When I lived in Brooklyn, I would occasionally go to a nearby park on a Sunday afternoon to throw a boomerang. When passers-by saw my clumsy attempts, they sometimes gave me a wide berth — too many Mad Max movies, I suppose. But when I finally managed to launch this deceptively simple-looking object into the urban sky, these same people stepped closer to admire its flight. The boomerang first shot forward while spinning vertically, then slowly shifted to a horizontal position parallel to the ground, all while circling back to its starting point, where it then hovered in place like a helicopter before sinking to the earth. Even New York City kids, notoriously blase, would ask, "Why does it come back? What's it used for? How is it made?"
Months later I found myself in Australia asking the same questions of an Aboriginal Elder of the Gunai clan in coastal East Gippsland, Victoria. Sixty-year-old Albert Mullett carves some of the finest traditional boomerangs found today, according to anthropologists from Sydney, who ought to know. Mullett is also a "keeper" — a custodian of traditional ways — at Krowathunkooloong, a tribal community center devoted to preserving indigenous culture. I was fortunate, he told me with a twinkle in his eyes; in the old days, an elder like him would never share his knowledge with a young person until that person had shown sufficient respect and understanding for several years.
I followed him through the display of weapons and artifacts that had been returned to the Gunai from government collections. The exhibits included one of Mullett's personal mementos: a wedding photograph of his uncle and aunt made during the Second World War. In the picture the newlyweds are walking under an archway of boomerangs formed by men of Aboriginal descent in Australian Army uniforms.
Mullett picked up a three-foot-long boomerang that he had created a few years ago, which now hung in the center. Made of lightweight, flexible blackwood — a kind of Acacia indigenous to Australia — it was incised with the distinctive ancestral diamond and wave patterns of the Gunai. "This is of my area and my people," he said. "In our dreaming (belief system) this represents the ocean," commented Mullett. It gleamed with its protective coating of fish oil.
Not all boomerangs boomerang: some aren't meant to return to the thrower; they simply fly farther than an unmodified piece of wood. But the one in Mullett's hand lived up to its name, and he rocked it on his fingertip. "We call the returning boomerang the magic boomerang," he said. "I make them after I see them in the trees" — much like Michelangelo once said that he "released" his sculptures from their native stone.
Back home, boomerang designers do things a bit differently. Americans sometimes call boomerangs "the thinking man's Frisbee": cheap to make, easy to test, yet possessed of astonishing, sophisticated aerodynamic properties. The American love affair with boomerangs began in 1979, when Benjamin P. Ruhe, a Smithsonian employee, organized the first annual Smithsonian Boomerang Throwing Tournament on the Mall in Washington, D.C.
Within five years the U.S. boomerang team had won its first international tournament, and it has not lost since. (Curiously, Australia has not done well at such competitions — perhaps modern Aussies take their national icon too much for granted.) Along the way, boomerang design has become a highly competitive high-tech business — one in which a few millimeters of material can spell the difference between ignoble crash and soaring flight.
At Superflight, Inc., in Palo Alto, California, for instance, Alan Adler, a physicist and the owner of the company, applies proprietary equations, computer-modelling techniques and NASA flow-visualization tunnels to refine his boomerangs. Thanks to designs such as his, as well as new polymers that offer the designer both strength and weight control, America's 'rang-throwers are setting records for consecutive catches, maximum time aloft and stunt-flying.
And yet Mullet's magic boomerangs may still have something to teach the Americans. Even as Australian Aboriginal people are reclaiming boomerangs as part of their cultural heritage, modern designers are going back to the same source, looking for hints that could change the shapes of boomerangs to come. In the never-ending search for the perfect boomerang, one step back may take designers two steps forward.
The boomerangs that developed in Australia were once the most refined and the most varied in the world. But they were not the earliest. In 1987 a 23,000 year-old mammoth tusk carved in the shape of a boomerang was discovered in a peat bog in Poland. And when the British archaeologist Howard Carter excavated King Tutankhamen's tomb in 1922, he found a box of gold-tipped, throwing sticks — non-returning, boomerang-like objects capable of flying great distances. Many cultures, it seems, independently discovered how to control the flight of a stick, but they never pursued the concept, favoring bows and arrows instead. Only in pre-European Australia, where arrows never flew, was the art of the boomerang brought to a high pitch.
Traditional boomerangs made by Aboriginal people come in a dizzying array of forms and sizes. Ornate, ceremonial X-shaped boomerangs from lush Queensland in the northeast (complete with stylized shark motifs) vie for attention with the sharply- pointed, unadorned fighting boomerangs of the barren northwest. Near the deserts of Cooper Creek, in the north-east section of the state of South Australia, six-foot boomerangs were wielded like swords or staves. In central Australia "hooked" boomerangs — shaped like the number seven — caught the rims of enemy shields and swung round to strike from behind. Outside the town of Broome, on the northwest coast, broad, heavy, "fishing" boomerangs knifed through water to stun fish trapped in tidal pools. The lightweight boomerangs of southeastern Victoria were made to cast hawk-shaped shadows over the water; by hovering them over ponds, hunters could scare flocks of ducks toward low-slung nets.
Faced with such a bewildering assortment, early ethnographers drew evolutionary charts that sought to classify every boomerang-esque shape. Indigenous peoples had names for them all — some Aboriginal people call throwing-clubs "nulla-nulla," for instance, and wooden staves, which are rarely if ever thrown, are called "murrawirri." But there were no universally accepted labels among the more than 250 Aboriginal languages. The waters of taxonomy were further muddied because observers could not agree, for instance, on when an oversize boomerang became a murrawirri.
To the untrained eye the subtleties of boomerang design are almost imperceptible. Even after Mullett showed me the identifying characteristics, I had trouble telling whether I was looking at a returning boomerang or not. Luckily, there are some rules of thumb. Paul S. Tacon, an archaeologist and social anthropologist at the Australia Museum in Sydney, and Philip G. Jones, Curator of the South Australia Museum and author of the popular Boomerangs-Behind an Australian Icon, agree on the following distinctions:
* Throwing sticks have little or no arch, and they do not return. Indeed, they can be virtually indistinguishable from nonreturning boomerangs, except that they are launched horizontally, whereas all boomerangs are launched vertically.
* Nonreturning boomerangs have a round or oval cross-section, except that part of the shape is often given a fluted indentation. They are usually more curved lengthwise than throwing sticks. Primarily a tool for hunting, their decor was minimal. "The elders tell me that kangaroos and wallabies have weak necks," Tacon noted—and so the neck was the usual target.
* Returning boomerangs have flat undersides, convex tops and pronounced crescent-shapes. The forward edge of the tip of the leading arm is warped upwards, as is the trailing edge of the following arm. Traditionally, every male of Aboriginal descent made his own returning boomerangs, and particularly fine models were traded across long distances. Returning boomerangs were usually elaborately decorated, either with totems of the maker's clan or with highly abstract patterns having religious significance. (After the Europeans arrived, the decor became more representational and less sacred.) Returning boomerangs had a place in ceremonies, entertainment, sporting events and in the hunting of birds.
Regardless of their form or function, all aerodynamically enhanced, curved objects made for throwing have been called boomerangs, ever since Captain Cook saw Tharawal-speaking men tossing "bumariny" on Botany Bay's shores. In what follows, however, the word "boomerang" refers only to those that return.
Every boomerang flies according to the same principles. The classic version has two blades, or arms, which the thrower holds so that one arm points forward while the other arm hangs down. To spin in the correct direction, the flat underside of the boomerang should be farthest away from the thrower's body.
A boomerang's arms are made to rotate in one direction only, and so boomerangs come in both right- and left-handed versions. Throw a leftie with your right hand and it won't fly properly.
In cross-section, a boomerang's convex top and flat bottom resemble an airplane wing. As the miniature airfoil cuts through the atmosphere, the air moving over the bowed top has to travel farther than the air moving across the flat bottom. Because the air on both sides must, according to Bernoulli's principle, reach the far end of the airfoil at the same time, the air on top has to move faster than the air on the bottom, thereby reducing the pressure on top and increasing it underneath. The result is "lift" — a push in the direction of the top of the airfoil. For a boomerang, which is thrown vertically, this lift comes initially from the side.
But there is more. Remember that as the boomerang as a whole moves forward, both arms of the boomerang are also spinning about their common center of gravity as fast as ten revolutions a second. The top arm thus rotates in the same direction as the throw, but the bottom arm moves opposite to that direction. This causes the top arm to have a faster relative velocity through the air than the bottom arm.
These inequalities are amplified by the fact that lift is proportional to the square of the air's velocity. Consequently, the top arm "feels" much more lift than the bottom arm.
This extra force on the top — technically called a "torque" — tries to tip over the spinning boomerang. The boomerang, however, resists this torque, since this same spinning motion acts like a gyroscope battling to stabilize it. The result of this contest of forces is a compromise known as "gyroscopic precession," in which the torque at the top is felt at 90-degrees forward in the direction of rotation. (We see the effects of gyroscopic precession everyday, whenever we ride a bicycle with no hands: try to push the spinning wheels down to the left, and the bike turns left.)
Gyroscopic precession makes a right-handed boomerang turn to the left and keep turning in that direction until it circles back to the thrower. In fact, if the boomerang is thrown hard enough, it will circle around again and again, turning more pirouettes until it stalls.
Meanwhile, as it moves, the boomerang gradually shifts away from its vertical starting position. The arms at the forward end of the spin cycle have slightly more lift than the arms at the aft end, in effect causing another case of gyroscopic precession that turns the boomerang to a horizontal position. The combination of this and the loss of forward motion due to aerodynamic drag causes the boomerang to hover horizontally in place — or "autogyrate" — until it sinks to the ground. Essentially, the boomerang does several things at once: fly around in a loop while shifting from a vertical position to a horizontal one, until hovering to the ground.
All those motions are affected by a thrower's strength and technique. But mostly they are determined by the shape of the boomerang's arms and the angle at which they are joined — which is why Adler describes boomerangs as "preprogrammed flying devices." By tinkering with such factors, the designer can increase or decrease a boomerang's spin, forward movement and hovering ability.
A boomerang's malleability, its ability to be "tuned," is part of its appeal. Eric A. Darnell is an international boomerang champion and the South Strafford, Vermont-based creator of a plastic, three-bladed boomerang, and he is an enthusiastic proponent of that tunable style. "One of the things I like about modern boomerangs - particularly the plastic ones," he says, "is that you can easily ask 'What if I twist it some more? What if I bend the blades up more? What if I bend them down? What's it do?'"
And though tolerances are tight, new boomerang designs are easy to test. "It's not like a glider or a full-scale airplane, where you've got one shot in a three-month time period," adds Ted E. Bailey, an Ann Arbor, Michigan inventor and boomerang-thrower who chairs the World Boomerang Association (WBA). "I can make dozens of iterations in a week if I want to."
The WBA and its sister organization, the United States Boomerang Association, sponsor competitions that inspire many of the new designs — conceptual breakthrough often seems the only way to beat the stunning current records.
The record for long-distance flight of a boomerang goes to Michel Dufayard of Charleville-Mecieres, France, who threw one 489.37 feet in 1992. As for maximum time aloft, John "Air" Gorski, owner of Skybooms in Avon, Ohio, set the unofficial record when he threw a boomerang that hovered in the air for 17 minutes and 6 seconds in August 1994, the day after the official tournament ended in Delaware, Ohio. Bailey, who was hanging around along with a crowd of other 'rang enthusiasts, says, "Forty-five seconds into the flight, we knew it was going to be a long one and put a stopwatch on it. The boomerang flew across the field, over the river and back, then caught a thermal over the highway and kept going up. The amazing thing to me was that he actually caught it on the return." The flight earned Gorski the nickname "Air."
However, this feat did not earn the official record, since the boomerang was not caught within a 50-yard radius of its takeoff point, as per WBA rules. That record goes to Darnell, who flew a boomerang on September 21, 1997 for one minute, forty-four and 87/100ths of a second.
Bailey adds that it is not unusual to have flights that last several minutes; lightweight (17 grams), specially-designed boomerangs are known for their ability to float up into the sky. "If they catch a thermal or a steady wind, they'll tack like a kite," Bailey said in a recent interview. "Sometimes one just goes up out of sight and disappears. We call that 'Losing it to the jetstream gods.'"
To beat these records, many competitors make their own boomerangs, and the designs can be quite whimsical: five-bladed versions made of plastic or foam, boomerangs shaped like various letters of the alphabet, and odd hybrids in the shape of animals, geometric forms, or cartoon characters.
The boomerang scene in America today is much like the surfing scene in California thirty years ago. Aficionados the likes of "Air" Gorski and Michael "Gel" Girvin of Berkeley, California, have appropriated a traditional wooden object and built a subculture around it, handcrafting their own tangerine-flaked, kandy-kolored streamlined babies (apologies to Tom Wolfe). Anything goes, and the elite throwers delight in stunts that could make up a boomerang version of the X Games: a boomerang returns to neatly knock an apple off the thrower's own head. Others throw and catch boomerangs at night, with Fourth of July sparklers on the ends. Darnell tells of a trick that even the physically squeamish can do with ease: throw and catch a boomerang while you're aboard an airplane that's crossing the International Date Line from west to east. "That way," Darnell explains, "you can say you threw it today and caught it yesterday."
To find inspiration, Darnell keeps a stock of classic, Aboriginal-made boomerangs. Each one, he says, is the culmination of thousands of years of testing by trial and error. "We like to claim that we invented everything now, but we didn't," he says. "They (Aboriginal people) knew what they were doing." After studying a turn-of-the-century fighting boomerang made from a mulga tree, for instance, he found that its underside was hollowed out and its top fluted. Like the dimples on a golf ball, the carving reduced weight and increased lift — vital considerations when dealing with a dense, heavy wood such as mulga, ideal for a fighting boomerang.
Bailey also stockpiles boomerangs for reference; by his most recent count, his collection numbers about 1,000. Much of the technology embedded in those airfoils "has been lost by modern man," he says, "and I incorporate some of it in my designs." When pressed for details, however, Bailey, like most other boomerang designers, becomes tight-lipped, jealously guarding the secrets of his trade.
Alan Alder is one exception to the rule of secrecy. For example, he told me, the leading edge of the traditional boomerang is quite sharp, and so he had expected to improve its flight by blunting the leading edges to more closely resemble the blunt front of the typical modern airplane wing profile. "I thought to myself, 'Well, this is the twentieth century. I'm going to apply twentieth-century airfoil shapes.'"
Yet, to Alder's surprise, the resulting boomerangs flew more poorly than the older, sharp-edged ones. After more investigation, he found that at low speed, air flowed irregularly over the new airfoils, creating a bubble of stagnant air that caused drag and reduced lift. "The sharper leading edges of the Aboriginal boomerangs were far superior in this respect, " he says.
Precisely how and when the early Aborigines perfected such aerodynamic subtleties is unknown. Archaeologists working in the remote Arnhem Land area of northern Australia recently discovered 12,000-year-old red-ochre stencils of boomerangs on the walls of a gorge, along with stick-figures of men throwing them.
Yet the primary purpose of boomerangs in traditional Aboriginal life is still unresolved. No two anthropologists seem to agree, and every document at the Australian Institute of Aboriginal and Torres Strait Islander Studies (AIATSIS) — the federally funded national research center for scholars of Aboriginal life — appears to emphasize a different use for boomerangs.
Certainly early white settlers were impressed by the havoc a boomerang could cause. According to an early nineteenth-century missionary: "A bombshell thrown amongst a company of soldiers cannot create a greater consternation than the flight of a boomerang towards a group. . . . They instantly scatter, and assemble together again the moment the dreaded instrument is seen to have finished its eccentric course. . . . Happy are they who escape from its destructive range."
But some anthropologists, such as Nic Peterson of the Australian National University in Canberra, Australia say the aggressive function of boomerangs has been exaggerated. "Spears were the preferred weapon," he says. And, in any event, Aborigines have seldom engaged in outright warfare. Different clans may feud, but they prefer acts of ritualized aggression to actual fighting. This activity, all part of tribal law or "yapa," still goes on. The aggrieved party hurls spears or boomerangs at the offender while the community looks on. The intent is to wound, not kill, and the guilty person, though unarmed, is free to try to dodge the projectiles if he can.
These days boomerangs are used mostly in ceremonies. Boomerangs, spears, clubs and throwing sticks are all symbols of manhood in Aboriginal society, says Paul Tacon. "They are sometimes secret, sacred objects used in 'men's business' ceremonies to celebrate maleness, where restricted knowledge is passed on and information exchanged." And the most important ceremony is probably "singing to the land." According to Stephen A. Wild, an ethnomusicologist at AIATSIS who studies song traditions in Aboriginal life, "Singing activates the powers of the Dreamtime," the creative epoch in Aboriginal cosmology.
During the song the singer clacks the tips of two boomerangs against each other very quickly; a good practitioner can create a nearly-continuous rattle for a snare-drum effect. This is usually done in discrete bursts according to a prescribed pattern. Because of the need for such ceremonies, no traditional Aboriginal man in central Australia would walk around without a pair of boomerangs in his hand or tucked into a belt made of hair, says Wild. (Women had little to do with boomerangs.)
"By singing to the land, humans look after the countryside, both physically and spiritually. Dreamtime is responsible for the fertility of the country and the plants and animals." And, he adds, traditional Aboriginal people believe that if the ceremonies are not performed, "everything will die off."
At one time it looked as if that dire prediction was being fulfilled, as traditional Aboriginal ceremonies disappeared, the Aboriginal population declined, dozens of native plants and animals became extinct, and the land itself blew away in dust storms caused by over-grazing.
But in the past two decades Aboriginal culture has begun to come back. The revival has made itself felt throughout Australia, extending as far as the souvenir boomerangs found at airport gift shops, which now carry prominent labels saying they are authentic artifacts made by Aboriginal cooperatives. The kitschier items — such as boomerang ashtrays — are disappearing for lack of interest, while the demand for authentic Aboriginal art is booming, with traditional "dot paintings" going for thousands of dollars in Sydney galleries.
On a grander scale, recent court decisions and land claims — some controversial — have been settled in favor of indigenous people, inspiring many an Aboriginal "corroboree," or celebration.
It was at one such corroboree in the state of Victoria that I finally met Mullett. I had been trying to contact him since I had first heard of his legendary skill at making boomerangs, and I'd been told he would be at this gathering. Still, I wasn't sure how he would receive me. After all, I was an outsider at a gathering honoring "Aboriginalness." Soon after I arrived, a man emerged from a knot of people and thrust what looked like a log at me. It was a didgeridoo: a native instrument made from a hollowed-out tree branch. When I looked at it quizzically, he put the four-foot-long instrument to his mouth and droned out the ancient, unearthly music of the Great South Land. Then he passed it to me again. Try as I might, though, I couldn't get it to make a sound. "Pucker your lips," he said, "like you're giving a kiss." I forced out a bleat. Laughing, the crowd pointed out Mullett.
After we got together, Mullett was pleased to find that I could make a boomerang return. (I dared not mention I had practiced with a plastic one.) He critiqued my technique and told me how best to catch the boomerang: "When he flattens out, you lose sight of him," he said. "You must watch him at all times and position yourself. If you're not in line, he will hit you in the ribs." He demonstrated by throwing his own boomerang. It soared 150 feet before coming back. Mullett stretched out his arms and caught it in a giant clap.
Since then, I have often found myself thinking about that day at the corroboree. Maybe this aerodynamically sophisticated flying device can become even more of an icon for contemporary Australia. Since practitioners of both Aboriginal culture and modern 'rang design are themselves boomeranging to the past for guidance, perhaps the people of the land downunder can do the same, and look to the boomerang for inspiration as Australia tries to come to terms with its Aboriginal heritage and bring back something for the future.
The Sciences, pp. 16-19, May/June 1998 issue, New York Academy of Science.
Dan Drollette is a freelance science journalist in Australia on a Fulbright Postgraduate Traveling Fellowship. In addition to The Sciences, he has written for Science, Scientific American and Australian Geographic, among other publications. He is the owner of three boomerangs.
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