Thursday, January 28, 2010
Tuesday, January 26, 2010
Amazing Owl Ears
Owls are nature’s stealth aircraft—they can fly more quietly than most any bird. Their wing feathers allow their wings to beat and glide through the air so silently that they can swoop down unawares and grab rodents and rabbits for their meals. The leading edges of an owl’s wings are serrated, which reduces eddies of air shed by the wing, and thus the noise.
An owl’s eyes are also amazing organs. They are very large—an owl’s stare from a photograph can be disturbingly intimidating. Their eyes are placed in front of their head—rather than at the sides, as for most birds. This gives an owl stereoscopic vision—excellent depth perception—so it can accurately pounce on its pray. Furthermore, owls use their eyes in the dark.
But an owl’s ears are probably their most incredible sensory organ. The eye of an eagle may be able to pick out dinner morsels a mile or so away, but the ear of the owl is equally impressive. Their large heads and fan-shaped feathers efficiently direct sound to their ear openings—and those openings are asymmetrical on the head. One is slightly higher than the other, which increases their ability to zero in on the location of animal sounds.
But the champion hearer of all is also the largest owl of all: the great gray owl. This bird lives in the far north; in central Canada and up into Alaska. It may be the largest owl in the Americas, but the smaller great horned owl is 50% heavier. Why? In order to keep warm in its frigid environment, the great gray owl puffs up its feathers, insulating its body.
And those ears of the great gray! It can sit on the branch of a tree and hear the sounds of a vole several hundred feet away, under several feet of snow! Think about what that implies about the acuteness of the hearing mechanism of this bird. Snow is a good thermal insulator and a good sound absorber. It does an excellent job of muffling the sounds of a skittering vole—who is comfy and believes itself safe, hidden under a deep snow bank. And what overly confident vole would think that an owl perched a football-field distance away could ever be a threat? There goes another meal for the great gray.
That extraordinary hearing capability of this owl implies yet another remarkable fact: the environment must be exceptionally quiet in that far frozen north. Even the slightest background noise—a gentle breeze wafting or any sound from another animal—would prevent the owl from picking out that buried vole. That silence is precious to the owl. It never gets that quiet in the States. The great gray owl had better remain in its isolated north country.
An owl’s eyes are also amazing organs. They are very large—an owl’s stare from a photograph can be disturbingly intimidating. Their eyes are placed in front of their head—rather than at the sides, as for most birds. This gives an owl stereoscopic vision—excellent depth perception—so it can accurately pounce on its pray. Furthermore, owls use their eyes in the dark.
But an owl’s ears are probably their most incredible sensory organ. The eye of an eagle may be able to pick out dinner morsels a mile or so away, but the ear of the owl is equally impressive. Their large heads and fan-shaped feathers efficiently direct sound to their ear openings—and those openings are asymmetrical on the head. One is slightly higher than the other, which increases their ability to zero in on the location of animal sounds.
But the champion hearer of all is also the largest owl of all: the great gray owl. This bird lives in the far north; in central Canada and up into Alaska. It may be the largest owl in the Americas, but the smaller great horned owl is 50% heavier. Why? In order to keep warm in its frigid environment, the great gray owl puffs up its feathers, insulating its body.
And those ears of the great gray! It can sit on the branch of a tree and hear the sounds of a vole several hundred feet away, under several feet of snow! Think about what that implies about the acuteness of the hearing mechanism of this bird. Snow is a good thermal insulator and a good sound absorber. It does an excellent job of muffling the sounds of a skittering vole—who is comfy and believes itself safe, hidden under a deep snow bank. And what overly confident vole would think that an owl perched a football-field distance away could ever be a threat? There goes another meal for the great gray.
That extraordinary hearing capability of this owl implies yet another remarkable fact: the environment must be exceptionally quiet in that far frozen north. Even the slightest background noise—a gentle breeze wafting or any sound from another animal—would prevent the owl from picking out that buried vole. That silence is precious to the owl. It never gets that quiet in the States. The great gray owl had better remain in its isolated north country.
Sunday, January 24, 2010
Friday, January 22, 2010
Extra Terrestrial Life
A question has hovered in the minds of people over the eons: Does life exist elsewhere in the universe? I have written before on this subject (“Life Out There,” 11/20/08). It’s an ongoing question that we’ve been unable to answer so far, but now seem to be closing in on. Several exciting initiatives recently have been launched—and some of them are providing tantalizing information.
There are fewer questions whose resolution would have a greater impact on us than: “Are we alone?” Many people have invested lots of energy into a belief system that the Earth is unique in the entire universe, and thus solitary in harboring life—especially intelligent life (whatever that is). Others are convinced that the conditions that fostered life here are common throughout the vast universe and thus life must be common. They argue that, even though Earth’s life-favoring conditions are incredibly rare, there is such an unimaginably large number of stars, that those conditions must have been duplicated many places.
This is similar to the ancient debate over whether the Earth sat at the center of the (then-known) universe. Arguments about our place in the cosmos raged on in those times, until science progressed to the point that the answer was found: we’re far from the center.
Similarly, our understanding is now growing about the possibilities of life elsewhere. In the last few decades we’ve discovered extremely tough species (dubbed “extremophiles”) in places here on Earth where we’d previously doubted any form of life could survive: scalding hot pools in Yellowstone, frigid locations in Antarctica, the sunless depths of the ocean. Simultaneously, NASA’s probes have discovered environmental conditions on other worlds in our solar system—a few moons of Jupiter and Saturn—that are quite similar to those tolerated by Earth’s extremophiles.
The December 2009 issue of National Geographic describes very recent results of astronomical studies that have identified nearly 400 planets orbiting stars other than the sun. Many people have long suspected that there must be planets circling other stars, but the proof has been lacking until now. Now we know: over 300 of the nearest stars have multiple planets! And those that we can detect thus far are just the bigger planets (far larger than Earth). Projects are underway that will soon be able to detect Earth-sized planets in the next few years—and even begin to analyze the contents of their atmospheres (if they have any).
Just as Johannes Kepler finally proved that the sun (not the Earth) is at the center of our local universe 400 years ago, we’re on the threshold of discovering if life on other earths exists—or not. Stay tuned.
There are fewer questions whose resolution would have a greater impact on us than: “Are we alone?” Many people have invested lots of energy into a belief system that the Earth is unique in the entire universe, and thus solitary in harboring life—especially intelligent life (whatever that is). Others are convinced that the conditions that fostered life here are common throughout the vast universe and thus life must be common. They argue that, even though Earth’s life-favoring conditions are incredibly rare, there is such an unimaginably large number of stars, that those conditions must have been duplicated many places.
This is similar to the ancient debate over whether the Earth sat at the center of the (then-known) universe. Arguments about our place in the cosmos raged on in those times, until science progressed to the point that the answer was found: we’re far from the center.
Similarly, our understanding is now growing about the possibilities of life elsewhere. In the last few decades we’ve discovered extremely tough species (dubbed “extremophiles”) in places here on Earth where we’d previously doubted any form of life could survive: scalding hot pools in Yellowstone, frigid locations in Antarctica, the sunless depths of the ocean. Simultaneously, NASA’s probes have discovered environmental conditions on other worlds in our solar system—a few moons of Jupiter and Saturn—that are quite similar to those tolerated by Earth’s extremophiles.
The December 2009 issue of National Geographic describes very recent results of astronomical studies that have identified nearly 400 planets orbiting stars other than the sun. Many people have long suspected that there must be planets circling other stars, but the proof has been lacking until now. Now we know: over 300 of the nearest stars have multiple planets! And those that we can detect thus far are just the bigger planets (far larger than Earth). Projects are underway that will soon be able to detect Earth-sized planets in the next few years—and even begin to analyze the contents of their atmospheres (if they have any).
Just as Johannes Kepler finally proved that the sun (not the Earth) is at the center of our local universe 400 years ago, we’re on the threshold of discovering if life on other earths exists—or not. Stay tuned.
Wednesday, January 20, 2010
Monday, January 18, 2010
The Larger Picture
One consequence of human evolution is that we gradually come to understand a larger and larger slice of the truth of our universe. Although we have physiologically evolved slowly over millions of years, the evolution of our cultural and mental dimensions has exploded over just the last ten thousand years or so. The development and growth of scientific understanding is directly due to that rapid cultural evolution.
Science has relentlessly progressed in a very consistent and logical manner. That is its principle attraction for me; it’s not a capricious thing, it doesn’t wander aimlessly, wasting time. I can depend on it; I can trust it. But it’s not the logic of science that is the key here—it’s the manner in which our understanding grows. Pure logic may be the essence of mathematics, but it’s only one tool in the search to grasp the larger picture. (Bernd Heinrich, one of my favorite writers on biology, nicely describes this idea.)
The search for knowledge cannot be a quirky, random process—especially if it’s scientific knowledge we seek. It must be directed and intentional. We must have some sort of idea where we’re going—some tentative expectations, some rough hypothesis. And here’s where a good dose of logic does help. It can guide the search and even alert us to significant observations.
The next stage of this investigative process is where true science—the search for reality—is crucial. We might have expectations about what we may find, but a true scientist will never ignore unexpected or anomalous observations. One should never reject observations that are unexpected. One should never become attached to one’s hypothesis or theory—that’s dogmatic and fallacious reasoning. The quest to expand human understanding has repeatedly faltered and bogged down in the quicksand of dogma and rigid belief.
It is, in fact, those seemingly inconsistent observations that have frequently led people to a larger picture of reality. Anomalies can be clues to the truth. They are often telling us something very valuable: that our limited viewpoint needs to be opened up, widened, even modified. If we choose to ignore the oddities (to stay ignorant!), we choose to limit ourselves to an inferior apprehension. We get locked into a belief that becomes increasingly like a straightjacket. That ossification of belief happens in all areas of human perspective—not just science.
So let me keep my eyes and mind open—not being distracted by every whim that comes along (that’s why I need that initial hypothesis to guide me)—but also not rejecting ideas and observations that don’t fit my prejudices. They just might hold the key to it all.
Science has relentlessly progressed in a very consistent and logical manner. That is its principle attraction for me; it’s not a capricious thing, it doesn’t wander aimlessly, wasting time. I can depend on it; I can trust it. But it’s not the logic of science that is the key here—it’s the manner in which our understanding grows. Pure logic may be the essence of mathematics, but it’s only one tool in the search to grasp the larger picture. (Bernd Heinrich, one of my favorite writers on biology, nicely describes this idea.)
The search for knowledge cannot be a quirky, random process—especially if it’s scientific knowledge we seek. It must be directed and intentional. We must have some sort of idea where we’re going—some tentative expectations, some rough hypothesis. And here’s where a good dose of logic does help. It can guide the search and even alert us to significant observations.
The next stage of this investigative process is where true science—the search for reality—is crucial. We might have expectations about what we may find, but a true scientist will never ignore unexpected or anomalous observations. One should never reject observations that are unexpected. One should never become attached to one’s hypothesis or theory—that’s dogmatic and fallacious reasoning. The quest to expand human understanding has repeatedly faltered and bogged down in the quicksand of dogma and rigid belief.
It is, in fact, those seemingly inconsistent observations that have frequently led people to a larger picture of reality. Anomalies can be clues to the truth. They are often telling us something very valuable: that our limited viewpoint needs to be opened up, widened, even modified. If we choose to ignore the oddities (to stay ignorant!), we choose to limit ourselves to an inferior apprehension. We get locked into a belief that becomes increasingly like a straightjacket. That ossification of belief happens in all areas of human perspective—not just science.
So let me keep my eyes and mind open—not being distracted by every whim that comes along (that’s why I need that initial hypothesis to guide me)—but also not rejecting ideas and observations that don’t fit my prejudices. They just might hold the key to it all.
Friday, January 15, 2010
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