Diamond is no longer nature’s hardest material

London: Diamond will always be a woman’s best friend but the gemstone is no longer the world’s hardest material, according to scientists.

Instead, a rare natural substance, called lonsdaleite, which is made from carbon atoms just like diamond, has emerged as 58 per cent harder than the gemstone, according to a report in the New Scientist.

An international team, led by Zicheng Pan at Shanghai Jiao Tong University, simulated how atoms in two substances believed to have promise as very hard materials would respond to the stress of a finely tipped probe pushing down on them.

The simulation revealed that the first one, wurtzite boron nitride, withstood 18 per cent more stress than diamond, while the second, the mineral lonsdaleite, 58 per cent more.

Rare mineral lonsdaleite is sometimes formed when meteorites containing graphite hit Earth, while wurtzite boron nitride is formed during volcanic eruptions that produce very high temperatures and pressures.

If confirmed, however, wurtzite boron nitride may turn out most useful of the two, because it is stable in oxygen at higher temperatures than diamond.

And, according to the scientists, this makes it ideal to place on the tips of cutting and drilling tools operating at high temperatures, or as corrosion resistant films on the surface of a space vehicle, for example. Paradoxically, wurtzite boron nitrides hardness appears to come from the flexibility of the bonds between the atoms that make it up.

When its stressed some bonds tend to re-orientate themselves by about 90 to relieve the tension.

Although diamond undergoes a similar process, something about the structure of wurtzite boron nitride makes it nearly 80 per cent stronger after the process takes place, the studys co-author Changfeng Chen of University of Nevada wrote in the Physical Review Letters journal.

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Most People Believe Dreams Are Meaningful

By LiveScience Staff

Dreams might mean nothing, but many people take them seriously nonetheless, as Sigmund Freud did, new research finds.

People in at least three countries, including the United States, believe dreams contain important hidden truths, said researcher Carey Morewedge, an assistant professor at Carnegie Mellon University in Pittsburgh.

In six different studies, Morewedge and his colleagues surveyed nearly 1,100 people about their dreams. The results are detailed in the February issue of the Journal of Personality and Social Psychology.

"Psychologists' interpretations of the meaning of dreams vary widely," Morewedge said. "But our research shows that people believe their dreams provide meaningful insight into themselves and their world."

In one study that surveyed general beliefs about dreams, Morewedge and co-author Michael Norton, an assistant professor at Harvard Business School, surveyed 149 university students in the United States, India and South Korea. The researchers asked the students to rate different theories about dreams.

Across all three cultures, an overwhelming majority of the students endorsed the theory that dreams reveal hidden truths about themselves and the world, a belief also endorsed by a nationally representative sample of Americans, Morewedge said.

In another study, Morewedge and his colleagues wanted to explore how dreams might influence people's waking behavior. A total of 182 commuters at a Boston train station were asked to imagine that one of four possible scenarios had happened the night before a scheduled airline trip: The national threat level was raised to orange, indicating a high risk of terrorist attack; they consciously thought about their plane crashing; they dreamed about a plane crash; or a real plane crash occurred on the route they planned to take.

A dream of a plane crash was more likely to affect travel plans than either thinking about a crash or a government warning, and the dream of a plane crash produced a similar level of anxiety as did an actual crash, Morewedge found.

Finally, Morewedge wanted to find out whether people perceive all dreams as equally meaningful, or whether their interpretations were influenced by their waking beliefs and desires. So, in another study, 270 men and women from across the United States took a short online survey in which they were asked to remember a dream they had had about a person they knew. People ascribed more importance to pleasant dreams about a person they liked as compared to a person they did not like, while they were more likely to consider an unpleasant dream more meaningful if it was about a person they disliked.

"In other words, people attribute meaning to dreams when it corresponds with their pre-existing beliefs and desires," Morewedge said. "This was also the case in another experiment which demonstrated that people who believe in God were likely to consider any dream in which God spoke to them to be meaningful; agnostics, however, considered dreams in which God spoke to be more meaningful when God commanded them to take a pleasant vacation than when God commanded them to engage in self-sacrifice."

More research is needed to explore fully how people interpret their dreams, and in what cases dreams may actually reveal hidden information, Morewedge said.

"Most people understand that dreams are unlikely to predict the future but that doesn't prevent them from finding meaning in their dreams, whether their contents are mundane or bizarre," he said.

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Darwin the Buddhist? Empathy Writings Reveal Parallels

Christine Dell'Amore in Chicago
National Geographic News

Charles Darwin probably didn't know it, but he held views on human empathy that mirror Buddhist beliefs, says a pioneer in decoding facial expressions. Based on his interactions with foreign cultures, Darwin came to define empathy as a desire to end someone's suffering to assuage one's own discomfort.

Buddhist teachings also see empathy as a somewhat selfish motivation, but one that the Dalai Lama, the spiritual leader of Tibet, calls the "seed of compassion."

"It's an amazing coincidence that [Darwin's] views on compassion and morality are identical to the Tibetan Buddhist view," said Paul Ekman, a psychologist whose work decoding so-called micro-expressions is the basis for the new Fox television show Lie to Me.

Indeed, after reading Darwin's work on emotions, the Dalai Lama told Ekman he "would consider himself a Darwinian."

The parallel inspired Ekman to study the little-understood trait of compassion, which he discussed this weekend in Chicago at the annual meeting of the American Association for the Advancement of Science.

Though everyone is capable of compassion, Ekman said, some people seem to manifest it without effort.

(A related study revealed how bullies seem to experience pleasure when they see others suffer.)

Until psychologists figure out why the disparity exists, he said, "the survival of our planet" depends on cultivating compassion.

Universal Trait

Darwin became fascinated with the expression of emotions during his five-year voyage on the H.M.S. Beagle in the 1830s.

The British naturalist couldn't understand the words or gestures of the people he met, but he had no trouble interpreting their facial expressions.

In his lesser known 1872 book The Expression of Emotions in Man and Animals, Darwin proposed that empathy is a universal trait. "He saw this book as an important contribution showing the commonality of all people," Ekman said. (Read more about Darwin's scientific legacy.)

It's also possible that Darwin encountered Buddhist teachings through letters from other scholars of the time, he added.

Over the past few years, Ekman examined Darwin's book along with Buddhist teachings and divided compassion into three types: simple, global, and heroic.

Simple compassion is the almost instinctual form that exists mostly between a mother and an infant.

Global compassion appears when people help distant strangers, such as the outpouring of international aid after the 2004 Indian Ocean tsunami.

And heroic compassion occurs when a person is motivated into epic acts of bravery, for instance, jumping into an icy pond to save someone else's life.

In a recent book co-authored with the Dalai Lama, Ekman suggests creating "compassion gyms" that could test a person's level of compassion and even offer exercises to prompt deeper caring for others.

The Dalai Lama, meanwhile, believes that just the sight of unbearable suffering is enough to inspire compassion.

Animal Emotions

Darwin also argued fervently in his 1872 book that animals and humans share the capacity for emotion, an idea that has been borne out by later research, Ekman noted.

(See photos showing how a dying elephant seems to elicit compassion from its herd.)

Many great ape studies, for example, show that the animals can place themselves into another's shoes, so to speak. This sensitivity comes from being self-aware, Barbara King, an anthropologist at the College of William and Mary in Virginia, told National Geographic News.

"We wouldn't be human in the ways we are human today if apes were not deeply emotional creatures and deeply social ones," King said. "We are … products of our past."

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