BBC BLOGS - Today: Tom Feilden

Archives for November 2010

Scientists capture antimatter

Tom Feilden | 09:44 UK time, Thursday, 18 November 2010

Antimatter trap at Cern

It's a staple of science fiction: the energy source that powers the Starship Enterprise, and the explosive charge fuelling a dastardly plot to blow up the vatican in Dan Brown's Angels and Demons.

But now antimatter has moved from the realm of science fiction - or more accurately science theory - to science fact. Researchers working on the Alpha experiment at Cern have succeeded in trapping 38 atoms of anti-hydrogen for one sixth of a second.

That may not sound like much of an achievement, but the problem with antimatter is that as soon as it comes into contact with ordinary matter they annihilate each other instantly. Studying such an elusive substance in a laboratory where everything is inevitably made of matter presents a unique challenge.

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The researchers at the Alpha experiment have got round this problem by trapping antimatter particles in a series of overlapping magnetic fields. For a brief moment the particles are held in suspended animation.

"Capturing anti-hydrogen is a major breakthrough in antimatter physics" claims Swansea University's Dr Niels Madsen, a co-author on the research paper published in the journal Nature. "Having the anti-atoms trapped will allow for comparisons of matter and antimatter to a level that, until now, would have been considered wishful thinking".



The equipment for the Cern antimatter experiment


The existence of antimatter was first suggested by the theoretical physicist Paul Dirac in the 1930's.

Working on a theory to combine quantum mechanics with Einstein's special relativity he realised his equations predicted a corresponding antiparticle for every particle in existence - identical in every respect, but with an opposite electrical charge.

It's important because scientists studying the origins of the universe believe that almost equal amounts of matter and antimatter were created in the big bang. The vast majority of these particles were instantly annihilated as matter and antimatter came into contact. The slight discrepancy in favour of matter accounts for all the stuff we see today - every atom in every star, galaxy, planet or cup of coffee in existence.

The problem is that scientists can't explain this discrepancy - exactly why there is any stuff at all left over to make up the universe.

Studying antimatter in the laboratory could shed new light on the problem, and help to explain the fundamental laws of physics. Warp speed ahead.

Black holes, carnivorous plants, smoking and... frogs

Tom Feilden | 10:16 UK time, Tuesday, 16 November 2010

It's one of those days. A lot seems to be going on and there's not enough space to fit it all on the programme. So for those of you interested in black holes, smoking, the discovery of new species and the latest developments in stem cell research....read on.

Smoking

One thing that did make it is a study of women who smoked heavily during pregnancy in the 1960's. It shows that their children were more likely to have become repeat criminal offenders as adults.

The findings, published in the Journal of Epidemiology and Community Health, held true even after a comprehensive range of social factors, like mental ill-health and deprivation, were taken into account.

The study drew on data supplied by mothers who had taken part in one of the biggest and longest running surveys designed to track the ongoing impact of a wide range of behaviours during pregnancy - the Collaborative Perinatal Project.

The team, lead by Dr Angela Paradis at the Harvard School of Public Health, ran criminal records checks on nearly 4000 individuals whose mothers had been enrolled in the project between 1959 and 1966 and who smoked more than 20 cigarettes a day during pregnancy.

"While not definitive", Dr Paradis concludes "the findings do support a modest causal relationship between smoking during pregnancy and adult criminal offending".

While all that was going on in Massachusetts, doctors in Glasgow have broken new ground by injecting stem cells into the brain of a stroke patient. The PISCES study - Pilot Investigation of Stem Cells in Stroke - is the world's first fully regulated clinical trial of a neural stem cell therapy.

According to professor Keith Muir, principle Investigator for the study, the patient underwent a successful surgical procedure at Glasgow's Southern General Hospital and has now been discharged.

"We hope that, in future, it will lead on to larger studies to determine the effects of stem cells on the disabilities that result from stroke".

The patient will be monitored closely for the next two years as part of a phase 1 clinical trial to assess the safety of the procedure.

Nasa picture of newly discovered black hole

Meanwhile astronomers monitoring the constellation Virgo say they've witnessed the birth of a black hole for the first time.

Originally spotted by an amateur astronomer in 1979, researchers have used NASA's Chandra X-Ray Observatory to study the object - believed to be the remnant of a supernova in the galaxy M100 some 50 million light years from earth.

NASA astrophysicist Kimberly Weaver says the black hole formed when a star 20 times more massive than the sun collapsed at the end of its life.

"What's really exciting about it is that we know the exact birth date of this black hole. Now we want to watch how this system evolves and changes because that's how we will understand the physics of black hole systems".

Back on terra firma researchers at Conservation International have identified three new species of frog in western Colombia.


Newly discovered species of frog

The expedition, lead by CI's amphibian specialist Dr Robin Moore, was actually on a quest to rediscover the Mesopotamia beaked toad, which hasn't been seen since the outbreak of the first world war and is listed as Critically Endangered on the IUCN Red List of Threatened Species.

Despite an intensive search extending from the cold, high cloud-forests to the tropical lowland rainforests of Colombia's Chocó and Antioquia departments, no trace of the elusive toad could be found.

Instead researchers returned having documented the discovery of three species new to science.

"After spending several days searching for the Mesopotamia beaked toad with no success, the team's spirits were pretty low" says Moore. "But finding these new species, including a new beaked toad, was like a shot of adrenaline. We definitely left on a high."

Newly discovered pitcher plant Nepenthesholdenii Cardamom

The penchant for describing new species isn't limited to South America. Scientists at Flora and Fauna International have announced the discovery of a new species of carnivorous pitcher plant, Nepenthes Holdenii, in Cambodia's remote Cardamom Mountains.

The large red and green pitchers are actually modified leaves designed to capture and digest insects. Photographer Jeremy Holden, who first found the plant and after whom it is named, says "The Cardamom mountains are a treasure chest of new species, but it was a surprise to find something as exciting and charismatic as an unknown pitcher plant".

But it isn't all good news for scientists set on discovering new species in obscure, unsurveyed regions of the planet. The Natural History Museum has suspended a planned expedition to Paraguay after protests that it might disturb one of the world's last uncontacted tribes.

As we featured on the programme last week anthropologists have warned that the expedition, to the remote Chaco region, was likely to make accidental contact with the Ayoreo people, putting them at risk of infectious diseases.

The 'golden age' of Arabic science

Tom Feilden | 08:22 UK time, Saturday, 13 November 2010

Arabic astrolabe

A brief thumb-nail sketch of the history of science typically begins in antiquity - with the likes of Pythagoras, Euclid and Plato - before leaping the best part of a thousand years to Kepler, Galileo and the European Renaissance of the 16th century.

What went in between is often dismissed as the Dark Ages - a period in which Europe, and scientific progress, slumbered.

But this, admittedly western, model overlooks the importance of a huge blossoming of science and scholarship in the Islamic world of the middle ages. A period in which the Ummayyad and Abbasid Caliphs created one of the greatest centres of learning the world had ever known - the Bayt al-Hikma, or House of Wisdom.

"Just because Europe was stuck in the Dark Ages," argues Jim Al-Khalili the professor of physics at the University of Surrey and author of Pathfinders: The Golden Age of Arabic Science, "we shouldn't assume that the rest of the world had stagnated. There was this great flourishing of scholarship and discovery in the Islamic world of the middle ages".

Great advances were made across a range of fields between the 9th and 13th centuries, from mathematics and astronomy to medicine and chemistry. The proof lies in the words we still use today: words like algebra, alchemy and alkaline; and in the names of stars like Dubhe, Megrez, Alioth, Mizar and Alkaid - five of the seven stars that make up one of the most familiar constellations in the night sky, the plough, or Ursa Major.

Among the many great thinkers of the period al-Hassan Ibn al-Haytham stands out as the father of the modern scientific method. Long before Francis Bacon and Rene Descartes al-Haytham was scrupulously gathering data and testing his ideas through meticulous observation and experiment.

According to Jim Al-Khalili, al-Haytham's work on the defraction of light puts him on a par with Galileo and Newton.

"We learn at school that Isaac Newton was the father of optics, using prisms to split light into its constituent colours. But al-Haytham also wrote extensively on light and optics and the Latin translations of his work were hugely influential in the European Renaissance."

Not all Al'Khalili's heroes were Arabs: Persians, Christians and Jews all played their part in this golden age.


al-Khwarizmi

One of the greatest mathematicians of the medieval world was al-Khwarizmi, a Persian credited with inventing algebra. Even the word "algebra" comes from the title of his great work, Kitab al-jebr, and the Latin translation of his name, Algorithmus, gives us algorithm.

Ultimately civilisations ebb and flow and the 'baton of enlightenment', as Al-Khalili describes it, ultimately passed to Europe. So much so that today, he says, science is widely regarded with suspicion in the Islamic world: a western, secular, even atheist construct.

But all that may be about to change: In Saudi Arabia a £20 billion pound endowment aims to turn the King Abdullah University of Science and Technology into a powerhouse to rival anything the West has to offer. Qatar is committed to invest 2.8 percent of its GDP on research, and Abu Dhabi is planning to raise the world's first fully sustainable city and innovation hub from the desert sands.

It's a modern, Arabic renaissance, that Jim Al-Khalili hopes will benefit us all.

"Look where the Muslim world was a thousand years ago. It was the centre of the civilised world. There's a long way to go, but the signs are that things are moving impressively rapidly in the right direction".

TWO GALAXIES FOR THE PRICE OF ONE

Tom Feilden | 18:00 UK time, Thursday, 4 November 2010

Two galaxies show the effect of gravitational lensing

Any child can tell you that light travels in straight lines, but it takes a genius like Albert Einstein to appreciate that (with apologies to George and Ira Gershwin) it ain't necessarily so.

Einstein's theory of General Relativity showed that gravity can bend light - a phenomenon known as gravitational lensing, and one which was spectacularly confirmed by a team lead by Sir Arthur Eddington in 1919.

The effect is normally extremely small, and it is only when light passes close to a very massive object, such as a galaxy containing hundreds of billions of stars, that it can be spotted.

Take a close look at the two images above. The first, taken by ESA's Herschel Space Observatory, shows an unusually bright orange blob located in the constellation Hydra.

The second, taken at higher resolution from the ground-based Keck Telescope and the Smithsonian Astrophysical Observatory's Submilimetre Array in Hawaii, shows that Herschel has found a gravitational lens.

The reason why this blob is so bright is that we are actually seeing two galaxies, with the red light from the more distant one bent around and superimposed over the light emanating from the nearer, blue, galaxy.

If light really did travel in straight lines we might expect the much longer wavelength light from the background galaxy to be "blotted out" by the stronger signal from the closer one. Instead this longer wavelength light has been magnified and distorted by gravitational lensing.

The overall effect is to increase the brightness, making the orange blob appear considerably closer to earth than it really is.

The images, published in the journal Science, are the first to come from the Herschel-ATLAS project - the largest imaging survey at sub-milimetre wavelengths conducted so far with ESA's Herschel Observatory.

The lead author, Dr Mattia Negrello from the Open University, says the findings will help to pinpoint many more examples of this rare phenomena.

"The big breakthrough is that we have discovered many of the brightest sources are being magnified by lenses," he explains.

"Which means we no longer have to rely on the rather inefficient methods at visible and radio wavelengths to find them."

How gravitational lensing works

How gravitational lensing works

The magnification created by the effect of gravitational lensing allows astronomers to see galaxies that would otherwise be hidden, providing key insights into the history of the cosmos and bringing us a step closer to understanding the complex birth of stars and galaxies.

According to Professor Rob Ivison from the Royal Observatory, Edinburgh, the technique promises to unlock the secrets of how galaxies form and evolve.

"Not only does the lensing allow us to find them very efficiently, but it helps us to peer within them to figure out how the individual pieces of the jigsaw came together back in the mists of time."

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