Tiny Silicon Chip Uses Quantum Physics to Slow Light Down

Scientists have built an optical device smaller than a dime that slows light down to 155 miles per second, the slowest ever managed on a chip.

The tiny silicon chip works at room temperatures and can be mass-produced, with 32 chips on a 4-inch silicon wafer. Previous efforts slowed light to just 0.01 miles per second, but this required a roomful of equipment and temperatures near absolute zero.

Those experiments were “fantastic and very inspiring, but with limited practical applications,” said electrical engineer Holger Schmidt of the University of California, Santa Cruz, who led the study published in November’s Nature Photonics.

Chips based on Schmidt’s work could be used to create all-optical systems that would potentially be “cheaper, faster and use less power,” said physicist John Howell from the University of Rochester, who was not involved in the study. Slowing light on a chip could eventually be used for optical memory, quantum cryptography, and to create simple quantum computers, he said.

Schmidt’s team’s method involves shining a red laser through a tabletop maze of mirrors into the optical chip. The laser, just a few times stronger than a laser pointer, travels through a channel on the chip, and hits a 4-mm-long capillary full of rubidium atoms. As the light smacks into the atoms, they absorb it and don’t let it through.

The scientists then shine another red laser into the rubidium atoms, triggering a quirky quantum mechanical effect that causes the rubidium’s electrons to occupy a different physical state. This turns the previously dense rubidium vapor transparent.

“That was really exciting,” Schmidt said. “Without that second beam, it would be opaque.”

Read more at Wired

Herbal remedies face licence rule

“Hundreds of traditional and imported remedies on the shelves of health food shops and herbalists are set to be banned under new licensing rules.

The EU directive aims to protect users from any damaging side-effects that can arise from taking unsuitable medicines.

Only high quality, long-established and scientifically safe herbal medicines will be sold over the counter.
Some traders who sell products imported from outside the EU say their business will be hit.

Herbal medicines – with names such as Cascara Bark and Horny Goat Weed – have become popular.
But from the first of May an EU directive will be enforced, under which all such products must be licensed, following fears that some products could cause harm.

Producers and independent health store owners say the directive, passed in 2004, is draconian and skewed in favour of the largest European manufacturers.

Selwyn Soe runs The Herbal Factory, a contract manufacturer of herbal remedies in Croydon, south London. He believes smaller firms like his own will be squeezed out altogether.

“Unfortunately it looks as if we will have to close down because of this legislation,” he said.

“The problem for us is that although we would have to pay many thousands of pounds for a licence to keep making each product, unlike a drug company we would not have a licence to make that product exclusively. It just will not be worth paying out the money.”"

Read more at BBC News

44% of Danish think religion is a bad thing

Close to half of Danes believe that religion makes the world a worse place. At the same time as many believe in God. But there is big difference between faith and religion, says a researcher. Religion is the root of all evil, says a proverb, based on past bloody religious conflicts. But there is some evidence that attitudes are returned when 44 percent of the Danish population responded that religion makes the world a worse place.

This is the result namely of a Gallup poll conducted last month.

By comparison, only 18 percent said religion makes the world better. The results related to the fact that Danes do not really understand religion, explains lecturer in Religion at Aarhus University Phil Zuckerman: ”The Danes are among the least religious and thinks very rationally. They simply do not understand religion, which is something very irrational. Therefore influenced their understanding of what they experience in the media. ”

Full Story at Berlingske

Secret Service Study Probes Psyche of U.S. Assassins

With public speculation mounting about what motivated a 22-year-old man to attempt to kill a congresswoman, a little-known study by the Secret Service suggests the truth may be frighteningly mundane.

The study of U.S. assassinations over the last 60 years debunks some key myths about the miscreants behind the attacks. The Exceptional Case Study Project, completed in 1999, covers all 83 people who killed or attempted to kill a public figure in the United States from 1949 to 1996.

“We approached a number of people, many in prison,” says forensic psychologist Robert Fein, who co-directed the study with Bryan Vossekuil of the Secret Service. “We said you’re an expert on this rare kind of behavior. We’re trying to aid prevention of this kind of attack. We’d welcome your perspectives.”

Fein interviewed 20 of the attackers who were still living and sifted old evidence from cases. His goal was to understand the sequence of thoughts, plans and motivations that transformed a downtrodden, but unremarkable person into an aspiring killer over a period of months or years.

Contrary to popular assumptions about public killings, the attackers didn’t conform to any particular demographic profile. But when Fein reconstructed their patterns of thinking, he was able to distill them into a handful of recurring motives for killing a public person — motives that seemed consistent regardless of whether a given individual was delusional or not (and three quarters of those who pulled the trigger were not).

Some hoped to achieve notoriety by killing a well-known person. Others wanted to end their pain by being killed by Secret Service. Still others hoped to avenge a perceived, idiosyncratic grievance unrelated to mainstream politics. Some hoped, unrealistically, to save the country or call attention to a cause. And some hoped to achieve a special relationship with the person they were killing.

Beyond these findings, the study overturns the image of the political or celebrity killer as a menacing stalker. It’s true that politicians and celebrities receive hundreds of threats each year — but those threats come from people other than the itchy-fingered trigger-pullers.

Unlike terrorists, who sow panic with public threats, just 4 percent of assailants in the study warned their targets by sending threats. That silence underlined their desire to fly under the radar, says J. Reid Meloy, a forensic psychologist at the University of California in San Diego who studies public figure killings.

The aspiring assailants often chose between several possible victims. And once they chose, they spent weeks, even sometimes years, planning and mulling their attacks.

Read more at Wired

Fruit Flies Help Solve Computer Problem

Fruit flies have solved a computing problem that has vexed computer scientists for decades.

Mimicking how some nerve cells in flies pick a leader to make decisions has led scientists to a computer algorithm that could make wireless sensor networks, such as those used for monitoring volcanic activity or controlling swarms of robots, much more efficient.

In such smart networks, some sensors can act as leaders to alert headquarters if, for example, a certain number of them detect rumblings indicating that a volcano might be waking up. The new approach, published in the Jan. 13 Science, achieves the same leader-follower relationships but eliminates a lot of cross-talk among sensors, saving energy and computing power.

A colleague's presentation on how nerve cells in fruit flies take on different jobs struck computational biologist Ziv Bar-Joseph as being very similar to a distributed computing problem. In distributed computing, many computer processors work together toward a common goal, but with minimal leadership. A handful of processors -- typically ones with many neighboring processors -- are designated leaders and set up to receive information from the processors around them and pass it on.

"People in computer science made assumptions about what sensors need to know," says Bar-Joseph, a researcher at Carnegie Mellon University in Pittsburgh who led the new work. But developing cells set up their networks without knowing much about their neighbors, he says. "They work in a much more constrained environment and still come up with solutions."

Similarly, when fruit fly larvae are developing, some cells take on particular tasks, such as becoming a precursor of the sensory bristles the flies use to read the air around them. Each bristle ends up surrounded by nonbristle cells. This layout, where there are enough specialized cells, or leaders, but no two are right next to each other, is very similar to how tasks are divvied up in distributed networks, says Bar-Joseph.

For 30 years, computer scientists had thought that to most efficiently designate a handful of processors as leaders that can quickly communicate with the rest of the network, each processor had to take stock of its local neighborhood. Then some processors would identify themselves as leaders, based in part on how many connections they have with other processors.

Young fruit fly nerve cells don't necessarily know how many cells are in their neighborhood, yet they manage to develop into appropriately distributed sensory bristles. Once a cell elects itself as a bristle, it sends out a protein signal that inhibits neighboring cells from becoming bristles.

Read more at Discovery News

Boy, 9, has Disney World trip ruined after US immigration rules him a threat

Civil servants Kathy and Edward Francis planned to surprise their grandson Micah Strachan with the holiday of a lifetime to Florida in February.

They were only going to tell Micah about it when they took him to the airport on February 19 for the flight to the US.

They had already spent more than £1,500 on plane tickets and had been organising the trip for months.

But this week US Embassy officials denied the schoolboy a visa to enter the US.

They said there was a risk he would not leave the US at the end of his holiday and refused his application under Section 214 (b) of the Immigration and Nationality Act.

Micah was born in Britain and has lived in Middlesex all his life with his mum Claudia Lewis.

He holds a South African passport because his grandparents Kathy and Edward, who have lived and worked in Britain since 1990, only got him a South African passport.

They are originally from South Africa.

A letter from Micah's primary school was included in his visa application confirming he attended the school.
But the US Embassy's rejection letter to Micah said: "Because you either did not demonstrate strong ties outside the United States or were not able to demonstrate that your intended activities in the US would be consistent with the visa status, you are ineligible."

His grandmother Kathy, from Brixton, South London, said: "It was going to be a total surprise. He would have loved it.

"We feel so deflated by the whole experience.

"I want to know why he would be deprived of the holiday of a lifetime.

"It's crazy to think that he wouldn't leave the country. This is causing severe stress on the family. I am going to fight this."

Tessa Jowell, Labour MP for Dulwich and West Norwood, said: "I was very concerned to learn about the situation facing my constituents and of course understand the distress the decision has caused.

"I have asked the American authorities to look again at this and very much hope they will feel able to reconsider their decision."

Read more at The Telegraph

'Great Grandmother of Crocodiles' Unearthed

The toothy animal, which hasn't been officially named yet, lived in what is now West Texas 225 million years ago. That timing is significant, because some of the world's first known dinosaurs emerged at around the same time period down in Argentina. (You can read about these early dinosaurs at Discovery News.)

This large section of what was then called Pangaea may have then been the birthing ground for some of Earth's largest and most famous reptiles. Pangaea was a supercontinent that existed before the component continents separated into their current configuration.

Perhaps because there was so much land to run on, the early crocodile ancestor was built more for land speed than aquatic surprise.

“This is a brand new animal and possibly the great-grandmother of all crocodiles,” Doug Cunningham who worked on the project, was quoted as saying in the TTU press release. He helped to performed a CT scan of the reptile's fossil.

"These early crocodiles look like your typical terrestrial animals," according to Cunningham. "An intact skull is very rare to find. One of the exciting things is we were able to see inside its brain case with the CT scan. We can see the brain evolved very slowly.”

It was this braincase, and also an ankle joint, that linked the early reptile to crocodiles.

“It has lots of sinuses in the braincase like those of modern crocs,” said Sankar Chatterjee, curator of paleontology at the Museum of Texas Tech, who also worked on the project. “These sinuses may be linked to their vocalization. Unlike most reptiles, crocs are very vocal and hear well. We described a similar animal from China that gives us some idea about the way this animal lived.

Read more at Discovery News

Household chores bad for heart

New research shows worrying about household chores such as cleaning, getting the car serviced and paying the bills may be even worse for your heart.

Scientists in the US tested over 100 working men and women and found those who took on most of the responsibility for running the home had significantly higher blood pressure readings than those who left it to their partners.

The findings, published in the journal Psychosomatic Medicine, suggest it’s not the workload itself but the stress about how to cope with it that causes the damage.

The strongest link with high blood pressure came from worries over how to get domestic chores done, such as cleaning, cooking and shopping.

Next came car maintenance and repair, paying the bills and keeping on top of the household budget.

But having to look after children or pets had no adverse effect on blood pressure.

Although there have been hundreds of studies investigating the links between stress at work and the risk of heart attacks and strokes, little research has been done into whether running a home and family has a similar effect.

Heart disease is Britain’s biggest killer.

Around 270,000 people suffer a heart attack every year and nearly one in three die before they even reach hospital.

High blood pressure, which affects one in five people in the UK, is one of the major risk factors.

The higher it climbs, the greater the force exerted by blood on the walls of the arteries when the heart beats.
The World Health Organisation estimates that 50 per cent of all heart attacks and strokes are due to raised blood pressure.

Clinical guidelines state the ideal limit for blood pressure is a systolic reading of 140mmHg and a diastolic reading of 90mmHg.

Systolic is the pressure inside arteries when the heart is forcing blood through them and diastolic is the pressure when the heart relaxes.

Scientists from the University of Pittsburgh School of Medicine recruited 113 men and women in full-time work.

Each one provided details on how many hours they worked and what level of responsibility they took on for running the home.

They then underwent regular blood pressure checks at a local clinic over a three-week period, before finally wearing a blood pressure monitor for a day to track changes at work and home.

Read more at The Telegraph

Scientists plan to probe Uranus ;)

“British space scientists are leading plans to send a probe to explore giant ice planet Uranus. They have put forward a detailed proposal to the European Space Agency to launch a joint mission with NASA to the distant world, 1.8 billion miles from the sun.

It would give scientists their first close-up views of Uranus since NASA’s Voyager 2 flew past and captured fleeting pictures 25 years ago.

The £400million mission is designed to go in orbit to study the rings around Uranus and answer questions such as why it gives off so little heat.

Uranus – first spotted by Sir William Herschel from Bath, England, in 1781 – also has the most powerful wind observed in the solar system, blowing at more than 500mph.

The planet is unusual because it is tilted right over on its side. Astronomers believe this was caused when Uranus was given a mighty whack by another world in a cosmic collision.

More than 160 scientists are backing the Uranus Pathfinder project which is led by Dr Chris Arridge, of University College London’s Mullard Space Science Laboratory in Surrey.

He told Skymania in an exclusive interview: “We’ve only really scratched the surface of Uranus. It is very difficult to observe from Earth because any detail is smeared out.”

Read more at CS Monitor

Ancient Mass Extinctions Hint at Possible Ocean Future

In sediment traces and fossil records from one of Earth’s most tumultuous periods, geologists have found a narrative linking mass extinctions with planetary biological and geological change.

After dramatic oceanic extinctions 250 million and 200 million years ago, the global carbon cycle turned chaotic. Earth’s biogeochemistry went boom and bust for millions of years thereafter, as if some regulating mechanism were lost — which is exactly what happened.

“People talk about saving biodiversity, and isn’t it good to have a variety of all these creatures. But the reason it matters is because ecosystem function is itself dependent on diversity in the face of normal environmental changes,” said geologist Jessica Whiteside of Brown University. “Lower diversity too much, and the system will lose its resiliency. It will become a slave to otherwise minor environmental changes.”

Whiteside specializes in reading the geological record of past extinctions, teasing from rocks and fossils the story of those times in Earth’s history when, for one reason or another, most forms of life ceased to exist.

In the new study, published Jan. 5 in Geology, Whiteside and University of Washington biologist Peter Ward focus on two mass extinctions with especially catastrophic marine consequences: the Permian-Triassic extinction event 250 million years ago, when 96 percent of all ocean species went extinct, and the Triassic-Jurassic extinction 200 million years ago, which extinguished 20 percent of all marine families.

Scientists say that another mass extinction is now underway, with extinction rates an order of magnitude higher than normal, both on land and at sea. Studies like Whiteside’s suggest what the extinction’s consequences could be — not just for people, on a scale of decades or centuries, but for how the planet will work, millions of years in the future.

Read more at Wired

Vaccinate all children against swine flu, say parents who lost girl

Lana Ameen, who had no underlying health problems, died on Boxing Day, two days after apparently catching a cold and developing a high temperature.

Her parents Zana and Gemma Ameen, a doctor and nurse, said the "price was too high" not to vaccinate children against the potentially deadly swine flu (H1N1) virus.

Mrs Ameen, 28, said: "We have been so shocked by what has happened and we feel very strongly that everyone, particularly children, should have the vaccine."

She believed Government policy was "clearly excluding a large amount of the public from being protected from this virus" and said: "The Government has made the swine flu vaccine from last year available now - we should all be having it."

She had tried to get Lana vaccinated on the NHS but was refused because her daughter had no health conditions.

She described Lana as a "bright and bubbly girl" who was a "sweetheart" and was "just so healthy".

In the last fortnight the Government has come under fire for restricting use of the seasonal flu jab, which protects against swine flu and two other strains, among children.

Only those with health problems, such as neurological disorders or asthma, are eligible for the seasonal jab.

Since October 13 of the 50 people known to have died of flu have been children under 15. Nearly a third of all the victims (15 of 50) were previously healthy, not being in any 'at risk' category. Forty-five of the 50 deaths were from swine flu.

The Ameen family, from Quinton, Birmingham, were visiting relatives in Stockport, Greater Manchester, when Lana became ill on Christmas Eve. That night they took her to Stepping Hill Hospital where she was diagnosed with an infection and sent home.

Read more at The Telegraph

Bird death mystery solved: they 'drank' themselves to death

Romeu Lazar, the executive director of the veterinary health department in the Black Sea port of Constanta said on Wednesday a post-mortem revealed the birds ate grape residue that had fermented and their bodies could not handle the alcohol.

He says they did not have avian flu, which hit the area several years ago.

Constanta residents found dozens of dead birds on the outskirts of the city last week. The reports come as other, larger bird deaths were reported in the United States and elsewhere.

Read more at The Telegraph

Dying Young Didn't Wipe Out Neanderthals

Dying young was not likely the reason Neanderthals went extinct, said a study out Monday that suggests early modern humans had about the same life expectancy as their hairier, ancient cousins.

Scientists have puzzled over why the Neanderthals disappeared just as modern humans were making huge gains and moving into new parts of Africa and Europe, and some have speculated that a difference in longevity may have been to blame.

If anything, higher fertility rates and lower infant mortality gave modern humans an advantage over the Neanderthals, who died off about 30,000 years ago, said the study in the Proceedings of the National Academy of Sciences.

Scientist Erik Trinkaus of Washington University studied fossil records to get an idea of the life span of Neanderthals and early modern humans, who co-existed in different parts of the world for about 150,000 years.

He found about the same number of 20- to 40-year-old adults in both populations, an indication that would reflect "similar patterns of adult mortality," said the study.

Read more at Discovery News

Oldest Winery Unearthed in Armenian Cave

Archaeologists say they have found the world's oldest known winery in a cave in Armenia, indicating that humans were distilling grapes during the Copper Age, more than 6,000 years ago.

"This is, so far, the oldest relatively complete wine production facility, with its press, fermentation vats and storage jars in situ," said Hans Barnard, the lead author of an article about the study published on Tuesday in the peer-reviewed Journal of Archaeological Science.

The artifacts were discovered by Armenian, U.S. and Irish archaeologists inside a cave complex in southern Armenia, near the border with Iran and close to a village that still makes its own wine, researchers said.

They were found on the same site where archaeologists had in June 2010 discovered a perfectly preserved leather moccasin dating back 5,500 years, considered to be the world's oldest shoe.

Radiocarbon analysis by researchers at University of California Irvine and Oxford University has dated the installation to between 4100 B.C. and 4000 B.C., or the Late Chalcolithic Period, also known as the Copper Age.

The findings included a rudimentary wine press and a clay vat surrounded by grape seeds, withered grape vines, and remains of pressed grapes, as well as potsherds and even a cup and drinking bowl.

"For the first time, we have a complete archaeological picture of wine production dating back 6,100 years," said Gregory Areshian, co-director of the excavation and assistant director of the University of California Los Angeles's Cotsen Institute of Archaeology.

Analysis of the residue found on the vat confirmed the presence of a plant pigment only found in grapes and pomegranates.

"Because no remnants of pomegranates were found in the excavated area, we're confident that the vessels held something made with grape juice," Mr Areshian said.

He added that the vat -- a shallow, three-foot square basin surrounded by a thick rim -- resembles wine presses in use as recently as the 19th century throughout the Mediterranean and the Caucasus.

Read more at Discovery News

Cases dropped against malaria homeopaths

“Officials have dropped charges against pharmacies alleged to have advised people to take homeopathic remedies to protect them against malaria instead of anti-malarial drugs. The General Pharmaceutical Council’s decision has been described as “shabby and irresponsible” by some who helped bring the case against the pharmacies. Charges were bought after an undercover investigation by campaigning group Sense about Science and BBC Newsnight. Experts advocate anti-malaria drugs.

Speaking about the latest decision, Tracey Brown, director of Sense about Science said “we may as well have no regulation of pharmacists at all”. It comes days after the Royal Pharmaceutical Society said they were “shocked” that one of the pharmacies involved, Ainsworths in London, is still suggesting taking homoeopathic remedies to prevent serious diseases such as typhoid, polio and malaria instead of proven drugs and vaccinations.

“I am shocked that a regulatory body would ignore its responsibility to protect patients”
Dr Simon Singh
Science writer and broadcaster

The 2006 undercover investigation showed that homeopathic pharmacies were recommending sugar pills which include no active ingredients instead of drugs and vaccinations for travellers to countries where malaria is endemic. At the time the head of the Royal London Homeopathic Hospital Dr Peter Fisher told Newsnight “there is absolutely no reason to think that homeopathy works to prevent malaria… people may even die of malaria if they follow this advice”.”

Read more at BBC News

Statue Pieces of King Tut's Grandparents Found

Egyptian archaeologists have unearthed six missing pieces from a 3,400-year-old colossal double statue of King Tut's grandparents, the Supreme Council of Antiquities announced Sunday.

Belonging to the statues of King Amenhotep III and his wife Queen Tiye, the fragments were found at the pharaoh’s mortuary temple in Luxor during work to lower the ground water on the west bank of the Nile.

Currently a centerpiece of the main hall at the Egyptian Museum in Cairo, the double statue was unearthed in 1889 at Medinet Habu on the west bank of the Nile by French Egyptologist Auguste Mariette.

“When the statue was first discovered an Italian team restored it and filled in the missing pieces with modern stonework,” Dr. Zahi Hawass, Secretary General of Egypt’s Supreme Council of Antiquities, said in a statement.

Ranging from 47 cm (18.50 inches) to 103 cm (40.55 inches), the uncovered fragments belong to the right side of Amenhotep III's chest, crown and leg.

The other pieces come from a section of Queen Tiye’s wig and from her left arm, fingers and foot.

The ninth ruler of the 18th Dynasty, Amenhotep III (1390-1352 B.C.) reigned for 38 years during a time when Egypt was at the height of prosperity and cultural development.

His mummy was found in 1898 in a tomb dubbed KV35 by French Egyptologist Victor Loret. Buried in the same tomb was an unidentified mummy known as the Elder Lady.

Recent DNA test has identified the mummy as Amenhotep III's wife Tiye, the daughter of non royal couple Yuya and Thuya.

Amenhotep III’s funerary temple was the largest in ancient Egypt and was guarded by two (still standing) gigantic statues of the Pharaoh, known as the Colossi of Memnon.

Unfortunately, the temple was demolished during the Late Period, and its blocks were reused in the construction of other buildings.

Read more at Discovery News

Bacteria Work as Hard Drives

A group of students at Hong Kong's Chinese University are making strides towards storing such vast amounts of information in an unexpected home: the E. coli bacterium better known as a potential source of serious food poisoning.

"This means you will be able to keep large datasets for the long term in a box of bacteria in the refrigerator," said Aldrin Yim, a student instructor on the university's biostorage project, a 2010 gold medallist in the Massachusetts Institute of Technology prestigious iGEM competition.

Biostorage -- the art of storing and encrypting information in living organisms -- is a young field, having existed for about a decade.

In 2007, a team at Japan's Keio University said they had successfully encoded the equation that represents Einstein's theory of relativity, E=MC², in the DNA of a common soil bacterium.

They pointed out that because bacteria constantly reproduce, a group of the single-celled organisms could store a piece of information for thousands of years.

But the Hong Kong researchers have leaped beyond this early step, developing methods to store more complex data and starting to overcome practical problems which have lent weight to skeptics who see the method as science fiction.

The group has developed a method of compressing data, splitting it into chunks and distributing it between different bacterial cells, which helps to overcome limits on storage capacity. They are also able to "map" the DNA so information can be easily located.

This opens up the way to storing not only text, but images, music, and even video within cells.

As a storage method it is extremely compact -- because each cell is minuscule, the group says that one gram of bacteria could store the same amount of information as 450 2,000-gigabyte hard disks.

They have also developed a three-tier security fence to encode the data, which may come as welcome news to U.S. diplomats, who have seen their thoughts splashed over the Internet thanks to WikiLeaks.

"Bacteria can't be hacked," points out Allen Yu, another student instructor.

"All kinds of computers are vulnerable to electrical failures or data theft. But bacteria are immune from cyber attacks. You can safeguard the information."

The team have even coined a word for this field -- biocryptography -- and the encoding mechanism contains built-in checks to ensure that mutations in some bacterial cells do not corrupt the data as a whole.

Professor Chan Ting Fung, who supervised the student team, told AFP that practical work in the field -- fostered by MIT, who have helped develop standards enabling researchers to collaborate -- was in its early stages.

But he said: "What the students did was to try it out and make sure some of the fundamental principles are actually achievable."

The Hong Kong group's work may have a more immediate application.

The techniques they use -- removing DNA from bacterial cells, manipulating them using enzymes and returning them to a new cell -- are similar to those used to create genetically modified foods.

Read more at Discovery News

Mona Lisa landscape location mystery 'solved'

Carla Glori believes that a three-arched bridge which appears over the left shoulder of the woman with the enigmatic smile is a reference to Bobbio, a village which lies in rugged hill country south of Piacenza, in northern Italy.

Her theory is based on the recent discovery by another art historian, Silvano Vinceti, of the numbers 7 and 2 artfully concealed in the span of the stone bridge.

Miss Glori believes the numerals are a reference to 1472, the year in which a devastating flood destroyed Bobbio's bridge.

Historical records show that the bridge, known as the Ponte Gobbo or Ponte Vecchio (the Old Bridge), was swept away when the River Trebbia burst its banks that year.

"Leonardo added in the number 72 beneath the bridge to record the devastating flood of the River Trebbia and to allow it to be identified," said Miss Glori, who sets out the theory in a new book, The Leonardo Enigma.

Leonardo was born in the town of Vinci in Tuscany but travelled extensively in Italy during his lifetime and worked in Venice, Rome and Bologna.

The artist started painting the Mona Lisa in 1503 or 1504 in Florence, but did not finish it until years later, after he had moved to France to work under the patronage of King Francois I.

Most art historians believe the background, which features valleys and mountains, is an idealised, composite landscape drawn from the artist's imagination, but Miss Glori is convinced that it depicts a specific place.

Read more at The Telegraph

Astronomers shed light on the dark ages of the Universe

For years scientists have known nothing about the "dark ages" of space – a period between the Big Bang 13.7 billion years ago and the creation of the first stars.

But Cambridge University researchers have now captured light emitted from a massive black hole to peer into this unknown portion of the history of the universe.

They discovered remnants of the first stars and evidence of the aftermath of an exploding star, which was 25 times larger than the sun.

Prof Max Pettini, of Cambridge's Institute of Astronomy, believes the discovery of these gases could help reveal the origins of the universe.

He said: "We have effectively been able to peer into the Dark Ages using the light emitted from a quasar.

"The light provides a backdrop against which any gas cloud in its path can be measured.

"We discovered tiny amounts of elements present in the cloud in proportions that are very different from their relative proportions in normal stars today.

"Most significantly, the ratio of carbon to iron is 35 times greater than measured in the sun.

"The composition enables us to infer that the gas was released by a star 25 times more massive than the sun and originally consisting of only hydrogen and helium.

"In effect, this is a fossil record that provides us with a missing link back to the early universe."

Cambridge's Institute of Astronomy teamed up with researchers at California Institute of Technology to carry out the groundbreaking research.

They used light emitted from a massive black hole, called a quasar, to 'light up' gases released by the young stars.

Read more at The Telegraph