We Don’t Know, But We Can Learn

I have repeatedly written about how differences between humans and the rest of the animal world are far less than we anthropocentric critters would like to think. Many of the distinctions that we humans previously believed set us apart from animals are relentlessly disappearing—and many more of them are now being understood as not unique at all, just a matter of degree.

But what does make us different from animals—even those closely related to us, such as the great apes? I won’t to try to answer that monster question here. I’ll simply note one key difference: our ability to reason, to think rationally, to look back and ponder what happened. It gives us a great advantage over the sharpest chimpanzee.

What does reason do for us? Well, countless things, but I’ll just look at one example here, for illustration: our ability to ponder our actions, after we’ve done something and to learn from the process. Most of what we do is programmed deeply within us. We’re usually not even conscious of what we’ve done or why. For example, we don’t know why we eat what we do—millions of years have taught us what foods have kept us alive and healthy, long before we thought about it. It’s the same for animals.

Our sex lives are governed by habits that we developed over eons—habits that kept our species going. We mostly don’t know why we do as we do in the sexual arena; again just like animals. We’re just driven. It’s very much an instinctual thing; behaviors that are deeply ingrained in us. Animals do the same.

These and countless other behaviors of ours are done without conscious thinking or planning—just like the animals. One might be inclined to disagree; to feel that we take these and other actions after carefully pondering them, but that’s not the case. Many clever experiments have shown that we take action first and think later. We’re more automatically programmed than we’d want to believe. For one thing, fast action (without taking time to think) is often necessary. And the majority of our actions cannot require thinking; otherwise, we’d be lost in the minutia of details and never do anything.

So how do we differ from our animal cohorts? Unlike them, after we take action, we are able to ponder what happened and gain insight into why we did it. We can ruminate over events and learn from them. That’s something that all other animals—not possessing our elevated cognitive abilities—(pretty much) cannot do. It’s how we learn.

So what are the benefits of this ability of ours to reason? Once we understand why we do something, we can see the necessity of modifying or controlling our urges, if need be. We can understand that certain inherent behaviors that drive us to consume unhealthy foods (foods that a million years ago made sense) are not what we should any longer be doing. Similarly, certain sexual behaviors that long ago were useful (such as procreating endlessly) are no longer useful.

This learning process is one way in which we forge morals. For example, if we can learn from our violent behavior towards one another—that violence is foolish—we can come to see that tolerance makes sense. If I get into trouble by following my instincts in a given situation, I can grow from the experience, adapt, and become smarter—even develop a moral sense about it. It’s given Homo sapiens a huge advantage—an advantage most animals don’t have. What puzzles me is why we seem to refuse to heed some of our obvious lessons.

Titmouse Thief Caught Stealing Dog Food

The Run Returns

What surveyors around here call a “wet weather stream” runs by the house. These streams are also called “runs.” Not much of a watershed feeds it—thankfully—or we’d have lost a lot more unsecured items over the years, when it becomes a raging torrent after heavy rains.

Our little run flows half the year—from late fall through late spring. During the summer thirsty trees along its banks eagerly drink up all its water (except just after a hard rain), so its flow dries up. When fall’s dormant period arrives those trees begin their slumber, which allows the stream to run along and eventually make its contribution to the Potomac River and then the Chesapeake Bay. That gives us a very nice change; half the year it babbles along and for the remainder of the year it can get very quiet.

So it’s now that time of year when the little stream begins its uninterrupted winter’s run. Its constant bubbly, burbly voice provides gentle background chatter. Reposing in the evenings in my outdoor tub, I listen to its light-hearted murmuring; noting that it sounds a little like indistinct cocktail-party chitchat. But every now and then a few burbles stand out from the quiet chatter—sounding eerily like random syllables of human speech.

In a few months there will be a short period, as late spring transforms into summer, when the run will dry up and fall completely silent. The awakened trees will once again suck up all its water, but the singing insects will have yet to begin their incessant summer chorus. The nights are ghostly silent then. The only sounds are the flapping of firefly wings—much too hushed for my old ears to perceive.

So for the next few winter months the stream’s subtle chatter will be my bathing companion—now and then irritatingly interrupted by a distant dog’s barking. I find the creek’s babble to be a soothing sound. I can lay back and let its lilting chorus lull me into reverie—well, except for those infrequent moments when the human-seeming syllables get tossed out. They almost cause me to sit up and peer into the darkness, fooled into thinking that I’m not alone after all.

December Deluge

The Deer Hunt

We are in the midst of deer hunting season—that time of year when the surging population of these large herbivores gets modestly diminished by their sole remaining predator: Homo sapiens. Long ago, wolves, cougars, and other large carnivorous animals checked the size of the deer herd. But now those wild predators are gone and deer are exceedingly abundant—for either their own good or ours.

The problems for us: they munch our gardens, carry Lyme disease, and joust with cars. The problems for them: they become crowded and disease prone. In recent years state officials are increasingly concerned about the spread of chronic wasting disease—a progressive, fatal disease that resides in the brain of deer. The apprehension is that it will decimate the wild herds and even may be unhealthy for humans to eat, although there currently exists no evidence that people can be infected.

When we first moved out here from the city 25 years ago deer hunting season was rather intimidating to us. The sound of a rifle being fired just over the ridge was startling, the sight of gun-toting guys roaming the woods (or cruising back roads, spotting deer from truck windows) was unsettling, the reports of human fatalities were tragic, and the remains of discarded beer cans and deer carcasses along these back roads were offensive.

Twenty-five years later we have adapted to the hunt. We are more aware of the manifold problems of a large deer population, we’ve grown accustomed to the sound of guns, trust local hunters, and we appreciate the occasional venison that our neighbors gift us with. It’s far healthier than feed lot-fed, antibiotic-stuffed beef.

State officials certainly have a deer dilemma on their hands. I don’t envy the hot spot they sit upon—tugged one way by suburbanites who are angry about their munched gardens and fender-bender repair bills, another way by health officials who warn of disease epidemics, another way by folks who feel that Bambi should never be targeted, and still another way by hunters who chafe at one more regulation they must comply with.

One response in our part of Virginia has been to extend the deer-hunting season, from a couple of weeks in November to two months that end in early January. Furthermore, hunters are allowed to shoot half a dozen deer during that time (although some old hands get far more than that, while the game warden tends to look the other way).

The “deer problem” is evolving rapidly, as are the “solutions,” as we learn more about the complexity of the situation. It’s another case of humans tampering with nature’s balance and then experiencing the consequences later. Hunting season will necessarily be with us for some time yet. I’m glad we don’t get as alarmed as we once did—but I still involuntarily flinch when a rifle shot blows away the quiet of the woods.

Chickweed Blossom (Only local plant to bloom in winter)

Winter Storms In

It’s more than a week into December and we’re finally getting our first taste of winter. It’s been an unusually warm fall—November set a 25-year record for the highest overnight temperatures. Although the days were typical for a November, it just did not get cold at night.

As a result, winter’s arrival was delayed this year. We found ourselves being bugged by insects that otherwise would have succumbed much earlier to the cold. Things being a little warmer, those bugs could hang on a little longer—crickets still singing and yellow jacket wasps still buzzing us on Thanksgiving, though they moved a lot slower than they did in July.

An “Indian fall” (sort of a hungover Indian summer) like this can also confuse plants. Early-spring blossoming shrubs and trees poke out a few tenuous buds—testing whether winter just might have already rushed by. I wince when I see these vulnerable shoots—knowing that they will soon be zapped by a cold snap.

And now it’s upon us. Winter blew in with chilling force, a few nights ago. Snow fell one evening and the thermometer followed suit a few hours later. We woke up to find that fall’s browns and grays had become masked with brilliant white. Honest winter is here. The remaining bugs and impulsive buds have expired. The long sleep begins, as eggs in the ground and more cautious buds hold their spring promise in abeyance.

Now is the time to get serious with the woodstove. No more small sticks of wood flashing briefly, and then going out. It’s time for serious logs and a perpetual fire. It’s one of my creature comforts to stand next to the woodstove and watch the birds’ antics out at the feeder. They fluff up to ward off the chill. No need to tell them that winter has stormed in.

Early December Snow

Empathic Animals

Empathy is most simply defined as the capacity to identify with another being. It’s often described as the ability to “get into the someone else’s shoes.” Until recently empathy was considered to be a uniquely human quality (maybe because we’re the only creature to wear shoes?), but that’s changing. One of the principle researchers who has been shifting minds on the issue is Frans de Waal, a primatologist who has observed chimpanzees for decades. He tells us that empathy is exhibited by many kinds of animals.

The most basic expression of empathy is mimicking. You laugh, I laugh. I yawn, you yawn. I use threatening body language and you reciprocate. Scientists like de Waal have observed our cousins the apes mimicking (aping?) each other in many ways.

In humans empathy crosses cultures and languages. That’s a prime reason why nonhuman primates can show it: we don’t need to know how to communicate by words with someone to feel empathy. Laughing and yawning are universal behaviors; they come naturally.

Since researchers are finding that our ape cousins commonly exhibit empathy (now that they no longer doubt apes have it), we now understand that evolution gave us this capacity; i.e., we’ve acquired it naturally. Long ago we lived in small groups that survived by exhibiting cooperation and empathy. It’s what gave us humans an advantage. Those primate species that lacked empathy were a little less fit and became extinct. We capitalized on our social connections and ability to bond—attributes that were strengthened by our propensity to identify with each other.

In small groups we struggled to survive and we thrived—aided by our empathic qualities. But it goes only so far. Our feelings of empathy tend to be limited to those closest to us; those whom we know and to whom we feel connected. In the last 10thousand years or so we’ve settled down into dense enclaves and find ourselves increasingly competing for resources. Our empathy for the “other” under these circumstances tends to dwindle. Aggression quickly follows.

War has been so constant throughout recorded history that some of us find ourselves concluding that Homo sapiens is by nature an aggressive species that can’t seem to control its violent habits. But for 99.9% of our existence as a species cooperation and empathy were crucial and prevalent. Which really is us: the deeper empathic animal or the warlike creature? Is our aggression just a veneer that we’ve acquired in the last several thousand years—a veneer we might peel away to reveal our empathic core? Of course, both emotions are us; we are both warlike and cooperative. It’s our choice… to decide which one we want to prevail.

November Spirea

Enticing Sky

When November rolls around I find my pulse quickening, as I gaze at the night sky. I’m anticipating the return of those glorious dark-sky winter nights, when the stars stand out ever so prominently. While the summer sky is beautiful to behold—I can stare deeply into it, the Milky Way dazzling in its brilliance, with the warm air caressing my skin and inviting me to tarry a while—it’s the winter sky that really excites me.

I think there are several reasons why. To begin with, the trees have shed their leaves, opening up a much more expansive overhead dome. While in the summertime I watch just a part of the sky peek between trees, now the whole celestial dome is open for viewing. The bare tree branches etch and frame the display with fascinating foreground patterns.

Secondly, the fall/winter sky is cold and clear. Too often in summer the sky is hazy or the day’s heat is being radiated back into space, causing the stars to twinkle and dance, so that nothing holds firm. But in winter the sky is crystal clean. The stars stand boldly and steadily out—almost audibly announcing their presence.

Thirdly, the winter night steals in much sooner in the evening and it dawdles much longer the next morning. In the summer I must wait until 10 PM to see a really dark sky. That’s too late for country living, when I want to be up and out by 6 AM in order to beat the day’s heat. A dark November and December sky abruptly descends upon you by 7 PM—early enough to invite you to linger under the glow of the stars before bedtime, if you bundle up a bit.

Lastly, winter brings those spectacular constellations and star clusters: the Pleiades, Hyades, and Orion. There are no stellar sights during the year that can match their winter displays. OK, I admit to being biased: the winter sky brings back my familiar friends who welcome me into their domain. Summer may have its Ophiuchus, Draco, Cygnus, and Bootes. (They’re not exactly household names.) I think they are pretty neat, but nothing beats Orion. Nothing beats Orion.

Musical Staff Sky (with blurry notes)

Leftover Crickets

Crickets are both extremely common critters and extremely accomplished songsters. There are hundreds of species found everywhere in North America. That’s the common part. Males are the singers. They have highly-specialized forewings that contain both a scraper and a file on each wing. This primitive “bow and string” instrument not only produces the song, but at the same time amplifies and broadcasts it. That’s the accomplished part.

The cricket’s song is seasonally heard well before—and long after—their musical cousins the grasshoppers, katydids, and cicadas. It is now late November, well after the other singers have fallen silent. But a couple rugged, dogged crickets persist. They seem to have found warm niches near the house that have allowed them to cozy down and extend their season. Surely by now their chances of reproduction via song is nil, yet they persevere.

Years ago a clever entomologist made note of the regular pulsations of the cricket’s song. On warm summer nights they pulse rapidly but slow down when cool fall nights arrive. In fact, an approximate “cricket thermometer” was discovered. If you count the number of pulses in 13 seconds and add 40, you come close to the Fahrenheit temperature. Thus on a 70-degree summer’s eve, you’d find yourself counting some 30 pulses in a 13-second period, or 2-3 pulses per second.

So how about these chilly November nights when I hear a dogged cricket singing? The other evening I found it easy to count the slow beats of a cricket’s song. He was sluggishly emitting a pulse every half-dozen seconds or so—telling me that the temperature was in the low 40s—pretty close to what my manmade thermometer read. I found myself musing about what he’d do when the temperature dropped below 40. Would he try to retract some of the chirps he’d produced, back in July?

Some folks consider the cricket’s song to be melodic and enchanting. Others view it as grating and tedious. One’s reaction seems to be in the ear of the observer. I see Mr. Cricket as some of both but mostly a resolute dude.

Business End of the Hornet

Face to Face With a Bald-faced Hornet

Earth-centered Confusions—Part 2

The third night sky object—the most charming and dramatic one—is the moon. When it’s overhead on a clear night it commands our attention like nothing else. We’re all familiar with the moon’s various phases during the lunar month. Paeans have been written and sung about the full moon and its influence on the moods of people—as well as wolves.

But understanding the moon’s journey—its location in and path across the sky—is far more complicated than either the sun or stars. Not only does the Earth rotate beneath it, but it is the only heavenly body that circles us. The Earth may have been demoted, as far as its place in the cosmos goes, but we retain the moon as our exclusive satellite. So when we follow the moon’s journey across our sky, we’re seeing the composite pattern of its monthly revolution around us and our daily rotation under it.

And the moon’s cyclical periods are neither simple nor match those of the Earth. The lunar month is some 29.5 Earth days long and there are 12.4 lunar months in an Earth year. They’re out of sync with each other, so events do not repeat themselves in a regular manner. As a result, you may get a straightforward track of the moon across the sky during a given night, but its location shifts quite a bit the next night. For example, tonight at 9:00 it may be directly overhead, but each subsequent night it shifts a substantial amount eastward. In a week it’ll be near the eastern horizon at 9:00, and then completely gone from the night sky the following week.

But there’s more. The moon’s orbital plane is at a slight angle to the ecliptic and it wobbles up and down a bit. That waver completes a cycle every 18.61 years. One needs a thorough knowledge of these wobbles in order to predict when lunar and solar eclipses will occur. There’s still more: The moon’s orbit about the Earth is not a perfect circle; it is egg shaped. So it’s closer to us at times (at perigee, when it’s also a little larger) and farther at other times (at apogee, when it’s a little smaller).

It makes my mind swoon to try to comprehend all these variations. I am humbled by the ancients who had the time and inclination to take note of all these lunar complexities and accurately predict their periodic occurrences in such exquisite observatories as Stonehenge and similar monuments.

The last and most complex of all the heavenly objects are the planets. Their behaviors are truly bizarre. If you mentally elevate yourself to a place high above the plane of the solar system, the orbits of the planets around the sun can be seen to be simple near-circles. From an Earth-centered perspective, however, the planets (Greek word for wanderer) trace weird paths across our sky. Although they may behave themselves nightly—arcing across the sky like the stars—their positions relative to those background stars wander in an almost inebriated manner, over a period of weeks or months.

Jupiter may be seen to slowly migrate westward, over a period of weeks, and then abruptly swing back to the east. It may next head west again and then dive below the western horizon, disappearing from the night sky, to reappear in the pre-dawn sky, now towards the east! In fact, these pop-up appearances of the planets—now at night in the west, now at dawn in the east—were so unaccountable that the ancients did not even recognize their reappearance as the same planet.

Only with a mixture of modern astronomy (handily found on web sites) and a little prehistoric sky monitoring can I follow the planets in their mysterious travels across the sky.

I am doing my best to comprehend the paths taken by heavenly bodies across my sky. It’s almost beyond me. I try to soak it all up from a combination of direct observation and reading books. I could do this for another few decades and still not quite approach the proficiency of my forebears. I often wish I had one of them by my side, passing on her clan’s wisdom.

Skimmer Convention on the Beach

Earth-centered Confusions—Part 1

I have written before (12/27/08 and 1/16/09) on the fact that, although we no longer view the heavens as revolving around a fixed Earth, it’s still how we directly experience the motion of celestial objects. Our precious little planet—once thought to be the center of the cosmos—was long ago displaced from its exalted position. In fact, it was exactly 400 years ago that Galileo, peering through his first telescope, provided the first solid evidence that the Earth moves; it revolves, rotates, spins through space.

Here are two irrefutable reasons why our current understanding of the non-Earth-centered cosmic arrangement is valid: (1) it’s far simpler than the old viewpoint and (2) we send space vehicles off to Saturn and it’s out there exactly where we expect it to be. These two results are at the core of the scientific principle: if it’s simpler, it’s probably closer to the truth (that’s how Nature works) and if it stands up under repeated trials (Mars and the moon are also where they are supposed to be), it gains credence.

The more I watch the sky—particularly in the midst of my reveries while reposing in the outdoor tub—the more intimately acquainted I become with its denizens. I see repeated and familiar sights; I pick up on the cycles and patterns of the march of heavenly bodies across my night (and day) sky. I get better at predicting how things will appear tomorrow or next week, as all the objects shift with respect to one another and to the horizons.

But my experience—despite my knowledge of astronomy and our real place in the cosmos—is from that Earth-centered perspective. And if I’m going to develop anything approaching the familiarity that the ancients did, I need to cultivate my Earth-centered understanding. There are a half-dozen or so types of objects floating across my sky. Each one has its peculiar path that it follows; each one behaves according to its own fashion. Most all of them pretty much follow an imaginary arc across the sky: the ecliptic, the path that the sun pursues each day. At our latitude it’s an arc that emerges from the eastern horizon, traverses the sky a little south of directly overhead, and dives below the western horizon.

The sun—the first object I’ll describe—traces the simplest path of all the celestial bodies. It rises in the east each morning, arcs across the sky on that ecliptic, and sets in the west. The peak of that arc (at noon) is high in the sky in the summer and lower (toward the south) in winter. Therefore, summer days are longer, because the sun has a longer path to tread. The sun’s diurnal journey sets the stage for all other heavenly bodies.

The second simplest set of objects to follow a daily path across the sky is the stars. The pattern of their motion is only a little more complicated than the sun. The stars trace a nighttime path that’s pretty much the same as the sun’s daytime route. Those stars that fall on the ecliptic—those that belong to the zodiacal constellations—do indeed follow the sun’s path. All stars rotate about the North Star, which appears never to change its position in the sky.

But the stars also exhibit an additional kind of motion—beyond the sun’s simplicity. For example, at noon the sun has attained its zenith and will return to that same spot each day. The star I see at its zenith at midnight tonight, however, will have moved a wee bit westward tomorrow night. That shift (about one degree) is imperceptible on a night-to-night basis, but over a month’s time that star (and all of its celestial companions) will have moved a good distance, like the creeping hands of a clock. In three month’s time that star that was at its zenith at midnight will now be seen down by the western horizon, about to set. Six months from now it will be directly underneath me—washed out by the noontime sun. Rest assured, a year from now I’ll find that it once again is perched directly overhead at midnight. By then, of course, my planet Earth will have completed one year’s revolution around the sun.

Next time: the third, the most romantic, and very complex night sky object.

Juvenile Ring-billed Gull (recent trip to the beach)

Cultural or Personal?

I am an inveterate watcher of things—be they nature, animals, or people. Furthermore, being a hermit, I lean towards the introverted end of the personality spectrum, so I’m more likely to watch people than join in their activities. Becoming a fly on the wall comes naturally to me. I’m also easily drawn to sitting at length and watching some intriguing activity of a bug or other critter.

This propensity to become immersed in watching often draws me deeply into an activity or event that I come upon. Hmmmm, what’s going on here? What is that creature doing? Why does he do it that way? I wonder what will happen next. My curiosity gets piqued. My imagination can go on a binge. It’s fun.

When I observe humans, I often find myself speculating whether the behavior I see stems from a cultural or from a personal attribute. General behaviors often originate from one’s culture. For example, people in the Middle East are warmly hospitable to visitors. People in Latin America highly value family connections. I have enjoyed traveling to other countries and watching the novel (to me) practices and traditions of diverse people—especially those surrounding food and holiday happenings.

From within my own culture I become very familiar with my people’s common (i.e., cultural) behaviors. In fact, the customs of our own culture can become quite invisible to us. (For example, I didn’t particularly notice how the typical American dresses until I once spent a month in fashionable northern Italy and returned home, to get jolted by the appearance of relatively casual-to-sloppy looking Americans.) Being familiar with my own culture, when I see one of my people acting uniquely or differently, I can guess that it’s probably a personal thing. That guy over there just did something unusual; it must be an individual eccentricity of his. Hmmmm, I wonder why he did that. What in his background may have led to that? Maybe I’ll strike up a conversation and see if I can find out.

But when I’m in a foreign culture and I observe someone doing something that appears unusual, I have little idea whether it’s a cultural or a personal thing. I’m fascinated. The mystery draws me in. There’s so much to learn about these folks.

Of course, one needs to be cautious and not jump to conclusions about these novel observations, since stereotyping can arise when I decide that what I see is a cultural thing, when in fact it may be personal. I don’t want to conclude, for example, that all Russians are well mannered, just because I saw one behave politely; or that all Californians are child abusers, just because I saw one slap his kid.

Opened Bald-faced Hornet Nest

It’s Falling—Part 2

As Fall comes on, birds forage for the last remaining sweet berries—either stocking up for their migration south or enjoying their last treats before being forced to eat dry, tasteless seeds on wintry days for those who remain here. I like to examine the clearing’s deciduous trees, looking for their old nests, hidden beneath canopies of leaves during the summer, but now exposed by the fallen leaves.

As I write, a large flock of grackles just descended on our dogwood trees, stripping every berry in just a few minutes. Luckily for the year-‘round avian residents, we are beginning to load up the bird feeder, since they were robbed of their berries by the invading grackles. If truth were to be told, I think the local birds favor the meaty sunflower seeds continually delivered to their feeder, spurning the bland dogwood berries.

Our neighborhood avian tenants begin to congregate in the Fall. Their summertime competitive engagements are now forgotten, as their offspring have either departed for new environs or joined the band as adults. The newly-formed flock hovers around the bid feeder, urging me to stock it with ever-increasing amounts of seeds. The flocking also boosts their safety—now that they can no longer evade predators by hiding in bushes or dense trees. In a cooperative group many eyes are better at avoiding being on the lunch menu for a hawk.

Fall also impacts many types of plants. It’s the time for them to propagate seeds for next spring’s rebirth. Some of those seeds get eaten and lost to plant reproduction, but they put out such a prolific harvest that a few find fertile ground for a renewed life next year. Some hide at the center of enticing fruits—indigestible and waiting to be pooped out later, at some distance away. Some seeds have become adept at latching onto animals’ coats and people’s pant legs—counting on help to spread their latent promise. Some simply count on the wind to blow them hither and yon.

Then last but (I’d like to believe) not least, Fall has its impact on us humans. For weeks in mid-to-late summer we fret over the lack of rain—watching one promising thunderstorm after another bypass us and dump on city folks, who just get annoyed by the showery inconvenience. Cheated of shower after shower, we water and water, in a struggle to keep plants healthy and growing. Now in the Fall those plants are preparing for dormancy. They no longer need water. We are reprieved!

Another wonderful gift of Fall to us is the disappearance of biting insects. We can once again pause and enjoy our surroundings, without being hassled by mosquitoes or gnats. Good riddance, suckers! I can now turn to more strenuous labors—cutting and gathering firewood, digging and transplanting, policing and cleaning the grounds—without heavily sweating and dehydrating myself in summer’s heat. My thoughts begin to turn towards indoor winter activities of writing and crafts.

Possibly the most iconic example of Fall for us is the return of the wood heating season. As plants enter their dormancy for winter, the woodstove is completing its summer dormancy. Thankful for my earlier labors that have seen a full winter’s supply of firewood set by, I’m ready to reawaken the stove for its frosty duties.

Welcome, Fall! You bring us such appreciated change.

Grackles Stealing Dogwood Berries

It’s Falling—Part 1

By mid October it’s clear that Fall has arrived in the northern Shenandoah Valley. Up to now we’ve had a few sporadic hints of autumn, but they were immediately followed by a few days of warm Indian Summer. But Fall is surely upon us now. Change can literally be felt in the air—a combination of sights, smells, sounds, and the touch of autumn molecules on your skin. It’s so refreshing!

Fall is a dynamic interim period, when the stasis of summer yields to autumn, followed by the stasis of winter. Days grow perceptively shorter now, the climate crisps, winds heighten, and temperatures tumble. Frost lurks around the next corner. Despite the fact that Nature is preparing for death and dormancy, Fall paradoxically seems a time of quickening. It rouses one’s spirit as it prepares the land for the coming hibernation.

Autumn is a celebration of summer’s bounty—when we harvest and take stock of what the garden has produced. The last fresh samples of the garden’s gifts are relished—knowing that it will be the better part of a year before we’ll be enjoying that newly-picked taste again. We’re fully thankful, however, for all we have been able to set by; stocking up the freezer, in canning jars, in bags of dried veggies, and have waiting in the fruit cellar.

Fall is a verb. Of 25 definitions for Fall in my dictionary, the first 17 treat the word as a verb, as an action. Moreover, Fall is an intransitive verb, because, first and foremost, it is an action verb. We experience the doings of its impact. Fall is dynamic—it moves, it IS. It’s on the road to somewhere, and we are caught up in the excitement of the journey and in anticipation of the destination. After the doldrums of late summer, we’re finally going places! Fall is in the driver’s seat and is taking us there.

Fall’s impact on Nature is profound. Deciduous trees quit drawing sustenance from their leaves and begin severing their connections, sealing off the interface at the leaf stem. As the leaves begin to disconnect, they lose their green chlorophyll color, change to red or yellow or orange, and float to the ground. Fall derives its name from this shedding of leaves.

Insects prepare either to die or to over-winter huddled under those discarded leaves. Colonies of wasps wrap up their summer’s labors, as the workers begin to perish, while the queens—full of eggs for the following spring—seek their winter’s slumber. Colonies of bees begin to huddle closer together to provide the warmth they need to survive the winter—bolstered by an ample supply of nourishing honey they’ve laid up during warmer times.

Next time: more impacts of Fall.

Red Eye Special

Hark, Sweet Cricket

Through the late summer and early fall our woods resound with the relentless cacophony of raucous insects. Cicadas, crickets, and katydids maintain a constant racket—cicadas taking the day shift, katydids covering the night shift, while the crickets are freelancers who set off any time (most all the time) they please.

I’m amazed at the amount of acoustic power these tiny critters can generate. Some folks consider the sound of a cricket to be melodic. Not me. Occasionally one of these noisemakers decides to invade the house. Oh, joy! Legend has it that a cricket in the house at the end of the season brings good fortune. So our luck must be on the upswing, because we've had several fall cricket invasions the last couple of years. This gift of cricket luck seems to me to be a mixed blessing, however.

While I can't attest to any good luck brought us by our most recent singing resident, I can confirm that he can become extremely irritating. His favorite singing spot is in the kitchen, behind the freezer. He seems to know that the little echo space he’s found augments his calls, while the body of the freezer keeps me from getting at him. For much of the day—and far too much of the night—the cricket sends out his raucous call, oblivious to the fact that no eligible female can respond to him while he remains in the house.

On the third morning of his visit, as Mr. Cricket began to call, I noted with excitement that he had moved! His irritating noise now came from under the computer. Aha! Maybe this was my chance to get him. If I could manage to capture him, I could escort him back outdoors and invite him to sing in much closer proximity to his fellow (female) critters.

Getting down on my knees, I gazed into the tangled maze of computer wires. Of course, as soon as he sensed my presence, he fell silent. I retreated. He soon began his call. I advanced. He stopped. We engaged in this dance a few times, until he got a bit complacent and continued his calling even when my face was close by.

There he was, hiding under a glob of wires! I grabbed a plastic cup—hoping to plop it down over him and prevent his escaping back behind the freezer. I lifted the cup, aiming at him, but he ducked farther back. Soon we were doing another type of dance, as the cricket feinted in one direction and I followed with my cup at the ready.

Eventually, he hopped into the clear. With great precision, like a skilled Samurai warrior, I aimed my cup and trapped him! I grabbed a card, slid it under the cup, and carefully lifted the makeshift cricket cage. Walking outside, I headed towards some brush where another cricket was calling. I lifted the cup and Mr. Cricket took a mighty leap towards freedom. I smiled, waved goodbye, and retraced my steps to the once-again quiet house.

The culture that created the legend of receiving good luck from a house cricket would possibly frown on my deed. Did the capture and banishment outdoors of this cricket cancel his gift of good luck? Did my unkind thoughts about the cricket's racket even foster a little bad luck? I don’t know, but I choose to take solace in the possibility that the cricket would have slowly perished of starvation behind the freezer (despite the many popcorn pieces that have fallen back there, over the years). I choose to believe that I saved him from much anguish and suffering so that at least I might be free of any cricket curse.

Paper Wasp Nest (There are TWO species of wasp sharing this nest)

Our Private Images

I’ve written before about the mental images we humans construct (on July 8 and 12 of this year)—how the impression we create of an object in our mind is a fragmentary and incomplete depiction of reality. (In those postings I described how our mental image of a tree contrasts radically with what the tree really is.) After we form these images, all of our future behavior is based on that incomplete, and usually flawed, impression. In a way it’s amazing that we can function this way at all, but evolutionary experience demonstrates that these imprecise images work quite well for us. They are neither accurate nor complete, but they do the job!

So our mental image is our attempt at capturing the useful (to us) essence of the actual thing, but that image and the object are two very different and separate entities, right? Well, maybe not. The image I create in my head—that collection of electrical signals—in some sense makes the object part of me. The tree and the mental image of it may be entirely different things, and yet they are intimately bound together. In a way, I have made the tree a part of me. It can be an instructive meditation to become more conscious of the deep connection that we have with the world around us, and thus how it has become part of us.

We humans also share our images with each other. So, is the image I’ve created in my head the same as yours? I don’t think we really know, and I’d guess that in several ways they differ. Yet we both are human, we both have essentially the same kind of senses, and we use them in very similar ways. We share a similar consciousness. We also share a very descriptive language. When I describe to you my image of an oak tree and you later gaze at it or touch it, the image you then form in your head probably closely matches the one you had previously constructed from my description.

This situation is quite different in the case of a description I might paint for you of a movie I just saw. When you later watch it, you might wonder if it’s even the same movie. This brings in a whole set of emotional responses that color our images—responses that we individually have to our sensory experiences. I’m trying to stick to images of physical things here. It’s tough enough to get a handle on them, trying to keep the emotions out of it!

When we compare our human mental images to those of another species, it’s a wholly different situation. Their senses are fundamentally dissimilar. My image of a fly and that of a spider’s must be hardly comparable. Furthermore, I can’t talk to a spider to compare our respective images. A dog who howls at the moon must have a very different mental image from me, a creature who has viewed photographs taken by Apollo astronauts who once walked there.

Our images are, by definition, very private things. Mine may resemble yours, but I can’t really know what your images are like. I try to keep in mind that although our images may be very different, they are just as valid or relevant to each of us.

Wooly Bear Caterpillar (Will it really be a cold winter?)

Our Peckerheads

There is no bird quite like the woodpecker. Its clownish actions, odd call, rapid hollow-limb drumming, hole drilling, and garish coloring make it unique. We have three species of woodpecker around here: pileated, red-bellied, and downy. Unless you consulted a bird field guide, it’s easy to get confused about the names of these birds. Just those species with red in their names can be perplexing: red-headed, red-naped, red-bellied, and red-cockaded.

The pileated woodpecker is the biggest of them all—up to a foot and a half long. It is the joker of the pack; the Woody Woodpecker cartoon is a caricature of the pileated. It has a laugh that spreads throughout the woods—making it sound derisive and superior. It’s a beautiful bird; seizing your attention when it flies, white wing patches flashing. The male and female look identical. The male delights in finding hollow limbs and filling the woods with his loud drumming—in the style of a gorilla defiantly pounding his chest.

I’ve watched two pileated woodpeckers chase each other around a tree trunk—feet clinging to the bark, feinting and dodging, trying to intimidate each other… sort of playing chicken, until one gives up and flies away. I once watched two hawks attack a pileated woodpecker, tearing loose a few feathers, and then fly off when they spotted me.

The middle-size resident woodpecker is the red-bellied; about half the size of the pileated. In my mind, this one ought to be named red-headed, but maybe that name had already been assigned—to one whose entire head is crimson, not just a red patch on top. The red-bellied loves our feeder. His eating habit is fascinating to watch: he grabs a sunflower seed, jams it in a crack in the feeder, bangs it hard a couple of times, and fishes the nut out with his long tongue. He also loves our cherry and mulberry trees and chastises me when I come to pick his fruit.

All woodpeckers—other than the pileated—have what is called an undulating flight. They noisily and fiercely pump their wings a few times and then coast for an equal period. This undulation saves flight energy and prevents lactose from building up in their muscles, when they momentarily relax their wings.

Last and least of our woodpeckers is the downy—it’s only the size of a bluebird. It has the tiniest red spot (only the male) on the back of its head. It’s a black-and-white checkerboard bird. The downy also loves the feeder, but grabs a seed and flies to a nearby tree, where he jams the seed in a crack in the bark and hammers away. I’ve watched one use the same crack for a dozen consecutive seeds.

A pileated woodpecker may look clownish, but I’d not want to have any part of my anatomy fall under the aim of that big bill. I’ve seen one excavate a four-inch hole in a dead tree trunk, in less than a minute. How can they do this without brain damage? They have a fluid sack surrounding their brain, which absorbs the shock of their blows. Otherwise they’d soon slide into the mental state of punch-drunk boxer.

Ready for Change

Avian Artists

I have written several times about my fascination with the songs of birds. Countless times I have been arrested in my labors by one of their melodies. Sometimes I’m just trying to identify who the artist is. Some birds—like the chickadee—are easy to identify. Its call is distinctive and it is tame enough that one can watch it sing in a nearby tree. Others are maddeningly challenging to identify—its call may not be distinct enough for me to identify and he refuses to come out of the woods so I can see him.

I’ve gradually and consistently come to appreciate birdsong—learning to recognize how a given species’ song changes over the seasons or to get lost in the amazement of just how that tiny bundle of feathers can produce such outspoken and gorgeous music. It can be as absorbing to me as attempting to appreciate the contrasts and qualities of Bach and Rachmaninov.

Serendipity recently found me reading a delightful book that was published over 100 years ago: Field Book of Wild Birds and Their Music by F. Schuyler Mathews. This remarkable man possessed both naturalist and musical skills. He interpreted and recorded the songs of birds in musical notation. (He was a little early for tape recorders, thankfully.) He wrote the scores of melodies of fifty New England birds—demonstrating that they sing with discernable scales, chords, tempos, and keys. They are true avian artists!

In a charming introduction to his book Mr. Mathews wrote, “This book is not the proper medium in which to set forth evolutionary theories of birdsong, but I must emphatically say that the bird sings first for the love of music and second for the love of a lady. I put the lady second, for, if he did not love music first he would not have sung to her, and birds, like the rest of us, are a trifle selfish. What we like most we think others will like as well, hence, in a moment of unselfishness we share the object of our selfishness!” That passage sets the tone for his enchanting book.

Now, when I pause to listen to a bird, I often see one of Mathews’s scores in my mind’s eye. I can hear the symphony; the various phrases and melodic passages. And I wonder, does the bird really have an intention for that song (such as seeking a mate or warning an adversary) or is he doing it purely “for the love of the music”?

Horntail Wasp

Horntail Wasp (doesn't sting)

Duking Doves

After several years of keeping their distance, mourning doves have begun flying to the feeder. This bird is usually a ground pecker—bobbing its head randomly about as it mincingly steps this way, then that. Over the last several years we might get a quick dove visit to the yard, but only briefly to peck around in the grass before it flew off—its wings whistling as if it was calling out in its effort to become airborne.

The mourning dove is a first cousin to the rock dove—the common city pigeon who loves to beg from soft-touch, park-bench sitting city people. They both are in the family Columbidae. (By the way, the city pigeon is an import from Europe.) While its city cousin is colored in shades of gray, the mourning dove is brown-gray, with a lovely reddish-brown belly.

Pete Dunne has written several books on birds. His descriptions of them often evoke a chuckle in me. He says that the mourning dove’s “head is small, almost ridiculously so.” The bird looks “like a teardrop with a tail or a pear on a stick. The turquoise-ringed eye is balefully black.” (He describes the city pigeon as a “tame to the point of being underfoot. Particularly in urban areas, attracted to anyone eating anything.”)

The mourning dove’s call has given it its soulful name, but I hear it as a sweet, comforting lullaby—reminding me of my mom’s soft songs when she put me to bed as a youngster. When few other birds are calling out (late morning, early evening), the dove’s gentle ooAAH, cooo, coo, coo wafts charmingly through the woods. The low-pitched call carries an impressively long distance through the trees. Sometimes I can hear three or four of them at scattered locations in the forest.

Over the past few years I have usually seen them in pairs (both sexes appear identical), the two of them always close and cordial companions. Lately, however, I’ve watched two doves duke it out at the feeder—one of them consistently bumptious and besting the other. What’s going on? It’s well past mating season, so it shouldn’t be two males competing for a female’s favors. I’m sure it can’t be the convivial mates in a squabble. I’ll just have to keep watching, and maybe the mystery will clear itself up some day. The closer I watch nature, the more I become aware of what I do not know.

Pete Dunne has spoiled me now. I can’t help looking at a mourning dove, chuckle over its “ridiculously” small head, and perceive it as a feeble-minded critter. When I do it seems to turn that “balefully black” eye on me, as if to ask who that pompous, nonflying dude with the fat head is.

Red Spotted Purple

Straightforward Darwin

This year is the 150th anniversary of the publishing of Darwin’s On the Origin of Species by Means of Natural Selection, or the Preservation of Favored Races in the Struggle for Life. It’s useful to see that complete title (a short one, compared to some titles of his day!), as a reminder of the actual message Darwin gave us. He described far more than evolution in that astounding book. In fact, the word evolution is not even in the title. In fact, evolution had already been an accepted process for decades before Darwin published his insights. What was not understood in his time was how the process unfolded. What caused new species to appear? Why did some persevere and others disappear?

Darwin’s contribution was to achieve a brilliant synthesis of an incredibly wide range of scientific observations of the natural world that he and others had been accumulating. The time—the middle of the 19th century—was ripe for his insights to appear. Science in England was brewing some mighty potent stews, as many good minds fed off each other.

It is not easy to describe Darwin’s insight, largely because it pulls together such a wide ranging and complex set of descriptions of the variability and propagation of life on Earth. Recently I read an elegant description of Darwin’s concept of natural selection, written by Chet Raymo, an author/astronomer who has repeatedly inspired me. It’s a neat four-step summary:

1. Species are variable (there’s great diversity in the world).
2. Variations are maintained during reproduction.
3. Individuals produce more offspring than are needed for the species to survive.
4. Those individuals who are well adapted to their environment will be more likely to survive and reproduce, thereby passing on their traits to succeeding generations.

That’s it in a nutshell! Straightforward Darwin. Note that this description is of the process of natural selection, not evolution. Or put another way, natural selection is what drives evolution.

A second thing to note is that Darwin’s insight occurred long before anyone knew that genes and DNA existed. Now we know that errors in the copying of DNA—mutations—can cause these variations. We also know that once the error pops up, it gets passed on to one’s offspring—preserved in the DNA. Most mutations are so minor as to have no influence on adaptability or ability to survive. But when an important mutation comes along, it either favors that individual and all her or his progeny or condemns them. In the former case they become Darwin’s “favored races in the struggle for life.”

Life is a struggle. It’s a relentless competition that causes every critter to be constantly looking over its shoulder, seeking any advantage to stay alive. Nature weeds out those less fit, the less adaptable—continually refining, changing the balance, and spawning diversity. We have Darwin to thank for this profound insight; as well as his courage to publish and stand behind this controversial discovery. By the way, this year is also Darwin’s 200th birthday.

Baby Milk Snake (with recently exited egg)

Life is Delightful

To be alive is a precious gift. Whether we’re in human form or are an insect, every one of us inherently knows that being alive is special. Every creature will valiantly struggle to stay alive, whenever death threatens. Nature has placed a tremendously strong drive in every one of us to hold on to our life.

One reason we embrace life so dearly, I think, is its promise to bring us countless forms of delight. The taste of exquisite food, the sight of a sunset sky, the love of another person—these are rewards we experience, and experiences from which we take great joy. Watch a bird soar, a dog chase a ball, a bear dive into a stream full of fish—and know that animals have the same ability to experience delight.

Some folks might point to a gloomier side of life, however. Life is fragile, they would say. We constantly are but a heartbeat away from death. Circumstances beyond our control can snatch this existence from us at any moment. We face constant threats. An animal inherently knows that it can be eaten—that a predator may lurk around the next bend. These threats can dampen our joy of life and fill us with dread.

Additionally, we humans fear death in our own special way—burdened with the knowledge that our mortality may come calling the next minute. Disease and violence may rob us of this precious life, and there may be little we can do about it. As Carlo Strenger (a philosopher and psychoanalyst) puts it, “…we all need protection from the unbearable knowledge that we are mortal.”

Rather than let these dark thoughts intrude on our enjoyment of life, I believe we can allow them to heighten our sense of the preciousness of living. Life’s very fragility and shortness makes it all the more cherished. Gold and diamonds are valued by many people simply because they are rare and thus expensive. Isn’t it the same for life?

Another author I have learned much from—Bernd Heinrich, a biologist—describes how we all (humans and animals) do things out of an urge to survive, without any conscious understanding of why we do them. We act in so many ways to enhance our staying alive. Why do we do this—simply to hang on to this existence or to take delight in all that life brings us? Heinrich also ponders the drive to stay alive, not as an effort to become immortal, but just to taste those delights. He writes, “I try to imagine what it would be like if I had the assurance that I’d never die, and wonder if life would be so sweet.” It seems to me that immortality would probably be excruciatingly boring.

Stink Bug (Smelled OK to me)

A Physics Digest—Part 8: Relativity and Astrophysics

This is the final entry of my physics digest and is appropriate as a conclusion: turning to look outwards at our magnificent and unimaginably large universe. When we attempt to comprehend the vastness of the universe we can’t help but see how tiny, alone, and precious our little planet is.

Albert Einstein founded the concept of relativity a little over a hundred years ago, by conducting brilliant thought experiments. (His experiments had to be conducted in his head, since he had no way to check them out in a lab. Years later technological developments allowed others to confirm his theories.)

Einstein realized that space and time are linked; whereas Newtonian mechanics assumes they are independent. When we move through space, for example, our sense of time can be altered. Motion, in fact, is relative; how it appears to someone at rest differs from someone who is moving. If I drive alongside a car on the interstate, it appears to hardly be moving; while someone standing by the roadside sees us both zipping past.

The first postulate of relativity is that all of nature’s laws are the same in any uniformly moving (constant speed) reference frame. If I toss up a ball while riding in that car, it will fall back into my hand, just as it will if I’m standing at roadside.

The second postulate of relativity is a little trickier: the speed of light is absolute; it's the same, regardless of one’s frame of reference. While things are relative at slower speeds (as when I’m driving in my car), the speed of light never changes (it would be measured the same for me as for the person standing by the roadside). How can light be absolute? Einstein realized that at near-light speeds both time and space contract, and they do so in a manner that, no matter how fast one goes, the speed of light is observed as constant. This happens because time slows down and objects mysteriously become squashed. It only happens for subatomic particles moving near the speed of light, not for plodding objects like people.

These results are all from the “special theory of relativity.” It’s special because it describes those objects moving at a constant speed. Einstein’s general theory—dealing with accelerating objects—took him another ten years to decode. He saw that an accelerating object behaves the same as if were under the influence of gravity. Release an apple (gravity acting upon it) and it will accelerate towards the ground. If you’re in an elevator that’s starting upward (accelerating), you feel heavier, as if suddenly under a stronger gravitational field. When the elevator starts down, you feel lighter, as if momentarily under less gravity. So motion and gravity are also linked.

Einstein realized that gravitational effects were still true for light waves—even though they have no mass. How can this be? It’s because huge bodies, like the sun, literally warp space around them. Light waves simply follow bent space. That’s another concept that physicists are still trying to wrap their minds around.

Finally, astrophysics: from the minute to the immense. The study of astrophysics often parallels the passage of time: how our universe began and is unfolding. It all apparently got underway with the Big Bang, about 14 billion years ago. An unimaginably tiny hot spot blew up and expanded into an unimaginably big universe. That’s the current best guess. Physicists continue to struggle with the mathematical description of that beginning.

The early universe—as it expanded outward—was composed almost entirely of hydrogen, with a dash of helium thrown in. That’s all. No carbon, oxygen, iron, lead. The first stars got formed when clouds of hydrogen collapsed, at which time the high pressure and temperature set off a nuclear fusion process. Those early stars burned hot and fast—lasting but a few million years. As they burned out they collapsed yet a little more, bringing crushing pressures inside, which created even more fusion into other elements. They then blew up in a super nova, spraying all those new elements into space.

Later forming stars (like our sun, born five billion years ago) were created when the new debris collapsed. But now there was only 99% hydrogen. Most of the other elements became fashioned into planets. Our sun is currently at its mid life. In another five billion years it will begin to die. It will do so at first by expanding, consuming, and frying the inner planets. What further evolutionary developments will alter life on our little planet in that upcoming five billion years? No one knows; we’ve just begun.

New tools have recently allowed astronomers to observe planets orbiting other stars. It gives us our first proof that Earth and her sister planets are not alone. We also recently have found that life is far more robust than we once thought, and that conditions exist elsewhere (on some of Saturn’s moons, for example) that likely are conducive to these tough forms of life. Will we find that our planet is not alone in harboring life in this vast universe? No one knows. It’s all speculation for now. But I’m doubtful that extraterrestrial life—if it’s out there—will be bipedal and speak English, as Star Trek would have us believe.

Question Mark (So named because of mark on underwing)

A Physics Digest—Part 7: Atomic and Nuclear Physics

Up to this point my physics digest has taken the classical or Newtonian viewpoint. Now it’s time to pass beyond and enter quantum theory. This is a term that’s been severely misused in recent years, as we’ve heard of everything from quantum Zen to quantum force—whenever someone wants to sound esoteric.

Around the end of the 19th century, experimental physicists were first able to explore elementary particles of matter: electrons, protons, and even smaller entities. The first surprise they met: while energy and radiation at the macroscopic level appear continuous, when you get down to the microscopic level, energy comes in discrete bundles, called quanta. The study of nature’s workings at wee scales is called quantum mechanics. It extends and modifies Newtonian mechanics into this realm.

A second surprise physicists discovered was that you cannot nail down both the speed and position of a tiny particle. If you constrain its location, you lose information on its speed. If you can accurately observe its speed, you’re not really sure just where it is. This vagueness is called Heisenberg’s Uncertainty Principle.

A third surprise: photons of light can behave either as a stream of particles or as a continuous wave. It all depends on how you observe them… literally. Before you observe them they exist only as possibilities. The observer impacts the observation. There is no separate, objective reality at the quantum level.

These findings threw many scientists (including, and especially, Einstein) for a loop. The quantum world is counterintuitive to us macroscopic beings. Physicists are still trying to come to terms with these bizarre results.

These findings also brought about a reconsideration of the structure of the atom. We now understand that the nucleus is surrounded, not by individual electrons in orbit, but by a cloud of electrons in some probabilistic state somewhere between a wave and a particle. Either? Both? Yes.

This uncertain nature of electrons is described by a wave equation—the microscopic world’s equivalent of Newton’s laws—which describes the probabilities of the behavior of electrons and other elementary things. We can only state what’s likely to be—not precisely what is—until we look at it. We then sort of make it come into being. Isn’t that weird?

If we move inward from the atom’s electron probability cloud, we find a lump of positively-charged protons—jammed tightly together in the atom’s nucleus. To keep the electrical repulsive force between them from breaking the nucleus apart, something called the strong (attractive) nuclear force was discovered. But when the nucleus gets rather big—like for uranium—an opposing force called the weak nuclear force comes into play and makes the nucleus rather unstable. Science is still trying to bring the description of these various forces under one umbrella (in the so-called Grand Unified Theory, or GUT).

The counteracting forces in a large nucleus like uranium causes it to be rather unstable and so it will slowly break down, emitting high-energy radiation. A uranium atom decays to the metal lead in some 14-15 steps, passing through nine different elements along the way. In nature this decay is slow—maybe on the order of thousands of years.

Each time a nucleus splits a little mass disappears, becoming transformed into pure energy. Einstein’s famous equation E = mc2 then comes into play. “E” is the energy released, “m” is the tiny bit of mass that is lost, and “c” is the speed of light. In English units c2 is about 2 followed by 20 zeroes, so the energy is large, even though the lost mass is small.

If we gather enough uranium together (far more concentrated than ever occurs in nature) we can reach a critical mass. Now the atoms decay almost instantaneously and achieve the explosive power of the atomic bombs dropped on Hiroshima and Nagasaki. But we can also slow down this process of fission by controlling it with graphite rods, and create a nuclear reactor. The released energy is used to boil water and spin an electrical turbine.

There’s a process even more powerful than the fission (splitting) of uranium atoms: the fusion (merging) of hydrogen atoms. It’s more powerful partly because we can jam together a lot more hydrogen than we can scarce uranium. (Hydrogen is the most plentiful element in the universe.) The hope is that we may soon create a peaceful use for nuclear fusion—in the generation of electricity. Its byproducts are far cleaner than the radioactive remains of current nuclear reactors.

Milk Snake Eggs (will hatch in another week or so)

A Physics Digest—Part 6: Light

Last time I described how the electromagnetic spectrum spans a huge frequency range—from radio waves to gamma rays, a factor of a trillion or so. Only the tiniest part (one billionth) of that range, in the very middle, is the light visible to our eyes. Everything we see is confined to that incredibly narrow strip—it’s our constricted view of life.

One property of visible light that’s crucial to our sense of sight is reflection. If ordinary objects didn’t reflect the sun’s light, we’d not see them (sort of like the Klingon cloaking device on Star Trek). Ordinary things don’t emit light on their own, so we need reflections from the sun or other light source to know they’re there.

While light waves reflect from opaque objects, they penetrate materials like glass and water—wherein they move more slowly. When a light wave is forced to slow down upon entering a transparent medium, it will bend or refract. If you look at a spoon sitting in a glass of water, it appears bent. Refraction is also used in eyeglasses and telescopes, to focus rays of light.

In air or in a vacuum all the colors (all frequencies) of light move at the same speed, but in glass the low frequencies (reds) move faster than high frequencies (blues). Thus light can get separated into its constituent colors upon entering a glass prism and becoming refracted. The same process creates a rainbow; each raindrop acts like a tiny prism.

Sunlight appears white because it contains all colors mixed together. (Actually, it’s a little yellowish, since the sun emits a little more light energy at yellow wavelengths.) So how does a red balloon appear red, when only “white” sunlight strikes it? The balloon absorbs all light frequencies other than red; only the red wavelengths are reflected. If all the colors get absorbed, it’s a black balloon.

Why is the sky blue? White sunlight enters our atmosphere and some of it gets scattered by particles in the air. Blue (high) frequencies get scattered more than any other color, so the sky gets filled with “blue rays” of light. Why is the sunset red? When overhead, the sun is whitish-yellow, but as it sets (or rises) its rays must then travel a longer path through the atmosphere to reach our eyes. The lowest frequencies (reds) are the least scattered color. So red rays penetrate the thick atmosphere best and are the ones we see.

Our eyes’ retinas contain light sensing rods and cones. Cones (at the center) respond to color and also give us acute central vision. Rods (surrounding the center) do not sense color and give us less detail in peripheral vision. They can “see” at light levels a hundredth of what cones need, however, so in dim light we can still see, but with fewer details and no color.

Two or more overlapping electromagnetic light waves can either reinforce or interfere with each other. Scientists have learned much about light—its speed, its color composition, and the nature of the media it’s traversing—by studying the reinforcement and interference patterns that the waves make.

Although we see most objects by the sunlight they reflect, a few things emit light themselves. Fireflies do it beautifully. An incandescent light does it by getting heated up so much that it glows. When some types of gas are zapped by electrical energy, the electrons in their atoms are bumped up to a higher energy state. These excited electrons quickly drop back to their usual lower energy level, and emit photons of light. This is how neon and fluorescent lamps glow.

The electrons in some elements don’t immediately jump back down to a lower energy state right away, but hold on for a while. This is phosphorescence. And when the emitted light waves are all in step with each other (reinforcing each other) we get the intense beam of a laser.

Every element emits its own unique signature of photons (i.e., color of light) when excited electrically. Astronomers use these signatures to determine what elements are present in various stars, so we don’t have to travel there to sample them directly.

Poke Milkweed

A Physics Digest—Part 5: Electricity and Magnetism

Our world is filled with electrical devices—in fact, all matter is electrical in nature. Every atom contains negatively-charged electrons orbiting a positive nucleus of protons. Positives and negatives attract each other. This is what holds an atom together. So what keeps all those mutually repulsive protons squeezed into an atom’s nucleus? The strong nuclear force—which we’ll get to in a later entry.

Some materials can be charged with static electricity by rubbing them. Shuffle across a rug in winter (when the humidity is low) and touch a door handle—watch the spark. Rub a balloon on your shirt and stick it to a wall: electrical attraction.

Some materials are good conductors of electricity; e.g., metals, which also conduct heat well. Other materials are poor conductors; e.g., rubber, so we coat electrical wires with rubber, in order to be able to handle them without a shock.

When electrical charges move along a wire, we have an electrical current; which can be thought of as analogous to water flowing through a hose. Voltage corresponds to pressure in the hose, and a battery is like the pump that pushes the water.

We can have direct current (DC), in which all the electric charge flows in one direction, or alternating current (AC), in which the charge reverses direction (60 times a second for the electric power coming into our houses). Voltage can do work as it pushes current, such as when it turns an electric motor. We measure the work that is done by the power it produces—in watts.

The discovery of magnetism predated our grasp of electricity by a few millennia. The Greeks played with magnetic stones they found. Material gets magnetized when clusters of atoms line up, military style. That lineup creates directional properties, for which we assign a north and a south pole to the magnet. Where did we get that convention? The Earth’s iron core creates a magnetic field that points towards the north and south poles. A magnetized compass needle aligns itself with this field. Some birds have a built-in magnetic compass to navigate themselves via Earth’s magnetic field.

A wonderful property of matter is that electricity and magnetism are coupled. When electricity flows in a wire, it sets up a magnetic field around it. Conversely, if you move a wire through a magnetic field, it causes an electric current to flow in the wire. Better yet, if you move a wire carrying current through a magnetic field a force on the wire can be felt. This is the essence of electric motors. That force can do work rotating a motor, maybe even moving an electric car.

One more fascinating property of electricity and magnetism is that their interaction creates electromagnetic radiation. If we vibrate a wire that’s carrying an electric current back and forth, we cause the wire’s surrounding magnetic field to similarly vibrate. This interaction sends out an electromagnetic wave, which happens to travel at the speed of light. In fact, these waves are light! They can move through the vacuum of space, like the heat radiation we saw earlier.

How fast we wave the wire back and forth determines the frequency of the electromagnetic wave. At low frequencies we get radio and microwaves (the latter can cook food). At mid frequencies we get infrared, visible light, and ultraviolet radiation. At high frequencies we get X-rays and gamma rays. These are all the same kind of waves, all moving at the speed of light.

On to more light next time.

Bald-faced Hornet Nest (We're keeping our distance)

A Physics Digest—Part 4: Sound

Sound begins when something vibrates—sending a sound wave through the air. The ear then gets stimulated and electrical impulses reach the brain. So does a tree make a sound when it falls? By this definition, only if an ear and a brain are present to sense the air’s vibrations.

While light and heat waves can travel through a vacuum, sound waves need a medium—a solid, liquid, or gas. (So a tree falling in outer space would be silent.) Sound waves travel at different speeds in different materials (they move faster in solids than air). A sound wave is transmitted within a medium when something makes a part of that medium vibrate. That part jostles neighboring parts, and the disturbance moves along—just like heat. Throw a stone into a pond and watch the circular vibration waves move outward. While the disturbance (energy) flows along, the material itself doesn’t. Watch a cork on the surface of the water bob up and down and notice that the cork doesn’t move outward with the wave.

The rate of vibration of sound is defined as its frequency. Our ears can register frequencies as low as 20 vibrations per second (Hertz), up to as high as 20,000 Hertz (although my aging ears quit at about 12,000). Sound waves transmit energy, which is often measured as loudness. Our remarkable ear can sense loudness levels of greater than a range of a factor of a trillion, so we squeeze that down into a workable logarithmic range of about 120 decibels.

Sound can become particularly attractive when we talk about music—although it can be very subjective. One person’s music is another’s noise. As a less subjective evaluation, we’d pretty much all of us define a jet engine as making a lot of noise.

Qualities of musical sounds that describe their properties are pitch (the same as frequency) and timbre. When a musical instrument makes a sound, it is composed of a fundamental tone (the basic pitch) and various overtones, which are whole-number multiples of the fundamental. The particular mix of these multiple tones defines the timbre of the instrument—its unique sound quality.

Musical instruments make sounds in three ways: by vibrating strings, vibrating air columns (horns and woodwinds) and vibrating surfaces (cymbals and drums). All of these sounds are simulated in a stereo system when an electrical signal causes a speaker surface to vibrate.

Our ear loves regular mathematical relationships between musical pitches. When the pitch of one sound is twice that of another, we hear an octave. When the ratios of pitches are whole number fractions—like 5/4 and 4/3—we hear musical intervals of a third and a fourth, respectively. That’s harmony!

Sycamore Tussock Moth Caterpillar (Halysidota harrisii)

Sycamore Tussock Moth Caterpillar (Halysidota harrisii)

A Physics Digest—Part 3: Heat

All matter we’re familiar with possesses some amount of heat, which means its atoms and molecules constantly jiggle about. The hotter something is, the greater the jiggle. Atoms in a solid can jiggle only so much, before they break loose and form a liquid. Heat it some more and atoms jiggle even more and spread out into a gas.

Temperature: it’s a measure of the thermal energy of something—it’s a way to quantify of the amount of kinetic (jiggling) energy of the atoms and molecules. The calorie: it’s a measure of the amount of heat energy it takes to raise the temperature of a body. We convert food calories (heat energy) into the energy of walking or doing the work of lifting things (like our bodies off the couch).

Heat always moves from hotter to colder bodies (cold doesn’t move); and does so in three ways. (1) Conduction—warmer jiggling atoms in a solid pass their jiggle on down the line. Good conductors (metals) pass it on faster than insulators. (2) Convection—hotter molecules and atoms in a liquid or gas move to cooler places and warm them. (3) Radiation—heat energy gets transferred by electromagnetic waves (we’ll look at them later).

Now comes the hard part: thermodynamics. No undergraduate class gave me more grief than thermo. Thermodynamics is the study of heat and how it’s transformed into mechanical energy. It’s a macroscopic discipline—not caring about the jiggling of individual atoms, just the net impact of what they do in concert. Thermodynamics is the basic study of how engines transform heat into useful energy: your car, a refrigerator, a nuclear power plant.

One of the basic concepts in thermodynamics is the temperature of absolute zero (there is no maximum temperature). Energy can always be extracted from any warm body; but when we get that body down to absolute zero, there is no energy at all (no more jiggle). Thus it’s the absolute ground floor for all heat calculations.

Similar to Newton’s discoveries for forces, thermodynamicists have discovered two basic laws. The First Law of Thermodynamics describes the conservation of energy—that it can neither be created nor destroyed, just transformed from one type into another. Thus when we add heat to a system we can then transform it into various forms of energy, knowing we can account for every portion without something mysteriously disappearing.

The Second Law of Thermodynamics tells us that heat always flows from hot to cold locations—always downhill. Thus energy always dissipates, is always deteriorating into less useful forms; eventually into waste heat. Entropy is a measure of this disorder.

American Lady, wing bottoms

American Lady, wing tops

A Physics Digest—Part 2: Properties of Matter

Matter is what physics is all about—in contrast to mind and spirit (which are the province of other specialties). All matter is composed of identical, infinitesimal building blocks: quarks and leptons. They come together to form a little bit bigger building blocks we call electrons, protons, and neutrons—which then form atoms. Everything in this wide universe is made up of only about a hundred kinds of atoms, arranged in endless possibilities. It’s all in how it’s assembled.

Of those 100 kinds of atoms, only about a dozen are used in the common stuff we see every day (most commonly carbon). When the universe was very young it consisted almost exclusively of hydrogen atoms—which are the simplest: one proton, one electron. Gradually, over time, other kinds of atoms got manufactured in the explosive belly of stars. We are stardust!

Atoms are ageless—once created, they’re pretty much forever. They move through us continually. Oxygen atoms you inhale today were once inhaled by Jesus (or maybe a gnat on his neck). Atoms are mostly nothing—each one is the tiniest speck of a nucleus, surrounded by vast space. We’re mostly nothing!

Matter comes in three basic flavors: solids, liquids, and gases. When atoms combine into molecules and get firmly locked into a structure, we call it a solid. When the molecules are ordered in a precise fashion, we call it a crystal—like the sodium chloride molecules in salt. An electrical attraction between atoms and molecules in a solid binds them tightly together. Solids possess density (how much mass is squeezed into a given volume)—thus the iron atoms in steel are heavier and packed together more tightly than the carbon atoms in wood.

Some solids also possess elasticity: the ability to distort under force and then bounce back, once the force is removed. But inelastic solids, like a lump of clay, get bent and stay bent.

In liquids the molecules are not fixed—there’s less electrical attraction between them—so they slide over each other and can assume the shape of the container they’re in. Analogous to the weight of a solid is pressure in a liquid: the force that a liquid exerts on the surface that contains it. Liquids also possess density; thus less dense oil will float on denser water. Useful properties of a liquid are hydraulics (a property of pressure) and capillarity (which allows trees to suck up water).

The third flavor of matter is gas—in which the molecules are even freer from each other. A gas will expand to fill its container, as its molecules spread out. But gas does have weight (also expressed as pressure), so we experience atmospheric pressure, when all that air piles up above us. Gas can also float less dense objects, such as air floating a helium-filled balloon. Gases can exert forces: hold your hand out of a moving car’s window and you’ll feel it.

The force of gas also holds up an airplane—which is far denser than air. How? Air flowing over the curved top of a wing must travel farther (and thus faster) than that across the flat bottom of the wing. Bernoulli showed us that the faster air moves, the lower is its pressure; so more pressure (force) is applied to the bottom of the wing, lifting it—along with the solid airplane attached to it.