David Adam

John Halpern, a psychiatrist at the university’s McLean Hospital, is set to study whether the compound MDMA can help ease anxiety in terminal cancer patients. MDMA — or to chemists 3,4-methylenedioxymethamphetamine — is better known as the dance-floor drug ecstasy. The study is the latest example of revived interest in the medicinal properties of controlled hallucinogenic or psychedelic drugs, loosely defined by their ability to alter perception, cognition or mood. Some researchers place MDMA in a different class, the empathogens, because it influences emotions.

Trials of MDMA for post-traumatic stress disorder are already underway in America, and psilocybin is being tried for anxiety and obsessive-compulsive disorder. There are even moves to reintroduce research on LSD at Harvard, where Halpern wants to test its abilities to treat cluster headaches — severe attacks that strike at the same time each day for weeks at a time.

“Drugs can be controlled but that doesn’t stop them from being useful,” Halpern says. “That’s what doctors are supposed to focus on, and that’s what I’m trying to do. The Leary connotations are understandable for a popular culture that is still struggling to resolve what happened in the 1960s. Let’s face it, it was a huge fiasco back then, but Tim Leary was not a physician and didn’t come to this from a medical approach.”

Halpern’s MDMA trial is different: 12 cancer patients with less than a year to live will be given varying doses under controlled conditions and strict supervision. Crucially, the trial was given the green light by several ethical review boards and approval from the Food and Drug Administration in December. One hurdle remains: Halpern has yet to receive a license from the Drug Enforcement Administration to handle the drug, though he expects to obtain one within weeks.

The ecstasy is not a chemical fix for the patients’ anxiety; instead it is intended to help them to open up and get the most from conventional counseling. Halpern says the drug allows people to talk about topics they would otherwise avoid. “It’s really tough doing psychotherapy with people who have anxiety disorders because when you get to the heart of the matter it causes a panic attack. For somebody who has a particularly gruesome time trying to talk about important end-of-life issues, it bubbles into anxiety and nothing gets achieved,” Halpern says.

“MDMA may be potentially useful in that it doesn’t induce that reaction. We want to see if that can translate into decreased anxiety and meaningful increases in the quality of life for these people.” The alternative, he says, is heavy doses of sedatives such as Valium. “At the moment these people have a choice of being oversedated and not having anxiety or being alert and suffering panic attacks.”

Patients volunteering for the trial will receive up to 125 mg of MDMA over two experimental sessions several hours apart — about the same or a little more than in a typical ecstasy tablet. They will also receive more conventional help during several non-drug sessions. Psychologists will assess their mental state before and after the trial to judge whether the drug has helped.

Rick Doblin, the founder and head of the Multidisciplinary Association for Psychedelic Studies, which funds the Harvard research, says the study could bring one step closer his goal of making MDMA a prescription medicine. “It’s going to be a hurdle, but as we get pilot studies that show promise I think it will get easier and easier to raise money for the research,” Doblin says. “A lot of people think what we’re trying to do is impossible and so don’t bother to help out. Now we’ve shown that it is possible.”

His group is funding the world’s only current clinical trial of MDMA. At his South Carolina clinic, psychiatrist Michael Mithoefer has given the drug or a placebo to victims of rape and sexual abuse who suffer from post-traumatic stress disorder. The trial started almost a year ago, and five of a total of 20 patients have been treated so far. Two more — the victim of a random shooting and a police officer involved in a violent incident — are lined up, and Mithoefer is preparing to extend the study to American soldiers traumatized by fighting in Iraq and Afghanistan after receiving permission from the FDA.

The research is controversial, and getting it off the ground proved difficult. The FDA originally approved the South Carolina study in November 2001 but insisted that Doblin’s group also get permission from an independent ethics review board; these oversee research and are usually attached to universities. The first seven applications to separate boards were rejected because of fears of legal action, because of experimental bias or in some cases with no explanation at all.

The dangers of ecstasy remain uncertain. In 2003, researchers at Johns Hopkins School of Medicine led by George Ricaurte were forced to retract claims that a single tablet could cause irreversible brain damage and even death in monkeys after they discovered a labeling mix-up meant they had used the wrong drug in their experiments. Just 18 days later, the South Carolina trial got the go-ahead from its eighth ethics review board.

But significant doubts over the long-term risks of MDMA remain: Animal studies show that it can lower levels of the neurotransmitter serotonin. It is difficult to judge whether similar changes occur in the brains of human users — though there is indirect evidence to suggest they do — and there is little evidence on what long-term effect, if any, this could have.

Some politicians and anti-drug campaigners have argued that research into the medical potential of illegal drugs presents a false reassuring message about their safety. Doblin rejects this, arguing that several controlled drugs already have “dual use” and are used for both recreation and medicine. Heroin is routinely prescribed as a painkiller (though not in the U.S., where synthetic versions are used), and cocaine is used as a local anesthetic for surgery around the nose because it numbs tissue so effectively. “No one has been saying that the rise in street use of methamphetamine is because some kids with attention deficit disorder get prescribed it,” Doblin says.

“We have to recognize there is no risk-free strategy. We’re not trying to sell what we’re doing as the way to solve all the problems with drugs. You look at the people who are taking MDMA for post-traumatic stress disorder and you would say that’s the opposite of ecstasy. They’re crying and shaking. They’re not saying, ‘Oh I’m so happy and I love the guy who did this to me,’” he adds.

Some people who take ecstasy in clubs break through emotional barriers to memories of childhood or other abuse, he says. Deliberately suppressing these feelings if they feel unable to talk about them with their friends at the time can then make the situation worse. “I think that’s the real risk of MDMA, more significant than the few cases of people who overheat and die and drink too much water and die.”

The results of the South Carolina trial are expected at some point next year. Doblin says the next stage will be two larger trials involving hundreds of people: One would take place in the United States and the second probably in Israel or Spain, where smaller studies are already planned.

Jose Carlos Bouso of the Autonomous University of Madrid started his own study of MDMA for patients with post-traumatic stress disorder in 2001. Spanish drug enforcement officials halted the work in 2002 after political pressure, but Doblin is hopeful that it will restart soon.

It’s not just interest in MDMA that is on the rise. Francisco Moreno at the University of Arizona at Tucson is currently writing up the results of a trial of eight people with obsessive-compulsive disorder treated with psilocybin. Psychiatrist Charles Grob at the University of California at Los Angeles is also testing psilocybin as a way to relieve anxiety in terminal cancer patients.

Elsewhere, a team at the Orenda Institute in Baltimore, Md., has asked the FDA for permission to give cancer sufferers LSD, and a Russian group in St. Petersburg led by Evgeny Krupitsky is investigating whether heroin addicts can be helped by treatment with the psychedelic drug ketamine, which is commonly used as a horse tranquilizer. And a small clinic in Peru is treating drug addicts with a hallucinogen — the native brew Ayahuasca — which is unusual because it contains dimethyltryptamine, or DMT, the only psychedelic compound our bodies produce naturally.

Mithoefer, who leads the South Carolina MDMA trial, says it is too early to tell if the compound has clinical benefits, though the early signs are good. “The trend that we’re noticing so far is that people are able to connect more deeply on an emotional level with the fact that they are safe now.”

The trial is double-blind — meaning neither the patients nor the scientists know who has been given the MDMA — but Mithoefer says there are several telltale signs, not least that pulse rate and blood pressure increase. “It’s a little hard to describe; there’s just a real sense of somebody having a new experience and connecting with their trauma.”

Each drug-assisted session lasts about eight hours, during which patients lie down and music is played — though psychedelic classics such as the Beatles’ “Sgt. Pepper’s Lonely Hearts Club Band” are out. “None of that stuff, because it has lyrics,” Doblin says. “Lyrics plant images into people’s minds, and we really want people to be free to bring up their own content.”

Halpern at Harvard hopes to get his trial of MDMA in cancer patients underway by the spring. “If it doesn’t work, then I’ll feel bad about that, but I’ll get another paper published and that will further my career and I suppose that’s nice,” he says. “But if it [MDMA] does help, it should be compelling, and that shouldn’t be thrown away because of the controversy over how some people end up abusing it.”

In their efforts to tackle inherited diseases and help infertile couples, scientists across the world are developing techniques and technology that ape the most basic — and morally complicated — of biological functions: human reproduction. Taken together, the work poses some troubling questions.

In the most recent research, the scientists claim to have grown eggs using stem cells scraped from anonymous human tissue. Others are trying to do the same with sperm. How long before they succeed? And could the two be combined to produce a synthetic embryo? No serious scientist advocates such a move, but as the parallel field of human cloning demonstrates, not everyone in a white coat is a serious scientist.

Further, some warn we may one day be able to incubate such fetuses outside the body, as described so memorably in Aldous Huxley’s dystopian classic, “Brave New World.” Work to develop such “artificial wombs” is already under way. So is artificial reproduction on the horizon?

“I have no doubt there are people fantasizing about creating a baby with no humans involved,” says Thomas Murray, president of the Hastings Center, a bioethics think tank in Garrison, N.Y. “I am sure there are people intrigued by that prospect, though I’m not one of them. It is never too early to start thinking about the moral implications. It’s amazing how quickly things develop and stun us.”

Those in doubt should pay a visit to the laboratory of Hung-Ching Liu, an embryologist at Cornell University in New York. In 2002, Liu stunned the world of reproductive medicine by claiming to have re-created a woman’s womb, using uterine cells grown on a biodegradable scaffold bathed in a broth of hormones and nutrients. When Liu placed fertilized human embryos created during in vitro fertilization treatment inside, they nestled into the wall of the womb and began to attach themselves to the endometrial cells that make up the lining — just as in the early stages of pregnancy. Liu stopped the experiments after a week because regulations prevent human embryos from being developed much further.

No such restrictions apply to animals and, in unpublished work, Liu says she has now grown mouse fetuses in her artificial womb for 17 of their 21-day terms. This is equivalent to about 31 weeks in humans, at which point babies have been viable for more than a month and can routinely be nurtured to normal development if born prematurely. Just as with the human embryos, the tiny bundles of mouse cells nestled into the artificial womb lining and began to attach themselves. Liu watched as blood vessels formed, then miniature placentas and, eventually, the amniotic sac — an embryo’s personal protective bubble.

Liu, of Cornell’s Center for Reproductive Medicine and Infertility, says: “Normally people don’t grow mouse embryos beyond 10 days. This goes way beyond that and forms a mouse shape housed inside a little bubble. It was wonderful. We were really amazed.”

But, peering inside, Liu could see that something had gone wrong. “The fetuses were not healthy. We could see the mouse inside but it was severely deformed.” Liu repeated the experiment more than 150 times. Not all the embryos developed, but for those that did, the story was the same. By 17 days it was clear that the fetuses were abnormal, so she pulled them out. “They were like a stillborn baby, just sitting there, doing nothing. I don’t think they were alive.”

When Liu cut them free from their amniotic sacs, the mice were dead. She thinks that the problem lies in the animals’ blood vessels, which do not form properly and so fail to circulate the required nutrients. “What other factors it needs to develop into a normal baby is still unknown. We’re only getting something that we think is close to the truth.”

Others are working at the other end of gestation, with equally startling results. A team at Temple University in Philadelphia, led by Thomas Shaffer, has developed breathable fluids that allow sheep delivered at half-term to survive outside their mothers. And scientists in the laboratory of the late Yoshinori Kuwabara in Tokyo have used tanks of synthetic amniotic fluid to incubate late-stage goat fetuses taken from pregnant animals for several weeks.

Some have speculated that the two ends of this research will eventually converge — allowing a two-cell embryo to develop into a living, breathing baby, entirely under laboratory lights.

Scott Gelfand, director of the Ethics Center at Oklahoma State University in Tulsa, was so concerned that he gathered experts together in 2002 for a conference titled “The End of Natural Motherhood: The Artificial Womb and Designer Babies.”

Murray, who attended the conference, says that while discussing the issue is easy, making it a reality is very, very difficult. “I think it is crucial for us to work out where to invest our moral anxiety, and I think that artificial wombs are not there yet. They are much more complicated than people think and not a neat lab trick like squeezing out the nucleus from a cell and putting a new one in its place.”

Although the ever-dependable Raelian cult says it has developed a device called a Babytron to incubate their clones, no reliable scientist believes that we are anywhere close to a working artificial womb capable of replacing a woman.

Embryos being made from synthetic eggs and sperm, however, is a different story. The artificial eggs that prompted the errant newspaper’s headline were prepared by a team led by Antonin Bukovsky at the University of Tennessee Graduate School of Medicine in Knoxville. Bukovsky says his technique could provide a potentially limitless supply of eggs — a scarce resource in fertility treatment and stem cell research. His claims have yet to be tested, and scientists have questioned why such groundbreaking results appeared in the little-known journal Reproductive Biology and Endocrinology, edited by Bukovsky. But it is clear in which direction research in the field is headed.

“It is not ridiculous to say this moves us toward the point where we can do completely artificial reproduction,” says Josephine Johnston, also at the Hastings Center. “But if you want a healthy baby, there are lots of easier ways and things people would rather do. It’s a bit like the whole debate in IVF and how we could design babies, but the fact is that most people don’t want to use IVF. They do it because they are desperate.”

As John Eppig, a developmental biologist at the Jackson laboratory in Bar Harbor, Maine, puts it: “I’m sure bioethicists are already thinking about this, but even if the ability to do it comes along, I don’t think it is going to replace the current method used to make babies in most homes.”

Like Liu, Eppig has been experimenting with mice, and his results also tell a cautionary tale. In 1996, Eppig succeeded in growing mouse eggs in his laboratory. He started with ovaries from newborn animals, cultured them and dissected out precursors of eggs, called oocytes, and associated cells. After careful nurturing, many of the resulting eggs began to grow when fertilized, but the 190 early-stage embryos transferred into female mice produced just one live pup. Eggbert, the first mouse born from a lab-cultured egg, was far from normal. He suffered from obesity and neurological problems.

Since then, Eppig’s team has worked to improve the culture medium used to grow the eggs, and in 2002 it reported the birth of 59 apparently healthy mice. Others are working to produce synthetic sperm and eggs from less obvious sources: the ubiquitous stem cells.

In 2003, Hans Schoeler and Karin Huebner at the University of Pennsylvania’s School of Veterinary Medicine said they had produced eggs from stem cells extracted from mouse embryos. Others, notably Toshiaki Noce at the Mitsubishi Kagaku Institute of Life Sciences in Tokyo, have tried to repeat the trick with sperm, though it is proving more difficult.

Synthetic eggs and sperm made from stem cells raise new ethical questions, mostly over parenthood. Schoeler and Huebner’s results suggest that eggs can be made even from male cells — potentially allowing a gay male couple to produce children through sexual reproduction. Contrary to some reports, the same is not true for lesbian couples. “To make a sperm you need a Y chromosome,” explains George Daley, a stem cell biologist at the Children’s Hospital in Boston. “There’s been all kind of speculation about whether you could make sperm from female cells. You can’t.”

Daley adds his voice to the chorus insisting no reputable scientists are involved in this research because they think it could be used for reproduction. “There are other issues that are more valuable to study, such as the development of the germ lineage, which has enormous implications for biology, fertility, the development of diseases and congenital defects. You can imagine all levels of bizarre scenarios but I think we need to stay focused on fundamental questions of medical importance.” Besides, he says, sperm and eggs generated from stem cells in a laboratory will probably not develop properly. “There are lots of reasons to think they are restricted or abnormal in some way and may not be able to support full development. This is a long, long way from reproduction in a dish.”

Eppig agrees: “Ethicists do need to be thinking about this and they do need to be thinking about it now. But actual applications are really not on the immediate horizon.”

Were significant advances to be made along the road of artificial reproduction and gestation, the issues would clearly be significant. “The issue with artificial wombs might not be so much in taking a fetus to term, but in using them to save very premature babies,” says Richard Ashcroft, a medical ethicist at Imperial College, London. If hospitals could use such wombs to keep babies alive that would otherwise be too premature to survive, it could well have implications for abortion law, he adds.

But as with all technological advances, new techniques are not guaranteed a market. How many couples would want to see their baby grow in an artificial womb unless there was no alternative? And as Ashcroft adds, for the vast majority of women, the importance of going through the birth process cannot be overstated.

Artificial sperm and eggs arguably raise more profound issues. Knowing that genetic material came not from living humans but from synthetic gametes grown in a lab would reinforce the distinction between parents as genetic donors and those who raise the child. For now, the sheer difficulty of perfecting the techniques necessary for fully artificial reproduction means the ethical issues are little more than talking points, says Eppig.

“All of these things are very, very hard to do. They are interesting mind games to discuss over a couple of beers after work. While we’re going to learn a lot about development from these studies, making embryos for animals and people is a long, long way off. How long? Don’t hold your breath.”

John McCloskey of the University of Ulster in Coleraine, who led the research, said: “Many of us are brought up to understand hazard as whenever you’ve had your bit of bad luck it doesn’t happen again. Lightning never strikes twice. But one great indicator that you’re going to have an earthquake is that you’ve just had one.”

He added: “These are very significant and extensive increases in stress. We cannot say for certain it will result in an earthquake, but it’s the biggest stress increase over a large area that we’ve measured since we started doing this research.”

A powerful undersea earthquake rocked parts of the region Wednesday but there were no reports of damage or casualties. The quake, which registered 6 on the Richter scale, struck about 19 miles beneath the seabed off Aceh province in Indonesia but did not cause a tsunami.

The new study shows that one of the regions at increased risk of a more powerful event is a 31-mile stretch of the undersea Sunda trench, next to the 745-mile-long zone that ruptured in December. Earthquakes in the Sunda trench triggered fatal tsunamis in 1833 and 1861.

Not all big undersea earthquakes cause tsunamis, but the scientists say their results emphasize the urgent need for a warning system in the Indian Ocean. Countries in the region and U.N. experts agreed on plans for a system last week at a meeting in Paris, but it will not be completed until the end of next year. Until the network of tidal gauges and seabed sensors is in place, Japan and the United States plan to issue alerts on seismic activity in the Indian Ocean.

The second area of concern identified in the new research is a 185-mile region of fault running directly beneath the island of Sumatra, close to the city of Banda Aceh, which was devastated in December and where rebuilding work is underway. The scientists estimate that stress in the Sunda trench region has increased by up to five bars; in the Sumatra fault it has been forced up by as much as nine bars.

McCloskey said there is a worrying recent precedent to consider: In 1998 seismologist Suleyman Nalbant, one of the authors of the new study, used the same technique to show that local seismic activity had increased stress by two bars on a 31-mile stretch of the Anatolian fault in Turkey, which has a very similar structure to the Sumatra fault. Less than 18 months later, the Turkish fault gave way near the city of Izmit and triggered a magnitude 7.4 earthquake that killed 20,000 people. He also warned that earthquakes in subduction zones — where one continental plate passes underneath another, as happens at the Indian Ocean boundary — frequently have struck in pairs.

In the Nankai trough to the southeast of Japan, five of the seven large earthquakes over the last 1,500 years have been followed by a similar event within five years. Three occurred within 12 months.

McCloskey said: “It’s by studying and reanalyzing what happened in the past that we are able to have some confidence in the relationship between the stresses we’re measuring and the occurrence of other earthquakes. But it should be stressed that the mapping is not one to one. It does not mean there will be another earthquake within a year or two, but certainly the risk has increased significantly as a result of what happened in December.”

His team used computer simulations of the earthquake prepared by an American team at Caltech in Pasadena, Calif., to re-create movement of the surrounding area. Because some regions of the affected fault slipped further than others, the resulting redistribution of stress through the ground was patchy and uneven — meaning seismologists could not be sure at first whether the risk of a second quake was raised or lowered.

To find out, McCloskey’s group used mathematical models of elastic materials, which essentially view the Earth as a giant rubber ball. For several points along the faults in the two danger zones they worked out whether the movement of the surrounding rocks freed the two surfaces to slide past each other or clamped them together, making an earthquake more or less likely. The results appear in the journal Nature.

Peter Styles, the president of the Geological Society, said: “It has become apparent over the last 10 years that when a major earthquake occurs it changes the stress in adjacent areas. Sometimes this can serve to lock the fault, but sometimes it can make another failure more likely. Every effort should be made to ensure that appropriate monitoring technologies and communication protocols are put in place to monitor the Indian Ocean.”

Nick Ambraseys, a seismologist at Imperial College in London, said: “There is nothing in [the new study] that enables, with any degree of certainty, the prediction of the immediacy of the next earthquake — except that an earthquake such as those of 1833 and 1861 is likely to occur sometime in the future. False alarms and inaccurate timing could create more problems than already exist.”

In separate research, marine scientists in the United States have highlighted the risk of a tsunami in the Caribbean, where there is no warning system. The team from the University of North Carolina and the University of Texas say that more than 35 million people could be affected if a powerful earthquake struck along the boundary between the North American and Caribbean tectonic plates. At least 10 significant tsunamis have been recorded in the region since 1492, six of which are known to have caused loss of life.

May’s warning coincides with a meeting of climate change skeptics Thursday at the Royal Institution in London organized by a British group, the Scientific Alliance, which has links to U.S. oil company ExxonMobil through a collaboration with a U.S. institute. Last month the Scientific Alliance published a joint report with the George C. Marshall Institute in Washington that claimed to “undermine” climate change claims. The Marshall Institute received 51,000 pounds from ExxonMobil for its “global climate change program” in 2003 and an undisclosed sum this month.

May’s warning comes as British scientists, in the journal Nature, show that emissions of carbon dioxide could have a more dramatic effect on climate than thought. They say the average temperature could rise 11 degrees Celsius, even if atmospheric carbon dioxide were limited to the levels expected in 2050.

David Frame, who coordinated the climate prediction experiment, said: “If the real-world response were anywhere near the upper end of our range, even today’s levels of greenhouse gases could already be dangerously high.” Emission limits such as those in the Kyoto protocol would hit oil firms because the bulk of greenhouse gases come from burning fossil-fuel products.

May writes that during the 1990s, parts of the U.S. oil industry funded skeptics who opposed action to tackle climate change. A Scientific Alliance spokesman said Thursday’s meeting was sponsored but that the funders did not influence policies. ExxonMobil said it was not involved.

One advisor is Sallie Baliunas, an astrophysicist at the Harvard Smithsonian Center, who is linked to the Marshall Institute. In 1998 Baliunas co-wrote an article that argued for the release of more carbon dioxide. It was mass-mailed to U.S. scientists with a petition asking them to reject Kyoto.

Tony Blair, at the World Economic Forum in Davos, Swizerland, Wednesday urged President Bush to sign a climate change accord. He said climate change was “not universally accepted,” but evidence of its danger had been “clearly and persuasively advocated” by a very large number of “independent voices.”

Miodrag Stojkovic, from the university’s Institute of Human Genetics, said: “We are ready to go as soon as the paperwork is sorted out. It has taken a year of work, and I am most pleased that the HFEA has recognized the potential of this technology in modern medicine.”

The Newcastle team will use the same technique used to create Dolly the sheep. They plan to insert DNA from skin cells into eggs left over from IVF treatment, which have had their own genetic material removed. Nurturing the eggs for six to eight days produces a tiny ball of around 100 cells, no bigger than a pinhead, from which stem cells can be extracted.

If the skin DNA was taken from a diabetic, then, in theory, the resulting embryonic stem cells could be grown into new pancreatic tissue and transplanted back into the patient with no risk of rejection.

“What we want to do is to see if these embryonic stem cells have the ability to differentiate into insulin-producing cells,” said Dr. Stojkovic. The scientists hope to produce the first stem cells within two years, though it could take at least five before any new therapies are tested in clinical trials.

Cloning human embryos to make babies is outlawed in the U.K., but so-called therapeutic cloning, where the embryo is destroyed after the stem cells are extracted, was made legal under strict guidelines in 2002.

Last year the Newcastle scientists became one of the first two groups in Britain to derive embryonic stem cells from spare IVF embryos. It asked the HFEA to allow the cloning research in February.

The chairwoman of the HFEA, Suzi Leather, said: “After careful consideration of … the project, the committee agreed to grant an initial one-year research license. This is an important area of research and a responsible use of technology.”

The first task for the Newcastle scientists will be to repeat the work of colleagues in South Korea, who in February cloned the world’s first human embryos and extracted stem cells. The South Korean team used dozens of fresh eggs from volunteers, which are more suitable for cloning than those left over after IVF.

Pro-life groups said they were taking legal advice in a bid to overturn the ruling. Jack Scarisbrick, national chairman of the group Life, said: “The decision is not unexpected given the HFEA’s track record.

“Therapeutic cloning involves the manufacture of a new kind of human being with the express purpose of destroying that life once stem cells have been stripped from it. It is … trivialization of human life of a most frightening kind.”

The U.N. will discuss moves to ban reproductive and therapeutic cloning in October.

The announcement marks a U-turn from Prof Hawking, who had argued that anything swallowed by a black hole was forever hidden from the outside universe. It has also lost him one of the most famous bets in science: in 1997 Hawking and fellow theoretical physicist Kip Thorne made a wager with John Preskill at the California Institute of Technology, who insisted that information carried by an object entering a black hole was not destroyed, and so could be recovered.

“I’m now ready to concede the bet,” Prof Hawking said yesterday. At stake was an encyclopedia — “from which information can be recovered at ease” — of the winner’s choice. “John is all American so naturally he wants an encyclopedia of baseball. I had great difficulty finding one over here, so I offered him an encyclopedia of cricket as an alternative,” Prof Hawking said. “But John wouldn’t be persuaded of the superiority of cricket.”

The about-turn ends a 30-year personal struggle for Prof Hawking. In 1974, while formulating new equations in an attempt to unite the heavyweight ideas of quantum mechanics and general relativity, he realised that black holes must emit heat, now known as Hawking radiation. The problem was that this radiation would carry energy away, meaning the black hole would gradually evaporate and then disappear in a final explosive outburst — taking the crucial information with it.

This contradicts the fundamental laws of quantum physics, which insist the information can never be totally wiped out.

While several physicists over the years offered solutions to this paradox, Prof Hawking preferred to believe that the intense gravity inside a black hole somehow unravelled the quantum laws. More intriguingly, he suggested that the vanishing information might travel through the black hole to a parallel universe — planting the seeds for a staple of science fiction.

“There is no baby universe branching off as I once thought,” Prof Hawking admitted yesterday. “I’m sorry to disappoint science fiction fans but if information is preserved there is no possibility of using black holes to travel to other universes. If you jump into a black hole, your mass energy will be returned to our universe, but in a mangled form which contains the information about what you were like.”

His new calculations suggest the surface of the black hole, the event horizon, has fluctuations that allow the information to escape. “It is great to solve a problem that has been troubling me for nearly 30 years, even though the answer is less exciting than the alternative I suggested.”

He presented his new work at a hastily scheduled session at the 17th international conference on general relativity and gravitation at the Royal Dublin Society. Such is his reputation, conference organisers allowed him to speak without previously seeing the work. Prof Hawking’s talk has been eagerly awaited for weeks after news of his change of thinking emerged when he spoke at a department seminar in Cambridge.

Puzzling
Gerry Gilmore, an astrophysicist at Cambridge University and a colleague of Prof Hawking, said: “At the moment everyone is reserving judgment, but Steve doesn’t say things like this very often and so it’s highly likely he’s on to something interesting. What it is may well be so esoteric that it’s not obvious to a non-expert, but then he’s not talking to non-experts.”

He said the findings could shed more light on quantum gravity — a puzzling concept that emerges when physicists try to resolve the forces of gravity, which describes how the universe works on its biggest scale, and quantum mechanics, which only works on the smallest.

Prof Hawking shot to fame with his best-selling book “A Brief History of Time,” which tried to explain how the universe works to a general audience. Despite being virtually paralysed with amyotrophic lateral sclerosis since his mid 20s, he travels the world on speaking engagements, communicating with a speech synthesiser and a hand-held device to select words. His speech comes five months after he survived a near-fatal bout of pneumonia, and follows a police inquiry into allegations of domestic violence against his wife, who was cleared of any wrongdoing.

After being given the baseball encyclopedia, which was flown to Dublin for the occasion, Prof Preskill said he was very pleased to have won the bet but added: “I’ll be honest, I didn’t understand the talk.” He said he was looking forward to reading the detailed paper Prof Hawking is expected to publish next month.