Category Archives: Science

China, Research, Science, Technology

A quantum leap in the pursuit of a secure and new type of internet

QUANTUM SCIENCE

Quantum

China’s quantum satellite, Micius. The satellite has beamed entangled particles of light to ground stations more than 700 miles apart.

Scientists have taken a major step towards building a global quantum internet by beaming “entangled” particles of light from a satellite to ground stations more than 700 miles apart.

The feat paves the way for a new kind of internet which draws on the curious ability for subatomic particles to be connected to one another despite being far apart and even on opposite sides of the planet.

Researchers believe that by linking particles together in this way, encrypted information could be sent from place to place across a quantum network with no danger of it being decrypted and read by others, as can be done on the existing internet.

Jian-Wei Pan, who led the research at the University of Science and Technology in Hefei in China, said the demonstration was a moment he had been dreaming of since 2003. “Many people thought it was a crazy idea, because it was very challenging,” he said.

The work obliterates the previous world record for sending pairs of photons that are connected to one another by a strange rule of quantum physics first spotted by Einstein. Until now, the farthest researchers had ever sent entangled photons stood at a mere 65 miles, less than one tenth of the distance achieved in the satellite experiment.

“It’s a first step, and a major step, toward creating a global quantum network,” said Pan. “All the previous methods are limited to about 100km so can only work within a city.”

The experiment relied on the world’s first quantum-enabled spacecraft: a Chinese satellite called Micius. As it soared over China, the satellite created pairs of photons with properties that were linked through quantum entanglement. It then beamed these simultaneously to ground stations in Delingha, Lijiang and Nanshan. Each pair of particles travelled up to 1,240 miles before they reached their destinations. Details of the study are published in Science.

Pan said that the kind of cryptography used to keep data safe today relies on complex mathematics which can often be defeated by hackers. “If a future quantum network is established, the security is ensured by the laws of physics, which are unconditionally secure,” he said. “It will be beneficial for all human beings.”

Martin Stevens, a physicist at the National Institute of Standards and Technology in Boulder, Colorado, said he was impressed with the work. “These types of experiments are not easy to do, even within the controlled confines of a laboratory environment. Doing them between two remote ground locations and a satellite flying overhead at a speed of thousands of kilometres per hour is mind-bogglingly difficult.”

In 2015, Stevens sent entangled photons down a 65-mile length of optical fibre. That is good enough for quantum communications between neighbouring towns, but it cannot work for much greater distances, because the signal is gradually lost the more optic fibre it travels down. The advantage of using a satellite is that the particles of light travel through space for much of their journey.

Anton Zeilinger at the Vienna Centre for Quantum Science also praised the work. “It’s an important step towards a worldwide quantum network. If you envisage a quantum network, the question is how to cover large distances and that cannot be done with glass fibres on the ground. You have to go into space, because in glass fibres you lose the signal. It’s very important to show that it works with satellites, so I’m very excited by this.”

Zeilinger is working with Pan on an intercontinental quantum network and hopes to have results to report before the end of the year.

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Britain, Environment, Government, Science

Reintroducing beavers could help fight flooding and pollution

ENVIRONMENTAL SCIENCE

Beavers were common inhabitants of the UK’s waterways for centuries.

A reintroduction of beavers to Britain could help clean up rivers, prevent flooding and minimise soil loss, an expert has claimed.

Professor Richard Brazier, a researcher at the University of Exeter, said unpublished preliminary results from a trial area in Devon showed muddy water entering an area where the creatures were living was three times cleaner when it left.

And he said farmers and agriculturalists should be grateful to the buck-toothed beasts cleaning up pollution caused by carbon and nitrogen from fertilisers being released into the environment.

Prof Brazier said: “We see quite a lot of soil erosion from agricultural land round here (near Okehampton).

“Our trial has shown that the beavers are able to dam our streams in a way that keeps soil in the headwaters of our catchment so it doesn’t clog up rivers downstream and pollute our drinking and bathing waters.

“Farmers should be happy that beavers are solving some of the problems that intensive farming creates.

“If we bring beavers back it’s just one tool we need to solve Britain’s crisis of soil loss and diffuse agricultural pollution of waterways, but it’s a useful tool.”

Prof Brazier’s claims were disputed by the National Farmers’ Union (NFU), which warned that the reintroduction of beavers to Scotland had led to fields and forests becoming damaged.

A spokesperson for the NFU said: “The knowledge of the impacts beavers have had to farmland, riverbanks and flood defences in Scotland is concerning. We await the (formal) results of the Devon trial and will analyse the outcomes then”.

Bavarian beavers thought to have escaped or been released into the wild in the Forfar area of Scotland about fifteen years ago have been blamed for damage to trees and water ditches.

Beavers were common inhabitants of the UK’s waterways for centuries, until hunting for their valuable pelts led to their eventual extinction.

Prof Brazier, an expert in Earth Surface Processes, insisted the animals could even play a useful role in preventing flooding – an increasingly common problem across parts of England.

He further added: “The public is currently paying people to build leaky dams to keep storm waters in the uplands.

“The beavers can do it free of charge and even build their own homes. They are busy as beavers. It’s a no-brainer.”

His claims were in part supported by Devon Wildlife Trust’s, who said that wildlife habitat in two areas in the north of the county had improved since the introduction of two beavers in 2011, with frogs and herons seeing particular benefits.

“We shouldn’t be surprised – beavers were part of our landscape and so many creatures evolved alongside them,” he said.

However, Professor Jane Rickson, a soil specialist from Cranfield University, Bedfordshire, joined the NFU in sounding a note of caution.

She agreed that in some places in the UK there was evidence of worrying soil loss, and said new policies were urgently needed.

Beavers may in fact reduce the river channel and remove vegetation, exposing banks to greater erosion and increasing, rather than decreasing, the risk of flooding, she warned.

And she said beaver dams should be “leaky” to avoid build-ups of large volumes of water.

An Environment Agency spokesman said: “Natural and hard flood defences both have an important role in keeping communities’ safe – though introducing beavers does not form part of our approach.”

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Science, Technology, United States

Scientists set sights on the Sun in understanding life and mankind

NASA: PARKER SOLAR PROBE

An artist’s impression of the Solar Probe Plus spacecraft approaching the sun.

The space race, once notorious for its drama and political intrigue in recent decades, still has the adroitness to shock. Scientists at NASA, the US space agency, retain the capacity to astonish with their ambition and innovation.

In spite of all that science has discovered about our universe, NASA and its counterparts around the world have long been frustrated by how the Sun has closely guarded its secrets. But the Parker Solar Probe mission, scheduled to launch in 2018, promises to change all that.

In what will become humanity’s first voyage mission to visit a star, the pioneering undertaking will seek to unlock the mysteries at the centre of our solar system. These include the origins of solar winds and why the Sun’s outermost layer is hotter than its surface.

The findings, NASA believes, could have far-reaching implications for how to forecast weather events in space which impact on life on Earth.

The project is to be commissioned over a period of some seven years, at a cost of £1.1bn. Whilst eye-wateringly expensive, if the mission is successful those costs will be far outweighed by crucial scientific insights into the star that gives us heat and light.

The probe will begin its nebulous journey next summer. The world will likely watch on in wonder and hope as scientists search for answers in understanding some of the great enigmas of life and mankind.

. It has hitherto been impossible to enter the sun’s atmosphere, where temperatures start at almost 1,400C.

. The launch date has been given as being between July 31 and August 19, 2018, from the Kennedy Space Centre in Florida. A super-powered probe travelling at 118 miles per second will overcome the supersonic solar winds, flares and radiation to allow it to get as close to the sun as possible.

. Scientists predict that the Parker Solar Probe will fly to within 3.7million miles of the surface. A previous attempt to gain insight into the star, by Helios 2 in 1976, came within 27 million miles.

. The Sun is Earth’s closest star and is some 93million miles from Earth.

. By predicting major weather events in space would greatly help to combat the threat of communication networks being destroyed on Earth.

. To combat the intense heat, scientists have created a 4.5in carbon composite shield which will maintain the instruments used to record solar flares and shocks at room temperature.

. The probe itself is named in honour of astrophysicist Eugene Parker, now 89, who in 1958 did groundbreaking and pioneering work on understanding solar storms and the solar wind – a stream of charged particles emitted by the sun that causes the Northern Lights.

. Its seven-year mission will use the gravitational field of Venus to orbit the sun 24 times. Scientists predict the probe getting closest in December 2024.

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