as the umbra passed over us. Diurnal birds circled and settled to roost. Lights came on in town. Stars and planets came out in the dark sky overhead. It was noon, but there was twilight all around us, like a 360-degree sunset. Too soon the trailing edge of the great shadow raced onward across the globe and we entered the lighter penumbra. As the sun emerged from behind the moon in the partial phase of the eclipse the temperature rose again and the fog vanished. Although we missed the main event it was still a full fight card, and in life you often have to swallow the bitter with the sweet.

One of the things you can’t control in this world is the weather. They say the city of Madras will have the best chance of cloud-free viewing. But I figure a great swath across the arid west including large parts of Idaho and Wyoming will have clear skies. That’s just the way it is most August days in these places, hot and bone-dry. But we could get out there and camp for four nights and wake up to rain or overcast or some other unusual or unlikely weather event and get skunked. But that’s OK. I mean of course I’ll be disappointed (and have to start planning for 08 April 2024), but that it will still be an adventure. And that’s what these umbral dreams are about—the adventure. A true hunter embraces the hunt; the outcome may not be the desired one, but there will still be the hunt. I like to think that the journey is just as important as the destination.

It’s going to be hard to find the right spot. It would be nice to have some shade and a water source. We are equipped for dry camping, but five days is a lot of water to pack. It’s not hard to ration for drinking and cooking, and you can do cleanup with a lot less if you plan ahead. But we will be in the heat and dust for five days. I’m going to need a creek to bathe in or a little brook to fill the sun shower. Water levels are falling and streams are drying up all over. And even though we’ll likely be in one of the many National Forests this is eastern Oregon. This is part Blue Mountains and part Snake River and much like the nearby Columbia Plateau and Great Basin. Hot summers, very little rainfall, cold winters, and snow at high elevations. Grasslands interspersed with forested slopes, rocky drainages, mesas, buttes, and arid landscapes. I expect there will be many old buck-hunting spots and other hunters camps near the roads, primitive but well-used, with flat spaces for a few vehicles and tents. The developed recreation sites will be the first to go and I don’t want to compete for any of those.  I’ve camped all over the west in such spots, usually they are empty in the summertime and don’t get action until deer season.

When you stand in the shadow of the moon you feel like dancing. Or running amok, naked and howling like the poor creatures who think the day has suddenly become night. It’s like the hand of god passing over the sun, you feel like you’ve forgotten to sacrifice an ox to Zeus and he’s letting you know you’ve fucked up. That terrifying and wonderful sensation of tininess, of irrelevance in the vastness of the cosmos surges through you and instead of despair it gives you joy and you shout and cheer with life. At least that’s what I think right now. Maybe after all the sunburns, bug bites, and rocks in my shoes I’ll feel differently. It’s going to depend, I imagine, almost entirely on how much water will be nearby. Nothing like a good cold soak on a hot day to improve the spirits.

So that’s what’s on my August calendar. If I were you I’d stay home and watch it on TV. Not that you shouldn’t enjoy this amazing natural phenomenon, I just figure you’ll get a better view and there will be one less car on the road.

Stay tuned for updates—I’m sure there’ll be enterprising live bloggers and all that sort of thing on the big day. Not me: I’ll be unplugged. But fully connected, I hope, with my umbral dream coming to life.


The earth’s orbit around the sun is nearly circular. It’s actually elliptical, but a circle is just a special case of the ellipse; we say that a circle has an eccentricity of zero. The eccentricity of an ellipse is greater than zero but less than one. The orbital path of the earth has an eccentricity of about 0.0167 which is pretty small and means the path is damn close to a circle. Halley’s Comet has an eccentricity 0.9671, that’s highly elliptical.

Another way to think about it is that the mean or average distance between the earth and the sun is about 93 million miles (150 million km). At aphelion, the furthest point in the orbit, the distance is about 94.5 million miles (152 million km). At perihelion, the closest point, that distance is about 91.4 million miles (147 million km). Now a few million kilometers might seem like a lot, and it is, but it’s not a lot compared to the total distance, only about one-and-a-half percent.

Aphelion is today, July 3rd. Perihelion will be on January 3rd, 2018. So we are furthest from the sun during our (northern hemisphere) summer and closest in our winter. It’s just the opposite ‘down under’ as they are experiencing winter right now. The seasons are due to the earth’s axial tilt of 23.5 degrees. At this time of year the earth’s northern hemisphere is leaning towards the sun and so we have summer. At the opposite end of the orbit, the perihelion in January, the northern hemisphere will be leaning away from the sun and thus we’ll have winter.

Interestingly the earth is moving most slowly in its path at aphelion and so summer in the north is longer by about five days than winter in the south. Which means our winter is about five days shorter than winter in the south. I don’t like that. I think it should be flipped around. I like winter way better than summer and I don’t like having to endure five extra days of hellish heat. And I feel cheated out of five days of blissful cold. But since I’m not moving to Chile or New Zealand I’ll just have to put up with it.

The idea that celestial bodies had elliptical orbits is due to Kepler. Ancient peoples knew the sun’s movement along its path through the sky (called the ecliptic) was not uniform. Lots of schemes were created to explain why this was so but nothing stuck until Kepler. Newton confirmed this work later by showing elliptical orbits to be a consequence of his own law of gravitation.

Standing on the equator the movement of the earth’s surface relative to its center is about 1000 miles per hour. In its nearly-circular orbit around the sun the earth is racing along at about 30 kilometers per second or 67,000 miles per hour. That’s quite fast—humankind’s fastest spacecraft (Helios 2) hit 70 km/sec or 157,000 mph. Escape velocity for an earth-launched vehicle is about 11 km/sec or 25,000 mph.

The next time you think you aren’t going anywhere in life just sit back and enjoy the ride that comes for free. It’s a pretty good one.