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Unleashing the power of quantum dot triplets
Date: July 24, 2014
Source: Springer Science+Business Media
Summary: Another step towards faster computers relies on three coherently coupled quantum dots used as quantum information units. Quantum computers have yet to materialize. Yet, scientists are making progress in devising suitable means of making such computers faster. One such approach relies on quantum dots-a kind of artificial atom, easily controlled by applying an electric field. A new study demonstrates that changing the coupling of three coherently coupled quantum dots (TQDs) with electrical impulses can help better control them.
Pic: Triple quantum dot system. Credit: © Tooski, S. B. et al.
Quantum computers have yet to materialise. Ye, scientists are making progress in devising suitable means of making such computers faster. One such approach relies on quantum dots — a kind of artificial atom, easily controlled by applying an electric field. A new study demonstrates that changing the coupling of three coherently coupled quantum dots (TQDs) with electrical impulses can help better control them. This has implications, for example, should TQDs be used as quantum information units, which would produce faster quantum computers due to the fact that they would be operated through electrical impulses.
These findings have been published in the European Physical Journal B by Sahib Babaee Tooski and colleagues affiliated with both the Institute of Molecular Physics at the Polish Academy of Sciences, in Poznan, Poland, the University of Ljubljana and the Jožef Stefan Institute in Slovenia.
The authors study the interplay between internal electrons — which, due to electron spins, are localised on the different quantum dots. They then compare them with the interactions of the conducting electrons, which, at low temperature, can increase the electrical resistance, due to what is referred to as the Kondo effect. This effect can be induced by coupling one of the quantum dots with the electrodes.
Tooski and colleagues thus demonstrate that by changing the coupling of the quantum dot with the electrodes, they can help induce the quantum phase transition between entangled and disentangled electron states. Such variations are typically detectable through a sudden jump in the entropy and the spin susceptibility. However, theoretical investigations outlined in the paper and based on numerical renormalisation group analysis suggest that the detection of such change is best achieved by measuring the electrical conductance. This is because, as the authors show, the conductance should be different for the entangled and disentangled states.
Story Source: The above story is based on materials provided by Springer Science+Business Media. Note: Materials may be edited for content and length.
Journal Reference: S. B. Tooski, Bogdan R. Bułka, Rok Žitko, Anton Ramšak. Entanglement switching via the Kondo effect in triple quantum dots. The European Physical Journal B, 2014; 87 (6) DOI: 10.1140/epjb/e2014-41025-6
Cite This Page: MLA APA Chicago: Springer Science+Business Media. “Unleashing the power of quantum dot triplets.” ScienceDaily. ScienceDaily, 24 July 2014. .
universal-abyss: Is it just me, but do you get that tingling sensation whenever you hear progress on the quantum computing front? This is yet another step, another piece of the thrilling puzzle. This is just so very intriguing.
universal-abyss: Freaking awesome - an incredibly detailed view of the galaxies using astrophotonics - to create a ‘Google street view’ of galaxies. My hands are wringing in anticipation of using this tool, to get ‘lost in space’ in incredible, mind-blowing detail. Damn, so when can we all use it? I want it NOW!
Australian researchers pioneer a ‘Google street view’ of galaxies
23 July 2014
Pic: Is purely an example, taken via http://www.google.com/sky/
A new home-grown instrument based on bundles of optical fibres is giving Australian astronomers the first ‘Google street view’ of the cosmos — incredibly detailed views of huge numbers of galaxies.
Developed by researchers at the University of Sydney and the Australian Astronomical Observatory, the optical-fibre bundles can sample the light from up to 60 parts of a galaxy, for a dozen galaxies at a time.
By analysing the light’s spectrum astronomers can learn how gas and stars move within each galaxy, where the young stars are forming and where the old stars live. This will allow them to better understand how galaxies change over time and what drives that change.
"It’s a giant step," said Dr James Allen of the ARC Centre of Excellence for All-sky Astrophysics(CAASTRO) at the University of Sydney.
"Before, we could study one galaxy at a time in detail, or lots of galaxies at once but in much less detail. Now we have both the numbers and the detail."
The Australian team is now a year or two ahead of its international competition in this field. In just 64 nights it has gathered data on 1000 galaxies, twice as many as the previous largest project, and over the next two years it will study another 2000.
CAASTRO funding was crucial in helping the team gain its lead. “They had a great idea but it was going to take time to pull the resources together,” said the organisation’s director Professor Bryan Gaensler. “CAASTRO was able to get it happening fast.”
Called SAMI (the Sydney-AAO Multi-Object Integral field spectrograph), the optical-fibre instrument was installed on the 4-m Anglo-Australian Telescope at Siding Spring Observatory in northwest NSW last year.
The technological leap is the ‘hexabundle’, sixty or more optical fibres close-packed and fused together, developed by the University of Sydney’s astrophotonics group led by Professor Joss Bland-Hawthorn.
Using the new instrument astronomers from the Australian National University and the University of Sydney have already spotted ‘galactic winds’—streams of charged particles travelling at up to 3,000 km a second—from the centre of two galaxies.
"We’ve seen galactic winds in other galaxies, but we have no idea how common they really are, because we’ve never had the means to look for them systematically. Now we do," said the University of Sydney’s Associate Professor Scott Croom, a Chief Investigator on the project.
The researchers are also uncovering the formation history of galaxies by looking to see if they are rotating in a regular way or if the movement of their stars is random and disordered.
"There are hints that galaxies with random motions sit at the centres of groups of galaxies, where many smaller galaxies may have fallen into them," said Dr Lisa Fogarty, a CAASTRO researcher at the University of Sydney who led this work.
On Thursday 24 July the researchers will release the first set of data from the instrument to the worldwide astronomical community and Dr Allen will give a related presentation at the annual scientific meetingof the Astronomical Society of Australia.
Hubble finds three surprisingly dry exoplanets: ‘Hot Jupiters’ had only one-tenth to one one-thousandth the amount of water predicted
Date: July 24, 2014
Source: Space Telescope Science Institute (STScI)
Summary: Astronomers have gone looking for water vapor in the atmospheres of three planets orbiting stars similar to the Sun — and have come up nearly dry. The three planets, known as HD 189733b, HD 209458b, and WASP-12b, are between 60 and 900 light-years away from Earth and were thought to be ideal candidates for detecting water vapor in their atmospheres because of their high temperatures where water turns into a measurable vapor.
Pic: This is an artistic illustration of the gas giant planet HD 209458b (unofficially named Osiris) located 150 light-years away in the constellation … Pegasus. This is a “hot Jupiter” class planet. Estimated to be 220 times the mass of Earth. The planet’s atmosphere is a seething 2,150 degrees Fahrenheit. It orbits very closely to its bright sunlike star, and the orbit is tilted edge-on to Earth. This makes the planet an ideal candidate for the Hubble Space Telescope to be used to make precise measurements of the chemical composition of the giant’s atmosphere as starlight filters though it. To the surprise of astronomers, they have found much less water vapor in the atmosphere than standard planet-formation models predict. Credit: NASA, ESA, and G. Bacon (STScI)
Astronomers using NASA’s Hubble Space Telescope have gone looking for water vapor in the atmospheres of three planets orbiting stars similar to the Sun — and have come up nearly dry.
The three planets, known as HD 189733b, HD 209458b, and WASP-12b, are between 60 and 900 light-years away from Earth and were thought to be ideal candidates for detecting water vapor in their atmospheres because of their high temperatures where water turns into a measurable vapor.
These so-called “hot Jupiters” are so close to their star they have temperatures between 1,500 and 4,000 degrees Fahrenheit, however, the planets were found to have only one-tenth to one one-thousandth the amount of water predicted by standard planet-formation theories.
“Our water measurement in one of the planets, HD 209458b, is the highest-precision measurement of any chemical compound in a planet outside our solar system, and we can now say with much greater certainty than ever before that we’ve found water in an exoplanet,” said Nikku Madhusudhan of the Institute of Astronomy at the University of Cambridge, England. “However, the low water abundance we have found so far is quite astonishing.”
Madhusudhan, who led the research, said that this finding presents a major challenge to exoplanet theory. “It basically opens a whole can of worms in planet formation. We expected all these planets to have lots of water in them. We have to revisit planet formation and migration models of giant planets, especially “hot Jupiters,” and investigate how they’re formed.”
He emphasizes that these results may have major implications in the search for water in potentially habitable Earth-sized exoplanets. Instruments on future space telescopes may need to be designed with a higher sensitivity if target planets are drier than predicted. “We should be prepared for much lower water abundances than predicted when looking at super-Earths (rocky planets that are several times the mass of Earth),” Madhusudhan said.
Using near-infrared spectra of the planets observed with Hubble, Madhusudhan and his collaborators estimated the amount of water vapor in each of the planetary atmospheres that explains the data.
The planets were selected because they orbit relatively bright stars that provide enough radiation for an infrared-light spectrum to be taken. Absorption features from the water vapor in the planet’s atmosphere are detected because they are superimposed on the small amount of starlight that glances through the planet’s atmosphere.
Detecting water is almost impossible for transiting planets from the ground because Earth’s atmosphere has a lot of water in it, which contaminates the observation. “We really need the Hubble Space Telescope to make such observations,” said Nicolas Crouzet of the Dunlap Institute at the University of Toronto and co-author of the study.
The currently accepted theory on how giant planets in our solar system formed, known as core accretion, states a planet is formed around the young star in a protoplanetary disk made primarily of hydrogen, helium, and particles of ices and dust composed of other chemical elements. The dust particles stick to each other, eventually forming larger and larger grains. The gravitational forces of the disk draw in these grains and larger particles until a solid core forms. This then leads to runaway accretion of both solids and gas to eventually form a giant planet.
This theory predicts that the proportions of the different elements in the planet are enhanced relative to those in its star, especially oxygen, which is supposed to be the most enhanced. Once the giant planet forms, its atmospheric oxygen is expected to be largely encompassed within water molecules. The very low levels of water vapor found by this research raise a number of questions about the chemical ingredients that lead to planet formation.
“There are so many things we still don’t know about exoplanets, so this opens up a new chapter in understanding how planets and solar systems form,” said Drake Deming of the University of Maryland, College Park, who led one of the precursor studies. “The problem is that we are assuming the water to be as abundant as in our own solar system. What our study has shown is that water features could be a lot weaker than our expectations.”
The findings are published July 24 in The Astrophysical Journal Letters.
Story Source: The above story is based on materials provided by Space Telescope Science Institute (STScI). Note: Materials may be edited for content and length.
Journal Reference: Nikku Madhusudhan, Nicolas Crouzet, Peter R. Mccullough, Drake Deming, Christina Hedges. H2O Abundances in the Atmospheres of Three Hot Jupiters. The Astrophysical Journal Letters, July 2 4, 2014
Cite This Page: MLA APA Chicago: Space Telescope Science Institute (STScI). “Hubble finds three surprisingly dry exoplanets: ‘Hot Jupiters’ had only one-tenth to one one-thousandth the amount of water predicted.” ScienceDaily. ScienceDaily, 24 July 2014. .
from-dust-of-stars: Flipping fascinating finds of dry Exoplanet ‘hot Jupiters’ leave us more questions on the hunt for exoplanets. Cool info though, no pun intended.
NASA’s Fermi finds a ‘transformer’ pulsar
Date: July 22, 2014
Summary: In late June 2013, an exceptional binary containing a rapidly spinning neutron star underwent a dramatic change in behavior never before observed. The pulsar’s radio beacon vanished, while at the same time the system brightened fivefold in gamma rays, the most powerful form of light, according to measurements by NASA’s Fermi Gamma-ray Space Telescope.
Pic: These artist’s renderings show one model of pulsar J1023 before (top) and after (bottom) its radio beacon (green) vanished. Normally, the pulsar’s wind staves off the companion’s gas stream. When the stream surges, an accretion disk forms and gamma-ray particle jets (magenta) obscure the radio beam. Credit: NASA’s Goddard Space Flight Center
In late June 2013, an exceptional binary containing a rapidly spinning neutron star underwent a dramatic change in behavior never before observed. The pulsar’s radio beacon vanished, while at the same time the system brightened fivefold in gamma rays, the most powerful form of light, according to measurements by NASA’s Fermi Gamma-ray Space Telescope.
“It’s almost as if someone flipped a switch, morphing the system from a lower-energy state to a higher-energy one,” said Benjamin Stappers, an astrophysicist at the University of Manchester, England, who led an international effort to understand this striking transformation. “The change appears to reflect an erratic interaction between the pulsar and its companion, one that allows us an opportunity to explore a rare transitional phase in the life of this binary.”
A binary consists of two stars orbiting around their common center of mass. This system, known as AY Sextantis, is located about 4,400 light-years away in the constellation Sextans. It pairs a 1.7-millisecond pulsar named PSR J1023+0038 — J1023 for short — with a star containing about one-fifth the mass of the sun. The stars complete an orbit in only 4.8 hours, which places them so close together that the pulsar will gradually evaporate its companion.
When a massive star collapses and explodes as a supernova, its crushed core may survive as a compact remnant called a neutron star or pulsar, an object squeezing more mass than the sun’s into a sphere no larger than Washington, D.C. Young isolated neutron stars rotate tens of times each second and generate beams of radio, visible light, X-rays and gamma rays that astronomers observe as pulses whenever the beams sweep past Earth. Pulsars also generate powerful outflows, or “winds,” of high-energy particles moving near the speed of light. The power for all this comes from the pulsar’s rapidly spinning magnetic field, and over time, as the pulsars wind down, these emissions fade.
More than 30 years ago, astronomers discovered another type of pulsar revolving in 10 milliseconds or less, reaching rotational speeds up to 43,000 rpm. While young pulsars usually appear in isolation, more than half of millisecond pulsars occur in binary systems, which suggested an explanation for their rapid spin.
“Astronomers have long suspected millisecond pulsars were spun up through the transfer and accumulation of matter from their companion stars, so we often refer to them as recycled pulsars,” explained Anne Archibald, a postdoctoral researcher at the Netherlands Institute for Radio Astronomy (ASTRON) in Dwingeloo who discovered J1023 in 2007.
During the initial mass-transfer stage, the system would qualify as a low-mass X-ray binary, with a slower-spinning neutron star emitting X-ray pulses as hot gas raced toward its surface. A billion years later, when the flow of matter comes to a halt, the system would be classified as a spun-up millisecond pulsar with radio emissions powered by a rapidly rotating magnetic field.
To better understand J1023’s spin and orbital evolution, the system was regularly monitored in radio using the Lovell Telescope in the United Kingdom and the Westerbork Synthesis Radio Telescope in the Netherlands. These observations revealed that the pulsar’s radio signal had turned off and prompted the search for an associated change in its gamma-ray properties.
A few months before this, astronomers found a much more distant system that flipped between radio and X-ray states in a matter of weeks. Located in M28, a globular star cluster about 19,000 light-years away, a pulsar known as PSR J1824-2452I underwent an X-ray outburst in March and April 2013. As the X-ray emission dimmed in early May, the pulsar’s radio beam emerged.
While J1023 reached much higher energies and is considerably closer, both binaries are otherwise quite similar. What’s happening, astronomers say, are the last sputtering throes of the spin-up process for these pulsars.
In J1023, the stars are close enough that a stream of gas flows from the sun-like star toward the pulsar. The pulsar’s rapid rotation and intense magnetic field are responsible for both the radio beam and its powerful pulsar wind. When the radio beam is detectable, the pulsar wind holds back the companion’s gas stream, preventing it from approaching too closely. But now and then the stream surges, pushing its way closer to the pulsar and establishing an accretion disk.
Gas in the disk becomes compressed and heated, reaching temperatures hot enough to emit X-rays. Next, material along the inner edge of the disk quickly loses orbital energy and descends toward the pulsar. When it falls to an altitude of about 50 miles (80 km), processes involved in creating the radio beam are either shut down or, more likely, obscured.
The inner edge of the disk probably fluctuates considerably at this altitude. Some of it may become accelerated outward at nearly the speed of light, forming dual particle jets firing in opposite directions — a phenomenon more typically associated with accreting black holes. Shock waves within and along the periphery of these jets are a likely source of the bright gamma-ray emission detected by Fermi.
The findings were published in the July 20 edition of The Astrophysical Journal. The team reports that J1023 is the first example of a transient, compact, low-mass gamma-ray binary ever seen. The researchers anticipate that the system will serve as a unique laboratory for understanding how millisecond pulsars form and for studying the details of how accretion takes place on neutron stars.
“So far, Fermi has increased the number of known gamma-ray pulsars by about 20 times and doubled the number of millisecond pulsars within in our galaxy,” said Julie McEnery, the project scientist for the mission at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Fermi continues to be an amazing engine for pulsar discoveries.”
Story Source: The above story is based on materials provided by NASA. Note: Materials may be edited for content and length.
Journal References: 1) B. W. Stappers, A. M. Archibald, J. W. T. Hessels, C. G. Bassa, S. Bogdanov, G. H. Janssen, V. M. Kaspi, A. G. Lyne, A. Patruno, S. Tendulkar, A. B. Hill, T. Glanzman. A State Change in the Missing Link Binary Pulsar System PSR J1023 0038. The Astrophysical Journal, 2014; 790 (1): 39 DOI: 10.1088/0004-637X/790/1/39
2) A. M. Archibald, I. H. Stairs, S. M. Ransom, V. M. Kaspi, V. I. Kondratiev, D. R. Lorimer, M. A. McLaughlin, J. Boyles, J. W. T. Hessels, R. Lynch, J. van Leeuwen, M. S. E. Roberts, F. Jenet, D. J. Champion, R. Rosen, B. N. Barlow, B. H. Dunlap, R. A. Remillard. A Radio Pulsar/X-ray Binary Link. Science, 2009; 324 (5933): 1411 DOI: 10.1126/science.1172740
Cite This Page: MLA APA Chicago: NASA. “NASA’s Fermi finds a ‘transformer’ pulsar.” ScienceDaily. ScienceDaily, 22 July 2014.
universal-abyss: Fascinating to see such unexpected behavior from a neutron star. So cool.
A crystal wedding in the nanocosmos may lead to fast multi-functional processing units on single chip
Date: July 23, 2014
Source: Helmholtz-Zentrum Dresden-Rossendorf
Summary: Researchers have succeeded in embedding nearly perfect semiconductor crystals into a silicon nanowire. With this new method of producing hybrid nanowires, very fast and multi-functional processing units can be accommodated on a single chip in the future.
Pic: Indium arsenide (green-cyan) is perfectly integrated into the silicon nanowire (blue). (Energy-dispersive X-ray spectroscopy). Credit: Copyright HZDR/Prucnal
Researchers at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), the Vienna University of Technology and the Maria Curie-Skłodowska University Lublin have succeeded in embedding nearly perfect semiconductor crystals into a silicon nanowire. With this new method of producing hybrid nanowires, very fast and multi-functional processing units can be accommodated on a single chip in the future. The research results will be published in the journal Nano Research.
Nano-optoelectronics are considered the cornerstone of future chip technology, but the research faces major challenges: on the one hand, electronic components must be accommodated into smaller and smaller spaces. On the other hand, what are known as compound semiconductors are to be embedded into conventional materials. In contrast to silicon, many of such semiconductors with extremely high electron mobility could improve performance of the most modern silicon-based CMOS technology.
Scientists from the HZDR, Vienna University of Technology and Maria Curie-Skłodowska University Lublin have now come a step closer to both these targets: they integrated compound semiconductor crystals made of indium arsenide (InAs) into silicon nanowires, which are ideally suited for constructing increasingly compact chips.
This integration of crystals was the greatest obstacle for such “hetero-nanowires” until now: beyond the nanometer range, crystal lattice mismatch always led to numerous defects. The researchers have now managed a near-perfect production and embedding of the InAs crystals into the nanowires for the first time.
Implanted atoms form crystals in the liquid-phase
In order to carry out this process, ion beam synthesis and heat treatment with xenon flash-lamps were used, two technologies in which the Ion Beam Center of the HZDR has held experience for many years. The scientists initially needed to introduce a determined number of atoms precisely into the wires using ion implantation. They then carried out the flash-lamp annealing of the silicon wires in their liquid-phase within a matter of only twenty milliseconds. “A silicon oxide shell, measuring merely fifteen-nanometers-thick, maintains the form of the liquid nanowire,” explains HZDR scientist Dr. Slawomir Prucnal, “while the implanted atoms form the indium-arsenide crystals.”
Dr. Wolfgang Skorupa, the head of the research group adds: “The atoms diffuse in the liquid-silicon-phase so rapidly that within milliseconds they form flawless mono-crystals delineated from their surroundings with nearly perfect interfaces.” In the next step, the scientists want to implement different compound semiconductors into Silicon nanowires and also optimize the size and distribution of the crystals.
Story Source: The above story is based on materials provided by Helmholtz-Zentrum Dresden-Rossendorf. Note: Materials may be edited for content and length.
Journal Reference: Prucnal, S. et al. III-V semiconductor nanocrystal formation in silicon nanowires via liquid-phase epitaxy. Nano Research, 2014 (in press) DOI: 10.1007/s12274-014-0536-6
Cite This Page: MLA APA Chicago: Helmholtz-Zentrum Dresden-Rossendorf. “A crystal wedding in the nanocosmos may lead to fast multi-functional processing units on single chip.” ScienceDaily. ScienceDaily, 23 July 2014.
universal-abyss: More exciting news in nanotechnology. The materials sciences are on fire with their drive for miniaturization, again to feed our insatiable appetite for cool, yet small, tech toys and tools.
New approach in search for extraterrestrial intelligence: Target alien polluters
Date: July 23, 2014
Source: Harvard-Smithsonian Center for Astrophysics
Summary: Humanity is on the threshold of being able to detect signs of alien life on other worlds. By studying exoplanet atmospheres, we can look for gases like oxygen and methane that only coexist if replenished by life. But those gases come from simple life forms like microbes. What about advanced civilizations? Would they leave any detectable signs? They might, if they spew industrial pollution into the atmosphere.
Pic: In this artist’s conception, the atmosphere of an Earth-like planet displays a brownish haze - the result of widespread pollution. New research shows that the upcoming James Webb Space Telescope potentially could detect certain pollutants, specifically CFCs, in the atmospheres of Earth-sized planets orbiting white dwarf stars. Credit: Christine Pulliam (CfA)
Humanity is on the threshold of being able to detect signs of alien life on other worlds. By studying exoplanet atmospheres, we can look for gases like oxygen and methane that only coexist if replenished by life. But those gases come from simple life forms like microbes. What about advanced civilizations? Would they leave any detectable signs?
They might, if they spew industrial pollution into the atmosphere. New research by theorists at the Harvard-Smithsonian Center for Astrophysics (CfA) shows that we could spot the fingerprints of certain pollutants under ideal conditions. This would offer a new approach in the search for extraterrestrial intelligence (SETI).
“We consider industrial pollution as a sign of intelligent life, but perhaps civilizations more advanced than us, with their own SETI programs, will consider pollution as a sign of unintelligent life since it’s not smart to contaminate your own air,” says Harvard student and lead author Henry Lin.
“People often refer to ETs as ‘little green men,’ but the ETs detectable by this method should not be labeled ‘green’ since they are environmentally unfriendly,” adds Harvard co-author Avi Loeb.
The team, which also includes Smithsonian scientist Gonzalo Gonzalez Abad, finds that the upcoming James Webb Space Telescope (JWST) should be able to detect two kinds of chlorofluorocarbons (CFCs) — ozone-destroying chemicals used in solvents and aerosols. They calculated that JWST could tease out the signal of CFCs if atmospheric levels were 10 times those on Earth. A particularly advanced civilization might intentionally pollute the atmosphere to high levels and globally warm a planet that is otherwise too cold for life.
There is one big caveat to this work. JWST can only detect pollutants on an Earth-like planet circling a white dwarf star, which is what remains when a star like our Sun dies. That scenario would maximize the atmospheric signal. Finding pollution on an Earth-like planet orbiting a Sun-like star would require an instrument beyond JWST — a next-next-generation telescope.
The team notes that a white dwarf might be a better place to look for life than previously thought, since recent observations found planets in similar environments. Those planets could have survived the bloating of a dying star during its red giant phase, or have formed from the material shed during the star’s death throes.
While searching for CFCs could ferret out an existing alien civilization, it also could detect the remnants of a civilization that annihilated itself. Some pollutants last for 50,000 years in Earth’s atmosphere while others last only 10 years. Detecting molecules from the long-lived category but none in the short-lived category would show that the sources are gone.
“In that case, we could speculate that the aliens wised up and cleaned up their act. Or in a darker scenario, it would serve as a warning sign of the dangers of not being good stewards of our own planet,” says Loeb.
This work has been accepted for publication in The Astrophysical Journal.
Story Source: The above story is based on materials provided by Harvard-Smithsonian Center for Astrophysics. Note: Materials may be edited for content and length.
Journal Reference: Henry W. Lin, Gonzalo Gonzalez Abad, Abraham Loeb. Detecting industrial pollution in the atmospheres of earth-like exoplanets. The Astrophysical Journal, 2014 (in press) [link]
Cite This Page: MLA APA Chicago: Harvard-Smithsonian Center for Astrophysics. “New approach in search for extraterrestrial intelligence: Target alien polluters.” ScienceDaily. ScienceDaily, 23 July 2014. .
from-dust-of-stars: Damn, wouldn’t it be the worst irony to find proof of extraterrestrial intelligence because they left behind pollutants? Sad to consider that this also may be how extraterrestrial intelligence would find us!
Massive neutrinos and new standard cosmological model: No concordance yet
Date: July 22, 2014
Source: Universidad de Barcelona
Summary: Neutrinos, also known as ‘ghost particles’ because they barely interact with other particles or their surroundings, are massless particles according to the standard model of particle physics. However, there is a lot of evidence that their mass is in fact non-zero, but it remains unmeasured. In cosmology, neutrinos are suspected to make up a fraction —- small but important -— of the mysterious dark matter, which represents 90% of the mass of the galaxy. Modifying the standard cosmological model in order to include fairly massive neutrinos does not explain all the physical observations simultaneously.
Neutrinos, also known as ‘ghost particles’ because they barely interact with other particles or their surroundings, are massless particles according to the standard model of particle physics. However, there is a lot of evidence that their mass is in fact non-zero, but it remains unmeasured. In cosmology, neutrinos are suspected to make up a fraction — small but important — of the mysterious dark matter, which represents 90% of the mass of the galaxy. Modifying the standard cosmological model in order to include fairly massive neutrinos does not explain all the physical observations simultaneously.
This is the conclusion of a new scientific paper published in the journal Physical Review Letters, signed by Licia Verde, ICREA researcher from the Institute of Cosmos Sciences of the University of Barcelona (ICCUB), Boris Leistedt and Hiranya V. Peiris, from the University College London.
A model that does not meet observed data
Some scientific studies suggest that the existence of massive neutrinos could potentially explain other physical anomalies and phenomena observed in the Universe (for instance, the number of galaxy clusters observed by the Planck satellite). This hypothesis represents an extension of the standard cosmological model and may have profound implications for both cosmology and particle physics.
In the article published in the journal Physical Review Letters, the research group demonstrates that adding such massive neutrinos to the standard model does not really explain all datasets. Researcher Licia Verde affirms that “the new paper proves that the new model is in fact not a satisfying solution, in the sense that it is not able to explain all data sets simultaneously. Therefore, it cannot be the correct model of the Universe.”
Neutrinos: elusive and difficult to detect particles
Neutrinos travel almost at the speed of light. Most of thousands of millions of neutrinos passing through Earth emanate from the Sun and the atmosphere. However, gamma ray explosions, star formation and other cosmic phenomena can produce these particles, which are extremely hard to detect. Huge laboratories, such as the IceCube in Antartica, are necessary, and they only capture a few neutrinos (leading to poor measurements of neutrinos masses). Therefore, measuring the exact masses of the neutrinos is a major milestone for the entire physics community.
“Neutrinos’ properties can be also measured by studying the cosmos — explains researcher Licia Verde — , but cosmological observations have not detected neutrinos’ mass yet.” According to Licia Verde, “we know that the mass of neutrinos is between ~0.05 eV and ~0.2 eV, so cosmology is closing in. There is a lot of work to do in order to get a robust measure but we hope that the next generation of cosmological data will be able to ‘see’ the mass of neutrinos and provide a more accurate measure of the mass of these particles.”
Licia Verde, ICCUB researcher, also participates in the international project Sloan Digital Sky Survey (SDSS-III), one of the largest galaxy survey. She was member of the Wilkinson Microwave Anisotropy Probe (WMAP) team, and was awarded with the 2012 Gruber Cosmology Prize for her pioneering contributions to the study of primitive Universe.
Story Source: The above story is based on materials provided by Universidad de Barcelona. Note: Materials may be edited for content and length.
Journal Reference: Boris Leistedt, Hiranya V. Peiris, Licia Verde. No New Cosmological Concordance with Massive Sterile Neutrinos. Physical Review Letters, 2014; 113 (4) DOI: 10.1103/PhysRevLett.113.041301
Cite This Page: MLA APA Chicago: Universidad de Barcelona. “Massive neutrinos and new standard cosmological model: No concordance yet.” ScienceDaily. ScienceDaily, 22 July 2014.
Pic: The research group demonstrates that adding such massive neutrinos to the standard model does not really explain all datasets. Credit: The Milky Way, NASA.
universal-abyss: The intriguing questions remain about the standard cosmological model - both exciting and frustrating at the same time.
Boosting the force of empty space: Theorists propose way to amplify force of vacuum fluctuations
Date: July 22, 2014
Source: Vienna University of Technology, TU Vienna
Summary: Vacuum fluctuations may be among the most counter-intuitive phenomena of quantum physics. Theorists have now proposed a way to amplify their force. The researchers believe that their proposed enhancement of the power of vacuum fluctuations can have profound implications for understanding Casimir and Van der Waals forces and it may even be used for applications in quantum information processing and other emerging quantum technologies.
Vacuum fluctuations may be among the most counter-intuitive phenomena of quantum physics. Theorists from the Weizmann Institute (Rehovot, Israel) and the Vienna University of Technology propose a way to amplify their force.
Vacuum is not as empty as one might think. In fact, empty space is a bubbling soup of various virtual particles popping in and out of existence — a phenomenon called “vacuum fluctuations.” Usually, such extremely short-lived particles remain completely unnoticed, but in certain cases vacuum forces can have a measurable effect. A team of researchers from the Weizmann Institute of Science (Rehovot, Israel) and the Vienna University of Technology has now proposed a method of amplifying these forces by several orders of magnitude using a transmission line, channelling virtual photons.
“Borrowing” Energy, but just for a Little While
If you park your car somewhere and later it is gone, that is most probably not due to vacuum fluctuations. Objects do not disappear or reappear, that would violate the law of energy conservation. In the world of quantum physics, however, things are a bit more complicated. “Due to the uncertainty principle, virtual particles can come into existence for a brief period of time,” says Igor Mazets from the Vienna University of Technology. “The higher their energy, the faster they will disappear again.”
But such virtual particles can have a measurable collective effect. At very short distances, vacuum fluctuations can lead to an attractive force between atoms or molecules — the Van der Waals forces. Even the ability of a gecko to climb flat surfaces can in part be attributed to vacuum fluctuations and virtual particles. The famous Casimir effect is another example of the power of the vacuum: The physicist Hendrik Casimir calculated in 1948 that two parallel mirrors in empty space will attract each other due to the way they influence the vacuum around them.
Atoms and Photons
Two atoms close to each other will also change the local vacuum around them. If one of them emits a virtual photon, which is almost instantly absorbed by the other, then on any timescale larger than the brief moment of the photon’s existence, nothing much has happened — the total energy is conserved. But the fact that virtual particles can be exchanged modifies the vacuum around the atoms, and this leads to a force.
“Usually, such forces are very hard to measure,” says Igor Mazets. “This is partly due to the fact, that such a photon may be emitted into any direction, and the chances of the second atom absorbing it are very small.”
But what if the virtual particle has a little help to find its way? Ephraim Shahmoon, Gershon Kurizki (Weizmann Institute of Science) and Igor Mazets calculated what happens to vacuum forces between atoms when they are placed in the vicinity of an electrical transmission line such as a coaxial cable or a coplanar waveguide (a device used in cavity quantum electrodynamics experiments as an open transmission line), cooled to very low temperatures. “In that case, the fluctuations are effectively confined to one dimension,” says Igor Mazets. The virtual particles will be forced to go into the direction of the other atom.
In that case, the fluctuation-mediated attraction between the atoms becomes orders of magnitude stronger than in free space. Usually, the force decreases rapidly with increasing distance between the atoms. Due to the transmission line, it falls off with one over the distance cubed, instead of one over the seventh power of the distance, as in the usual case.
The researchers believe that their proposed enhancement of the power of vacuum fluctuations can have profound implications for understanding Casimir and Van der Waals forces and it may even be used for applications in quantum information processing and other emerging quantum technologies.
Story Source: The above story is based on materials provided by Vienna University of Technology, TU Vienna. Note: Materials may be edited for content and length.
Cite This Page: MLA APA Chicago: Vienna University of Technology, TU Vienna. “Boosting the force of empty space: Theorists propose way to amplify force of vacuum fluctuations.” ScienceDaily. ScienceDaily, 22 July 2014.
Pic: Two atoms exchanging a virtual photon. Empty space around them is not as empty as one might think. Credit: Image courtesy of Vienna University of Technology, TU Vienna
universal-abyss: Still working on the elusive, enticing quantum information processing dream.
MIT creates graphite ‘solar sponge’ that converts sunlight into steam with 85% efficiency
By Sebastian Anthony on July 22, 2014 at 11:33 am
MIT is reporting that it has created a new, cheap material — using a microwave, no less — that converts sunlight into steam with an amazing 85% efficiency. This could have major repercussions in the realms of desalination and sterilization, and perhaps for concentrated solar thermal power generation as well.
The new material, developed by MIT mechanical engineer Hadi Ghasemi, consists of a thin double-layered disc. The bottom layer consists of spongy carbon foam that doubles up as a flotation device and a thermal insulator that prevents solar energy from dissipating into the fluid underneath. The top layer — the active layer — consists of flakes of graphite that were exfoliated using a microwave. The microwave causes the graphite to bubble up “just like popcorn” according to Gang Chen, another researcher involved with the work. [doi:10.1038/ncomms5449 - “Solar steam generation by heat localization”]
When sunlight hits the graphite, hot spots are created that draw water up through the carbon foam via capillary action. When the water reaches the hot spots in the graphite, there’s enough heat to turn the water into steam. The efficiency of the material is linked to the amount of incoming light — at a solar concentration (intensity) of 10 times that of a typical sunny day, 85% of incoming solar energy is converted into steam (assuming there’s enough water nearby; this doesn’t magically create steam out of thin air). “There can be different combinations of materials that can be used in these two layers that can lead to higher efficiencies at lower concentrations,” says Ghasemi. Graphene, anyone?
As for what this little spongy steam-maker might actually be used for, there’s a variety of possibilities. The low solar intensity requirement (10x is easy to obtain with a simple lens or reflector) means this could a very good way of producing clean water or sterilizing equipment (to this day, steam is still a very popular way of sterilizing things). Bulk desalination is another possibility, though we wonder if the carbon foam wouldn’t get clogged up with the leftover salt crystals.
And then there’s the most exciting possibility: Good ol’ power generation. In modern-day concentrated solar thermal power generation, fresnel lenses or parabolic reflectors are used to concentrate sunlight by up to 1,000 times. If steam can be produced with just the intensity of 10 suns, then system costs can probably be reduced and overall efficiency increased. A lot more work needs to be done before this stuff revolutionizes power generation, though: So far, though, MIT hasn’t gone any further than “ooh, this stuff produces steam!” As we mentioned before with regards to desalination, it’s very likely that this new material would clog up with mineral deposits rather quickly (i.e. fouling), completely destroying any semblance of efficiency.
Still, it’s clearly early days. Problems like fouling (limescale! corrosion!) have been around forever, and as such there are lots of ways to combat it. If MIT really has stumbled across a way of cheaply and easily producing steam from sunlight, then this could be big news.
from-dust-of-stars: Damn, this is awesome, 85% sunlight-to-steam conversion efficiency with new ‘sponge.’ How awesome is this?!
What an exciting possibility for power generation, purifying water and sterilizing equipment.
Still in early stages - much research still required to make this a viable possibility.
from-dust-of-stars: Freaking fascinating advances in nanomaterial production to help improve photoconductivity and electrical conductivity for microdevices. Cool. More fun gadgets will be so thankful.
Scientists use simple, low cost laser technique to improve properties and functions of nanomaterials
Date: July 22, 2014
Source: National University of Singapore
Summary: By ‘drawing’ micropatterns on nanomaterials using a focused laser beam, scientists could modify properties of nanomaterials for effective applications in photonic and optoelectric applications.
Pic: Mesoporous silicon nanowires were scanned by a focused laser beam in two different patterns, imaged by bright-field optical microscope, as depicted by (a) and (c), as well as fluorescence microscopy, as depicted by (b) and (d). Evidently, the images hidden in boxes shown in (a) and (c) are clearly revealed under fluorescence microscopy. Credit: Image credit: National University of Singapore
By ‘drawing’ micropatterns on nanomaterials using a focused laser beam, scientists could modify properties of nanomaterials for effective applications in photonic and optoelectric applications.
The challenges faced by researchers in modifying properties of nanomaterials for application in devices may be addressed by a simple technique, thanks to recent innovative studies conducted by scientists from the National University of Singapore (NUS).
Through the use of a simple, efficient and low cost technique involving a focused laser beam, two NUS research teams, led by Professor Sow Chorng Haur from the Department of Physics at the NUS Faculty of Science, demonstrated that the properties of two different types of materials can be controlled and modified, and consequently, their functionalities can be enhanced.
Said Prof Sow, “In our childhood, most of us are likely to have the experience of bringing a magnifying glass outdoors on a sunny day and tried to focus sunlight onto a piece of paper to burn the paper. Such a simple approach turns out to be a very versatile tool in research. Instead of focusing sunlight, we can focus laser beam onto a wide variety of nanomaterials and study effects of the focused laser beam has on these materials.”
Micropatterns ‘drawn’ on MoS2 films could enhance electrical conductivity and photoconductivity
Molybdenum disulfide (MoS2), a class of transition metal dichalcogenide compound, has attracted great attention as an emerging two-dimensional (2D) material due to wide recognition of its potential in and optoelectronics. One of the many fascinating properties of 2D MoS2 film is that its properties depend on the thickness of the film. In addition, its properties can be modified once the film is modified chemically. Hence one of the challenges in this field is the ability to create microdevices out of the MoS2 film comprising components with different thickness or chemical nature.
To address this technological challenge, Prof Sow, Dr Lu Junpeng, a postdoctoral candidate from the Department of Physics at the NUS Faculty of Science, and their team members, utilised an optical microscope-focused laser beam setup to ‘draw’ micropatterns directly onto large area MoS2 films as well as to thin the films.
With this simple and low cost approach, the scientists were able to use the focused laser beam to selectively ‘draw’ patterns onto any region of the film to modify properties of the desired area, unlike other current methods where the entire film is modified.
Interestingly, they also found that the electrical conductivity and photoconductivity of the modified material had increased by more than 10 times and about five times respectively. The research team fabricated a photodetector using laser modified MoS2 film and demonstrated the superior performance of MoS2 for such application.
This innovation was first published online in the journal ACS Nano on 24 May 2014.
Hidden images ‘drawn’ by focused laser beam on silicon nanowires could improve optical functionalities
In a related study published in the journal Scientific Reports on 13 May 2014, Prof Sow led another team of researchers from the NUS Faculty of Science, in collaboration with scientists from Hong Kong Baptist University, to investigate how ‘drawing’ micropatterns on mesoporous silicon nanowires could change the properties of nanowires and advance their applications.
The team scanned a focused laser beam rapidly onto an array of mesoporous silicon nanowires, which are closely packed like the tightly woven threads of a carpet. They found that the focused laser beam could modify the optical properties of the nanowires, causing them to emit greenish-blue fluorescence light. This is the first observation of such a laser-modified behaviour from the mesoporous silicon nanowires to be reported.
The researchers systematically studied the laser-induced modification to gain insights into establishing control over the optical properties of the mesoporous silicon nanowires. Their understanding enabled them to ‘draw’ a wide variety of micropatterns with different optical functionalities using the focused laser beam.
To put their findings to the test, the researchers engineered the functional components of the nanowires with interesting applications. The research team demonstrated that the micropatterns created at a low laser power are invisible under bright-field optical microscope, but become apparent under fluorescence microscope, indicating the feasibility of hidden images.
The fast growing field of electronics and optoelectronics demands precise material deposition with application-specific optical, electrical, chemical, and mechanical properties.
To develop materials with properties that can cater to the industry’s demands, Prof Sow, together with his team of researchers, will extend the versatile focused laser beam technique to more nanomaterials. In addition, they will look into further improving the properties of MoS2 and mesoporous silicon with different techniques.
Story Source: The above story is based on materials provided by National University of Singapore. Note: Materials may be edited for content and length.
Journal Reference: Junpeng Lu, Jia Hui Lu, Hongwei Liu, Bo Liu, Kim Xinhui Chan, Jiadan Lin, Wei Chen, Kian Ping Loh, Chorng Haur Sow. Improved Photoelectrical Properties of MoS2Films after Laser Micromachining. ACS Nano, 2014; 8 (6): 6334 DOI: 10.1021/nn501821z
Cite This Page: MLA APA Chicago: National University of Singapore. “Scientists use simple, low cost laser technique to improve properties and functions of nanomaterials.” ScienceDaily. ScienceDaily, 22 July 2014.
Oceans vital for possibility for alien life
Date: July 20, 2014
Source: University of East Anglia
Summary: Researchers have made an important step in the race to discover whether other planets could develop and sustain life. New research shows the vital role of oceans in moderating climate on Earth-like planets Until now, computer simulations of habitable climates on Earth-like planets have focused on their atmospheres. But the presence of oceans is vital for optimal climate stability and habitability.
Researchers at the University of East Anglia have made an important step in the race to discover whether other planets could develop and sustain life.
New research published today in the journal Astrobiology shows the vital role of oceans in moderating climate on Earth-like planets.
Until now, computer simulations of habitable climates on Earth-like planets have focused on their atmospheres. But the presence of oceans is vital for optimal climate stability and habitability.
The research team from UEA’s schools of Mathematics and Environmental Sciences created a computer simulated pattern of ocean circulation on a hypothetical ocean-covered Earth-like planet. They looked at how different planetary rotation rates would impact heat transport with the presence of oceans taken into account.
Prof David Stevens from UEA’s school of Maths said: “The number of planets being discovered outside our solar system is rapidly increasing. This research will help answer whether or not these planets could sustain alien life.
“We know that many planets are completely uninhabitable because they are either too close or too far from their sun. A planet’s habitable zone is based on its distance from the sun and temperatures at which it is possible for the planet to have liquid water.
"But until now, most habitability models have neglected the impact of oceans on climate.
“Oceans have an immense capacity to control climate. They are beneficial because they cause the surface temperature to respond very slowly to seasonal changes in solar heating. And they help ensure that temperature swings across a planet are kept to tolerable levels.
“We found that heat transported by oceans would have a major impact on the temperature distribution across a planet, and would potentially allow a greater area of a planet to be habitable.
“Mars for example is in the sun’s habitable zone, but it has no oceans — causing air temperatures to swing over a range of 100OC. Oceans help to make a planet’s climate more stable so factoring them into climate models is vital for knowing whether the planet could develop and sustain life.
“This new model will help us to understand what the climates of other planets might be like with more accurate detail than ever before.”
‘The Importance of Planetary Rotation Period for Ocean Heat Transport’ is published in the journal Astrobiology on Monday, July 21, 2014. The research was funded by the Engineering and Physical Sciences Research Council (EPSRC).
Story Source: The above story is based on materials provided by University of East Anglia. Note: Materials may be edited for content and length.
Cite This Page: MLA APA Chicago: University of East Anglia. “Oceans vital for possibility for alien life.” ScienceDaily. ScienceDaily, 20 July 2014. .
Pic: Planet Earth. New research shows the vital role of oceans in moderating climate on Earth-like planets. The presence of oceans is vital for optimal climate stability and habitability, according to a new article. Credit: NASA/ GSFC/ NOAA/ USGS
universal-abyss: Give me some waves, dude! Exciting new way to narrow down and identify exoplanets.
Mysterious dance of dwarf galaxies may force a cosmic rethink
Date: July 21, 2014
Source: University of Sydney
Summary: The discovery that many small galaxies throughout the universe do not ‘swarm’ around larger ones like bees do but ‘dance’ in orderly disc-shaped orbits is a challenge to our understanding of how the universe formed and evolved. The researchers believe the answer may be hidden in some currently unknown physical process that governs how gas flows in the universe, although, as yet, there is no obvious mechanism that can guide dwarf galaxies into narrow planes.
The discovery that many small galaxies throughout the universe do not ‘swarm’ around larger ones like bees do but ‘dance’ in orderly disc-shaped orbits is a challenge to our understanding of how the universe formed and evolved.
The finding, by an international team of astronomers, including Professor Geraint Lewis from the University of Sydney’s School of Physics, is announced today in Nature.
“Early in 2013 we announced our startling discovery that half of the dwarf galaxies surrounding the Andromeda Galaxy are orbiting it in an immense plane” said Professor Lewis. “This plane is more than a million light years in diameter, but is very thin, with a width of only 300,000 light years.”
The universe contains billions of galaxies. Some, such as the Milky Way, are immense, containing hundreds of billions of stars. Most galaxies, however, are dwarfs, much smaller and with only a few billion stars.
For decades astronomers have used computer models to predict how these dwarf galaxies should orbit large galaxies. They had always found that they should be scattered randomly.
“Our Andromeda discovery did not agree with expectations, and we felt compelled to explore if it was true of other galaxies throughout the universe,” said Professor Lewis.
Using the Sloan Digital Sky Survey, a remarkable resource of colour images and 3-D maps covering more than a third of the sky, the researchers dissected the properties of thousands of nearby galaxies.
“We were surprised to find that a large proportion of pairs of satellite galaxies have oppositely directed velocities if they are situated on opposite sides of their giant galaxy hosts,” said lead author Neil Ibata of the Lycée International in Strasbourg, France.
“Everywhere we looked we saw this strangely coherent coordinated motion of dwarf galaxies. From this we can extrapolate that these circular planes of dancing dwarfs are universal, seen in about 50 percent of galaxies,” said Professor Geraint Lewis.
“This is a big problem that contradicts our standard cosmological models. It challenges our understanding of how the universe works including the nature of dark matter.”
The researchers believe the answer may be hidden in some currently unknown physical process that governs how gas flows in the universe, although, as yet, there is no obvious mechanism that can guide dwarf galaxies into narrow planes.
Some experts, however, have made more radical suggestions, including bending and twisting the laws of gravity and motion. “Throwing out seemingly established laws of physics is unpalatable,” said Professor Lewis, “but if our observations of nature are pointing us in this direction, we have to keep an open mind. That’s what science is all about.”
Story Source: The above story is based on materials provided by University of Sydney. Note: Materials may be edited for content and length.
Journal Reference: Neil G. Ibata, Rodrigo A. Ibata, Benoit Famaey, Geraint F. Lewis. Velocity anti-correlation of diametrically opposed galaxy satellites in the low-redshift Universe. Nature, 2014; DOI: 10.1038/nature13481
Cite This Page: MLA APA Chicago: University of Sydney. “Mysterious dance of dwarf galaxies may force a cosmic rethink.” ScienceDaily. ScienceDaily, 21 July 2014.
Pic: At approximately 2.5 million light-years away, the Andromeda galaxy, or M31, is our Milky Way’s largest galactic neighbor. Credit: NASA/JPL-Caltech
universal-abyss: Ah, galaxies dance to their own beat, causing a rethink of cosmological models? Interesting.
Children as young as three recognize ‘cuteness’ in faces of people, animals
Date: July 21, 2014
Source: University of Lincoln
Summary: Children as young as three are able to recognize the same ‘cute’ infantile facial features in humans and animals which encourage caregiving behavior in adults, new research has shown. A study investigating whether youngsters can identify baby-like characteristics – a set of traits known as the ‘baby schema’ – across different species has revealed for the first time that even pre-school children rate puppies, kittens and babies as cuter than their adult counterparts.
Pic: Baby schema: adults and babies. Credit: Image courtesy of University of Lincoln
Children as young as three are able to recognize the same ‘cute’ infantile facial features in humans and animals which encourage caregiving behavior in adults, new research has shown.
A study investigating whether youngsters can identify baby-like characteristics — a set of traits known as the ‘baby schema’ — across different species has revealed for the first time that even pre-school children rate puppies, kittens and babies as cuter than their adult counterparts.
The discovery that young children are influenced by the baby schema — a round face, high forehead, big eyes and a small nose and mouth — is a significant step towards understanding why humans are more attracted to infantile features, the study authors believe.
The baby schema has been proven to engender protective, care-giving behavior and a decreased likelihood of aggression toward infants from adults.
The research was carried out by PhD student Marta Borgi and Professor Kerstin Meints, members of the Evolution and Development Research Group in the School of Psychology at the University of Lincoln, UK.
Marta said: “This study is important for several reasons. We already knew that adults experience this baby schema effect, finding babies with more infantile features cuter.
“Our results provide the first rigorous demonstration that a visual preference for these traits emerges very early during development. Independently of the species viewed, children in our study spent more time looking at images with a higher degree of these baby-like features.
“Interestingly, while participants gave different cuteness scores to dogs, cats and humans, they all found the images of adult dog faces cuter than both adult cats and human faces.”
The researchers carried out two experiments with children aged between three and six years old: one to track eye movements to see which facial areas the children were drawn to, and a second to assess how cute the children rated animals and humans with infantile traits.
Pictures of human adults and babies, dogs, puppies, cats and kittens were digitally manipulated to appear ‘cuter’ by applying baby schema characteristics. The same source images were also made less cute by giving the subjects more adult-like features: a narrow face, low forehead, small eyes, and large nose and mouth — making this study more rigorous than previous work.
The children rated how cute they thought each image was and their eye movements were analysed using specialist eye-tracking software developed by the University of Lincoln.
The research could also lead to improved education in teaching children about safe behavior with dogs.
Professor Kerstin Meints, Professor in Developmental Psychology at Lincoln’s School of Psychology, supervised the research.
She said: “We have also demonstrated that children are highly attracted to dogs and puppies, and we now need to find out if that attractiveness may override children’s ability to recognise stress signalling in dogs.”
“This study will also lead to further research with an impact on real life, namely whether the ‘cuteness’ of an animal in rescue centres makes them more or less likely to be adopted.”
This research was published in the scientific journal Frontiers in Psychology.
Story Source: The above story is based on materials provided by University of Lincoln. Note: Materials may be edited for content and length.
Journal Reference: Borgi, M., Cogliati-Dezza, I., Brelsford, V., Meints, K., Cirulli, F. Baby schema in human and animal faces induces cuteness perception and gaze allocation in children. Frontiers in Psychology, July 2014 DOI: 10.3389/fpsyg.2014.00411
Cite This Page: MLA APA Chicago: University of Lincoln. “Children as young as three recognize ‘cuteness’ in faces of people, animals.” ScienceDaily. ScienceDaily, 21 July 2014.
from-dust-of-stars: Wow - How young we are, to choose who and what we find ‘cute.’ Fascinating!
Scientists experimentally re-create conditions deep inside giant planets, such as Jupiter and many exo-planets
Date: July 17, 2014
Source: DOE/Lawrence Livermore National Laboratory
Summary: Lawrence Livermore scientists for the first time have experimentally re-created the conditions that exist deep inside giant planets, such as Jupiter, Uranus and many of the planets recently discovered outside our solar system.
Researchers can now re-create and accurately measure material properties that control how these planets evolve over time, information essential for understanding how these massive objects form. This study focused on carbon, the fourth most abundant element in the cosmos (after hydrogen, helium and oxygen), which has an important role in many types of planets within and outside our solar system. The research appears in the July 17 edition of the journal Nature.
Using the largest laser in the world, the National Ignition Facility at Lawrence Livermore National Laboratory, teams from the Laboratory, University of California, Berkeley and Princeton University squeezed samples to 50 million times Earth’s atmospheric pressure, which is comparable to the pressures at the center of Jupiter and Saturn. Of the 192 lasers at NIF, the team used 176 with exquisitely shaped energy versus time to produce a pressure wave that compressed the material for a short period of time. The sample — diamond — is vaporized in less than 10 billionths of a second. Though diamond is the least compressible material known, the researchers were able to compress it to an unprecedented density greater than lead at ambient conditions.
"The experimental techniques developed here provide a new capability to experimentally reproduce pressure-temperature conditions deep in planetary interiors," said Ray Smith, LLNL physicist and lead author of the paper.
Such pressures have been reached before, but only with shock waves that also create high temperatures — hundreds of thousands of degrees or more — that are not realistic for planetary interiors. The technical challenge was keeping temperatures low enough to be relevant to planets. The problem is similar to moving a plow slowly enough to push sand forward without building it up in height. This was accomplished by carefully tuning the rate at which the laser intensity changes with time.
"This new ability to explore matter at atomic scale pressures, where extrapolations of earlier shock and static data become unreliable, provides new constraints for dense matter theories and planet evolution models," said Rip Collins, another Lawrence Livermore physicist on the team.
The data described in this work are among the first tests for predictions made in the early days of quantum mechanics, more than 80 years ago, which are routinely used to describe matter at the center of planets and stars.While agreement between these new data and theory are good, there are important differences discovered, suggesting potential hidden treasures in the properties of diamond compressed to such extremes. Future experiments on NIF are focused on further unlocking these mysteries.
Story Source: The above story is based on materials provided by DOE/Lawrence Livermore National Laboratory. Note: Materials may be edited for content and length.
Journal Reference: R. F. Smith, J. H. Eggert, R. Jeanloz, T. S. Duffy, D. G. Braun, J. R. Patterson, R. E. Rudd, J. Biener, A. E. Lazicki, A. V. Hamza, J. Wang, T. Braun, L. X. Benedict, P. M. Celliers, G. W. Collins. Ramp compression of diamond to five terapascals. Nature, 2014; 511 (7509): 330 DOI: 10.1038/nature13526
Cite This Page: MLA APA Chicago: DOE/Lawrence Livermore National Laboratory. “Scientists experimentally re-create conditions deep inside giant planets, such as Jupiter and many exo-planets.” ScienceDaily. ScienceDaily, 17 July 2014. .
Pic: The interior of the target chamber at the National Ignition Facility at Lawrence Livermore National Laboratory. The object entering from the left is the target positioner, on which a millimeter-scale target is mounted. Researchers recently used NIF to study the interior state of giant planets. Credit: Image by Damien Jemison/LLNL
universal-abyss: To look inside the Giant, to try to unravel their mysteries via simulations - Awesomely fun.