Do you like fridge magnets? A new technology being developed by British scientists could put an even bigger one inside your refrigerator. Once Karl Sandeman, a physicist at Cambridge University, has helped resolve the practical issues, the cooling power of the 21st century fridge will come from a 19th century discovery - and it promises to cut energy consumption by 40% and save the ozone layer.

The key is a material that cools when it is put in a magnetic field. The idea - which is ambitious, but feasible - is to replace the present system used by refrigerators the world over. Your kitchen fridge has a compressor, which turns a gas into a liquid, releasing heat (which you'll feel at the back of the fridge). The liquid is then pumped round the inside walls of the fridge, where it draws heat from the contents; that turns it into a gas, which is pumped on to the compressor.

But what if you could replace the fluid with a magnet? "The amazing thing about magnetism is that it's actually a quantum mechanical phenomenon," says Sandeman. "It's all down to something mysterious called spin. The electrons act almost like a miniature bar magnet."

Temperature change

As a quantum mechanical property of the electron, spin is usually taken to mean its rotational momentum (like the Earth rotating around its axis). That momentum - described as "up" or "down" - creates a tiny magnetic field. When all the electrons in a material spin in the same way, their fields combine to create what we perceive as magnetism. However, an iron magnet heated to 700C will "disorder" and lose its powers, known as a magnetic phase transition.

In 1881, the German physicist Emil Warburg put a block of iron into a strong magnetic field and found it increased very slightly in temperature. Scientists now know the electrons pivot in the field to align at a lower energy state, releasing surplus energy. The metal warms up in what's known as the magnetocaloric effect, which is greatest near the magnetic phase transition temperature.

"If you can suddenly alter the degree of ordering of all these little spins, then you get a large response," says Sandeman. For iron at room temperature, the response is just 0.1C. Some materials cool in a magnetic field, a property that's used in low temperature research. Finding the right room temperature material is the key to a magnetic fridge, where the cooling power is derived from a positive magnetocaloric effect coupled to heat exchange.

One material works nicely: the element gadolinium (Gd). It's a silvery-white metal that's strongly attracted by a magnet, has a magnetic disordering temperature of 20C, and a giant magnetocaloric effect of several degrees. A waste product from permanent magnet manufacture, gadolinium costs around £100 per kg; a magnetic fridge would use 0.15kg. Sandeman's current research, however, is looking at other possibilities.

"The quest is to get away from these expensive rare earth materials and look for magnetic materials which have a phase transition at room temperature," says Sandeman, whose research job at Cambridge University is funded by the Royal Society. He also works with Professor Derek Fray, a leading expert in materials chemistry. "What I'm actually working with is an alloy of two magnetic materials, cobalt and manganese," says Sandeman.

When these elements are mixed with non-magnetic "spacers" like silicon, the cost falls to £5 per kg. Strangely, his latest experimental alloy has a negative magnetocaloric effect - it cools in a magnetic field. This could also be harnessed for fridges through a heat exchange process.

A Cambridge University spin-out company, Camfridge Ltd, has built two prototype magnetic fridges that use gadolinium. While the latest one is little more than fridge innards, the team - which includes Sandeman as chief scientific officer, Fray and experienced business people - is striving to develop the revolutionary effect for commercial exploitation in fridges and, perhaps, air conditioning.

"It's a sea change in thinking," says Sandeman. "It never ceases to amaze me how you can take a block of this stuff and stick it into a [magnetic] field. The prototype is operational and has achieved a large temperature span."

A magnetic fridge works like this. Powdered gadolinium (with coarse grains for good heat transfer qualities) is put into a magnetic field. It heats up as the randomly ordered magnetic moments - the electrons with spin - are aligned, or "ordered", by the field. The newly-acquired heat - a boost of between 2-5C, depending on the gadolinium's original temperature - is removed by a circulating fluid, like a conventional fridge.

The magnetic field is removed and the gadolinium cools below its starting temperature as the electrons resume their previously disordered state. Heat from the system to be cooled - your fridge interior - can then be transferred to the now cooler metal. Then all you do is endlessly repeat. But unlike conventional fridges, which need very toxic chemicals, the only liquid needed for heat transfer is water, alcohol or, more likely, antifreeze.

Cutting energy use

A more advanced prototype next year will optimally bring together three elements - temperature span, cooling power and efficiency - along with a faster motor. This will allow less gadolinium to be used with a smaller magnet, saving materials costs. Camfridge's managing director, Neil Wilson, says: "In terms of technical specification, that prototype will get us to a domestic fridge. Commercial manufacturers have hit the wall; there is not much more they can do. We're wanting to cut the energy use by half."

Professor Stephen Blundell, of Oxford University, also understands the issues well, as he's written a textbook on magnetism and researches magnetic properties in materials. Magnetocaloric effects are becoming more practical, he thinks, thanks to improved magnet technology and new materials. A magnetic fridge would be compact, less noisy and won't need harmful gases.

"I think this technology has real potential, but it is still at the early stages. The claims of 40% efficiency savings seem a little speculative, though not completely unreasonable," says Blundell.

Some 15% of UK energy is used in refrigeration and cooling for air conditioning, and much more in warmer countries. Garry Staunton, head of low carbon research at the Carbon Trust, which is financially supporting the magnetic fridge's development along with Cambridge University and other investors, says that 22m tonnes of UK carbon dioxide emissions annually are due to refrigeration and air conditioning. Efficiency improvements to domestic fridges since 1990 have seen a 27% reduction in their energy use.

Increasing energy efficiency with new technology is the key to stabilising and reducing carbon emissions. Consumers seem willing to support and demand new energy-efficient appliances in their homes, while everyone has felt the sharply rising cost of electricity. As the fridge magnet moves inside the fridge, it may become the exciting new green technology of the 21st century.

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The Ballocillos were on their way to Nestor's office in Makati City last December 6 when two armed men shot them at close range.

The Parañaque police and the National Bureau of Investigation said earlier the killing could be work-related.

At a press conference Thursday, Rosales said a colleague from Camp Crame had introduced him to a psychic, whose name was withheld for security purposes.

The psychic volunteered to help solve the case, asking the police director for basic details.

"I was asked to give the name and birthdays of the victims," Rosales said.

He accepted the offer after having seen on television how the Federal Bureau of Investigation in the United States was assisted by psychics and clairvoyants in crime detection and investigation, he added.

Foreign intelligence and police agencies have started to tap people with psychic capabilities for help in resolving puzzling crimes.

Rosales said the psychic had already provided names that could help identify the gunman and his location.

He said the information would be compared to results of the investigation conducted so far through conventional means.

"The psychic's findings would just help provide the leads. We will still rely on the scientific findings. But it would be helpful if the psychic's information corroborate our investigation," he said.

Meanwhile, Parañaque City police chief Superintendent Ronald Estilles said they were working double time to capture the killers.

Estilles told the Inquirer Thursday that five witnesses were ready to identify the suspects.

The scientists broadened their investigation to three families related to the child and found that none had experienced pain at any time in their lives. All six family members had bruises and cuts and most had fractured bones. Two were missing the front third of their tongues after biting themselves in childhood.

The way in which the young street performer died also highlighted the importance of pain as a built-in defence mechanism to stop people damaging themselves.

Detailed neurological tests on the families, all of whom originated in northern Pakistan, revealed they responded normally to touch, temperature, tickling and pressure and had no signs of nerve disease. An explanation for the rare condition only became apparent when a team of scientists led by Geoff Woods, a medical geneticist at Cambridge, conducted extensive genetic tests that revealed they all carried an extremely unusual mutation in a single gene.

The defect, in a gene called SCN9A, disrupts the flow of sodium ions in specific nerve fibres that sense damage. The results of the research are published on Thursday in the journal Nature.

John Wood, a neurobiologist at University College London and co-author of the study, said: "The mutation means that the very first stage of that electrical signal is lost, so the pain signal doesn't reach the brain." Scientists have previously written about people who do not feel pain, but in all other cases they suffered other medical problems because of the damage to their nerves.

Woods, from the University of Cambridge institute for medical research, said: "This paper shows that rare diseases can still be of great importance because of the insights they give into biological and developmental processes."

The researchers included a number of investigators from Pakistan and other United Kingdom institutions. The work, which was carried out with the drug company Pfizer, paves the way for a new approach to managing pain, the scientists believe.

They hope drugs that block the same biological pathway affected by the mutation will yield new and potentially safer pain medications.

"This gives us an excellent target to develop painkillers, because we know that if we can block this sodium channel, you will lose the perception of pain, but it will not affect you in any other way," said Wood.

"Potentially this is as important as the identification of the morphine receptors. It is fascinating that this same gene, when mutated to encode a hyperactive channel, has also been found to contribute to ongoing pain in some heritable human disorders."

-- Guardian Unlimited © Guardian News and Media Limited 2006

The stories are perplexing as they are scary with strange things happening inside the cave.

People have strayed and lost direction in the cave only for them to be found hours later unable to explain how they lost their way.

"So many strange things happen here even though people do not seem to believe them," says Paul Ndung'u.

The locals have named the place "kirima kia ngoma" (Devil's place) as they claim it is under the control of evil spirits.

No one knows how the crater came to be called Menengai but the locals say the name is a Maasai word meaning a place of corpses.

"It is believed the name means the place of the dead in the Maasai because many of them died here in the 19th century when they fought among themselves," says Daniel Kanyingi.

Woman slipped and fell into the crater

He said that it is alleged that one of the battles took place at the crater and morans, from one of the warring clans were thrown in the calderas.

The second meaning, "devils residence" relates to a story that mysterious people once lived in the crater.

"The sound of the crater sometimes gives the impression of cow bells. And because of the hot spots in the crater, they said the inhabitants must be devils because animals cannot kindle fire," adds Ndung'u.

Recently, a woman slipped and fell into the crater as she tried to rescue her son.

Magdalene Waithera was in a group that had gone to rescue her son, 12, who had been trapped in the ravine.

Mr Johnstone Kamau, a witness, said the woman was trying to look into the crater after she called her son and he responded.

"When she heard him respond, she moved forward and attempted to look inside, but she slipped and fell," he said.

The child was, however, rescued later alive by the police.

Last year, a man who had gone to graze his animals in the crater failed to find his way out despite knowing the area for a long time.

Peace and tranquility inside the crater

John Kirutu, 12, is rescued days after he plunged into the crater while playing with friends.

A search was mounted and two days later, he was found wandering deep into the crater.

Kanyingi says a young boy also went missing in the crater and was found after seven days in the crater staring at birds but he was in good health.

"Some do not find their way for days but when they are found they do not show signs of fatigue or hunger," he says.

He says that the boy told the search party that he had been watching a beautiful vision without realising the passage of time.

Despite the dreadful tales, peace and tranquility inside the crater provides Christians visiting the area a conducive environment to pray and fast. But there are claims that some of them have committed suicide, like the two catholic priests who jump to their deaths into the dormant volcano.

Ndung'u says the incident happened in November last year, when a catholic priest plunged his vehicle into the 900-metre crater.

"He drove straight to the view point without breaking and in a matter of seconds what remained was a mangled wreck of the twisted metal and his lifeless body," he says.

Tales of ghosts

But pilgrims still flock the site to pray. Recently, The Standard met Mr Paul Walingo from Kakamega, who has spent almost two weeks in the cave praying and fasting.

He says the place is perfect to drown life's hostilities and get in touch with one's inner soul.

Relatives and friends could not hold their tears back after they received information of the death of Magdaline Waithera, who died while attempting to save her son. Pictures by Lucas Thuo

"I feel very close to God whenever I come to pray here. It is a perfect place to reflect on one's life," he says.

He dismisses the tales of ghosts as rich imaginations.

"I usually pray till late in the evening and have never seen what the locals are talking about," he says.

But Mr Simon Kamenju, 69, says the existence of demons is real. He says during the planting season, they plough the land towards the southern end of the crater and plant wheat and maize, which are soon harvested by the ghosts.

"Things happen so fast. You will see some crops, people harvesting and before long, the flurry of activities are over and the land would revert back to its former state of grassland and the people would also disappear," he says.

Kamenju recalls that in the 1960s, ghosts used to practice agriculture on the floor of the crater in large scale.

"What we are seeing is small scale farming by the ghosts who reside in the floor of the crater unlike 40 years ago," he alleges.

Flying umbrella

He says these ghosts are responsible for capturing human beings and hiding them in the underworld.

However, the spirits capture only those who attempt to destroy the fauna in the crater.

"Some of those who wander, do so after harvesting firewood inside the cave. But as soon as they drop the firewood, they find their way back," he says.

Although the volcano is dormant, residents say that the crater has some hot spots where steam jets fill it with vapour at times.

The latest mystery about the crater is a "flying umbrella" that appears whenever it rains. But no one knows where the umbrella goes after the rains.

"When it rains, there is a huge formation of what looks like an umbrella that seem to shield the crater from the rain but disappears as soon as the rain subsides," says Kamenju.

As the site puzzles the visitors, residents fear for their children. The cliff is not fenced off and hence poses danger to children playing around the area.

"We fear for our children's safety, especially when there is no one to watch over them," says Mrs Sarah Maina.

An advocacy group "Campaign to Defend the Constitution" -- which monitors right-wing religious activities -- says the game is violently pro-Christian and has petitioned retail giant Wal-Mart Stores Inc. to pull it from its shelves.

The critics describe it as "a violent video game in which born-again Christians aim to convert or kill those who don't adhere to their extreme ideology."

"After you kill somebody you need to recharge your soul points and to do that you need to bend down in prayer. ... I think the message is extremely clear," said Clark Stevens, co-director of Campaign to Defend the Constitution.

A Wal-Mart spokeswoman said the company was selling it in stores where it expected demand.

The game's maker dismissed criticism.

"The reality is that our game perpetuates prayer and worship and that there is no killing in the name of God.

"There is killing of course, it is a video game. But the basis of the game is spiritual welfare," said Troy Lyndon, CEO of Left Behind Games Inc.

"The antichrist is the main bad guy and so you are dealing with his henchmen. Both sides are trying to win the hearts and the minds of people who are not on either side," Lyndon, who describes himself as a "follower of Christ," told Reuters.

He added that sales of the game have been brisk. It was launched in stores last month.

America has some 60 million evangelical Christians by some estimates and church attendance rates are much higher here than in other parts of the developed world -- so there is a huge market for consumer goods with Christian themes.

This also means America's "culture wars" often have religious undertones.

Many mainstream Christians and secular groups accuse some conservative evangelicals of displaying intolerance toward other faiths and beliefs -- in this case through video games.

"We are trying to tell families that this game is faith-based violence and is not suitable for families," said Rev. Timothy F. Simpson, a Presbyterian minister and the interim president of the Christian Alliance for Progress.