Please Feed the Jays
If Lassen National Park rules about not feeding animals are serious, the Clark's Nutcrackers must be a sting operation. I love the bright, adaptable family of birds called Corvids, in part because I share a name with many of them -- the Jays. But their handsome, social cousins, resident 8000 feet above sea level, in our telescope set-up area in the Bumpass Hell parking lot, mooched with professional skill and zeal. They obviously expected much of their calories from passers-by, and mere regulations provided no cause to abandon a good thing, particularly if someone was willing to sneak past the rangers, and feed them.
There is reason not to do so. Animals are often susceptible to human disease, and even if not, most of what we provide is junk food, long on calories but short on proteins and minerals. A steady supply causes nutritional problems. Yet I must admire the birds for trying. Furthermore, for all the terrible things we have done to our less technically advanced neighbors, many of those who have survived us best, have done so by learning to coexist -- I have raccoons and opossums under the back deck, rats in the roof, and squirrels and birds at the front-yard feeder. It is kind and just to leave wild habitat for other creatures, but I would hate to deny a species the chance to survive by changing: I have more faith in their adaptability than in our good will.
Grinning, I turn from the plump gray birds to my equipment. I have brought one of the smallest telescopes to the fourth annual Lassen Star Party -- an Intes six-inch f/10 Maksutov, and an observing program that many would say is out of proportion to its size. I have been doing a "Herschel list" -- not the "Herschel 400" list of 400 deep-sky objects, that the Astronomical League recommends for moderately experienced observers, but the full list of all 2514 deep-sky objects found by the great observer, William Herschel, during his systematic survey of the sky visible from England, almost two centuries ago. I had already observed approximately half that list, in the course of other programs, and the bright half, at that. The 1200-odd that remained, are tough for only six inches of aperture. Yet some people enjoy landing giant fish with light tackle. Ask them why I do what I do.
With an hour to true sunset, the Sun slides behind the high ridge to the west. Promptly, several of us find Venus, first in binoculars, then with the naked eye. Mercury remains elusive. Perhaps it is too close to the Sun, or has already set. But how wonderful to be reminded that the day does not chase the inhabitants of night away, it merely hides them: The Sun does not make us see more, it makes us see less. Mars, too, soon becomes visible. Today is the Fourth of July, and Mars Pathfinder has landed. To our feigned dismay, we cannot see it, nor even the great dust storm which may have threatened its operation. Yet it, too, is still there, merely hidden, and will commence its survey of Martian geology and -- who knows -- Martian paleobiology, before long.
The remaining Herschel objects are nearly all galaxies, which of course dominate any catalog of faint fuzzies for the visual observer. There are hundreds of prominent star clusters and nebulae in the Milky Way, but by the time you have aperture to see most of them, you can see thousands of nearby galaxies, and when you can start to pick out more than a few of their own clusters and nebulae, you have aperture enough to see tens of thousands, or hundreds of thousands, of galaxies, even farther away. Most of my list lies in the third or so of the sky centered on the heart of the Virgo galaxy cluster, which now lies south and west at twilight. I would like to log as many objects here as I can, before the eastward march of the Sun blocks my view for months.
I have had good luck so far. I started a month ago, and found the first sixty objects from sites not nearly so dark, like California's Fremont Peak State Park, or the hills of the San Francisco Peninsula, above Palo Alto. Last night, from a lower parking lot at Lassen's Devastated Area, I found another fifty. Tonight, the dark sky and far southwest horizon promise many more. Besides, a companion with a 12-inch Meade LX200 has set up next to me. I, too, am a Jay, so perhaps I can mooch a look or three through his telescope, if the viewing gets tough or the fields get crowded.
Twilight does not descend -- rather, the shadow of the world rises from the east to engulf the sky. There is Polaris -- I align my telescope. Before the sky is dark, I have found sufficient stars to set on the field of my first object, which is for the moment invisible. Yet at 121x, before long, the target appears, even while the sky remains faintly blue to the naked eye. The galaxies, too, are still there by day, when the harsh Sun draws attention to nearer objects and screens the wider truth beyond. Soon full night is upon us, and the sky is wonderfully black and transparent. The rising Milky Way seems bright enough almost to cast a shadow. The Pipe Nebula, the North American Nebula, and the Pelican Nebula are prominent to the naked eye -- I have seen all three without optical aid before, but this is the first time I have clearly seen the Gulf of Mexico and the Florida Peninsula, in the North American Nebula, with no such assistance. The joke of the evening is that if we could make the stars go away, it might get really dark. Here, in the wilderness, far from the glare and bustle at the heart of the cluster of cities to the south, the light of stars is almost all that remains. Only one shallow light dome lifts above the south horizon -- we conclude it is Chico, California.
I have separated my list of targets into groups by hour of right ascension, and have sorted each group by declination. Thus I can start in the south and work north as objects sink toward the horizon. The galaxies are usually close enough together to move from one to another quickly, star-hopping, often without changing eyepieces. My friend with the big Meade is willing to help: The six-inch actually can find all the targets, but when two are close together, or when there is a dense cluster of galaxies, it is hard to tell which is which, and the larger aperture proves invaluable. I have long since surveyed most of the glare and bustle at the heart of Virgo cluster, to the depth of the Herschel list and beyond, but there are several outlying small groups which I have not looked at closely, like the ones centered on NGC 4266 or 4365. In these, there are as many as a dozen galaxies visible in the 12-inch, at one time, with a 20 mm Nagler eyepiece. These regions must be the Chicos of the sky.
For all the 8000-foot altitude, cold is not a problem, perhaps because the air is calm. I wear a warm wool hat and a down vest over my street clothes, but I have not put on any of the extra layers, that I sometimes use at lower sites. I quit at about 0200, after four hours observing, with eighty more objects logged. The next night, at the Devastated Area again, I do almost fifty. On the final night, I return to Bumpass Hell. The Clark's Nutcrackers are back, and there is a Red Fox scavenging someone's abandoned sandwich from the edge of the parking lot. I log almost another fifty Herschel targets, then start the long drive home. I cruise down the dark Central Valley, till dawn breaks clear. The western mountains are visible, and the entire Sierra Nevada, from Mount Lassen to Mount Whitney, stands in violet silhouette against the eastern sky, as one by one the stars go slowly out.
Yet the galaxies are still there. My mind is full of galaxies. The sea of space is replete with island universes, and I am awash in the waves that break upon their shores. In four nights, I have looked at over 200 galaxies, in a survey guaranteed to prefer the large and bright over the small and faint. A big galaxy contains hundreds of billions of stars. In four nights, my eyes have gazed upon the integrated light of nearly ten to the fourteenth suns. The total number of galaxies in my logbook is about ten times as great. That's ten to the fifteenth suns. 1000000000000000 suns. What can such a number mean? What should it make me think about, to look at such a sight?
I wonder who might be looking back. Astronomers have a perspective larger than that of most debaters on the subject. "Chance in a thousand million that any given star has a planet with intelligent life," say some. "Chance in a million million." I'm not worried, I've got ten to the fifteenth stars in play, just me personally. If the odds are as good as a chance in a million million, it's near certainty that somewhere, somehow, someone was looking back at me. Maybe I should have waved. If the odds are worse, no problem, got lots more galaxies where those came from, all I need is to buy a bigger telescope -- or mooch one.
And the odds should not be bad. Frank Drake described something like a giant Pachinko machine. You drop stars in a hopper at the top. Each cascades down through an array of shiny brass pins, erratically bouncing this way and that. If all the probabilities turn out right, then it falls out the bottom over a special bin that says "Jackpot! Intelligent life here!" The rate at which stars enter the bottom bin is equal to the rate at which they fall out of the top one, times the probability that all the bounces come out just so.
In our own galaxy, the average rate of star formation, labeled "R", is about ten per year -- the rate at which stars leave the top bin. The probability, "p", used to worry people -- no one had any idea how many stars had planets, or how many planets had life, and so on, and conservative assumptions set some of those probabilities very small. But the pins are bending. Spectrometric study of other stellar systems suggests several tens of percent of stars have planets. The microorganism-like structures in Martian meteorites, and the prospect of thermal vents warming the oceans of Europa, suggest that our own solar system harbors not one, but three, likely locations for life. The heyday of Martians may be past, and if hypothetical Europan organisms have a day in the Sun, it will probably be in some far-off aeon when the Sun itself is warmer. Still, one win and two possibles in a single solar system makes me think that perhaps a substantial fraction of stars with planets, have had or will have life on one of their worlds.
The trend toward complex behavior is broad in the animal kingdom. Horses and harvest mice use tools, as do my friends, the Corvids. Some birds even make tools. Structure-building and environment-modifying behavior, albeit probably more instinctive than intellectual, is wider spread -- spider webs are good examples. Survival seems to favor complex behavior; thus I believe a substantial fraction of life-bearing worlds eventually harbor something we might call intelligence. I think one to ten percent of stars reach the "Jackpot!" bin.
How long does a star stay there? Suppose the lifetime, "L", of an intelligent civilization is 1000 years. Then, if you take a snapshot of the universe, you see last year's jackpots, plus the year before's, and the year before that's, and so on back to 1000 years ago. Thus the number, "N", of extant civilizations is N = RpL -- and that, in a nutshell, is the famous "Drake equation". For this galaxy, it works out to N = 0.1 to 1 times L, if you take my numbers for R and p.
L is a big uncertainty. The only data we have, is us. We have been capable in principle of radio communication at interstellar distance for less than a hundred years, and during much of that time it looked like we would blow ourselves up in atomic war by a week from Tuesday. If L is less than 100 years, technological civilizations are scarce, and most will be gone before we know them. Yet L might be larger in two ways.
First, who says we just care about technological civilizations? If we last long enough to go find them, it might be fun to meet folks with art or culture advanced enough to impress us. For our own history, that gives L of 10000 or 20000 years -- back at least to the era of Lascaux Cave or of the Solutrean laurel-leaf blades. Or, it might do to meet someone with intelligence that split the difference between us and the most advanced non-human terrestrials. I'm not sure who the latter are, but our ancestors had cranial capacity half way between chimp and modern human, over a million years ago. L = 1000000 is promising.
The second way to stretch L is more thought-provoking. Suppose a fraction of civilizations survive the self-destructive phase that we seem to be going through, and live a really long time. It doesn't take a high percentage of civilizations lasting for a billion years, before the most common civilizations around become old ones. What's more, very old civilizations might have expanded notably. Even if the speed of light should prove unbeatable, that doesn't keep a billion-year civilization from expanding through the Virgo galaxy cloud -- after all, it's only a couple hundred million light years across. Look at it another way: If my numbers are correct, the ten to the fifteenth stars I have observed, have produced at least ten to the thirteenth jackpots -- 10000000000000 intelligent civilizations. If just one of those lasted billions of years, it should long since have explored this galaxy, and many others, and be sitting in our laps right now.
So, where are they? That puzzle is the "Fermi Paradox", for Enrico Fermi was indeed the first to realize that even very scarce long-lived civilizations could explore and influence a vast volume of space. For a long time, it was easy to use the Fermi Paradox as an argument that the probability "p", in the Drake equation, had to be very, very, small; for if it weren't, "they" would have to be here, wouldn't they? That argument gets ever less tenable as scientific discovery keeps bending the Pachinko pins, but the question doesn't go away: Where are they, I say, where are they? It's enough to drive you crazy.
It's enough to make you think about the rules against feeding animals in Lassen National Park. I don't know if a billion-year-old civilization would have attitudes about conservation, or about the natural world, or about preserving indigenous cultures, like we do, but a deliberate hands-off policy, imposed and enforced, is one way to explain away the Fermi Paradox. The trouble is, nobody asked me if I like a hands-off policy, and I don't. I think I would prefer to be a raccoon, or a corvid. Thank you very much, but I would rather rely more on my own adaptability than on somebody else's good will. So if anybody out there is listening, I hope some of you are willing to sneak past the rangers. I hope some of you will come and feed the Jays.