Science & TechnologyS


Telescope

Ganymede Has a Magnetic Field

Tudor Vieru
Softpedia
Wed, 20 Jul 2011 03:48 UTC
Image
© NASA/JPLThis mosaic of images shows the surface of the Jovian moon Ganymede
Investigators recently discovered that Ganymede, in orbit around Jupiter, is the only moon in our entire solar system to feature a magnetic field. Thus far, studies only identified such structures on planets such as Earth and some of the gas giants.

One of the easiest way to check for the existence of magnetic fields is to try and see whether the object you are interested in features auroras at its poles. The northern/southern lights are always produced by the interactions between a magnetosphere and charged particles from the Sun.

The latter come in waves, and slam against specific layers of the atmosphere, that repel the. However, there is currently no known mechanism through which a magnetosphere can exist without a magnetic field. And the existence of a magnetic field calls for some very specific properties.

For example, as far as our planet goes, the magnetosphere is created by the motions of the solid core inside a thick layer of magma in the mantle. The core is made up almost entirely out of iron, and so the motion creates a huge dynamo effect.
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Beaker

US: DARPA project seeks immortality, suspended animation

John Oates
The Register
Tue, 19 Jul 2011 03:26 UTC
Shot? Blown up? Chill out until you reach hospital

The Defense Advanced Research Projects Agency (DARPA) is offering money to researchers looking at identifying and controlling timing mechanisms in cells, including those of the human body.

The blue sky gazing loon-collective notes that no single "master switch" has been found to control genes' activities.

But it hopes that the "Biochronicity" programme will find a way to understand and predict "temporal features of biological systems".

The four-year programme will start by identifying "episequences and validation in experimental biological systems".

After two years, DARPA hopes to move to Phase II, which aims to conduct Live Fire Tests.
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Question

Twisted Tale of Our Galaxy's Ring: Strange Kink in Milky Way


Science Daily
Tue, 19 Jul 2011 16:45 UTC
Milky Way
© ESA/NASA/JPL-CaltechIn a strange twist of science, astronomers using the Herschel Space Observatory have discovered that a suspected ring at the center of our galaxy is warped for reasons they cannot explain.

New observations from the Herschel Space Observatory show a bizarre, twisted ring of dense gas at the center of our Milky Way galaxy. Only a few portions of the ring, which stretches across more than 600 light-years, were known before. Herschel's view reveals the entire ring for the first time, and a strange kink that has astronomers scratching their heads.

"We have looked at this region at the center of the Milky Way many times before in the infrared," said Alberto Noriega-Crespo of NASA's Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. "But when we looked at the high-resolution images using Herschel's sub-millimeter wavelengths, the presence of a ring is quite clear." Noriega-Crespo is co-author of a new paper on the ring published in a recent issue of Astrophysical Journal Letters.

The Herschel Space Observatory is a European Space Agency-led mission with important NASA contributions. It sees infrared and sub-millimeter light, which can readily penetrate through the dust hovering between the bustling center of our galaxy and us. Herschel's detectors are also suited to see the coldest stuff in our galaxy.

When astronomers turned the giant telescope to look at the center of our galaxy, it captured unprecedented views of its inner ring -- a dense tube of cold gas mixed with dust, where new stars are forming.
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Info

Taste Test: Swiss Chocolate vs. Made in China

Remy Melina
Live Science
Tue, 19 Jul 2011 12:08 UTC
Chocolate
© stockxpertKnowing the origin of a bar of chocolate — whether it's from Switzerland or China — sets up participants' expectations and seemed to influence how much they enjoy the candy, a new study shows.
Swiss chocolate's reputation influences how people rate it in taste tests, a new study shows. When consumers are told that they're about to eat a chocolate bar from Switzerland, they prefer it to that same bar tagged "made in China."

If they are told about the Swiss chocolate bar's origin after they taste the candy, however, they say they prefer the Chinese chocolate.

Researchers from Babson Collegein Wellesley, Mass., gave participants the same squares of Trader Joe's brand chocolate. Half of the participants were told that the chocolate was made in Switzerland, while the other half were told it was made in China.

"When they were given the country of origin before tasting, the students liked the chocolate more when they were told it was from Switzerland," the authors write in a recent issue of the Journal of Consumer Research. "This was expected because Switzerland has a strong reputation for chocolate whereas China does not."
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Clock

Why Does Time Fly?

Martin P. Paulus
Scientific American
Tue, 19 Jul 2011 14:30 UTC
Clock
© Sawayasu TsujiSome seconds are longer than others.
Everybody knows that the passage of time is not constant. Moments of terror or elation can stretch a clock tick to what seems like a life time. Yet, we do not know how the brain "constructs" the experience of subjective time. Would it not be important to know so we can find ways to make moments last, or pass by, more quickly?

A recent study by van Wassenhove and colleagues is beginning to shed some light on this problem. This group used a simple experimental set up to measure the "subjective" experience of time. They found that people accurately judge whether a dot appears on the screen for shorter, longer or the same amount of time as another dot. However, when the dot increases in size so as to appear to be moving toward the individual -- i.e. the dot is "looming" -- something strange happens. People overestimate the time that the dot lasted on the screen. This overestimation does not happen when the dot seems to move away. Thus, the overestimation is not simply a function of motion. Van Wassenhove and colleagues conducted this experiment during functional magnetic resonance imaging, which enabled them to examine how the brain reacted differently to looming and receding.
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Question

Does the Multiverse Really Exist?

George F. R. Ellis
Scientific American
Tue, 19 Jul 2011 14:18 UTC
Multiverse
© Levi Brown
In the past decade an extraordinary claim has captivated cosmologists: that the expanding universe we see around us is not the only one; that billions of other universes are out there, too. There is not one universe - there is a multiverse. In Scientific American articles and books such as Brian Greene's latest, The Hidden Reality, leading scientists have spoken of a super-Copernican revolution.

In this view, not only is our planet one among many, but even our entire universe is insignificant on the cosmic scale of things. It is just one of countless universes, each doing its own thing.

The word "multiverse" has different meanings. Astronomers are able to see out to a distance of about 42 billion light-years, our cosmic visual horizon. We have no reason to suspect the universe stops there. Beyond it could be many - even infinitely many - domains much like the one we see. Each has a different initial distribution of matter, but the same laws of physics operate in all. Nearly all cosmologists today (including me) accept this type of multiverse, which Max Tegmark calls "level 1."
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Control Panel

Scientists Discover New Water Waves

Lisa Zyga
PhysOrg
Tue, 19 Jul 2011 08:30 UTC
Image
© Jean Rajchenbach, et al./American Physical SocietyThe even (left) and odd (right) standing solitary waves, whose motions can be seen in the video below.
By precisely shaking a container of shallow water, researchers have observed wave behavior that has never been seen before. In a new study, Jean Rajchenbach, Alphonse Leroux, and Didier Clamond of the University of Nice-Sophia Antipolis in Nice, France, have reported the observation of two new types of standing waves in water, one of which has never been observed before in any media.

In their study, which is published in a recent issue of Physical Review Letters, the scientists explain how they discovered the new waves. They confined water inside a Hele-Shaw cell, which is a container made of two parallel glass plates separated by a small gap. In this case, the plates were positioned vertically, like the two sides of an ant farm. The plates were 30 cm wide, and the gap between them was just 1.5 mm. The water inside was about 5 cm deep.

The researchers mounted the Hele-Shaw cell on a shaker, which vertically vibrated the cell and the water inside. While carefully controlling the vibration frequency and amplitude, they recorded the water surface deformation with a high-speed camera.

When the researchers slowly increased the oscillation amplitude, two-dimensional standing waves with large amplitudes began to form on the water's surface. As the researchers explained, these waves are called Faraday waves, which form on the surface of a vibrating fluid when the vibration frequency exceeds a certain value, and the surface becomes unstable.
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Frog

Tortoise Populations Can Withstand Fires Every 30 Years


PhysOrg
Tue, 19 Jul 2011 09:30 UTC
Image
© Andrés GiménezThe fire killed 100 percent of the spur-thighed tortoises (Testudo graeca) aged under four.
Populations of spur-thighed tortoises (Testudo graeca), a species classified as vulnerable and at risk of extinction, can withstand fires if outbreaks occur once every three decades or more. However, the youngest tortoises are more vulnerable, and disappear after each fire. These are the results of a study by Spanish researchers, who analysed the impact of a 2004 forest fire in the Sierra de la Carrasquilla mountains in Murcia (Spain) on these reptiles.

"Tortoises can withstand high temperatures, but this does not mean their shells are completely fire proof", Ana Sanz-Aguilar, lead author of the study, tells SINC. Currently a postdoctoral scholar at the Centre for Functional and Evolutionary Ecology in Montpellier, France, she collaborated with the Miguel Hernández University (UMH) and the Mediterranean Institute for Advanced Studies (IMEDEA-CSIC) for this research.

One such forest fire occurred on 1 August 2004 in the Sierra de la Carrasquilla mountains in Murcia, Spain, which incinerated a 250-hectare area that was home to a large population of these reptiles. The researchers have been studying the behaviour of more than 1,000 of the animals over the past decade.

The study, published in the journal Biological Conservation, shows that the tortoises' response to fire varied greatly according to their age, with the fire killing 100% of the animals aged under four and causing increased mortality rates of 62% in sub-adults (aged from 4 to 8) and 12% in adults (over 8 years of age).
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Telescope

Stellar Eclipse Gives Glimpse of Exoplanet

Jennifer Chu
PhysOrg
Tue, 19 Jul 2011 07:00 UTC
Image
© Jason Rowe/NASA/Ames/Jaymie Matthews/UBCA rendering of the silhouette of 55 Cancri e transiting its parent star, compared to the Earth and Jupiter transiting our sun. Image:
A group of astronomers led by an MIT professor has spotted an exoplanetary eclipse of a star only 40 light years away - right around the corner, astronomically speaking - revealing a "super-Earth."

The far-out planet, named 55 Cancri e, is twice as big as Earth and nearly nine times more massive. It is most likely composed of rocky material, similar to Earth, supplemented with light elements such as water and hydrogen gas. Scientists estimate the planet's surface is much hotter than ours: close to 2,700 degrees Celsius.

Exoplanets - planets outside our own solar system - have captivated astronomers in recent years as interest in finding life on other Earth-like planets has intensified.

But Josh Winn, the Class of 1942 Career Development Assistant Professor of Physics at MIT, says exobiologists should probably not flock to 55 Cancri e looking for signs of life: The temperatures are just too high to sustain living organisms. But he suspects the exoplanet will attract the telescopes of many astronomers, mainly for reasons of visibility: 55 Cancri e is relatively close to Earth compared to other known exoplanets, and, as a result, the star around which the planet orbits appears roughly 100 times brighter than any other star with an eclipsing planet.
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Telescope

Scientists Discover 10 New Planets


PhysOrg
Tue, 19 Jul 2011 08:00 UTC
Image
© Shutterstock
A total of 10 new planets have been unearthed by an international team of scientists, and one of these is orbiting a star just a few tens of millions years old.

Using the CoRoT (Convection, Rotation and Transits) space telescope, operated by the French Space Agency (CNES), astrophysicists from the UK and France were able to see planets from outside our solar system, so-called 'exoplanets', when they were in transit, i.e. when they passed in front of their stars.

As well as the planet orbiting the unusually young star, the team also uncovered seven hot Jupiter-like planets, two Neptune-sized planets orbiting the same star, and a planet slightly smaller than Saturn.

Dr. Suzanne Aigrain from the Department of Physics at Oxford University in the United Kingdom said: 'Finding planets around young stars is particularly interesting because planets evolve very fast initially, before settling into a much steadier pattern of evolution. If we want to understand the conditions in which planets form, we need to catch them within the first few hundred million years. After that, the memory of the initial conditions is essentially lost. In the case of CoRoT-18 [the planet orbiting the young star], different ways of determining the age give different results, but it's possible that the star might be only a few tens of millions of years old. If this is confirmed, then we could learn a lot about the formation and early evolution of hot gas giant planets by comparing the size of CoRoT-18b to the predictions of theoretical models.'
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