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Comment by Dr. Krishna Kumari Challa on September 17, 2016 at 7:20am

Comment by Dr. Krishna Kumari Challa on September 13, 2016 at 6:55am

After launching the world's first hack-free satellite,  China has tested its first quantum radar which could detect objects, including stealth aircraft, within the range of 100 kilometres.

The first Chinese quantum radar was developed by the Intelligent Perception Technology Laboratory of the 14th Institute of China Electronics Technology Group Corporation (CETC)

Quantum radar is a device that uses quantum entanglement photons to provide better detection capabilities than conventional radar systems.

The method would be useful for tracking targets with a low radar cross section, such as modern aircraft using stealth technology or targets employing active countermeasures to jam or baffle enemy radar.

The technology may also find use in biomedicine, since quantum radar requires lower energy and can be used to non-invasively probe for objects with low reflectivity, such as cancer cells.

Earlier, China launched the world s first quantum communications satellite, which uses quantum entanglement for cryptography.

Comment by Dr. Krishna Kumari Challa on September 2, 2016 at 8:01am

Comment by Dr. Krishna Kumari Challa on September 1, 2016 at 7:39am

Comment by Dr. Krishna Kumari Challa on August 31, 2016 at 9:29am

A possible four-phase coexistence in a single-component system

Explanation...

Japanese scientists have shown through simulations that four phases of a substance can coexist at thermal equilibrium, where all parts are at the same temperature and pressure—a situation that seemingly goes against the laws of thermodynamics. 

The findings, published in Nature Communications, not only deepen our basic understanding of phases of a substance existing in equilibrium, but may also be applied to the development of functional materials possessing phase-change properties.

 We constantly come across instances where various phases of a substance—such as gas, liquid, and solid—coexist with each other. For example, water (liquid) and ice (solid) coexist in shaved ice, a popular summer treat. Furthermore, the three phases of gas, liquid, and solid in water molecules coexist at a particular temperature and pressure known as the triple point. In a new study, the research group led by Professor Hajime Tanaka of the Institute of Industrial Science at the University of Tokyo has shown that four phases—three crystalline phases and one liquid phase—can coexist. These findings violate the Gibbs phase rule, which states that no more than three phases of a substance made from a single component can coexist at thermal equilibrium. 

the group systematically determined the particular temperature and pressure of the quadruple point where the four phases coexist, and defined the phase transition behavior—switching from one phase to another—around this point. This study may also prove useful in the development of functional phase-change materials as it demonstrates that multiple phase transformation can be induced near the quadruple point. 

Abstract:

For different phases to coexist in equilibrium at constant temperature T and pressure P, the condition of equal chemical potential μ must be satisfied. This condition dictates that, for a single-component system, the maximum number of phases that can coexist is three. Historically this is known as the Gibbs phase rule, and is one of the oldest and venerable rules of thermodynamics. In the paper published the researchers make use of the fact that, by varying model parameters, the Gibbs phase rule can be generalized so that four phases can coexist even in single-component systems. To systematically search for the quadruple point, they used a monoatomic system interacting with a Stillinger–Weber potential with variable tetrahedrality. Their study indicates that the quadruple point provides flexibility in controlling multiple equilibrium phases and may be realized in systems with tunable interactions, which are nowadays feasible in several soft matter systems such as patchy colloids.

http://www.nature.com/ncomms/2016/160825/ncomms12599/full/ncomms125...

Comment by Dr. Krishna Kumari Challa on August 25, 2016 at 8:45am

"Biological Pollution"

Most countries in the world have little capacity to deal effectively with invasive species, a study suggests.

The spread of non-native species threatens livelihoods and biodiversity, but the issue is worsened by global trade, travel and climate change.

Writing in Nature Communications journal, and international team forecast how the spread of species could change over the 21st Century.

They show that one-sixth of the world's land surface is vulnerable to invasion.

However, they predict that non-native plants, animals and microbes will increasingly threaten developing countries with some of the last remaining biodiversity hotspots, due to increased air travel and the expansion of agriculture.

This could endanger livelihoods and food security in fragile economies that are ill-prepared to deal with the expansion of invasive organisms.

Rampant globalisation will lead to invasions in countries with the least capability to deal with them. Low-income countries stand to lose a lot by having their natural resources sapped by invasive species.

Invasive species often travel as stowaways or contaminants in goods imported by planes and ships. They also arrive as exotic pets or plants that subsequently escape or are released deliberately into the wild.

This can pose challenges native species that have evolved over thousands of years to be well adapted to their ecosystems. Consequently, new arrivals can quickly change the nature of a whole region and often outcompete native organisms for resources and habitat.

Burmese pythons originally arrived in the US as exotic pets, but they escaped and quickly established themselves in the Florida Everglades, where they have contributed to a catastrophic decline in native mammals.

In Europe, forests and woods have been transformed by introduced diseases and pests such as Dutch elm disease and Ash dieback.

Biological invasions in the developing world so far have included influxes of Diamondback moths, which can devastate broccoli, cabbage and other crops; Panama disease, which wiped out banana plantations in central and south America; and prickly pear, which devastated grassland in Africa, leading to cattle being malnourished.

Comment by Dr. Krishna Kumari Challa on August 19, 2016 at 8:55am

The link between pollinator problems and neonicotinoids, a group of agricultural pesticides commonly associated with declines in honeybees, continues to build with two new studies published this week.

Within species, a population’s odds of going extinct increased with use of the pesticides, the research team worked on this  writes in the August 16 Nature Communications. That goes for both wild bees that forage on oilseed rape, and those that don’t — though populations of known foragers were three times as likely to disappear.

Taken together, the results add some long-term data to the idea that even though wild species aren’t pollinating neonicotinoid-doused crops, the effects of exposure may still appear at the regional and national level. 

Impacts of neonicotinoid use on long-term population changes in wild bees in England

http://www.nature.com/ncomms/2016/160816/ncomms12459/full/ncomms124...

Comment by Dr. Krishna Kumari Challa on August 19, 2016 at 7:58am

A black hole analogue, which traps sound instead of light, generates "Hawking radiation," a key prediction by the theoretical physicist. 

Stephen Hawking proposed in 1974 that quantum effects at the event horizon might cause black holes to be…not completely black. 

Recently scientists observed spontaneous Hawking radiation, stimulated by quantum vacuum fluctuations, emanating from an analogue black hole in an atomic Bose–Einstein condensate. Correlations are observed between the Hawking particles outside the black hole and the partner particles inside. These correlations indicate an approximately thermal distribution of Hawking radiation. They found that the high-energy pairs are entangled, while the low-energy pairs are not, within the reasonable assumption that excitations with different frequencies are not correlated. The entanglement verifies the quantum nature of the Hawking radiation. The results are consistent with a driven oscillation experiment and a numerical simulation.

http://www.nature.com/articles/nphys3863.epdf?referrer_access_token...

Comment by Dr. Krishna Kumari Challa on August 18, 2016 at 10:10am

Quantum satellite launch is helping China develop a communications system that ‘cannot be hacked’

Scientists think that using technology harnessing quantum physics is the key to beating electronic snoopers.

China launched the first-ever quantum satellite Monday (Aug. 15) in an effort to help develop an unhackable communications system.

The launch of the world’s first “quantum satellite” is just the beginning of China’s ambitious plans to develop a communications system that cannot be cracked by hackers, according to a lead engineer on the project.

The satellite was launched from the Jiuquan space centre in Gansu province in northwest China this week.

One of the tasks during the satellite’s mission will be to try and send coded communications back to earth that cannot be read by eavesdroppers. How is this possible? High quality Physics!

"Entangled" particles are intimately and curiously linked to each other; even if they're separated by billions of miles of space; a change in one somehow affects the others.

QUESS will send messages to ground stations using entangled photons. Such a system is theoretically impossible to hack. In addition, any attempts to eavesdrop would be picked up via an induced change in the photons' state.

It will attempt to do so by transmitting information through photons, tiny particles found in subatomic or quantum physics.

Researchers believe that information sent through photons cannot be intercepted or analysed by people without the right codes.

The mission to establish a hacker-proof communication link between space and earth requires scientists to carefully adjust the satellite’s position so it can beam single photons on to a targeted area just a few square metres wide on the ground.

They also need to test and fine tune each scientific device on the satellite . Similar ground-based quantum communications systems have also been set up in the US, Europe and Japan, but China has the largest network and is leading the development of the technology in space.

A wiretap splits off a large number of electrons to read the signal and still leaves enough electrons in the line to carry the same signal to the legitimate recipient.

A quantum network, however, carries information by photons and under the law of quantum physics it is impossible to measure their properties without altering them.

If an eavesdropper tries to copy the quantum states, this introduces errors in the transmitted key and gets noticed by the legitimate users.

Some experts think that one possible way of hacking the system a Trojan Horse. It involves firing an extra beam of light at one key part of the communications equipment and light reflected back would carry information processed by the system.

But commercial quantum network applications had been deployed in many countries, but not a single report of a security breach had been reported so far.

China thinks .. To be a quantum hacker you must have a PhD in quantum physics, that’s the minimum requirement. Such a high entry barrier will keep most hackers out of this game.

Comment by Dr. Krishna Kumari Challa on August 18, 2016 at 9:04am

The dodgy academic journals publishing anti-vaxxers and other 'crappy science'
http://www.smh.com.au/national/the-dodgy-academic-journals-publishi...

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