January 17, 2012
Rereading Darwin: Science now takes for granted the importance of forces and time spans we can’t perceive directly
January 17, 2012
Two centuries before Charles Darwin wrote On the Origin of Species, Bishop James Ussher calculated the age of the Earth. To do so, the Primate of All Ireland (time has given his title a certain irony) carefully mined the Old and New Testaments for genealogical information that might lead him back to the date of Creation. In so doing, he concluded that the Earth was only about 5,600 years old. It’s easy to ridicule the bishop and his date, but to do so misses a larger point. Ussher’s approach was rigorous—even elegant—and he seemed to understand that the Earth’s age could only be inferred through careful observation of evidence. What doomed his result—and, indeed, many a conclusion in science—were faulty assumptions. The bishop, who took as an axiom that the biblical account of Creation was literal, painstakingly did the math attendant on the notorious biblical begats. He then dutifully added to his tally the five days that separated the creation of the Earth from the creation of human beings, and arrived at the exact date of Creation: October 23, 4004 B.C. Of course, he was wrong.
A Subtle Blow
By the 18th century, scientists in various disciplines had used diverse approaches to calculate the planet’s age and reached different conclusions. As they did, the Earth got older. Still, by the mid-19th century, when Darwin was writing the Origin, the age of the planet was a contentious issue. Although the 4004 B.C. date had fallen from favor, estimates still varied wildly and tended to err on the side of youth.
What Darwin realized was that a youthful Earth was appealing not only because it adhered to the biblical time line, but also because it was simply easier to imagine. He knew that his own argument for natural selection depended on vast conceptions of time, and he also understood that the time spans required would be nearly impossible to comprehend. In a section of the Origin entitled “On the Lapse of Time,” he wrote:
It is hardly possible for me even to recall to the reader, who may not be a practical geologist, the facts leading the mind feebly to comprehend the lapse of time. He who can read Sir Charles Lyell’s grand work on the Principles of Geology … yet does not admit how incomprehensibly vast have been the past periods of time, may at once close this volume.Darwin feared that his readers would be unable to understand the deep time over which natural selection acts, and that their failure would be problematic for his argument. Those with limited imaginations might as well put away his book at once.
From the time he began writing in his notebooks after returning from his voyage on the HMS Beagle, Darwin knew that his was a radical theory, time spans aside. In 1837, 22 years before the publication of the Origin, he wrote “cuidado” (caution) in his journal as he thought about the implications of his ideas. As many have noted before, in the new Darwinian reality, human beings were still a unique species—but no more so than any other species, living or extinct. Gone forever was the notion that we were special, that our origins were unlike those of any other organism on Earth. Darwin carefully avoided mentioning human beings in the Origin, writing, in a masterpiece of understatement buried on page 488 of the first edition: “Much light will be thrown on the origin of man and his history.” Indeed.
Still, when I recently reread the Origin, I was struck by a subtler blow the book delivers to human hubris. The Origin remains, even in the 21st century, a radical work, which argues that the fundamental forces driving life on this planet occur on timescales that render the span of a human life insignificant. Furthermore, although the effects of natural selection are there for all to see, its daily operation is almost completely hidden from view. Both our life spans and our five senses are inadequate to the task of comprehension: The most powerful mechanism of organic change lies well beyond our everyday experience.
The Dangers of Extrapolation
By Darwin’s time, 19th-century geologists and paleontologists were well aware of the fossil record—and they knew that fossils were old. Naturalists recognized the characteristic appearance and extinction of faunas in the geologic record; by the mid-1800s, they had named the periods and even established their order of succession. But the implications of the fossil record for the age of the Earth remained controversial. One group of scholars constructed increasingly elaborate theories of successive catastrophes that reconciled the fossil record with a young Earth. Lyell and Darwin belonged to another camp, pioneered by James Hutton, which argued that the fossil history was evidence of a far more ancient Earth. As Hutton put it in a 1785 paper presented to the Royal Society of Edinburgh, Earth’s geology revealed “no vestige of a beginning, no prospect of an end.”
The matter was far from settled. Indeed, the assignment of accurate absolute dates to the geologic timescale would have to wait for the discovery of radioactive decay at the turn of the 20th century. That’s not to say no one tried; clever calculations were certainly attempted during Darwin’s lifetime. Most notably, the influential physicist William Thomson—better known as Lord Kelvin—argued for the power of physical approaches to the question of time spans. He used the rate of cooling of an originally molten Earth to conclude that our planet was likely 100 million years old.
Here again, as with Bishop Ussher, the flaw was not in the method, but in its underlying assumptions. Kelvin knew nothing about radioactivity and the constant heat it supplied. His model of a cooling Earth failed to account for new heat contributed by radioactive decay. Nor did he consider the transfer of heat from Earth’s deep interior to its crust by convection. These omissions led to a serious underestimate of the planet’s age.
At the same time that Kelvin was making the case for a 100-million-year-old Earth, geologists championed a completely different approach. Their argument depended on careful observation of the speed of deposition and erosion in contemporary landscapes. Geologists in the 19th century understood that these processes, writ large, could carve canyons, build up or erase thick sedimentary layers and reshape topography. By looking at these large-scale phenomena in terms of slow—but measurable—current rates of deposition and erosion, they could estimate how long those processes had been at work to generate contemporary geologic features. This approach, sometimes called uniformitarianism, would lead to significantly greater estimates of the age of the Earth.
In the first edition of the Origin, Darwin employed this method to calculate the age of the Weald, a sandstone formation in Southern England. This feature, once covered by a layer of chalk (still visible in nearby formations), had been completely denuded. Based on estimates of the rate of erosion, Darwin calculated that it would have taken at least 300 million years to remove all of the sediments covering the Weald. This estimate was three times greater than even the most generous prevailing notions of the age of the Earth. Kelvin was unimpressed with both the method and the result that Darwin obtained. And, as it turns out, Darwin was wrong, too. The Weald, in an unusual turn, was younger than he thought. Shortly after its publication in 1859, Darwin acknowledged that his estimate was likely incorrect, and the episode continued to disturb him. In an 1860 letter to his friend Asa Gray, he complained that “in fact geologists have no means of gauging the infinitude of past time.” A few months later, he wrote to his friend Lyell about the dangers of extrapolation:
Having burnt my own fingers so consumedly with the Wealden, I am fearful for you.… for Heaven-sake take care of your fingers; to burn them severely, as I have done, is very unpleasant.By the third edition of the Origin, published in 1861, the discussion of the age of the Weald was entirely gone. Telling time was proving trickier than Darwin had thought…
January 17, 2012
Have you had it up to here with supposed allies who issue ultimatums to Washington? Hamid Karzai, the president of Afghanistan, seems to come up with a new one whenever he’s in a bad mood. Last week’s was: Hand over all the prisoners in the main detention facility in Parwan within a month. And what about the Pakistanis? In the aftermath of the NATO raid that killed 24 Pakistani soldiers, the military leadership ordered the C.I.A. to close the Shamsi airbase it uses to launch aerial drones — this from a country whose military we train and finance, and whose pockets we deeply line. And it’s not just the allies: Iran has threatened to close the Straits of Hormuz if the West doesn’t suspend its program of sanctions.
Remember when it was the United States that was issuing all the ultimatums? Those were the days. Right after 9/11, according to Bob Woodward’s book, Bush At War, Deputy Secretary of State Richard Armitage handed a list of seven demands to Pakistan’s intelligence chief — cut off support to al Qaeda and the Taliban, give the United States overflight and landing rights, etc. — and Pakistan complied. President George W. Bush gave the world a clear choice: stand with us, or stand with the terrorists. And remember when British Prime Minister Tony Blair, America’s closest ally, said that he could only join the U.S. war effort in Iraq if the allies got a resolution at the United Nations authorizing the use of force? Bush decided against seeking the resolution, and gave Blair the same choice: in or out. And Blair went in.
So what’s gone wrong? How come the United States is suddenly on the receiving end of so many ultimatums? Conservatives know the answer: Because we’re weak, of course. Because Barack Obama insists on engaging countries that only understand force. Iran rattles its sabre because it knows Obama will never use the supreme sanction of war. Karzai threatens us because — well, that’s different.
Afghanistan is our ally. So is Pakistan. They don’t issue ultimatums because we’re weak; they do so because they’re weak. The only way either Karzai or Pakistan’s military leaders can shore up their fading support at home is by standing up to Washington, which needs them and therefore cannot afford to call their bluff. Come to think of it, the same is true of Iran, which surely knows that blocking oil shipments could provoke a devastating retaliation. But it’s the best card they’ve got.
Historically, of course, the ultimatum is a tool of the strong against the weak: open up the gates or we’ll raze your city, rape your women, and enslave your men. But nowadays, powerful countries wish to be seen as rule-abiding, and are less inclined to shake their fist at weaker states. The ultimatum has become largely a tool of the weak — a form of asymmetric warfare. Stop violating Afghanistan’s sovereignty, Karzai seems to be saying, or we’ll do something suicidal. After all, he’s also threatened to join the Taliban if the West continues to press him to reform his government. He might never carry out any of these threats, of course: The ultimatum is issued publicly because it is aimed at the domestic public as much as it is at the adversary. But the power he has over the West is the power to harm Western interests — even if that means harming himself.
It’s an infuriating situation. You’d like to be able to say, “Fine: join the Taliban for all I care.” You’d like to tell Pakistan’s Gen. Ashfaq Kayani to get lost. But, as both leaders know, it’s not in the U.S. interest to call their bluff. So the White House instead dispatches Sen. John Kerry to talk one or both of them off the ledge. There’s really no good alternative: Even the Republican candidates for president, who uniformly scorn Barack Obama for failing to credibly threaten Iran with war if it doesn’t end its nuclear program, have very little to offer on Afghanistan or Pakistan.
The real reason the United States has been the target of these vexing ultimatums is that over the last decade it has meddled deeply with the sovereignty of brittle states, which in turn react with intense resentment. The solution is to stop provoking this form of asymmetric warfare. By accelerating the troop withdrawal from Afghanistan, Washington will put an end not only to the insoluble relationship with Karzai but also to its dependence on Pakistan, whose hinterland serves as a staging area for attacks on American troops in Afghanistan. The United States has already muted its neuralgic relationship with Iraq by withdrawing its troops there altogether. And one of the side-benefits of the White House’s planned pivot to Asia is that the United States will have less frictional relationships with allies like Japan and South Korea than with Afghanistan and Pakistan…
January 17, 2012
Do sports build character? For those of us who claim to be educators, it’s important to know. Physical-education teachers, coaches, boosters, most trustees, and the balance of alumni seem sure that they do. And so they push sports, sports, and more sports. As for professors, they often see sports as a diversion from the real business of education—empty, time-wasting, and claiming far too much of students’ attention. It often seems that neither the boosters nor the bashers want to go too far in examining their assumptions about sports.
But in fact, sports are a complex issue, and it’s clear that we as a culture don’t really know how to think about them. Public confusion about performance-enhancing drugs, the dangers of concussions in football and of fighting in hockey, and the recent molestation scandal at Penn State suggest that it might be good to pull back and consider the question of athletics and education—of sports and character-building—a bit more closely than we generally do.
The first year I played high-school football, the coaches were united in their belief that drinking water on the practice field was dangerous. It made you cramp up, they told us. It made you sick to your stomach, they said. So at practice, which went on for two and a half hours, twice a day, during a roaring New England summer, we got no water. Players cramped up anyway; players got sick to their stomachs regardless. Players fell on their knees and began making soft, plaintive noises; they were helped to their feet, escorted to the locker room, and seen no more.
On the first day of double practice sessions, there were about 120 players—tough Irish and Italian kids and a few blacks—and by the end of the 12-day ordeal, there were 60 left. Some of us began without proper equipment. I started without cleats. But that was not a problem: Soon someone who wore your shoe size would quit, and then you could have theirs.
The coaches didn’t cut anyone from the squad that year. Kids cut themselves. Guys with what appeared to be spectacular athletic talent would, after four days of double-session drills, walk hangdog into the coaches’ locker room and hand over their pads. When I asked one of them why he quit, he said simply, “I couldn’t take it.”
Could I? There was no reason going in to think that I would be able to. I was buttery soft around the waist, nearsighted, not especially fast, and not agile at all. It turned out that underneath the soft exterior, I had some muscle, and that my lung capacity was well developed, probably from vicious bouts of asthma I’d had as a boy. But compared with those of my fellow ballplayers, my physical gifts were meager. What I had was a will that was anything but weak. It was a surprise to me, and to everyone who knew me, how ferociously I wanted to stay with the game.
Did I love the game? I surely liked it. I liked how, when I was deep in fatigue, I became a tougher, more daring person, even a reckless one. One night, scrimmaging, I went head-on with the star running back, a guy who outweighed me by 20 pounds and was far faster and stronger. I did what the coaches said: I squared up, got low (in football, the answer to every difficulty is to get low, or get lower), and planted him. I did that?, I asked myself. I liked being the guy who could do that—sometimes, though alas not often enough. The intensity of the game was inebriating. It conquered my grinding self-consciousness, brought me out of myself.
I liked the transforming aspect of the game: I came to the field one thing—a diffident guy with a slack body—and worked like a dog and so became something else—a guy with some physical prowess and more faith in himself. Mostly, I liked the whole process because it was so damned hard. I didn’t think I could make it, and no one I knew did either. My parents were ready to console me if I came home bruised and dead weary and said that I was quitting. In time, one of the coaches confessed to me that he was sure I’d be gone in a few days. I had not succeeded in anything for a long time: I was a crappy student; socially I was close to a wash; my part-time job was scrubbing pans in a hospital kitchen; the first girl I liked in high school didn’t like me; the second and the third followed her lead. But football was something I could do, though I was never going to be anything like a star. It was hard, it took some strength of will, and—clumsily, passionately—I could do it.
Over time, I came to understand that the objective of the game, on the deepest level, wasn’t to score spectacular touchdowns or make bone-smashing tackles or block kicks. The game was much more about practice than about the Saturday-afternoon contests. And practice was about trying to do something over and over again, failing and failing, and then finally succeeding part way. Practice was about showing up and doing the same drills day after day and getting stronger and faster by tiny, tiny increments, and then discovering that by the end of the season you were effectively another person.
But mostly football was about those first days of double sessions when everyone who stuck with it did something he imagined was impossible, and so learned to recalibrate his instruments. In the future, what immediately looked impossible to us—what said Back Off, Not for You—had to be looked at again and maybe attempted anyway…
January 17, 2012
This image has been posted with express written permission. This cartoon was originally published at Town Hall.