The Problem with Space Elevators

One of the more popular proposals for overcoming the Earth’s gravity and putting payloads into space without the expense and risk of chemical rocket launches is the space elevator. The proposals have several forms, but the simplest appears to be as follows.

Step one: Put a satellite into geosynchronous orbit. This is the orbital track 22,300 miles above the equator where a satellite moves at the same relative speed as a point on the ground. Thus the satellite does not appear to move in the sky from the viewpoint of a person standing on Earth. Many communications and weather satellites already occupy such orbits.

Step two: Drop a thread of incredibly¹ high tensile strength from the satellite to that point on the ground. You can use any existing or conceivable material: cables made of a single long-chain molecule, or spider silk, or carbon nanotubes … whatever is so tough that you can’t break it no matter what kind of stress you put on it. Reinforce that initial thread with enough additional cables and material so that the tether reaching down to the Earth will not break and will form a stable structure you can climb on. The limiting factor here will be adding so much reinforcement that your tower falls of its own weight.

Optionally: As you build your tether and tower down from the satellite, extend another tower up into the space beyond your geosynchronous orbit. This will supposedly stabilize the satellite, so that instead of perching at the top of a tower, it is actually at the midpoint of a span anchored by a farther satellite 44,600 miles out. That farther satellite will be moving at supraorbital speeds, so that it pulls outward on the whole structure, creating tension. Of course, that puts even more stress on your tower materials.

Step three: Attach an elevator cage to the tower and haul your passengers and cargo up to the geosynchronous platform. At that point, space ships can match orbits with the platform, take on and discharge people and goods, then accelerate away to the Moon, Mars, the stars. Arriving passengers and cargo would enter the cable car and descend to Earth.

The concept of a space elevator—sometimes also called a “skyhook”—has been in development over most of the 20th century by various authors and inventors.² Arthur C. Clarke—no slouch as a scientist—used the concept as the centerpiece of his 1979 novel The Fountains of Paradise. Frederik Pohl and I used a similar concept for orbital transfers in our collaborative 1994 novel Mars Plus, the sequel to his award-winning Man Plus. There is even a national 2011 Space Elevator Conference this coming August in Washington, DC, to discuss progress on the concept.

The only trouble is, I don’t believe such a thing will ever be built. Aside from the expense and the improbability of (1) discovering a sufficiently high-tensile-strength filament and (2) producing it in the requisite 22,300-mile length to anchor the orbital platform, my main objection is coriolis force.

Coriolis force is in play anytime you work around a spinning object, whether a disk or a globe. It results from the different parts of the object moving at different absolute speeds.

As a thought experiment, consider the Earth. With a circumference at the equator of 24,900 miles and a rotation period of 24 hours, a person standing in Quito, Ecuador, just south of the equator is moving east at a little more than 1,000 miles an hour.³ A person standing at the north polar axis—or say just south of it, one foot away from the exact point—is moving in a tight little circle just over six free in circumference.⁴ North Polar man is moving east at only about 3 inches an hour. Anyone standing along a line between Quito man and Polar man is moving more slowly the farther north his location happens to be.

If Polar man faces south and throws a baseball straight at Quito man, it’s going to land somewhere out in the Pacific. This is because Polar man’s baseball is moving east at just 3 inches an hour, while Quito man is spinning east at a 1,000 miles an hour. To hit Quito, Polar man has to throw the ball well to the east of his target.

This has nothing much to do with the fact that the baseball is in the air while the world turns beneath it. If the man at the pole starts walking due south, with every step he encounters ground that’s moving toward the east just a little faster than he is. With every step the ground is accelerating him eastward, putting a drag on his shoe leather. It’s not much of a drag, but between the pole and the equator, he accelerates from a virtual standstill to moving eastward at 1,000 miles an hour. If he runs, the effect is more pronounced, although probably still not noticeable. If he gets in a super-fast race car and accelerates southward at 1,000 miles an hour—taking about six hours for the trip—he’ll find his tires smoking from the eastward drag.

What applies to bodies moving across the surface of a spinning globe equally applies to bodies moving outward on a spinning disk. Objects placed near the center of a phonograph record, say, move more slowly than objects at the edge. They may hold the same relative position, but the object at the edge has to move much faster to stay in line with the object at the center.

In the case of the space elevator, that disk is the plane that includes the planet’s center of mass, the location of the tower base at the equator, and the geostationary platform 22,300 miles above it. The people and cargo waiting for the elevator on Earth are moving east at 1,000 miles an hour. The platform in geosynchronous orbit above them is stationary from their point of view. But to keep up with the surface, the platform is actually moving east at slightly more than 6,800 miles an hour.⁵

Just like the man walking south, any people and cargo riding up the elevator to the platform need to acquire 5,800 miles an hour of eastward speed by the time they reach the top. Throughout their transit to the platform, the tower structure will be constantly pushing them eastward faster and faster, and accepting a corresponding westward drag on its structure. Similarly, any people and cargo coming down the tower must lose speed. As they descend, they will drag eastward on the tower, and it will pull them westward.

If you creep up or down the 22,300-mile-high tower, you can acquire or lose this speed gradually. The drag on the tower would minimal, like the wear on shoe leather for a man walking south. But if you shoot up or down the tower at any speed, the eastward push and westward drag—that is, the amount of energy consumed over the shorter period of time—is going to be much greater. The force on the tower will be much more noticeable, like the burn on the tires of Polar man’s high-speed racer.

You might overcome this tower push and pull by firing rocket motors to the west as you go up, or east as you come down. But timing the rocket thrust to the current lateral inertia of the cable car is going to be tricky. And we’re dealing with impressive amounts of force the more quickly you travel along the cable. Get it wrong, and you’re going to put even more strain on the tower structure.

Alternatively you might simply travel on the tower at a walking pace, like Polar man going south. At that speed, about 5 miles an hour, it will take you twenty-six weeks—or half a year—to travel the 22,300 miles. And the additional food, water, and air you need for that journey will only add to the weight you need to accelerate or decelerate. Oh, and pack a library of entertaining videos and good books, a gym for working out, and good company to pass the time.

Unlike my previous blogs discussing the impossibility of time travel, transporter beaming, and planetary terraforming, space elevators are theoretically possible. But I don’t think they are ever going to be feasible or practical. Still, they’re fun to think about and read about. And, like wormholes and supra-light travel, they save a science fiction writer and his or her characters a lot of time and effort.

A friend of mine feels it’s bad policy for me, a science fiction writer myself, to publicly question these staples of the art. But while I enjoy a good read and can accept a bit of science fallacy for the sake of story, I do believe in a future of wondrous advances. I want to see them happen. I want our scientists and engineers to make them happen. And I don’t want people believing too strongly in alternative futures that simply are not going to come around. Go that route, and you might as well believe we’ll be advance through magic rings, swords of power, and the benevolence of dragons.

1. Some would say “magically.”

2. Inventors and contributors include Russian rocket scientist Konstantin Tsiolkovskii and Leningrad engineer Yuri Artsutanov, who seem to be the original inventors. Jerome Pearson of STAR, Inc., claims to have conceived a similar idea when he was working at Wright-Patterson Air Force Base in Ohio. Physicist and science fiction author Robert L. Forward, in collaboration with several other noted scientists, proposed an alternative to an equatorial tower, the “space fountain.” It would use a stream of magnetically accelerated projectiles to raise a space platform off the ground and into orbit. Instead of riding up a solid monofilament tether, the cargo would tag along with the projectiles.

3. That is, 24,900 miles divided by 24 hours equals 1,037.5 miles per hour. … I always have to check my math.

4. More checking. A circle with a radius of one foot has a diameter of two feet, which multiplied by pi yields a circumference of 6.28 feet. Multiplying that by 12 inches to the foot and dividing by 24 hours of travel time yields just over 3 inches per hour.

5. Check again. At 22,300 miles above the Earth’s surface, the platform is actually 26,263 miles from the center of the planet. (Earth’s diameter is 7926 miles, which divided by two yields a radius of 3,963 miles from the center to the equator. Add that to the elevation of 22,300 miles.) That orbital radius of 26,263 miles represents a diameter of 52,526 miles and a circumference, or distance traveled in 24 hours, of 164,931 miles. The geosynchronous platform is actually moving at 6,872 miles an hour—or just about 5,800 miles an hour faster than the cargo waiting in Quito.

One Magic Trick

If you could perform just one act of magic to change the workings of the physical universe, what would it be? Would you change the laws of gravity, so that humans might soar like birds? Change the chemical linkages governing human nature, so that we might live together without greed and aggression? Change all the iron atoms to gold, so we might all be rich?

Be careful what you wish for. If you change gravity, the planets might fly out of their orbits and then fall apart. If you change human nature, people might become like slugs or three-toed sloths.¹ If you enrich the world with gold, the metal will surely lose its value—and soft gold makes a poor substitute for hard iron in highrises and railroads. And the Earth with a core of molten gold would be denser, with a much higher gravity acceleration.

It’s fun to think about how you might reorder the world if you had godlike powers. For myself, being a hopeless romantic with a conservative streak, I would slow down the energy release of the most fragile and energetic molecular bonds. Trinitrotoluene would not explode but instead burn with the steady flame of a wax candle. The bonds in long-chain hydrocarbons like gasoline and kerosene would release their heat slowly, like a lump of coal. Plastic explosives would burn and glow like wood embers. Cordite and gunpowder would fume like peat and dried dung.

The world would certainly be a quieter place. Hand guns, machine guns, grenades, and high-explosives would never have been invented. Soldiers who really wanted to go to war—and who doesn’t?—would be forced to use spears and swords. It takes skill to do battle with edged weapons. It also takes longer and gives the participants time to get tired and think about what they’re doing.

Without the internal combustion engine, we would all be less free in our choices of where to go today and how to get there. We would still have the steam engine, however, suitable for railroad locomotion and large automobiles, because fuel will still burn and release heat. But we would have to give up the leaf blower and the chainsaw. (Hooray!) Probably also the motorcycle. (Wait a minute! This might not be working out.)

Of course, nothing in this magic trick would change the properties of magnets and electric circuits. We would still have the electric light, the computer, and powerful motors and batteries to drive cars and motorcycles, among other things. We could generate energy as we do now with solar thermal and photovoltaics, wind turbines and hydroelectric dams, and steam plants that rely purely on heat rather than rapid combustion.

The magic trick would still allow for some explosions. Any dust that contains a particle of fuel, from coal dust to wheat flour, will explode when it reaches the correct dispersal in air. That’s why grain elevators go boom. But it is difficult to pack that energy into a small space like a bullet cartridge. So my trick still works in eliminating the explosive force of war.

It also eliminates the good that explosive force does in the world: breaking up solid rock for mines, dams, canals, and seaways; blowing obsolete buildings apart with timed charges, rather than dismantling them one floor at a time. But this loss of explosive power only means that the movements of modern civilization would take a little longer. Mines and canals would have to be cut with machines driven by steam or electric motors.

Of course, I would have to be extremely careful and specific in the phrasing of this magic trick. I would want to get all the clauses right, as it were. The slowdown in exothermic reactions would have to be precisely stated and limited to the most energetic of molecular bonds. I would not want an across-the-board slowdown, where the breakup of carbohydrates and proteins would be subject to a percentage decrease in energy output, proportional to the loss of volatility in hydrocarbons and nitrates. That would have devastating effects on metabolism, for both humans and the animals and plants that serve us. Bread and meat would no longer nourish. You would have to eat huge quantities, perhaps more than your stomach could hold or the workings of your cells could process, to get the same nutritional value. While this sounds dandy for dieters, the long-term effect would be starvation and death.

I would also have to consider whether this magic trick is supposed to take effect tomorrow, or to have been in place since the Big Bang. If the world started afresh tomorrow, then a lot of people still paying for their BMWs and SUVs would be mad when they turned the key and heard a sullen blurp rather than the roar of an engine. Western civilization would fall when ships, railroads, and trucks could no longer keep goods moving. Better to take the long route and have the trick in place from the dawn of time.

The resulting effects on civilization would not be so bad. We would return to a standard of warfare known to the Romans and Greeks, lacking the explosive power of Chinese gunpowder.² To swords and spears, add the artillery of catapult and trebuchet, and the napalm of Greek fire. In time, the western Enlightenment would give us steam power and electricity to replace slave labor. We might end up in a Steam Punk world—except that while modern chemistry might not give us plastique, we would still have plenty of plastics and other durable synthetics like nylon and kevlar.

What about nuclear energy? The bonds being broken in fission and formed in fusion, and so releasing impressive amounts of energy, are not the covalent bonds of electron sharing that hold molecules together, but instead are the bonds holding together neutrons and protons in the atomic nucleus. My magic trick would need a big and complicated clause—essentially a whole other contract—to safely change the nuclear forces. It’s easy enough to imagine a world without the explosive power of enriched uranium and plutonium, or the heat released by turning deuterium and tritium into helium. But mess about with these forces on a grand scale, and the sun and stars go dark. Better to let Dr. Einstein and the Manhattan Project people have their place in history and contain the ill effects through political means.

But then, creating a world without explosives based on molecular bonds among carbon, nitrogen, and oxygen wouldn’t really change much. You could still get a dandy molecular explosion just by bringing hydrogen and oxygen together—look at the fuel mix of the Atlas rockets and the Space Shuttle. You could make a workable grenade out of a plug of elemental sodium and a cup of water. The human thirst for big explosions would not go unrewarded.

And with sufficient electric power and the right chemicals, you can make a high-powered laser. If you don’t like the idea of a machine gun sweeping the battlefield, imagine the original death ray. You can have it in various colors or even invisible beams of infrared and ultraviolet, so that the weapon lacks the minimal courtesy of the tracer rounds in a machine-gun spray.

No, perform an exquisitely precise magic trick to take the power of chemical explosives out of the world, and even if you get it right … not much changes. Humans are awfully clever at getting what they want by exploiting the world and the way it works. And if you try to change that in human nature … imagine life as a three-toed sloth, hanging upside down in a tree with moss growing on your fur.

1. This was the root cause of a planet’s demise, as well as the rise of an insanely aggressive colony of flesh eaters, in the movie Serenity.

2. It’s my understanding, subject to revision with better data, that the ancient Chinese did not actually use gunpowder as a military explosive until sometime in the West’s Middle Ages—somewhere between the Tang and Song dynasties—long after the fall of the Western Roman Empire. Before that, the Chinese used the explosive formula only for fireworks. Ah yes, and without those energetic exothermic reactions we would lose the bright sparklers and aerial displays that help us celebrate Fourth of July. We’d have to remember the American Revolution with a sword dance.

Success as a Trap

The principle of evolution says that the species which is best adapted for an environment, or a particular niche in that environment, flourishes at the expense of other species less well adapted for that niche. It is in this sense, adaptation, that evolutionary competition arises—not necessarily based on who is the more ruthless killer or fastest eater. But being too snugly fitted into your niche can be a trap when that niche changes.

Sharks—ruthless killers and fast eaters themselves—seem to be the exception. They predate the dinosaurs by some 200 million years, and they have evolved very slowly since then, according to the fossil record based on their teeth.¹ As the marine biologist Matt Hooper observed in Jaws: “What we are dealing with here is a perfect engine, an eating machine. It’s really a miracle of evolution. All this machine does is swim and eat and make little sharks.” In the open ocean, that appears to be good enough, so long as you’re near the top of the food chain. And if a bigger predator comes along—a plesiosaur or a whale with a taste for shark meat—then being good at making lots of little sharks might even save the species.

In most evolutionary niches, however, the question for a species is not good or bad adaptation, survival or death, yes or no, but instead better or worse. If you are a Galapagos finch with a long, thin beak, perfect for plucking tiny seeds out of the cracks in the rocks and breaking their delicate shells, you’re going to be at a disadvantage when the bushes serve up big, tough seeds that don’t roll into cracks and are better broken by a short, stout beak.² But that doesn’t mean you starve and die out. You just have to work harder and eat less than your stout-beaked cousins.

And of course, there are imaginary cases of total maladaptation. Transport an orchid from the Amazon jungle to the Sahara desert, and it dies. But the orchid on its own never tried to survive in the desert to begin with.³

It is, however, a fact of evolution and of life in general that the more perfectly you are adapted to fit your niche—that is, the more successful you are—the more vulnerable you become to changes in the environment. The best example is parasites and symbiotes: kill their host, kill the species.

That principle also works in reverse: if your species becomes dominant in a stable environment, your genome settles into a pattern of virtual standstill, or equilibrium, in terms of development. When individuals do arise with mutations that change their bodily fitness, so they are less well adapted to the niche, those mutations and the individuals who carry them are quickly weeded out. The herd and its predators also tend to cull the oddities: the strange, the malformed, the sickly, the malcontent. The population loses its phenotypic diversity, if not its innate genetic diversity. Then a new and more rapidly evolving parasite can arise to exploit the dominant genome and wipe out large populations.⁴

Among humans, the utility and popularity of certain plants and animal species, tailored as seeds and embryos by selective breeding or gene modification and nurtured by special techniques such as irrigation and feed lots, fertilizers and antibiotics, raises this group vulnerability. We have populated the world with species of corn and wheat, chickens and cows, that are physically and genetically uniform. Wily bacteria and the vagaries of climate are constantly prowling the outskirts of our pastures and fields, looking for an opportunity to make a kill.⁵

We’ve also populated the world with humans who are becoming more uniform and less adaptable. As farms and cities arose, people became less able to forage in the woods for their survival. As farms become mechanized, people move into cities seeking work in factories and service. As factories become automated, people become less handy with tools and practical matters. And as service jobs become mechanized, people become less socially adept. They live through work and social exchanges moderated by the dream world of technology.

In the “less developed” countries, we have rural regions where people know how to farm but not hunt—which is probably a blessing, because we’ve also eliminated most of the huntable species. In the cities of “economically developed” countries, we have people who know how to manipulate a computerized database to get the things they want, but they would starve on a working farm.⁶

We used to make products designed to be repaired and maintained, things that will keep going past their obsolescence if you or a local mechanic know a bit about machinery. In the last thirty years or so, however, every appliance from automobiles to refrigerators, typewriters to cash registers, has become digital. They depend on chips and codes that either work or don’t. When these appliances fail, the best you can do is throw them away and buy a newer model. Maintain-and-repair has become diagnose-and-replace.

We build factories with few laborers and no craftsmen; they employ mostly accountants, warehousemen, and janitors. Machines do almost all of the manufacturing, according to plans and orders written by people in other cities and removed in time by months or years. The machines are fast and efficient, perfected for making the products they were designed to make. But to retool for a different product—to make refrigerators instead of cars, for example—is a major undertaking. It’s cheaper to tear down the factory and build a new one.

Believe that I like technology; it’s a fascinating subject. I am no luddite. And the technology I’m describing—both in terms of farmed species and digital factories—has given us in the western and developed countries a life of leisure and wealth of goods beyond the imagining of people just two hundred years ago. If this pattern goes on, if our adaptation to this niche becomes ever more perfect, then the world of 2211 will be as incomprehensible to us as today’s urban living would be to a European of 1811.

But taking the majority of humans out of the active business of providing a living may be a trap. We can provide for them materially. Mechanized farming and manufacture creates enough wealth to feed, clothe, house, and entertain the world. But how do we provide for them psychologically? A quarter of a million years or more of scratching the dirt for roots and hunting with a sharp stick has ingrained pride of self-sufficiency and personal skills in the human psyche. We really were not made to sit on a couch, drink beer, and watch other people play football—or not all day, every day.⁷

More than that, a society whose needs and their fulfillment are in such perfect balance, where supply is matched to demand by computer prediction, and the necessities of life are provided by a complex technology that only a fraction of the population understands, is terribly vulnerable. Economists in their modeling isolate such cases with the phrase “other things being equal,” ceteris paribus. But all else is never equal or static.

The more successful you become, the more efficiently you harvest your niche, the more vulnerable you become to the disruptions that punctuated equilibrium was meant to exploit. In a world of hunter-gatherers, who know hunger and scrambling are the norm, an ice age or an asteroid strike does not wipe out the species. In a world of urban dwellers, who think meat and bread come from the supermarket, a failure of the fuel supply or the electric grid, let alone a cosmic catastrophe, will mean widespread death.

I don’t dwell on these things, no one can. We can’t put the genie of technology back in the bottle. And I wouldn’t wish the life of a hunter-gatherer or a poor dirt farmer on anyone—it’s that life for which the phrase “nasty, brutish, and short” was coined.

Still, we can be too perfectly specialized, too modularized, interconnected, and trained in the esoterics of a surprisingly fragile system. For all our sophistication, we live on a tectonically active planet under a variable star surrounded by rocks and ice in unstable orbits. And ceteris is never paribus.

1. As sharks have no bones, only cartilage, not much else survives from the distant past. See Shark Evolution from the ReefQuest Centre for Shark Research.

2. See Jonathan Weiner’s The Beak of the Finch.

3. Human intervention does change things. We’ve made corn and cotton grow in sandy soils and arid regions by selective breeding and arranging for irrigation and fertilizers. But their survival here is a result, at best, of directed evolution and lots of pampering.

4. But never—or seldom—all of the individuals in a species. The principle of punctuated equilibrium, described in 1972 by Stephen Jay Gould and Niles Eldredge, suggests that evolution is not necessarily a slow and gradual adaptation as once thought. Populations become stable in beneficial environments, and the effects of mutations over time are largely negative, so they die out. But when the environment changes, placing stress on the population through lack of food or other adverse conditions, mutations may suddenly offer advantages. The mutation rate doesn’t change so much as the opportunities offered by changes in design increase. And in some cases, such as the recombination of parts of chromosomes in cells under environmental stress (that is, the “jumping genes”), the mutation rate does actually tend to increase.

5. I’m not necessarily speaking of human-induced climate change through carbon emissions. We live on a tectonically active planet under a variable star. Flood and drought, the advance and retreat of the ice, plagues and locusts, have long been artifacts of human history.

6. This is certainly true in the U.S., where farms are mostly corporate factories with the land dedicated to one species of one plant or animal. In traveling down the Po Valley in Italy, I saw more family farms, with orchards and vineyards planted among the fields. Most of Europe seems to have developed this way. With smaller farms more closely tied to smaller, family-owned boulangeries and charcuteries in town, the Europeans seem better prepared for apocalypse.

7. See my blog Automation, Work, and Personal Meaning from February 27, 2011.

Writing a Good Commandment

I’m not in the religion business, but as a writer and communicator I’m intrigued with how the underlying revelation and message of the founder—Buddha, Jesus, Mohammad, whoever—is interpreted through the religion’s formal structure and followed by its adherents. As in most things human, it matters what the words are and how they are used.

Every religion has a teaching and a text: the sermons of Gautama Buddha in the sutras, the parables of the Christ in the New Testament, the visions of Mohammad in the Koran.¹ You can go back to the words that were written down very close to the time of utterance and say, “See, this is what he said.” But texts evolve rapidly when they are translated from one language to another. The New Testament went from Aramaic to Greek to English, and has seen numerous rewrites since then, while the Koran has stayed in its original Arabic. Yet the understanding of any text still evolves slowly over time, as scholars and preachers reinterpret the words, and as the words themselves acquire new meanings.²

So the choice for any would-be prophet is how to treat the words. Do you want to be as specific and exact as possible, hoping to nail down the exact behavior you’re promoting? Or do you want to be more flexible and general, hoping to engender positive behavior from your current and future followers? The former assumes that your adherents will act as programmable “meat robots,” following exactly the rules you prescribe. The latter requires you to place a large measure of trust in your adherents, that they have heard and understood the spirit of your words and will execute the intention faithfully.

Frank Herbert had the flavor of this in the Dune novels, with Duke Leto’s training of his son Paul: “Give as few orders as possible. Once you’ve given orders on a subject, you must always give orders on that subject.” In other words, it’s easier to lead by example and through the transmission of values than by giving specific instructions. This approach trusts in the intelligence and good will of your followers.

In religion, we can see the differences between these styles of commandment in the Judeo-Christian-Islamic reliance on scripture and the Buddhist reliance on understanding.

The Old Testament, especially Leviticus, is full of specific rules for living. What you can’t do on the Sabbath, what foods you must not eat, what sexual practices are forbidden, even how to cut your hair. The Koran picked up and amplified many of these rules. They are specific and eternal.

Take the injunctions against eating pork and shellfish. These prohibitions made sense in the ancient Middle East, when lack of refrigeration made all shellfish suspect and trichinosis was widespread in pigs and wild game. Adherents as a whole became healthier and stronger. Modern technology has since rendered these and similar dietary rules largely unnecessary, and yet modern practitioners still follow them. Some do it as a form of self-discipline,3 which is useful unless you happen to be starving to death by the seashore. Some follow so blindly and rigidly that the image or suggestion of a pig offends them and the game of football is offensive because the ball is covered in pigskin. Taking offense against the practices of others over rules that you are meant to follow will make you unpopular.

Earning interest on a loan is forbidden in the New Testament and the Koran. Christians have come largely to ignore the matter, and so the West developed the “time value of money” as a key component of finance. Our wealth has grown ever since. Muslims remain faithful to their injunction, and so their financial choices and institutions are constrained.

Compare all this specific and technical instruction with the teaching methods of Buddhism. Once a follower has absorbed and understood the realities of suffering and release in the Four Noble Truths,⁴ the rest is the general guidelines of the Noble Eightfold Path.⁵

Buddhism trusts the user to interpret and deal correctly with the details. For example, in the steps dealing most directly with ethical conduct and interpersonal relations, “right speech” is simply abstaining from lying, divisive speech, abusive speech, and idle chatter. There is no list of forbidden words or sentiments. Once you’ve heard the truth, you know when you are telling a lie and what divisive and abusive speech might be. Figure the rest out for yourself.

“Right action” is abstaining from taking life, stealing, and unchastity. And “unchastity”—a thorny area in any religion—is relatively loosely defined, at least for lay followers: getting sexually involved with those who are protected by their families, with those who refrain for reasons of self-discipline, those who are committed to another, and those with whom involvement entails punishment. That is, don’t get involved where sexual attachment would create division or abuse. For monks, the rule is simpler: it’s a form of discipline, so don’t get sexually involved with anyone.

“Right livelihood” is similarly general and obvious: don’t trade in weapons and instruments of death; don’t trade in people as slaves or prostitutes; don’t trade in meat or raise animals for food; don’t make or sell intoxicants or addictive drugs; don’t trade in poisons or products that kill.

In all of this, as well as in the other five steps dealing with wisdom and mental discipline, there is no cause for horror or disgust. You don’t swoon at the sight of meat or beat up cowboys and shepherds on principle because they raise animals for food. You simply realize that killing and eating animals—which exhibit intelligence and volition, and may possess a state of awareness similar to that of humans—is bad for your karma or spiritual balance. Besides, relishing a thick steak and pining when you can’t have one are forms of attachment to desire.

Buddhists, virtually alone among the major religions, seem to be able to coexist peacefully with neighboring faiths—with Confucianism, Taoism, and even Communism in China; with Shinto in Japan; and with native animism and even Islam in Indonesia. Being preoccupied with their own reactions to the causes of suffering and seeking release, Buddhists neither take nor give offense. And Buddhists have never engaged in a holy war.

Buddhism is also the only major religion that doesn’t have a god. Gautama Buddha is an exemplar, a source of strength, not an all-powerful creator and granter of wishes. While Buddhists acknowledge the existence of various gods and demons, and revere the near-godlike bodhisattvas who are one step removed from Buddha, they do not worship these beings as supreme entities.

Buddhism is today celebrated as an early form of psychology and as having therapeutic benefits. This is true in that the practice focuses on mental states and our conscious knowledge and use of them. Buddhism has more to do with the mind and the suffering it creates through attachment to desire than with the existence and eventual destination of some invisible part of us called “the soul.” In this sense, Buddhism is very modern and potentially timeless.

All prophets, both past and future, tell us stories and establish rules about what it means to be human and attain a proper relationship with everything else—the universe, the forces of nature, the forces of mind, other people, and the good influence that is a god or gods. How you do this depends on whether you trust your worshippers’ intelligence and understanding. If you trust them, you cite guidelines and examples, knowing they will be interpreted correctly. If you don’t trust, you give specific orders and injunctions, hoping they will be followed exactly.

Which approach has better stood the test of time?

1. A Muslim would object to this: the Koran is held to be the verbatim word of god as dictated by Mohammad to his companions, who wrote it all down. But when divine thought passes through the human mind to take form in a human language, issues of grammar and word choice cannot help but distort the original, immediate flash of understanding. This happens to writers all the time.

2. Anyone who doubts that words can change, even when they have exactly the same form and grammatical usage as when they were written down, should consider the English word “nice.” Today it means pleasing, agreeable, delightful. “She’s a nice person.” It can also mean accurate, exact, or skilled. “That was a nice shot.” But the original Latin root, nescius, combining the elements of “not” and “knowing,” meant ignorant or incapable. Middle English understood “nice” to mean foolish or stupid, and Old French took the word to mean silly or simple. Tell Chaucer that he’s a “nice guy” and you might get a black eye.

3. In the matter of self-discipline, there’s an anecdote about the science fiction writer Avram Davidson, a devout Jew. Once in visiting a friend on the Sabbath he walked up six flights of stairs rather than do the prohibited “work” of pushing an elevator button. This is taking a biblical injunction to extremes—and perhaps playing some mind games with it along the way.

4. The Four Noble Truths, in brief, state that (1) suffering exists, (2) it arises from attachment to desires, (3) suffering ceases when attachment to desire ceases, (4) freedom from attachment and suffering is possible through the Noble Eightfold Path.

5. The Noble Eightfold Path is a guide to wisdom, ethical conduct, and mental discipline. The steps, in brief, are (1) right understanding and (2) right intention—contributing to wisdom; (3) right speech, (4) right action, and (5) right livelihood—contributing to ethical conduct; and (6) right effort, (7) right mindfulness, and (8) right concentration—contributing to mental discipline and effective meditation.