Genesis of Eden Diversity Encyclopedia



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NS 29 jun 02

Feeling good? You'll never guess why

SEMEN makes you happy. That's the remarkable conclusion of a study comparing women whose partners wear condoms with those whose partners don't. The study, which is bound to provoke controversy,showed that the women who were dimft exposed to semen were less depressed. The researchers think this is because mood-aftering hormones in semen are absorbed thmugh the vagina. They say they have ruled out other explanations. "I want to make it clear that we are not advocating that people akmin from using condoms," says Gordon Gallup, the psychologist at the State University of New York who led the team. "Clearly an unwanted pregnancy or a sexually transmitted disease would more than offset ariy advantageous psychological effects of semen." His team divided 293 female students into groups depending on how often their partners wore condoms, and assessed their happiness using the Beck Depression Inventory, a standard questionnaire for assessing mood. People who score over 17 are considered moderately depressed. The team found that women whose partners never used condoms scored 8 on average, those who sometimes used them scored 10.5, those who usually used them scared 15 and those who always used them scored 11.3. Women who weren't having wx at all scored 13.5. What's more, the longer the interval since they last had sex, the more depressed the women who never or sometimes used condoms got. But the time since the last sexual encounter made no darence to the mood of women who usually or always used condoms. The team also found that depressive symptoms and suicide attempts were more common among women who used condoms regularly compared with those who didn't. The resufts will appear in the joumal Archives ofSeKual Behavior. And Gallup told NewScientistthat his team already has unpublished data from a larger gmup of 700 women confirming these findings. In this study, the never-use-condoms group were more depressed than the usually- use-condoms group, suggesting the discrepancy in the smaller study was a sampling error, he says. But is it really the semen that affects women's mood? The researchers say they looked at altemative explanations such as whether women who seldom use condoms took oral contraceptives, how often they had sex, the strength of relationships, and the possibility that having a certain type of personality influenced the decision to use condoms. But none of these factors can explain their findings, they say. In fact, the results aren't a complete surprise because semen does contain several mood-altering hormones, including testosterone, oestrogen, follicle-stimulating hormone, luteinising hormone, prolactin and several different prosUglandins.

"Clearly an unwanted pregnancy or a sexually-transmitted disease would offset any advantageous psychological effectsof semen"

Some of these have been detected in a women's blood within hours cvf exposure to semen. The question many people will ask is whether oral sex could have the same mood-enhancing effects. 'Since the steroids in birth conw pills suraw the digestion process, I would assume that the same holds tme fbr at least some of the chemicals in semen,' Gallup says. "I understand that among some gay males who have anal intercourse, it is not uncommon to attempt to retain the semen for extended periods of time," he adds. "Suggesting, of course, that there may be psychological effects.' But further research will be needed to confirm whether exposure to semen thmugh oral or anal sex really does affect mood in heterosexual or homosexual partners. But why should semen have such an effect? "it makes no sense to me fbr this phenomenon to have evohred,' says Satoshi Kanazawa, an evolutionary psychologist at the Indiana Unversity of Pennsylvania. But Gallup counters that men whose semen promotes long-term mood enhancement might have more chances to indulge in sexual acdft. Previous studies have suggested that exposure to semen -either vaginally or orally - may help prepare a women's immune system fbr pregnancy (New Scientist, 9 February, p 32). Raj Persaud 0

World's flowers bloom after recount

THE world has gained an extra ioo,ooo species of flower overnight. But unless more is done to identify and protect the plants, they may go extinct before we even get a chance to enjoy them, warns a leading taxonomist. David Bramwell, director of the jardin Canario Viera y Clavijo in Las Palmas, the Canary Islands, has attempted what he says is the first systematic estimate of the number of flowering plants. By his reckoning, past estimates of around 300,000 species are about 40 per cent too low. "After 250 years of cataloguing and describing the plant kingdom, we just do not know how large the world's flora is," Bramwell writes in the current issue of Plant Talk, the bulletin of the National Tropical Botanical Garden based in Hawaii. He says there is no central list of plant species, and past estimates have been back-of-an-envelope calculations, with no published evidence of what they are based on. Bramwell took the number of known species in the largest country in each of six regions. Then he added the number of endemic species in other countries in the region and subtracted those plants that lived in more than one place, to prevent double-counting. He reached a figure Of 420,ooo. And as many as a fifth could be in danger of extinction, he says.

The two regions richest in flowering plants, Bramwell says, are the rainforests of the Amazon basin and South-East Asia. But, surprisingly perhaps, the Mediterranean basin comes third. Brazil comes top in the individual country list with 70,000 species.

On top of that, there are another estimated 5o,ooo plants still waiting to be discovered, says Bramwell. He says the neglected science of taxonomy must be revived, and soon, to try and identify the species before they are gone for good. Fred Pearce 0

Till death us do part

Every year men in India get away with thousands of dowry-related murders


AT INDIA's largest burns centre in Victoria Hospital, Bangalore, a macabre scene is played out with horrifying regularity. A badly burnt woman is brought in by her husband and in-laws. The woman claims a kerosene stove burst in the kitchen, and the doctor notes her statement. Hours or days later she dies, and the police dismiss the case as an accident. A new study, the first of its kind, provides appalling proof of what many in India already acknowledge - that many of these "accidents" are in fact dowry- related murders or forced suicides, acts of unimaginable violence against wives who can't meet their husbands'and in-laws' demands for yet more money. The study suggests that in spite of India's strict anti- dowry laws and long-running campaigns by women's groups, incidents like these are on the rise across India. Worse still, the guilty nearly always go unpunished, experts told New Scien tist, either because police and forensic pathologists fail to investigate the cases, or because rampant corruption scuttles them at a later stage. Women's rights activists, doctors, lawyers and judges are demanding strict enforcement of the existing laws. Otherwise thousands of women will suffer a brutal death and millions more will continue to endure violence and intimidation. The study was carried out by Baldev Raj Sharma, a medical-legal expert at the Government Medical CoRege Hospital's department of forensic medicine in Chandigarh, Punjab, and his colleagues. His analysis Of 385 bum deaths at his hospital between 1994 and 2001 shows that most of the 292 women who died were not victims of kitchen accidents (BUMS, VOI 28, p 250). What's more, the numbers are rising. In 1994, bums accounted for 12 per cent of postmortems at the hospital. In 2001, the flgure had jumped to nearly 30 per cent. However, the police reports Sharma examined concluded that 97 per cent of the women were burnt in accidents in the kitchen, usually due to a burst kerosene stove.,Yet in s-Qme of their homes, kerosene wasn't even used in the kitchens. And while most kitchen accidents cause bums on the arms, chest and abdomen, many of these women suffered 8o to go per cent bums. "How can that be accidental?" asks Sharma. "Tbe most alarming thing is that it is young females who are involved. They are newly married, or within five years of marriage' In traditional Indian homes, girls leam to cook when they are around 13, which is when you might expect the most accidents to occur. Most bums victims in the West are children and the elderly. In stark contrast, only 4 per cent of the -deaths studied by Sharma were among girls younger than 15 (see Table, P 14). The number j umps to i 6 per cent for women aged 16 tO 20 - the age at which most women marry - and tO 28 per cent for those aged 21 tO 25. The most damning statistic is that every one of the married women was bumed in her in-laws'home. "That speaks for itself," says Sharma. VVhy then, in the face of seemingly overwhelming evidence, do the guilty nearly always go free? The problem is not with the anti-dowry laws -they are stringent enough, says N. R. Madhava Menon, one of India's foremost legal experts and vice-chancellor of the West Bengal National University of juridical Studies in Kolkata (formerly Calcutta). "The villain of the piece is the investigation," says Menon. And the problem starts with the woman's dying declaration. "There is a belief that the dying will not lie. It's a legal presumption," says L. Thirunavukkarasu of St John's Medical College in Bangalore, who performed many postmortems on bums victims when he was head of forensics-at Victoria Hospital. Invariably, the victim is brought to hospital by her husband and her in-laws, the very people who may have tried to kill *her or forced her to attempt suicide (the law treats those responsible as guilty in both cases). The woman is told that her own parents will be hurt if she doesn't say it was an accident, or is beseeched to consider the fate of her children if she dies and her husband goes to jail, or wamed that she will have to come back home if she survives. "Even if I send the in-laws outside, she'll invariably lie. As a doctor, I ask for the statement, and I record it," says Thirunavukkarasu. However, manywo men survive long after they have given their flrst statement. In fact, Sharma found that fewer than 4 per cent of the women died within an hour because of shock, while more than half survived for anywhere from three days to over a week before succumbing to infections. Sometimes, in the hours or days before her death, the woman reveals that she tried to commit suicide after being unbearably tormented at home, or even accuses her husband and in-laws of trying to kill her. In such cases, the courts are forced to consider an her statements and look at other evidence. Some evidence comes from the post- mortem, which must be performed on the body of any woman who died an unnatural death within seven years of marriage. And experienced forensic pathologists can usually tell whether bums are accidental from their nature and extent. Yet even then the system fails, says Tbirunavukkarasu. The problem is that such evidence is not enough in itself. But because the police invariably do not start investigations until the woman dies, supporting evidence from the scene is usually lost. Simple facts such as whether there really was a kerosene stove that burst, or whether the incident even happened in the kitchen, are sometimes not established, says Thirunavukkarasu. "It should be completely obligatory on the part of the police to take the help ofthe forensic scientists and forensic pathologists. If they don't, they should have to explain why they didn't," he says. There are problems with the post- mortems too. For instance, hospitals in Bangalore do not have a standard procedure for bums victims. And sometimes, if a doctor has determined the cause of death - hanging or burning, say -forensic pathologists do not perform further tests. "Suppose her blood contains lots of barbiturates. How do you account for it?" asks Thirunavukkarasu. Investigations are also hampered by apathy in government hospitals, according to Donna Femandes, founder of Vimochana, a Bangalore-based women's rights organisation (the name means liberation). Until two years ago, Victoria Hospital's bums ward was like a railway station, she says. People wandered in and out as they pleased, and staff had to be bribed to change sheets or give injections. "It was a hell-hole," says Femandes. And this remains the state of many hospitals across the country. However, after years of campaigning Vimochana has forced the authorities to transform Victoria's bums unit. It's now an air-conditioned modem facility with social workers on hand to ensure that the women are treated - and also to protect them if they decide to tell the truth. Most deaths of young women in the city are still dismissed as accidents, though. "According to the reported deaths - and they are all under-reported - almost ioo women die every month in Bangalore [of unnatural causes such as hanging, poisoning or bums]. 'And 70 tO 8o per cent of these deaths are deemed accidental, says Fernandes. "The interest and commitment to find out the truth are not there.' As a consequence, official figures on dowry-deaths don't mean much. The National Crime Records Bureau in Delhi reported about 6ooo dowry deaths a year in the iggos. Unofficial estimates are much higher. Himendra Thakur of the US-based Intemational Society against Dowry and Bride-Buming in India estimated in 1999 that nearly 25,000 women are murdered or forced to commit suicide every year. Aside from sheer negligence, corruption at all levels is sabotaging efforts to crack down on the culprits. According to justice Michael Saldanha of the Kamataka High Court in Bangalore - the highest court of law in the state - police officers and doctors are sometimes influenced through family or political connections, or bribed to falsely document the case, leading to inconsistencies between the various pieces of evidence that undermine the case. "One good ground, and the dying declaration is shot down, and the accused is acquitted," says Saldanha. Corruption can even extend as far as the public prosecutor. "When they don't succeed with the police and the doctor, they get hold of the prosecutor," says Saldanha. "And he'll very cleverly sabotage the case. He'll not produce some vital document. Or he'll keep back some vital witness." The problem is so bad that in Karnataka state an astounding 97 per cent of the accused in dowry death cases are acquitted. And after appeals to the High Court, the acquittal, reach nearly 99 per cent. This problem affects the entire country, creating a climate in which some men feel they can get away with murder. So how can the violence be stopped? "You've got to ruthlessly implement thi law," says Saldanha. He points out that under Indian law, the sentences handed down in the few prosecutions that do succeed are less than those for normal murders. "If for murder you provide capital punishment, why should you not provide capital punishment for this? This is far more horrifying." Saldanha adds that one section of India's anti-dowry law states that if a woman dies, any property orlvealth given as a dowry should be returned to her own family, regardless of whether her husband was convicted or acquitted. "Judges in India had totally overlooked [that] section As a result, when the case fails, the husband and in-laws are left with the loot. And that gives them a tremendous appetite to do it again. He hopes enforcing this provision will end what has become a sickening business for some. But the deaths won't stop unless people really want them to. Menon says the public doesn't support the police enough, by testifying as witnesses, for instance, or providing evidence. "Society will have to take a leading role and revolt against this, and see that the system is taken to its logical end. "O

Phone safe debate reignites

The latest evidence suggests that cell phone radiation can damage human cells


THERE is fresh concern about the safety of mobile phones after further evidence emerged that low levels of microwaves can affect cells. The findings add weight to claims that cellphone radiation could cause headaches, tiredness and even the growth of tumours. Dariusz Leszczynski at the Radiation and Nuclear Safety Authority in Helsinki has found that an hour's exposure to mobile phone radiation affects numerous proteins in human cells grown in culture and makes the cells shrink. While this does not necessarily mean mobiles are a health threat, Leszczynski says the changes he discovered could affect the blood-brain barrier that protects brain cells from toxins and infection. They could also affect a cell's ability to self-destruct when damaged, a process called apoptosis. "While this would not induce a tumour or mutation, it would support the development of one, by preventing the cell from dying," he says. Human studies are now urgently needed. Two years ago, Britain's former chief scientist William Stewart led a government inquiry into the health effects of mobile phones. It concluded that although there was no evidence of any risk to health, we should adopt a precautionary attitude until further evidence was available. "I advocate that even more strongly now than two years ago, because of the evidence that has been coming out since then," Stewart told New Scientist. Leszczynski will tell the Bioelectromagnetic Society meeting in Quebec this week that he has traced a chain of events that leads to changes in cell function. It's the first evidence that mobile phone radiation can affect human cells without heating them, he says. Such non-thermal effects have only been seen in nematode worms before (New Scientist, 9 February, P 4). And these worm studies, done by David de Pomerai of the University of Nottingham, didn't imply there was any health risk. Leszczynski found phone radiation affected hundreds of proteins, but he focused on the finding that it both activates and increases production of one stress protein called HSP27. This protein is known to inhibit some of the proteins involved in apoptosis. HSP27 is also thought to help regulate the permeability of the blood-brain barrier through its effect on the fibres that maintain the shape of the cells lining the brain's blood vessels. Leszczynski used fluorescent dyes to show that these fibres did indeed change after cells were exposed to radiation. And if cells in the blood-brain barrier shrink as a result, unwanted molecules could creep into the brain. "If the blood-brain barrier is even temporarily affected by mobile phone radiation it might have long-term health effects," he says.

"Its thefirst evidence that microwave radiation from cellphones can affect human cells without heating them"

Other studies on the effects of radiation on the blood-brain barrier have produced conflicting results. De Pomerai says Leszczynski's work is "significant", but it does not reveal exactly how mobile phone radiation causes these changes. "Until you can demonstrate a mechanism and demonstrate that it is not a heat-activated process people will dismiss it." Leszczynski is now working backwards from the effects he's seen to try to identify the point at which radiation is interacting with the cen. But Michael Repacholi of the World Health Organization still questions whether heating effects could be entirely ruled out because of the methods Leszczynslci used to regulate the cells'temperature. "There are much more effective ways of doing this," he says. The bulk of evidence so far suggests that mobiles don't give you cancer, adds Repacholi. "The implications here for health are zero," he says. indeed, a team at the Washington University School of Medicine in Missouri reported this week that rats exposed to mobile phone radiation for four hours a day for two years didn't get cancer. Whether or not there are non-thermal effects is significant because mobile phone regulations are based solely on avoiding the heating effect of microwave radiation. Most scientists believe heating is the only way microwavest could possibly damage cells because they don't have enough energy to break even weak chemical bonds. Mays Swicord at Motorola's Florida Research Labs, for instance, says he has spent 30 years looking for a possible mechanism for- -- non-thermal effects and has yet to see any reproducible evidence. "It's difficult for me to believe that non-thermal effects exist," he says. But Stewart says you can't yet rule out non-thermal effects. What's important is to find out if there are any health risks at aH, he says. "I don't care if it's non-thermal or thermal, what I'm worried about is whether there are effects.

World Beneath the Quantum

FOR a theory that has the world's finest physicists baffled, quantum mechanics is fantastically successful. It has made possible computers, lasers and nuclear reactors and explained how the Sun shines and why the ground beneath our feet is solid. But it is also strange, frustrating and incomprehensible. It insists that the microscopic world is a shadowy realm where nothing is certain - where an electron can be in two places at once and photons at opposite extremes of the Universe can communicate by some kind of weird telepathy. But some physicists are beginning to suspect that there's another level of reality beneath the quantum world. Nobel prizewinner Gerard't Hoot believes that underpinning quantum weirdness is an old-fashioned deterministic theory - one in which there's a simple relationship between cause and effect. Antony Valentine of Imperial College in London has now gone even further. He thinks that quantum mechanics may not always have applied, and that in the early Universe matter danced to a different tune. What's more, some non-quantum stuff may even have survived to this day, tantalising us with the possibility of eavesdropping on secure cryptographic channels, constructing computers which outperform even the fastest quantum computers and, most remarkable of all, sending signals faster than the speed of light. The reason for believing in a deeper level is that quantum theory merely predicts the probable outcomes of measurements, not certainties. To Valentine, it's a bit like an actuary predicting the probability that a man will die at a particular age. "This does not preclude a deeper level of cause and effect, which could be used to predict precisely when a given man dies," says Valentine. "It might depend on the detailed condition of his heart and arteries." Indeed, everywhere in physics where a theory predicts probabilities, physicists believe there is a deeper level of certainty. Everywhere, that is, except quantum physics. Why not there too? Most physicists would say that this deeper level of explanation - a lower stratum or "hidden variable theory" - is unnecessary because quantum mechanics already fits all known experimental results. "They're saying quantum theory works now - why look farther?" says Valentine. Nevertheless, a few people have tried. One attempt is the "pilot-wave" theory, proposed by French physicist Louis de Broglie in the 1920s and developed by American physicist David Bohm during the early 195os. Whereas in quantum mechanics the wave function is nothing more than a mathematical convenience for calculating the probability that a particle will be found at a particular point in space, in pilot-wave theory the wave is real. It's an invisible but physical wave that guides particles along, and has a current that drives the precise motion of the particle, just as an ocean current drives a piece of flotsam. This theory reproduces all the statistical predictions of quantum mechanics. "Most physicists are quite sceptical about this interpretation - including myself," says Lucien Hardy of the University of Oxford. "But it is important because it establishes the possibility of giving quantum theory a so-called hidden-variable interpretation.'

However, most physicists are put off this interpretation by a property called non-locality - physical influences that travel faster than light. Of course, even conventional quantum mechanics assumes non-local effects. Between measurements, the spin of an electron can be loosely thought of as in a state of high anxiety, flitting randomly from spinning in one direction, dubbed "up", to spinning the opposite way, dubbed "down". This has a remarkable consequence if two "entangled" electrons have a total spin of zero between them - that is, the spin of one is up and the other down. Nature forbids the total spin from ever changing. So if the electrons are separated and a measurement on one finds it spinning "up", the far-away electron must at the very same instant plump for spinning "down". And vice versa. "It doesn't matter if one electron is in a steel box buried under the sea floor and the other is on the other side of the Galaxy," says Valentine. "Eachwillrespond instantaneously to the other's state, in total violation of Einstein's cosmic speed limit, the velocity of light ' " Yet while it's possible to think of non-locality as a quirk of quantum mechanics - something that's peripheral to the meat of the theory -the same can't be said for pilot-wave theory. Non- locality lies at its very core. Take those two electrons again. Pilot- wave theory says that the pair of particles we see moving about in three- dimensional space is actually the projection of a single system that exists in six-dimensional 11 configuration space". "The two particles are connected because they are really a single, higher-dimensional system," says Valentine. Most physicists remain uneasy about non- locality because in our everyday experience things do not seem to be inextricably linked. Any theory that places this at its centre seems suspect. 't Hoot, of the University of Utrecht in the Netherlands, is dead against the idea of non- locality. Yet he thinks that a novel kind of hidden- variable theory might offer a way around it. His idea, formulated in the late iggos, is that some kind of deterministic theory can be applied at the very smallest scales of space and time. If you could zoom in and observe events that last just 10^-41 seconds, in an area no more than 10^-11 metres across, you would find a classically predictable theory with no need for probabilities and uncertainty't Hoot describes it as being like a game of chess played on a board with microscopic squares. Quantum mechanics is then a kind of statistical theory that tallies all the smallest-scale events to give a fuzzy average description of what's going on. He has several rezcsons for believing quantum theory is built on deeper foundations. One is our inability, despite 8o years of effort to reconcile gravity with the quantum world. Superstring theory makes many claims, he says, but it's far too vague to be even remotely acceptable. Another reason is more deep-seated. "Just like Albert Einstein, I am unhappy about the fundamental statistical nature of the predictions of quantum mechanics," he says. 't Hoot is still developing his ideas, but even if he's right, there'd be no way of telling. By his reckoning we may never see the deterministic layer underneath quantum mechanics, or even be able to prove that it exists. Vvlhich is why Valentini's latest ideas are so appealing. He thinks we should find hard evidence that these solid foundations really exist. Valentine believes that instead of rejecting non-locality, we should embrace it. He points out that in conventional quantum mechanics, a "suspicious coincidence" obscures non-locality. For example, you might think that by using pairs of linked electrons like the pair described above, you could create an instantaneous communication system that defied the rule against anything travelling faster than light. But, frustratingly, that's impossible, because you can never know before a measurement which way an electron is spinning. So if one direction of spin codes for a "1" and the other a "0" and you want to send a "1", you can only be 50 per cent sure of sending a "i" - a level of uncertainty, or "noise", that scrambles ariy message. "Although non- locality is a fundamental feature of quantum theory, nature provides precisely the amount of quantum noise necessary to make it unusable," says Valentine. "Is that simply a coincidence? I don't think so' ' He uses a thermal analogy. If the whole Universe was in a state of thermal equilibrium - that is, characterised by a single temperature - heat could not do any work. It couldn't move a piston, for example. "It isn't that heat intrinsically can't do work," he says. "It's just that temperature differences are needed to do work." in this imaginary state of universal thermal equilibrium, random temperature fluctuations in any machinery would be of precisely the right size to make any small random temperature differences unusable. Valentine suspects that quantum theory may merely describe a particular state of the Universe in which quantum noise acts like these random temperature fluctuations, making non-locality unusable and effectively preventing messages being sent faster than light. According to Valentine, in this special state we are unable to observe non-local signals because they "cancel out" at the statistical level. This could apply to any hidden-variable theory, but Valentine has done most of his work on a type of pilot-wave theory. His ideas are certainly controversial. "These conclusions depend on a particular interpretation of pilot-wave theory which, whilst being perfectly respectable, has the support of only a small number of physicists," says Hardy. But on the whole, physicists - including Hardy - do not dismiss it. "Valentine is a serious physicist and a very deep thinker," says HardY. "I am a big fan of Antony Valentine," says Lee Smolin of the Perimeter Institute for Theoretical Physics in Waterloo, Canada. "I think his ideas are the most interesting and potentially true ideas concerning the foundations of quantum theory that I have heard for some time." if Valentine is right, the implications are profound. just after the big bang, the Universe may have existed in a state in which non-locality was not cloaked by random noise, he says. Interactions between particles in this early Universe then rapidly caused it to relax into the special "equilibrium state" we find today. These interactions, Valentine suggests, imply that the pilot-wave currents driving particles along were so convoluted that they scrambled the particles' probability distributions. This can be likened to interactions between hot gas particles - which on average transfer energy from fast-moving to slow-moving particles - causing the gas to relax into a state of thermal equilibrium. In our world, the probable location of a particle is related to the square of the amplitude of its wave function. But in this early Universe, before quantum noise set in, probability distributions might have been more sharply defined than the square of the wave function. With less quantum noise to blur things, it would have been possible to locate particles with greater certainty. And since non-locality wasn't blurred out, this means that at this time, signals could travel faster than light. For example, there would be less uncertainty about the spin state of an entangled pair of electrons, so a message could be encoded in electrons on one side of the Universe and sent to the other instantaneously. Valentine has reason to believe this was the case. According to him, a solit second after the Universe's birth there were two competing processes going on. One was the interaction between particles - analogous to the interaction between molecules in a gas - which drove the Universe towards a noisy equilibrium. But this approach to equilibrium was countered by the tremendous expansion of the Universe which was pulling matter apart. only when the expansion had slowed could particle interactions dominate, says Valentine, snowing matter to slip into the blurry, uncertain form we see today. This point was probably reached when the Universe was about io-41 seconds old, he suggests. With the transition occurring so quickly, you might think there could be no significant consequences. Not so, says Valentine. This transition could solve the puzzle of why far-flung parts of the Universe are at the same temperature and have the same matter density. How could they have influenced each other if there wasn't even time for light to have travelled from one to the other? The standard solution to this conundrum is inflation, a hypothetical super-fast expansion of the Universe in which it arose from a volume so small that very early on all parts knew about each other. But if there was no speed limit, there is no puzzle. There would be consequences for inflation too, if it really occurred. Quantum fluctuations in the fields that physicists believe drove inflation should be imprinted on the cosmic microwave background as small variations in temperature. "Those variations may therefore reflect quantum fluctuations in the early Universe," says Valentine. "If the actual fluctuations don't obey the rules of quantum mechanics, we ought to be able to see the fossil imprint in the microwave background today." Data from NASA's satellite observatory NL4,P could provide the answer next year, he says. What makes Valentini's theory even more surprising is that some non-quantum matter might have survived to the present day. Since the key to the transition to the equilibrium state is the interaction between particles, any particles that ceased to interact around the cut-off point about io-43 seconds after the big bang could get left behind. In particular, Valentine suggests that some gravitons - the hypothetical carriers of the gravitational force - could have become isolated at about the time of the transition. In other words, gravitons left over from this time might still be in a non-quantum state today. According to Valentine, there may be hitherto unknown non-quantum particles too. "It's conceivable they may even make up the invisible dark matter which dominates the Universe," he says. "Matter following familiar quantum theory could be a minor component of the Universe." Particles of non-quantum matter would look like normal particles, they'd simply not obey the statistics of familiar particles. The location of a particle trapped in a box, for example, would not be dependent on the square of its wave function: its position could be pinned down more precisely. How could we test such an outlandish idea? identifying gravitons that survive from the instant after the big bang seems unlikely, and even getting hold of dark matter might be difficult, to say the least. But it is conceiva6le that dark matter particles could decay into photons that preserve the non-quantum behaviour of their parents. if you could detect such photons - by pointing a telescope at a small region of dark matter - they would behave differently from quantum photons. Pass ordinary photons through a pair of slits, for example, and they produce distinct dark and light bands of interference. The bands produced by non- quantum photons, on the other hand, would beblurred. There's even some possibility that non- quantum matter is being created in today's Universe. Valentine's guess is that gravity could shift matter that obeys quantum theory back to its primordial non- equilibrium state. This would probably take the ferocious gravity of a singularity in a black hole, though. if we could somehow get hold of non- quantum matter, it would be magical stuff. For one thing we could violate Heisenberg's uncertainty principle, which puts a limit on how accurately we can measure things such as the location of a particle. To locate a particle, it has to interact with something else, for example when a photon bounces off it in a detector. The problem is that there is an uncertainty even in the position of the photon. "However, if we had photons obeying a probability distribution sharper than that of standard photons, we could locate things with greater certainty," says Valentine. This also means we could use the stuff to eavesdrop on secure cryptographic channels, says Valentine. Quantum cryptography is loo per cent secure because any attempt at eavesdropping would be notice ' d. The simple act of reading the secret key transmitted as a string of quantum is and os introduces disturbances (New Scientist, 2 October 1999, p 28). But if eavesdroppers possess non-quantum matter, they could beat the uncertainty principle and distinguish the state of the bits without disturbing them. This is because non-quantum particles contain less noise. just a very weak interaction between them and the quantum bits - an interaction too weak to disturb the bits - is enough to leave a discemable signature in the non-quantum particles that could be used to decrypt the message. And there's more. Non-quantum matter would enable us to build a computer which massively out-performs "conventional" quantum computers. These hypothetical machines would exploit the fact that a particle such as an atom can be in many states at once - a so-called superposition - to do large numbers of calculations simultaneously (New Scientist, 8 lune, p 24). The problem is that you need a carefully crafted quantum program that concentrates the answer in a single branch of the superposition, from where it can be read. So far such algorithms have been found for only a few specialised problems. But using non- quantum matter you could in theory access all the myriad parallel calculations of a quantum computer. it could be used to observe the computer's quantum state without collapsing the wave function, enabling us to read the results of all the parallel computations. But far more remarkable than all this would be faster-than-light communication. You could exploit non-locality without quantum noise getting in the way, using it to control robotic probes on planets at the other end of the Solar System in real time, for example. Troublesome time lags while instructions "crawl" at the speed of light across space would become a thing of the past. Vvlhy send humans on long, dangerous missions to Mars when robots, controlled from a comfortable lab on Earth, could do the job perfectly well? And this sort of communication would force us to revise relativity theory, says Valentine. Contrary to what is suggested by Einstein's theory, there would have to be an underlying preferred time - a sort of Universe-wide GMT. Valentine will have a hard time convincing sceptics. But it could be worth it. " It would mean that physics was finally making progress on a problem on which we have been stuck for many decades," says Smolin. "Right now we're staring into a sort of quantum fog," says Valentine "If we admit that an unexplored level might lie behind it, a whole new world comes into focus." 0 Fu rther reading: The Quantum Theory of motion by Peter Holland (Cambridge University Press, 1993) "Subquantum information and (amputation" by AntonyValentini (www.arxiv.orgiabsiquant-ph/0203049) "Hidden variables, statistical mechanics and the early universe" by AntonyValentini (www.arxiv.orglabsiquant-ph/0104067) "Signal-locality and subquantum information in deterministic hidden-variable theories" byAntonyVaILInfini (www.arxiv.orgiabsiquant-ph/0112151) "How does God play dice? Pre-determinism atthe Planck scale" by Gerard't Hooft (www.arxiv.orgiabsthep-th/0104219)

Estrogenic environment

PEOPLE don't quite know what to make of Theo Colborn. Is she the prophet of a new environmental threat or an errant alarmist? Hunched over a computer at the World Wildlife Fund in Washington DC, Colborn is amassing a database of chemicals she believes are hijacking our hormone systems, damaging men's fertility - even putting them at higher risk of developing testicular cancer. And what's more these chemicals are on the increase. Colborn is at the forefront of a 14-year debate on what are known as endocrine disruptors: pollutants that mimic or block the effects of human hormones. While some researchers argue there is no proven link between endocrine disruptors and reproductive problems in people, Colborn and her team believe these chemicals can have serious side effects even at low levels. Until recently, the debate focused on oestrogen mimics - chemicals that behave like female hormones. Some researchers link these to falling sperm counts and increases in cancer rates, while others strongly dispute any link. This debate is still unresolved, but now the hot topic is a new class of chemicals called androgen disruptors, which either mimic or suppress the action of male hormones such as testosterone. In theory, they could have an even greater impact on male fertility than oestrogen mimics. How worried should we be?

The first hints that pollutants might be able to interfere with male hormones tumed up over 20 years ago. Mike Howell, a fish biologist at Samford University, Alabama, discovered that female mosquitofish living in Florida rivers were starting to look like males. The fish, found downstream from a paper mill, had mysteriously developed an enlarged anal fin. This is normally a characteristic of male mosquitofish and it is used in mating. Since then masculinised females have turned up in other species of fish in American, Canadian and European waterways. The answer to this particular mystery only emerged last year. Howell's team analysed samples of polluted water taken downstream from another paper mill. They found traces of several androgens, the first ever spotted in the environment. One of them was androstenedione a precursor to testosterone and an anabolic steroid favoured by bodybuilders. This time, though, the hormone had appeared in the water because of the wood pulp churned out by the mill. Bacteria in the water were converting chemicals called sterols in the pine pulp into androstenedione. The team suspects that similar biological processes maybe releasing many more androgens into the environment. But it's not just androgens we have to worry about, it's also anti-androgens, chemicals that block the action of normal male hormones in the body. Anti-androgens could exert their effects in a number of ways: by stopping the production of testosterone, blocking its ability to signal to cells to switch on key genes, or even by directly quashing the activity of genes testosterone normally switches on (see Diagram, P 45). This is worrying, because testosterone is vital for the normal development of the male sex organs. It's only eight years since Earl Gray and his team at the US Environmental Protection Agency, the EPA, discovered these anti-androgens in the environment. These chemicals can end up in our food in the form of fungicides that are commonly sprayed onto fruit and vegetables. The team found the fungicide vinclozin stunted the sexual development of male rat pups in the womb. The list of anti-androgens keeps growing, and includes some chemicals known for their effects as oestrogen mimics. Phthalates, used to soften plastics, can also act as anti-androgens, as can DDE, a metabolic breakdown product of the pesticide DDT. Is there any evidence that anti-androgens could cause reproductive problems in humans? In theory at least they could, as animal studies show. The herbicide linuron, for example, is an anti-androgen that can cause sterility in mate rats exposed to it in the womb. Paul Foster, then a researcher at the industry-funded Clrr Centers for Health Research in North Carolina, found that it impairs the development of the cells in embryos that go on to form sperm. Linuron can also damage the developing testis to such an extent that the adult rat can be sterile and have shrunken testes. Male rats exposed to phthalates also have low sperm counts and a higher risk of developing testicular cancer, says Foster, now a consultant with the EPA. Trouble is, Foster's work has so far only involved using high doses of anti-androgens: in the case of phthlates, 300 times the amount to which people are normally exposed. And it's the question of dose that is central to the whole endocrine disruptor debate. Few scientists would dispute that endocrine disruptors are bad news in high doses. One of the most infamous examples is diethylstilboestrol, a synthetic oestrogen prescribed to pregnant women up until the 1970s to reduce miscarriage. Women whose mothers took DES have fertility problems and a higher rate of gynaecological cancers. The main sticking point is whether endocrine disruptors can cause problems at low doses. Sceptics argue that the levels of endocrine disruptors we normally experience are too low to have a serious effect. What's more, our food contains many natural compounds that mimic or suppress the action of hormones, and this doesn't seem to harm us. "Almost everything we eat is hormonally active," says Stephen Safe, a toxicologist at Texas A&M University in College Station. "Just because something has an activity doesn't mean that the world shuts down. Let's see if there are any adverse effects first." But the mere fact that endocrine disruptors play havoc with hormones in lab animals is enough for some to seek action. And researchers such as Foster believe that developing fetuses and infants are likely to be more sensitive due to their smaller size. What's more, if the development of the sex organs is disrupted at a crucial stage, the effects will be permanent. "Why play that kind of Russian roulette in our bodies?" says Sheldon Krimsky, an urban and environmental policy professor at Tufts University in Massachusetts, and author of the bookHonnonalChaos. And there's another problem: many of these compounds aren't excreted by the body. Instead, they gradually build up inside tissues. For instance, levels of phthalates in American women of childbearing age are higher than those in any other age or gender group, according to the US Centers for Disease Control and Prevention in Atlanta. Most of us are carrying hundreds of assorted synthetic chemicals in our tissues, particularly in body fat. It really becomes an issue when body fat breaks down, releasing the accumulated chemicals into the blood. This can happen during early pregnancy and when a woman is breastfeeding. And no one understands how the chemicals in this cocktail might interact with one another to increase or reduce the overall effect on our health. Researchers have done some low-dose experiments on animals, but the results are hotly contested. University of Missouri biologist Fred vom Saal, who has long been involved in the low- dose debate, feels the evidence is clear: even doles in the parts per billion range can cause reproductive and developmental abnormalities. He claims to have demonstrated such effects in mice using bisphenol-A, a polycarbonate that appears in everything from plastic wrap to baby bottles. "This is the next tobacco," he says. The chemicals industry, which funds its own research in this area, disputes these findings. it insists that bisphenol-A is safe. Gray points out that other researchers have yet to reproduce the results vom Saal found in this particular study. But he acknowledges that the results of different experiments in a similar vein are consistent with vom Saal's low-dose hypothesis. Gray is trying to study the effects on lab animals of known anti-androgens, including vinclozolin, other fungicides and phthalates. His team is currently looking at the effect on rat fetuses of giving high doses in short bursts. "It's clear that these chemicals are producing cumulative effects," Gray says. The team hopes to tackle low dose levels of a variety of mixtures next So far, however, no one has produced low- dose evidence that can convince the sceptics. But while the scientists wrangle over the methodologies of their experiments, is there any evidence that the human population is being affected by endocrinedisniptors? Perhaps the strongest evidence comes from the finding that testicular cancer rates have doubled in the Western world since the 196os- The rate is especially high in Denmark, where Niels Skakkebaek and his colleagues at the National UniversityHospital in Copenhagen are researching male fertility. Skakkebaek points out that a number of male reproductive problems, including testicular cancer, malformed genitals and reduced sperm counts, are all increasing together and says they are therefore linked. The team believes this is the result of abnormal development of the testes, which they call testicular dysgenesis syndrome or TDS. "It reflects the existence of a common underlying cause resulting In a maldeveloped testis," he says. TDS starts, Skakkebaek believes, with disruption of testicular development in the womb. If hormone disruptors interfere with the cells which develop into sperm, this could predispose individuals to cancer and infertility later in life, he says. But if endocrine disruptors were to blame, you would expect a fairly consistent rise in -reproductive problems in the countries where these chemicals are common. That hasn't happened. Instead there are large regional differences in rates of testicular cancer. "If fertility is declining, it's not due to some global contaminant," Safe says. Denmark, for example, has one of the highest recorded rates of testicular cancer - four times that of nearby Finland, which has the lowest. What's more, experts are still divided on the issue of whether sperm counts really are declining. A team at the University of Minnesota is now collecting data that will allow them to estimate differences in semen quality between countries. Skakkebaek's team is now trying to find out why there is such a difference in testicular cancer rates between Denmark and Finland. They are looking into differences in exposure to endocrine disruptors and cancer-causing chemicals In the two countries. For almost four years now, the team has been measuring the concentrations of these chemicals in breast milk and pregnant women's blood, and studying these women's babies once they are bom.

"Many common chemicals have not been tested for endocrine-disrupting effects. A ban on them all would be unworkable as we are so dependent on products they are used to make'

So far, the team has surveyed several thousand newboms, but has yet to analyse their findings. Another possible line of ' evidence comes from hypospadias. This is a common birth defect in boys in which the penis doesn't develop properly and the urethral opening may appear anywhere along the shaft - even within the scrotum. In the US, i in 125 boys are bom with varying degrees of hypospadias. And the prevalence of hypospadias has increased in recent decades. According to the Centers for Disease Control and Prevention, the rate among Americans nearly doubled between 19 68 and 1993, the same period when the suspect anti-androgens entered periods of higher production. Seven European countries, including Norway, Sweden, England and Wales, Hungary, Denmark, Italy and France, also reported increasing rates of hypospadias in the 6os, 7os and 8os, according to the International Clearinghouse for Birth Defects Monitoring Systems. But again regional differences complicate the picture. Outside the US, increases were most notable in Norway and Denmark while rates levelled off in Britain, Canada and the northern Netherlands after l985- "We still don't have any idea what causes hypospadias in 95 per cent of children," says Larry Baskin, a urologist at the University of Califomia at San Francisco. But he believes that a majority of the defects are caused by exposure to anti-androgens during pregnancy, and perhaps also to oestrogen mimics. The researchers suspect anti-androgens may also cause undescended testicles. For Safe, however, regional differences are enough to let endocrine disruptors off the hook. In fact, he points to one study that found fewer babies were being bom wfth undescended testicles. Making a concrete link between a given disease and an individual endocrine disruptor may be impossible, Colbom admits, given the large number of industrial compounds out there and individual variations in exposures. Not to mention the long interval between exposure in the womb and effects which may only appear at sexual maturity. But without convincing evidence, it will be hard to persuade policy makers and industry to take action. So far, very few of the 15,000 chemicals produced in the highest volume in the US have been tested for any endocrine-disrupting effects. Testing costs, and a blanket ban on all these chemicals, would be unworkable, not least because we are so dependent on the products they are used to make. How are we to resolve this impasse? Sceptics like Safe are calling on Colbom and her like-minded colleagues to come up with precise, testable hypotheses on how endocrine disruptors work and what their effects are. Proponents such as vom Saal say current toxicology methods just aren't up to the job of detecting the subtle low-dose effects of endocrine disruptors. Some of these show an unusual relationship between dose and effect,they argue. Unlike many chemicals, which have stronger effects as the dose increases, hormone disrupters could have their strongest effect at low dose, and no effect at high dose. Ibis makes it dffficult to use traditional toxicology models to predict how they could affect people. Foster, on the other hand, thinks that toxicologists already know how to deal with unusual dose-effe@ relationships. The biggest problem, he says, is that when scientists test endocrine disruptors on experimental animals, normally only a few of them develop any reproductive changes. We need to develop new toxicological methods that can reveal these subtle, unpredictable effects, he argues. The EPA has created a screening programme to figure out how best to evaluate low-dose reproductive and developmental effects and dose-response relationships for endocrine disrupting chemicals. Environmentalists welcome the development, but say that studies have not progressed far because the governing panel can't agree on how best to proceed. As a result, it has yet to come up with a solution that satisfieseveryone. In the meantime, Colbom keeps collecting information for her Intemet database, in the hope that the weight of accumulated data will sway opinion in her favour. Despite the difficulties in proving a link with human disease, Colbom advocates a precautionary approach. It's time we stopped arguing and started being much more cautious about what we release into the environment, she says. "Every generation we wait, that's one more grandchild, daughter, or s on:lo ' Julie Wakefield is a science writer based in Washington DC