NS 12 aug 2000

LOST for words

FOCUS The speakers of many smaller languages are being evicted from the Tower of Babel

IN THE Navajo nation, which sprawls across four states in the American Southwest, the native language is dying. Most of its speakers are middle-aged or elderly. Although many students take classes in Navajo, the schools are run in English. Street signs are in English, food on the supermarket shelves is labelled in English, and the reservation's newspaper, the Navajo Times, is printed in English. Not surprisingly, linguists doubt that any native speakers of Navajo will remain in a hundred years'time. Navajo is far from alone. Half the world's 6800 languages are likely to vanish within two generations-that's one language lost every ten days. Never before has the planet's linguistic diversity shrunk at such a pace. English is the third most widely spoken language in the world, with more than 320 million people speaking it as their first language, but its closest relativesthe three Frisian languages spoken on the coast of Holland and Germany-are all on the danger list. 'At the moment, we're aiming for about three or four languages dominating the world," says Mark Pagel, an evolutionary biologist at the University of Reading who has studied language diversity. "It's a mass extinction, and whether we will ever rebound from the loss is difficult to know." At the end of September, linguists will meet to discuss the problem at the Foundation for Endangered Languages in Charlotte, North Caro@a. Isolation breeds linguistic diversity: as a result, the world is peppered with languages spoken by only a few people. Only 250 languages have more than a million speakers, and at least 3000 have fewer than 2500 (see Graph). It is not necessarily these small languages that are about to disappear. Most of the 250 languages spoken in the Democratic Republic of Congo have fewer speakers than Navajo, yet they are not in trouble. But Navajo is considered endangered despite having 150 000 speakers, according to Ethnologue, a catalogue of world languages and their speakers compiled by Dallas-based research organisation SIL International. What makes a language endangered is not just the number of speakers but how old they are. If it is spoken by children it is relatively safe. The critically endangered languages are those that are only spoken by the elderly, according to Michael Krauss director of the Alaska Native Language Center in Fairbanks. Why do people reject the language of their parents? It begins with a crisis of confidence, when a small community finds itself alongside a larger, wealthier society, says Nicholas Ostler, of Britain'S Foundation for Endangered Languages in Bath. "People lose faith in their culture," he says. "When the next generation reaches their teens, they might not want to be induced into the old traditions."

Danger list

The change is not always voluntary. Quite often governments try to kill off a minority language by banning its use in public or discouraging its use in schools, all to promote natiortal unity. The former US policy of running Indian reservation schools in English, for example, effectively put languages such as Navajo on the danger list. But it can also backfire by inspiring resistance among speakers: Agaw, the language of the Ethiopian Jews known as Falasha, survived in Africa despite centuries of persecution by Christian rulers. Ironically, among the 70,000 Falashas who emigrated to Israel between 1984 and 1991, the language is now losing ground to Hebrew.

Salikoko Mufwene, who chairs the linguistics department at the University of Chicago, argues that the deadliest weapon is not government policy but economic globalisation. He says it is not realistic to expect a minority language to survive if no business is conducted in it. "Native Americans have not lost pride in their language, but they have had to adapt to socioeconomic pressures," he says. "They cannot refuse to speak English if the majority economy is run in English." Look at Europe and Africa, he says. Europe has 9 per cent of the world population, but only 3 per cent of the world's languages. While Africa, with its largely local economies, has 15 per cent of the world's population speaking nearly a third of all languages. But are languages worth saving? At the very least, linguists say, there is a loss of data for the study of languages and their evolution, which relies on comparisons between languages, both living and dead. When an unwritten and unrecorded language disappears, it is lost to science. Language is also intimately bound up with the practices and rituals unique to a culture, so it may be difficult to preserve one without the other. "If a person shifts from Navajo to English, they lose something," Mufwene says. "Do they also lose Navajo culture? We don't really know. But can they preserve the Navajo culture if they are surrounded by people that practise another culture? Probably not." The loss of diversity may also deprive us of different ways of looking at the world, says Pagel. There is mounting evidence that Teaming a language produces physiological changes in the brain. "Your brain and mine are different from the Frenchspeaking person's," Pagel says, and this could affect the way we think. "The patterns and connections we make among various concepts may be structured by the linguistic habits of our community." Despite linguists'best efforts, many languages are likely to disappear over the next century. But a growing interest in cultural identity may prevent the direst predictions from coming true. The key to fostering diversity is for people to learn their ancestral tongue as well as the dominant language, says Doug Whalen, founder and president of the Endangered Language Fund in New Haven, Connecticut. "Most of these languages will not survive without a large degree of bilingualism," he says. In Califomia, volunteers have provided life support to several indigenous languages on the verge of extinction. These apprentices pair up with one of the last living speakers of a Native American tongue to leam traditional skills such as basket weaving, with instruction exclusively in the endangered language. After about 300 hours of training they are generally sufficiently fluent to transmit the language to the next generation. In New Zealand, classes for children have slowed the erosion of Maori and rekindled interest in the language. A similar approach in Hawaii has produced about 8000 new speakers of Polynesian languages in the past few years. But Mufwene says that preventing a language dying out is not the same as giving it new life by using it every day. "We must always remember the distinction between preserving a language and revitalising it," Mufwene says. "Preserving a language is more like preserving fruits in a jar." However, preservation can bring a lan guage back from the dead. The best-known example is Hebrew, which existed only in written form for hundreds of years until the late 1800s, when Jews living in Palestine decided to revive it. They spoke it crudely at first, with no guide to rhythm, intonation or idiomatic speech. The language that has emerged would probably be difficult for an ancient Hebrew @peaker to understand, but the mere possibility of revival raised by the story of Hebrew has led many speakers of endangered languages to develop systems of writing where none existed before. For many ordinary speakers of endangered languages life is a constant battle against linguistic imperialism. That may be what one Navajo woman had in mind recently when she took a marking pen to her local supermarket. Beneath the English words on each sign, she wrote the translation in Navajo. Jonathan Knight, San Francisco

fifth dimension

TO UNIFY the four fundamental forces of nature, theoretical physicists find it helpful to invent extra dimensions of space. To explain away the fact that we don't notice them, they argue that the extra dimensions are curled up so small they're undetectable. But now a team of Cambridge University researchers says that one of the extra dimensions could be big enough to show up in the latest particle accelerators, such as the one at CERN near Geneva. "The signature might be detectable at the Large Hadron Collider when it begins operation in 2005," says team member Ben Allanach. The current favourite theory for unifying the forces is known as string theory, which requires nine space dimensions. Physicists can look for extra dimensions by searching for the peculiar particles they would bring into being. The force fields of nature should extend into the dimensions and bounce around, producing "echoes" in the form of particles dubbed Kaluza-Klein particlesan infinite series for each particle of nature. But KK echoes are not easy to catch. To experience a small extra dimension, a particle must have a large energy, and the fact that no KK echoes have been spotted at the highest energies reachable today-about 1000 gigaelectronvolts (GeV)-suggests that these extra dimensions cannot be bigger than 10-" metres But the Cambridge group has calculated that this is not the case. "This is only true if all forces extend into the extra dimensions," says Allanach. "It may be that only gravity notices them." In this case, there would be KK echoes of the graviton. Since gravitons are force carriers of gravity, extra gravitons modify gravity. "Incredibly, an extra space dimension could be as big as 1 millimetre and its effect-a modification of the inverse square law over small distance-still be missed by lab experiments," says Allanach But there is another way to spot the extra dimension. Allanach and his colleagues, Andy Parker, Bryan Webber and Kosuke Odagiri, say that if the lowest-energy KK echo of a graviton has an energy less than 2000 GeV, it will be created in CERN's Large Hadron Collider. Quark-quark collisions are expected to create large numbers of particles including electrons and positrons. Some of the electrons and positrons could be decay products of KK gravitons. "On a plot of the number of electronpositron pairs against their energy this would show up as a spike at the energy of the heavy graviton," says Allanach. Such a spike could be caused by another particle, but the collision tracks would reveal the true culprit. "The result is exciting not only because it shows that the LHC has an excellent chance of detecting extra dimensions, but also @ecause they can distinguish KK gravitons," says Joe Lykken of Fermilab near Chicago. Marcus Chown

source: High Energy Physics e-print 0007009 at http://xxx.soton.ac.uk

Reading your mind

CANADIAN researchers have witnessed the emergence of a conscious thought. Using imaging scanners to measure brain activity, they recorded the moment when volunteers became conscious of images appearing in front of them-and found that it all depends on how many neurons are firing in the brain. Ravi Menon and his colleagues at the University of Western Ontario showed people pattems of black and white stripes. While keeping the width of the stripes the same, they increased the contrast slightly with each image they showed. The volunteers were asked to press a button as soon as they could see a pattern appearing. At first, the observers spotted no pattem at all. But when the contrast reached about 2 per cent they started pressing the button to show that they could see the stripes. The researchers imaged the brains of the volunteers continuously during the experiment, using a non-invasive method of brain imaging called fmrl. This visualises the amount of oxygen in the blood, a measure which correlates with neural activity. There was an increase in brain activity in the primary visual cortex of all the volunteers, corresponding to each button press, and the signal got stronger as the pattem became easier to see. "The neurons fire more as the contrast increases," says Menon. But the researchers could spot the signals even before the volunteers started pressing the button. "They first pushed the button at 2 per cent. But we saw a detectable response at 1 per cent," says Menon. He argues that the difference between an unconscious response to the stripes and a conscious one is all down to the level of brain activity"You need a certain number of neurons to-fire to cross the threshold into consciousness," he says. Cognitive neuroscientist David Perrett of the University of St Andrews agrees. "Conering the number of neurons firing is the only way to think about consciousness," he says. "Consciousness is brain activity.But psychologist Max Velmans of Goldsmiths College in London says that is just part of the story. He argues that other elements, such as which neurons are firing and at what frequency, influence consciousness. "If you go to the cinema," he says, "all of your visual neurons are firing. Then you feel something crawling up your leg. The signals from your leg in terms of energy are far less than the flooding of your visual system from the film. But it is more important to attend to your leg." Neuroscientist Susan Greenfield from the University of Oxford says the work supports her idea that consciousness is like a "dimmer switch" that can be turned on gradually. "I am delighted that they are looking at something quantitative, so that we can look at degrees of consciousness,' she says. Joanna Merchant