Saturday, April 24, 2010
Tuesday, April 20, 2010
Sparse Space
If you go outside on a clear night in the country, you can see as many as 3000 stars with the naked eye. The sky seems filled with stars. Look at a photo of a distant galaxy taken by the orbiting Hubble Telescope and you see millions of stars and maybe several distant background galaxies. Space seems so full of planets, stars, and galaxies; and yet it’s vastly empty.
It’s hard to wrap your head around just how sparse space is, or just how far it is between the heavenly bodies we see out there. I’ve often tried to grasp the profound emptiness of it all, or to comprehend just how isolated our little planet is in this cosmic void, but it’s a very big stretch of imagination.
So here’s a way to get a feel for the barrenness of space—putting it in terms of distances we can more easily get a feel for. Let’s look first at our solar system. Our sun dominates it; over 99% of the mass of our solar system resides in the sun. Eight planets, a few proto planets (Pluto was recently designated as one of them), and countless asteroids… all orbit our sun.
To reduce our solar system to a more understandable scale, imagine the sun to be the size of a basketball. Place it on the goal line of a football field. To that scale, our Earth is the size of a fat grape seed, out at the 10-yard line… a wee grape seed revolving out there about 30 feet away. Mars is half that grape seed size, sitting out on the 15-yard line. Jupiter is the size of a walnut at midfield… a walnut out there 150 feet away! Let’s round out our solar system: Pluto is a tiny dot out there about 3 ½ football fields away. Thus, to this scale (the sun the size of a basketball), our solar system has a diameter of about seven football fields.
To consider celestial bodies beyond our solar system, we need to make the scale even smaller. Collapse those seven football fields down to a basketball, and then place that basketball-size solar system on the goal line again. Where’s the nearest star, Alpha Centauri? It’s five miles away. Nothing of any substance exists around our basketball-sized solar system, until you get out there five miles. That’s a pretty empty “local” stellar neighborhood!
Our solar system sits out near the edge of the Milky Way Galaxy. So again, to this second scale, the center of our galaxy is 4000 miles away. That’s about the distance from Washington, D.C. to the Amazon. Let’s go one more: the nearest galaxy to us is Andromeda. By this scale, that closest galaxy (to our basketball-size solar system) is 360,000 miles away—or half again the distance to the moon. Pretty sparse territory.
One often hears talk about humans soon traveling by space ship to the stars. On old Star Trek episodes you can watch the USS Enterprise zip from one star system to another in a few hours. The reality of it is that these distances are far greater than we can imagine. Planet Earth is like a vanishingly small speck of dust on a vast ocean. Even though the universe has uncountable stars and planets, we’re pretty much alone. Maybe we’d better think of taking better care of our home—it is all we’ve got for the foreseeable future, until the far distant day when we just might span those incredible distances.
It’s hard to wrap your head around just how sparse space is, or just how far it is between the heavenly bodies we see out there. I’ve often tried to grasp the profound emptiness of it all, or to comprehend just how isolated our little planet is in this cosmic void, but it’s a very big stretch of imagination.
So here’s a way to get a feel for the barrenness of space—putting it in terms of distances we can more easily get a feel for. Let’s look first at our solar system. Our sun dominates it; over 99% of the mass of our solar system resides in the sun. Eight planets, a few proto planets (Pluto was recently designated as one of them), and countless asteroids… all orbit our sun.
To reduce our solar system to a more understandable scale, imagine the sun to be the size of a basketball. Place it on the goal line of a football field. To that scale, our Earth is the size of a fat grape seed, out at the 10-yard line… a wee grape seed revolving out there about 30 feet away. Mars is half that grape seed size, sitting out on the 15-yard line. Jupiter is the size of a walnut at midfield… a walnut out there 150 feet away! Let’s round out our solar system: Pluto is a tiny dot out there about 3 ½ football fields away. Thus, to this scale (the sun the size of a basketball), our solar system has a diameter of about seven football fields.
To consider celestial bodies beyond our solar system, we need to make the scale even smaller. Collapse those seven football fields down to a basketball, and then place that basketball-size solar system on the goal line again. Where’s the nearest star, Alpha Centauri? It’s five miles away. Nothing of any substance exists around our basketball-sized solar system, until you get out there five miles. That’s a pretty empty “local” stellar neighborhood!
Our solar system sits out near the edge of the Milky Way Galaxy. So again, to this second scale, the center of our galaxy is 4000 miles away. That’s about the distance from Washington, D.C. to the Amazon. Let’s go one more: the nearest galaxy to us is Andromeda. By this scale, that closest galaxy (to our basketball-size solar system) is 360,000 miles away—or half again the distance to the moon. Pretty sparse territory.
One often hears talk about humans soon traveling by space ship to the stars. On old Star Trek episodes you can watch the USS Enterprise zip from one star system to another in a few hours. The reality of it is that these distances are far greater than we can imagine. Planet Earth is like a vanishingly small speck of dust on a vast ocean. Even though the universe has uncountable stars and planets, we’re pretty much alone. Maybe we’d better think of taking better care of our home—it is all we’ve got for the foreseeable future, until the far distant day when we just might span those incredible distances.
Sunday, April 18, 2010
Thursday, April 15, 2010
From Flocking to Fighting
One of the joys of spring is watching and listening for the return of migrating birds. Those first calls of the phoebe, the robin, the wood thrush, or the indigo bunting are sure to bring wide smiles to our faces and an excited, “Did you hear that!?” All’s right with our little vernal world when we know that our winged travelers have come back for the season.
But there’s another fascinating spring event that I like to observe: the year-round resident birds, as they morph from close-knit feeding buddies in a flock, to sparring rivals, who enter into courting rituals.
Throughout the winter we have chickadees, titmice, and goldfinches flocking at the feeder—maybe a dozen or more of each species. To my untrained eye years ago, they all seemed to be close-knit friends, but that was a bit of anthropomorphizing on my part. Birds rarely are friendly with one another—tolerant is a better word for it (at best). In fact, they most always aggressively establish a pecking order that determines who dominates. At the feeder, sweet little chickadees are the most submissive and intimidated. Titmice pick on them, while they in turn are subservient to finches and nuthatches. Small woodpeckers come next, topped off by the cardinals.
But there’s also a harder-to-distinguish pecking order that gets established within each species. It’s more difficult to follow, because I’m as yet unable to tell one titmouse from another. Thus I can detect a hierarchy process going on, but do not know which bird is boss, or if he stays boss for long.
Despite the pecking order dynamics, however, during the winter the birds flock together in a decently non-combative manner around the feeder. Come spring, though, inner mating urges begin to control their behavior. It’s combat time. Winter’s proximity gives way to spring’s territorial jousting. The birds begin to call incessantly, in order to establish their mating and breeding turf. It’s fun to watch their antics, as they begin to challenge each other for the nicest patch of ground. They dive, feint, chase, squabble, show off, sing vociferously, and just as quickly stop and perch next to one another, as if a truce was suddenly called.
I’ve read that the dominant male of each species (the one in command at the winter feeder) gets the first pick of breeding territory. Around here that means the clearing, as it’ll have the highest population of insects during the summer. Maybe someday I’ll learn how to trap and band birds, so I can identify individuals. Then I can verify if Dominant Tom Titmouse at the feeder is the same guy whose mate now reigns in the nesting box in the back yard, or if Submissive Sam managed to outwit Tom or sing better than he did, and get the prime location.
But there’s another fascinating spring event that I like to observe: the year-round resident birds, as they morph from close-knit feeding buddies in a flock, to sparring rivals, who enter into courting rituals.
Throughout the winter we have chickadees, titmice, and goldfinches flocking at the feeder—maybe a dozen or more of each species. To my untrained eye years ago, they all seemed to be close-knit friends, but that was a bit of anthropomorphizing on my part. Birds rarely are friendly with one another—tolerant is a better word for it (at best). In fact, they most always aggressively establish a pecking order that determines who dominates. At the feeder, sweet little chickadees are the most submissive and intimidated. Titmice pick on them, while they in turn are subservient to finches and nuthatches. Small woodpeckers come next, topped off by the cardinals.
But there’s also a harder-to-distinguish pecking order that gets established within each species. It’s more difficult to follow, because I’m as yet unable to tell one titmouse from another. Thus I can detect a hierarchy process going on, but do not know which bird is boss, or if he stays boss for long.
Despite the pecking order dynamics, however, during the winter the birds flock together in a decently non-combative manner around the feeder. Come spring, though, inner mating urges begin to control their behavior. It’s combat time. Winter’s proximity gives way to spring’s territorial jousting. The birds begin to call incessantly, in order to establish their mating and breeding turf. It’s fun to watch their antics, as they begin to challenge each other for the nicest patch of ground. They dive, feint, chase, squabble, show off, sing vociferously, and just as quickly stop and perch next to one another, as if a truce was suddenly called.
I’ve read that the dominant male of each species (the one in command at the winter feeder) gets the first pick of breeding territory. Around here that means the clearing, as it’ll have the highest population of insects during the summer. Maybe someday I’ll learn how to trap and band birds, so I can identify individuals. Then I can verify if Dominant Tom Titmouse at the feeder is the same guy whose mate now reigns in the nesting box in the back yard, or if Submissive Sam managed to outwit Tom or sing better than he did, and get the prime location.
Tuesday, April 13, 2010
Friday, April 9, 2010
Spring Overshoot
Every second or third spring we get a serious case of temperature overshoot. Week after frigid week creeps by in February and March, when we crave warm weather—much as kids impatiently wait for Santa to drop by with his load of goodies. Then in late March or early April, those warmer days finally arrive and we revel in their luxury. But even before we get a chance to enjoy the pleasantness, the temperature slides on up past cordial to somewhere near tropical. From chilly 50s to pleasant 70s, then on into the nasty 90s.
It’s not fair! We’ve far too quickly morphed from shivering to sweltering. A couple of brief days of delight get sandwiched between two disagreeable extremes. Besides it being unfair, the body can’t adjust that quickly. Come July, I can endure 94 degrees pretty decently. But the 94 we had today… in early April?? Whoa!
But the problem with spring’s overshoot goes far beyond our physical uncomfortableness. It even goes beyond the sadness of watching flowers wilt and die well before their time. (In cooler weather, they’d last a couple of weeks, not a measly two days.) The hardest part is watching all the fruit trees pop into bloom one afternoon—knowing that a night of killing frost is surely coming. We can pretty well count on a 26-degree night in the next few days, when all those vulnerable blossoms will get zapped by Jack Frost, die, and turn a ghastly brown the next day. It seems so unnecessary. Why must the weather make these wild swings? Why does it so sneakily lure the buds open, only to kill them the next day?
Mother Nature can seem cruel, but it’s mostly our perception that reads motives into natural events. A gorgeous sunset does not intend to please us. A drought is not our punishment. An earthquake has no malevolence in it. It just is. Our suffering is caused more by doing things like building houses in a flood plain or planting a delicate cherry tree that is susceptible to frost.
Oh well, so we lose a cherry or peach or pear crop every two or three years. But those other years… oh, how sweet their fruit is! Besides, we planted a backup years ago: strawberries. They’re smart enough to blossom later, when all the frosts have passed.
It’s not fair! We’ve far too quickly morphed from shivering to sweltering. A couple of brief days of delight get sandwiched between two disagreeable extremes. Besides it being unfair, the body can’t adjust that quickly. Come July, I can endure 94 degrees pretty decently. But the 94 we had today… in early April?? Whoa!
But the problem with spring’s overshoot goes far beyond our physical uncomfortableness. It even goes beyond the sadness of watching flowers wilt and die well before their time. (In cooler weather, they’d last a couple of weeks, not a measly two days.) The hardest part is watching all the fruit trees pop into bloom one afternoon—knowing that a night of killing frost is surely coming. We can pretty well count on a 26-degree night in the next few days, when all those vulnerable blossoms will get zapped by Jack Frost, die, and turn a ghastly brown the next day. It seems so unnecessary. Why must the weather make these wild swings? Why does it so sneakily lure the buds open, only to kill them the next day?
Mother Nature can seem cruel, but it’s mostly our perception that reads motives into natural events. A gorgeous sunset does not intend to please us. A drought is not our punishment. An earthquake has no malevolence in it. It just is. Our suffering is caused more by doing things like building houses in a flood plain or planting a delicate cherry tree that is susceptible to frost.
Oh well, so we lose a cherry or peach or pear crop every two or three years. But those other years… oh, how sweet their fruit is! Besides, we planted a backup years ago: strawberries. They’re smart enough to blossom later, when all the frosts have passed.
Tuesday, April 6, 2010
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