Tag: Science & Technology

LONDON: In a breakthrough, scientists have discovered a new form of light, which will impact our understanding of the fundamental nature of light.

One of the measurable characteristics of a beam of light is known as angular momentum. Until now, it was thought that in all forms of light the angular momentum would be a multiple of Planck’s constant, the physical constant that sets the scale of quantum effects.

Now, researchers from Trinity College Dublin’s School of Physics and CRANN Institute have demonstrated a new form of light where the angular momentum of each photon (a particle of visible light) takes only half of this value.

This difference though small is profound, researchers said.

“We’re interested in finding out how we can change the way light behaves and how that could be useful. What I think is so exciting about this result is that even this fundamental property of light, that physicists have always thought was fixed, can be changed,” said Assistant Professor Paul Eastham.

“Our discovery will have real impacts for the study of light waves in areas such as secure optical communications,” Professor John Donegan said.

“This discovery is a breakthrough for the world of physics and science alike,” said Professor Stefano Sanvito, Director of CRANN.

In the 1830s, mathematician William Rowan Hamilton and physicist Humphrey Lloyd found that upon passing through certain crystals, a ray of light became a hollow cylinder.

The team used this phenomenon to generate beams of light with a screw-like structure.

Analyzing these beams within the theory of quantum mechanics they predicted that the angular momentum of the photon would be half-integer, and devised an experiment to test their prediction.

Using a specially constructed device they were able to measure the flow of angular momentum in a beam of light. They were also able, for the first time, to measure the variations in this flow caused by quantum effects.

The experiments showed a tiny shift, one-half of Planck’s constant, in the angular momentum of each photon.

Theoretical physicists since the 1980s have speculated how quantum mechanics works for particles that are free to move in only two of the three dimensions of space.

They discovered that this would enable strange new possibilities, including particles whose quantum numbers were fractions of those expected. This work shows, for the first time, that these speculations can be realized with light.

The research was published in the journal Science Advances.
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LONDON (TIP): Inspired by the ‘liquid wire’ technique in spider webs, scientists have created novel composite fibres which extend like a solid and compress like a liquid.

Pulling on a sticky thread in a spider’s web and letting it snap back shows that the thread never sags but always stays taut – even when stretched to many times its original length.

This is because any loose thread is immediately spooled inside the tiny droplets of watery glue that coat and surround the core gossamer fibres of the web’s capture spiral.

“The thousands of tiny droplets of glue that cover the capture spiral of the spider’s orb web do much more than make the silk sticky and catch the fly,” said Fritz Vollrath from the Oxford University in UK.

“Surprisingly, each drop packs enough punch in its watery skins to reel in loose bits of thread. And this winching behaviour is used to excellent effect to keep the threads tight at all times, as we can all observe and test in the webs in our gardens,” Vollrath said.

The novel properties observed and analyzed by the scientists rely on a subtle balance between fibre elasticity and droplet surface tension.

The team was also able to recreate this technique in the laboratory using oil droplets on a plastic filament.

This artificial system behaved just like the spider’s natural winch silk, with spools of filament reeling and unreeling inside the oil droplets as the thread extended and contracted. “While the web is simply a high-tech trap from the spider’s point of view, its properties have a huge amount to offer the worlds of materials, engineering and medicine,” said Herve Elettro, a doctoral researcher at the Universite Pierre et Marie Curie in France. “Our bio-inspired hybrid threads could be manufactured from virtually any components,” Elettro. “These new insights could lead to a wide range of applications, such as microfabrication of complex structures, reversible micro-motors, or self-tensioned stretchable systems,” he said.

TOKYO (TIP): After analyzing a 3D map of 3,000 galaxies that are 13 billion light years from Earth, an international team led by Japanese researchers has found that theoretical physicist Albert Einstein’s general theory of relativity is still valid.

Since it was discovered in the late 1990s that the universe is expanding at an accelerated rate, scientists have been trying to explain why.

The mysterious dark energy could be driving acceleration, or Einstein’s theory of general relativity, which says gravity warps space and time, could be breaking down.

“We tested the theory of general relativity further than anyone else ever has. It’s a privilege to be able to publish our results 100 years after Einstein proposed his theory,” said project researcher Teppei Okumura from Kavli Institute for the Physics and Mathematics (Kavli IPMU) at University of Tokyo.

To test Einstein’s theory, the team led by Okumura and colleagues, with researchers from Tohoku University and Kyoto University, used “Fast Sound Survey” data on more than 3,000 distant galaxies to analyze their velocities and clustering.

The results indicated that even far into the universe, general relativity is valid, giving further support that the expansion of the universe could be explained by a cosmological constant as proposed by Einstein in his theory of general relativity.

“Having started this project 12 years ago, it gives me great pleasure to finally see this result come out,” added Karl Glazebrook, professor at Swinburne University of Technology who proposed the survey.

No one has been able to analyse galaxies more than 10 billion light years away but the team managed to break this barrier thanks to the FMOS (Fiber Multi-Object Spectrograph) on the Subaru Telescope which can analyse galaxies 12.4-14.7 billion light years away.

AHMEDABAD (TIP): Getting rid of stubborn stains from clothes will no more be a herculean task. The Facilitation Centre for Industrial Plasma Technologies (FCIPT), a division of Institute for Plasma Research (IPR) in Gandhinagar, has manufactured a technology wherein a cloth can be rendered stain proof.

The FCIPT has developed nano particle powder wherein titanium metal is vaporised with plasma to form titanium dioxide (TiO2). These nano particles, when mixed with alcohol -like in the case of deodorants – and sprayed on clean clothes prove to be excellent stain cutters. “The TiO2 nano particles get trapped between fibres of the cloth and form a protective coat. The moment a tough stain like say turmeric enriched curry falls on the your nano-treated shirt or top, one just has to leave it in the sun for two to three hours and the stain vanishes instantly,” says C Balasubramanian, senior scientist at FCIPT.

“The sun’s ultraviolet rays activate the TiO2 which helps oxygen from atmosphere to convert to radical oxygen that reacts with stain molecules and breaks it down – thereby removing stains. This process is called a self-cleaning cloth,” Balasubramanian explained.

Once sprayed, the TiO2 coat remains for more than 20 washes. Balasubramanian adds, “Normally, preparing TiO2 through a chemical process involves several steps over many days. At FCIPT we have prepared a process to produce nano particles of high purity in large quantities through plasma treatment in 2 to 3 minutes flat,” the scientist said. Dr S K Nema, senior scientist at FCIPT, said, “We have developed a system where textile rolls are passed through plasma which modifies the surface of the textile up to a few nano meters.” Source: TOI

Google’s parent holding Alphabet has developed a new walking robot designed to interact with the world like a human.

The robot was showcased at the New Economic Summit in Tokyo and was created by Alphabet-owned Japanese robotics company Schaft. During the demonstration, it was shown how the robot can navigate its way through uneven terrain while carrying a load of upto 60 kgs.

Schaft explained during the summit that the robot is essentially designed to be more cost effective and power efficient so it can be used by normal civilians. A spokesperson from Schaft told Spectrum IEEE that the presentation was more about showcasing what the robot can do and not some kind of a product announcement.

“[The presentation] wasn’t a product announcement or indication of a specific product roadmap. The team was simply delighted to have a chance to show their latest progress,” the spokesperson said.

Schaft was acquired by Google in late 2013 and since acquisition has kept a low profile by shutting down its website and very few public appearances. it also bagged the inaugural US Defense Advanced Research Projects Agency robotics challenge with a bipedal robot with arms.

It follows a very different design philosophy compared to Alphabet’s other robots made by Boston Dynamics, which has reportedly been put up for sale by Google.

LONDON (TIP): Scientists have developed a system, inspired by insect eyes, that may allow drones to adjust their speed to their surroundings and fly on their own – without human intervention and control.

After studying how insects navigate through dense vegetation, researchers at Lund University in Sweden came up with the system that can be applied to flying robots.

By adapting the system to drones, they can be made to adjust their speed to their surroundings and fly on their own, researchers said.

The research shows how bees that fly through dense forests assess light intensity to avoid other objects and find holes in the vegetation to enable them to navigate safely.

The ability to avoid collisions is crucial to animals and insects that live in environments with many obstacles.

The results show that insects, such as the green orchid bee in the Panama rainforests, apply a strategy where they assess the light intensity to navigate quickly and effectively without crashing.

They are guided by the intensity of the light that penetrates the holes in leaves to determine whether a particular hole is sufficiently large for them to fly through safely without hitting the edges.

“The system is so simple – it’s highly likely that other animals also use light in this way. The system is ideal for adapting to small, light-weight robots, such as drones. My guess is that this will become a reality within five to ten years,” said vision researcher Emily Baird.

Before it is realised, the biological results from the rainforest must be transformed into mathematical models and digital systems that make it possible for robots to fly in complicated environments completely without human intervention, researchers said.

“Using light to navigate in complex environments is a universal strategy that can be applied by both animals and machines to detect openings and get through them safely.

“Really, the coolest thing is the fact that insects have developed simple strategies to cope with difficult problems for which engineers have still to come up with a solution,” said Baird.

WASHINGTON (TIP): American scientists have created in a lab the smallest viable genome existing in nature with just enough essential genes for an organism to function and reproduce on its own, in a major step toward unlocking the mysteries of how life is created.

The synthetic genome of this bacteria, dubbed JCVI-syn3.0, only carries 473 genes, compared to about 20,000 for a human being.

But lead researchers Craig Venter –the first to sequence the human genome — and Clyde Hutchinson and their colleagues have not yet determined the functions of 149 of the genes, about a third of the total.

“Investigators’ first task is to probe the roles of those genes, which promise new insights into the basic biology of life,” said Chris Voigt, a synthetic biologist at Massachusetts Institute of Technology who did not participate in the research.

But several potentially homologous genes have been found in other organisms, suggesting they encode universal proteins with functions that for now remain undetermined.

Researchers used a design-build-test process to identify quasi-essential genes, which are required for robust growth but not for life. The study was published in Thursday’s edition of the journal Science.

Through a series of experiments, they obtained a synthetic, reduced genome that was as small as possible because no more genes could be disrupted.

“The only way to answer basic questions about life would be to get to a minimal genome,” Venter explained in a teleconference.

“Probably the only way to do that would be to try to synthesize a genome.”

This pursuit is what led the scientists to turn to Mycoplasma, bacteria with the smallest known genomes of cells that replicate autonomously.

“If you know nothing about airplanes and you’re looking at (a Boeing) 777 and you’re just trying to find out functions of parts by removing them, and you remove the engine from the right wing, the airplane can still fly and land,” Venter explained.

“So you might say that’s a nonessential component and you don’t really discover the essentiality until you remove the second one.

“And that’s what’s happened over and over again in biology where we would have what appeared to be a non-essential component until we removed its counterpart.”