Science and nature blog

New hope for endangered bald ibis

2009-05-07T08:23:00.001-07:00

New hope for endangered bald ibis

Bald ibis cling to survival in the Middle East and Africa

Two young adult bald ibis spotted in Syria could be mean new hope for the critically endangered species, Scottish-based conservationists report.

The bird, which was revered by the Egyptian Pharaohs, clings to survival in the Middle East and Africa.

RSPB staff picked up a report of two birds that did not have identification rings during a visit to Syria to study rare migratory species.

This would suggest the pair were previously unknown to conservationists.

Martin Scott, who works on the Western Isles and is one of four RSPB officers on the trip, said in an internet blog that it could also indicate there was an as yet undiscovered location where the bald ibis was surviving.

Hunters, poisonings and starvation have been blamed for the species' decline.

The RSPB officers were able to watch two tagged birds, nicknamed Sultan and Zenobia, on a reserve.

They have also observed sociable lapwings - another endangered bird - during their visit.

Giant laser experiment powers up

2009-05-06T19:08:00.001-07:00

Giant laser experiment powers up

NIF is a step on what is still a very long road to fusion reality

The US has finished constructing a huge physics experiment aimed at recreating conditions at the heart of our Sun.

The US National Ignition Facility is designed to demonstrate the feasibility of nuclear fusion, a process that could offer abundant clean energy.

The lab will kick-start the reaction by focusing 192 giant laser beams on a tiny pellet of hydrogen fuel.

To work, it must show that more energy can be extracted from the process than is required to initiate it.

Professor Mike Dunne, who leads a European venture that is also pursuing nuclear fusion with lasers, told BBC News that if NIF was successful, it would be a "seismic event".

"It would mark the transition for laser fusion from 'physics' to 'engineering reality'," he said.

The world is looking to NIF to provide a clear, unequivocal demonstration that lasers can initiate fusion energy gain

Prof Mike Dunne
European Hiper project

The California-based NIF is the largest experimental science facility in the US and contains the world's most powerful laser. It has taken 12 years to build.

"This is a major milestone," said Dr Ed Moses, director of the facility.

"We are well on our way to achieving what we set out to do - controlled, sustained nuclear fusion and energy gain for the first time ever in a laboratory setting."

'Building blocks'

Experiments will begin in June 2009, with the first significant results expected between 2010 and 2012.

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A pea-sized spherical capsule is filled with fusion fuel

This comprises a 150-microgram mix of deuterium and tritium

The NIF laser set-up pulses for 20 billionths of a second

For that time, it generates about 500 trillion watts

That's equivalent to five million million 100-watt light bulbs

All the laser power is focused on to the capsule's surface

The fuel is compressed to a density 100 times that of lead

It is heated to more than 100 million degrees Celsius

Under these extreme conditions, fusion is initiated

"We have an incredible amount to do and an incredible amount to learn," added Dr Moses.

Fusion is looked on as the "holy grail" of energy sources because of its potential to supply almost limitless clean energy.

But the challenge of creating a practical fusion reactor has eluded scientists for decades. Now, however, they believe they are nearing their goal.

"We are now very close to the culmination of 50 years' effort," explained Professor Dunne.

There are currently several experimental facilities around the world aimed at demonstrating the building blocks of nuclear fusion.

In this process, two heavier forms of hydrogen, known as deuterium and tritium, are fused together to form helium.

Deuterium is commonly found in seawater, whilst tritium can be prepared from lithium, a relatively common element found in soil.

When these isotopes are combined at high temperatures, a small amount of mass is lost and a colossal amount of energy is released.

Energy gain

Fusion naturally occurs at the centre of stars where huge gravitational pressure allows the process to happen at temperatures of about 10 million Celsius.

At the much lower pressures on Earth, temperatures to produce fusion need to be much higher - above 100 million Celsius.

NIF will focus on a process known as inertially confined fusion, in which these extreme temperatures are achieved using ultra powerful lasers.

"When all NIF lasers are fired at full energy, they will deliver 1.8 megajoules of ultraviolet energy to the target," explained Dr Moses.

The laser power will be focused on to a tiny pellet inside a small cylinder

NIF's beams are intended to deliver more than 60 times the energy of any previous laser system. When fired, the pulse will last just a few nanoseconds (billionths of a second) but it will impart an energy equivalent to 500 trillion Watts - more than the peak electrical generating power of the entire United States.

This intense energy will be focused on a ball-bearing-sized pellet of fuel, ablating the surface and compressing the remaining material inwards.

"This process will create temperatures of 100 million degrees and pressures billions of times greater than Earth's atmospheric pressure, forcing the hydrogen nuclei to fuse and release many times more energy than the laser energy required to spark the reaction," said Dr Moses.

This "energy gain", as it is known, is key. If it works, NIF will release 10 to 100 times more energy than the amount pumped into the lasers to kick-start the reaction.

Other experiments have shown that ignition is possible, but so far none have been able to demonstrate a net energy gain.

"The world is looking to NIF to provide a clear, unequivocal demonstration that lasers can initiate fusion energy gain," said Professor Dunne.

"This would lay the fundamental physics question to rest, allowing the community to focus on harnessing this energy."

Twin track

Although NIF is only at the beginning of its experimental life, scientists are already planning its successor, a European project known as Hiper (High Power Laser Energy Research).

"The technology of NIF allows the laser to fire every few hours," explained Professor Dunne, director of Hiper.

"This is right for the demonstration of the physics 'proof of principle', but does not meet the requirement of a laser fusion power plant, which needs to operate a few times per second."

Hiper aims to lay the foundations of this continuous fusion cycle by showing it can ignite a steady stream of fuel pellets.

Inside one of NIF's two laser bays

"This means a fundamentally different laser technology, a new approach to fuel pellet production, and a suite for robotic handling capability," said Professor Dunne.

In October 2008, Hiper received approximately 13m euros of funding to carry out a feasibility study. It also has access to European hardware and capability worth a further 50m euros.

If all goes well, engineers will begin to build the Hiper facility towards the end of the next decade, bringing the vision of a commercial fusion reactor one step closer to reality.

At approximately the same time, scientist will also get their hands on another mammoth fusion experiment, the International Thermonuclear Experimental Reactor (Iter), currently being built in Cadarache, France.

Iter will attempt to initiate fusion using a different method, known as magnetic confinement, in which a super-heated volume of gas is constrained by magnetic fields in a doughnut-shaped vessel known as a tokamak.

"We are entering a period when much of the technology development is common to both approaches," said Professor Dunne.

"We believe that the two-track approach is essential given the scale of the problem, and the predicted impact on society."

Evolution study focuses on snail

2009-05-06T12:12:00.001-07:00

Evolution study focuses on snail

By Sarah Mukherjee Environment correspondent, BBC News

The banded snail has been studied for at least 60 years

Members of the public across Europe are being asked to look in their gardens or local green spaces for banded snails as part of a UK-led evolutionary study.

The Open University says its Evolution MegaLab will be one of the largest evolutionary studies ever undertaken.

Scientists believe the research could show how the creatures have evolved in the past 40 years to reflect changes in temperature and their predators.

The six-month study, starting in April, will ask people to submit data online.

'Ideal organism'

Professor Jonathan Silvertown, from the OU, said: "I was thinking about Darwin year and how we could help people get an idea of what Darwin was talking about.

"The banded snail has been studied for 60 or more years, so it's an ideal organism to use. It's something that's very common, we know what the genetics are and it's safe to handle."

Professor Silvertown said there were two main evolutionary drivers that affect where yellow and brown banded snails are found.

The first is climate - darker-shelled snails tend to be further north, and scientists believe this is because dark shells get warmer quicker than lighter ones.

Darker-shelled snails could also be active for longer - which would make a difference to how much they could eat and how many offspring they could have.

The second evolutionary driver is predation by thrushes.

The birds hunt by sight and they find it more difficult to find yellow-striped shells around grass and brown shells against brown leaves - so yellow-shelled snails have been more common in grassland and darker ones in areas with brownish background environments.

'Genuine study'

"We think [the snails] have changed in the last 40 or 50 years," said Professor Silvertown.

"Firstly, the climate has warmed up, so we think the distribution of colours has probably changed.

"Secondly, thrushes have become far less common in the last 30 years or so - so snail colouring in different habitats might be less important."

This is what the Evolution MegaLab, which will run from April to October, will be trying to discover.

"There's a lot of historical data on the website," said Professor Silvertown.

"We have data from the past on 8,000 or so snail populations, so if you submit your data on the website, it will automatically make a comparison telling you whether there's been any change in your area."

Professor Silvertown said this was a genuine scientific study and not just a public relations exercise.

It has been funded in part by the Royal Society and the British Council, and he and his team are hoping that a major report will be published on the data collected at the beginning of next year.

He also points out that this could be an invaluable tool for researchers of the future who will be able to look at this project and compare any further evolutionary changes.

'War' on poisonous Australia toad

2009-05-06T08:29:00.001-07:00

'War' on poisonous Australia toad

Cane toads are only harmful to humans if their poison is swallowed

People in the Australian state of Queensland have taken part in a mass capture of poisonous cane toads as part of a collective effort at pest control.

The celebratory cull is known as Toad Day Out and was advocated by a Queensland politician, Shane Knuth.

The toads have to be captured alive and unharmed, examined by experts, and then killed humanely under the event rules.

Cane toads were introduced to Australia from South America in 1935 to eat beetles, but became a pest themselves.

"This is an example of how the war against cane toads can be won," said Mr Knuth, who hopes to take Toad Day Out nationwide.

Critics of the toads blame them for the deaths of crocodiles that may have feasted on them, inadvertently poisoning themselves.

Children also took part in collecting the creatures. "I've got no clue how many we've got but they're all fat!" said one boy involved in the hunt for the toads.

The majority of toads will be turned into fertiliser or donated to the science department of James Cook University.

But a few of the largest ones will be stuffed by a local Queensland taxidermist.

Nasa's Discovery returns to Earth

2009-05-05T10:33:00.001-07:00

Nasa's Discovery returns to Earth

The shuttle took new solar panels to the International Space Station

Nasa's space shuttle Discovery has landed after a 13-day mission to the International Space Station.

The shuttle touched down at Kennedy Space Center in Florida, hours after its return was postponed because of concerns about poor weather conditions.

Discovery's seven crew members installed an extra pair of solar wings on the International Space Station.

The shuttle launched on 15 March, docking with the ISS to deliver the final set of solar arrays.

Sandra Magnus - who had been stationed at the ISS for four months - returned to earth on Discovery.

Meanwhile, a Russian space capsule with an American billionaire passenger on board has docked with the ISS.

The passenger, Charles Simonyi, is a software designer and is making his second trip as a space tourist.

He was accompanied by Russian and American astronauts.

Retirement

The shuttle undocked from the ISS on Wednesday after eight days there.

The crew spent five hours on Thursday inspecting the shuttle's outer surface using a laser and camera mounted on a 15m (50ft) boom connected to Discovery's robotic arm.

The shuttle, as seen from the ISS, includes a novel heat-shield tile

The images were then sent back to Mission Control as part of a routine procedure that ensures the integrity of the shuttle's heat-shield tiles.

The tiles are designed to dissipate heat as the orbiter returns to Earth through an increasingly thicker atmosphere.

Under the shuttle's left wing is a single tile that includes a "bump", which interrupts the normally smooth airflow around the tiles.

The disrupted airflow will increase the temperature of the tiles around it by a small amount and is part of a test of candidate tiles for future missions.

Current designs for those missions mean spacecraft will endure significantly more heat on re-entry than the space shuttles, which might be retired next year.

Nasa is preparing space shuttle Atlantis to be rolled out towards the launch pad on 31 March.

Atlantis is scheduled for a 12 May lift-off on a mission to service the Hubble Telescope. The mission has been delayed since October 2008.

Nasa delays space shuttle landing

2009-05-05T06:03:00.001-07:00

Nasa delays space shuttle landing

The shuttle took new solar panels to the International Space Station

Nasa has delayed attempts to land space shuttle Discovery due to concerns about heavy winds and cloud-cover.

The shuttle had been scheduled to land at Kennedy Space Center in Florida and controllers have one more opportunity on Saturday if the weather clears.

Its seven crew members had packed away their equipment as they made final preparations to come home.

Discovery launched on 15 March, docking with the International Space Station to deliver a final set of solar arrays.

As and when it finally returns to earth, the orbiter will have Sandra Magnus on board. She has been stationed at the ISS for four months.

Meanwhile a Russian space capsule with an American billionaire passenger on board has docked with the ISS.

The passenger, Charles Simonyi, is a software designer and is making his second trip as a space tourist.

He was accompanied by Russian and American astronauts.

On the tiles