New way to probe Earth’s deep interior using particle physics proposed Reply

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Researchers from Amherst College and The University of Texas at Austin have described a new technique that might one day reveal in higher detail than ever before the composition and characteristics of the deep Earth.

There’s just one catch: The technique relies on a fifth force of nature (in addition to gravity, the weak and strong nuclear forces and electromagnetism) that has not yet been detected, but which some particle physicists think might exist. Physicists call this type of force a long-range spin-spin interaction. If it does exist, this exotic new force would connect matter at Earth’s surface with matter hundreds or even thousands of kilometers below, deep in Earth’s mantle. In other words, the building blocks of atoms—electrons, protons, and neutrons—separated over vast distances would “feel” each other’s presence. The way these particles interact could provide new information about the composition and characteristics of the mantle, which is poorly understood because of its inaccessibility.

 

“The most rewarding and surprising thing about this project was realizing that particle physics could actually be used to study the deep Earth,” says Jung-Fu “Afu” Lin, associate professor at The University of Texas at Austin’s Jackson School of Geosciences and co-author of the study appearing this week in the journal Science.

 

This new force could help settle a scientific quandary. When earth scientists have tried to model how factors such as iron concentration and physical and chemical properties of matter vary with depth—for example, using the way earthquake rumbles travel through the Earth or through laboratory experiments designed to mimic the intense temperatures and pressures of the deep Earth—they get different answers. The fifth force, assuming it exists, might help reconcile these conflicting lines of evidence.

 

Earth’s mantle is a thick geological layer sandwiched between the thin outer crust and central core, made up mostly of iron-bearing minerals. The atoms in these minerals and the subatomic particles making up the atoms have a property called spin. Spin can be thought of as an arrow that points in a particular direction. It is thought that Earth’s magnetic field causes some of the electrons in these mantle minerals to become slightly spin-polarized, meaning the directions in which they spin are no longer completely random, but have some preferred orientation. These electrons have been dubbed geoelectrons.

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Temporary Electronic Tattoos Could Make Telepathy, Telekinesis Possible Reply

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Temporary electronic tattoos could soon help people fly drones with only thought and talk seemingly telepathically without speech over smartphones, researchers say. Commanding machines using the brain is no longer the stuff of science fiction. In recent years, brain implants have enabled people to control robotics using only their minds, raising the prospect that one day patients could overcome disabilities using bionic limbs or mechanical exoskeletons.

 

But brain implants are invasive technologies, probably of use only to people in medical need of them. Instead, electrical engineer Todd Coleman at the University of California at San Diego is devising noninvasive means of controlling machines via the mind, techniques virtually everyone might be able to use. His team is developing wireless flexible electronics one can apply on the forehead just like temporary tattoos to read brain activity.

“We want something we can use in the coffee shop to have fun,” Coleman says.

 

The devices are less than 100 microns thick, the average diameter of a human hair. They consist of circuitry embedded in a layer or rubbery polyester that allow them to stretch, bend and wrinkle. They are barely visible when placed on skin, making them easy to conceal from others. The devices can detect electrical signals linked with brain waves, and incorporate solar cells for power and antennas that allow them to communicate wirelessly or receive energy. Other elements can be added as well, like thermal sensors to monitor skin temperature and light detectors to analyze blood oxygen levels.

 

Using the electronic tattoos, Coleman and his colleagues have found they can detect brain signals reflective of mental states, such as recognition of familiar images. One application they are now pursuing is monitoring premature babies to detect the onset of seizures that can lead to epilepsy or brain development problems. The devices are now being commercialized for use as consumer, digital health, medical device, and industrial and defense products by startup MC10 in Cambridge, Mass.

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Next Generation Solar Cells Made From Graphene — One Photon Can Be Converted Into Multiple Electrons Reply

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A new discovery by researchers at the ICFO has revealed that graphene is even more efficient at converting light into electricity than previously known. Graphene is capable of converting a single photon of light into multiple electrons able to drive electric current. The discovery is an important one for next-generation solar cells, as well as other light-detecting and light-harvesting technologies.

 

A paradigm shift in the materials industry is likely within the near-future as a variety of unique materials replaces those that we commonly use today, such as plastics. Among these new materials, graphene stands out. The single-atom-thick sheet of pure carbon has an enormous number of potential applications across a variety of fields. Its potential use in high-efficiency, flexible, and transparent solar cells is among the potential applications. Some of the other most discussed applications include: foldable batteries/cellphones/computers, extremely thin computers/displays, desalination and water purificationtechnology, fuel distillation, integrated circuits, single-molecule gas sensors, etc.

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According to New Findings, Subsurface Life On Mars Was Once Possible Reply

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McLaughlin Crater is 90.92 km (56.50 mi) in diameter and 2.2 km (1.4 mi) deep with a floor that is well below Martian “sealevel” and contains clays that bear iron and magnesium as well as carbonate.

 

By the time eukaryotic life or photosynthesis evolved on Earth, the martian surface had become extremely inhospitable, but the subsurface of Mars could potentially have contained a vast microbial biosphere. Crustal fluids may have welled up from the subsurface to alter and cement surface sediments, potentially preserving clues to subsurface habitability. Many ancient, deep basins lack evidence for groundwater activity. However, McLaughlin Crater, one of the deepest craters on Mars, contains evidence for Mg–Fe-bearing clays and carbonates that probably formed in an alkaline, groundwater-fed lacustrine setting. This environment strongly contrasts with the acidic, water-limited environments implied by the presence of sulphate deposits that have previously been suggested to form owing to groundwater upwelling. Deposits formed as a result of groundwater upwelling on Mars, such as those in McLaughlin Crater, could preserve critical evidence of a deep biosphere on Mars. Scientists suggest that groundwater upwelling on Mars may have occurred sporadically on local scales, rather than at regional or global scales.

 

“This environment strongly contrasts with the acidic, water-limited environments implied by the presence of sulphate deposits that have previously been suggested to form owing to groundwater upwelling.”

 

Water-made channels which are now dry, appear to flow down the walls of McLaughlin Crater and stop well above the crater floor, which indicates they once provided water to a lake. “The deposits in McLaughlin Crater could have very high preservation potential for organic materials, in much the same manner as turbidites do on Earth.”

 

Cyanobacteria, which are common in alkaline lakes on Earth may have aided in the formation of carbonate minerals in lakes such as the McLAughlin Crater on Mars. Sometimes these bacteria become form microscopic fossils. If similar conditions existed in the craters ancient alkaline lake fossils of micro-organisms may still be there awaiting us.

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First evidence for extraterrestrial life might come from dying stars Reply

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Even dying stars could host planets with life—and if such life exists, we might be able to detect it within the next decade. This encouraging result comes from a new theoretical study of Earth-like planets orbiting white dwarf stars. Researchers found that we could detect oxygen in the atmosphere of a white dwarf’s planet much more easily than for an Earth-like planet orbiting a Sun-like star.

“In the quest for extraterrestrial biological signatures, the first stars we study should be white dwarfs,” said Avi Loeb, theorist at the Harvard-Smithsonian Center for Astrophysics (CfA) and director of the Institute for Theory and Computation.

 

When a star like the Sun dies, it puffs off its outer layers, leaving behind a hot core called a white dwarf. A typical white dwarf is about the size of Earth. It slowly cools and fades over time, but it can retain heat long enough to warm a nearby world for billions of years.

 

Since a white dwarf is much smaller and fainter than the Sun, a planet would have to be much closer in to be habitable with liquid water on its surface. A habitable planet would circle the white dwarf once every 10 hours at a distance of about a million miles.

 

Before a star becomes a white dwarf it swells into a red giant, engulfing and destroying any nearby planets. Therefore, a planet would have to arrive in the habitable zone after the star evolved into a white dwarf. A planet could form from leftover dust and gas (making it a second-generation world), or migrate inward from a larger distance.

 

If planets exist in the habitable zones of white dwarfs, we would need to find them before we could study them. The abundance of heavy elements on the surface of white dwarfs suggests that a significant fraction of them have rocky planets. Loeb and his colleague Dan Maoz (Tel Aviv University) estimate that a survey of the 500 closest white dwarfs could spot one or more habitable Earths.

 

The best method for finding such planets is a transit search – looking for a star that dims as an orbiting planet crosses in front of it. Since a white dwarf is about the same size as Earth, an Earth-sized planet would block a large fraction of its light and create an obvious signal.

 

More importantly, we can only study the atmospheres of transiting planets. When the white dwarf’s light shines through the ring of air that surrounds the planet’s silhouetted disk, the atmosphere absorbs some starlight. This leaves chemical fingerprints showing whether that air contains water vapor, or even signatures of life, such as oxygen.

See on phys.org

Space-based solar farms would solve mankind’s energy needs overnight, but there are huge technical hurdles Reply

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“Ex-Nasa scientist seeks visionary billionaire to help change the world.  High risk venture. Return not guaranteed. GSOH a plus.”

 

John Mankins, the scientist in question, has not yet reached the point of placing a classified ad, but it could soon be an option. The 25-year veteran of the US space agency is the man behind a project called SPS-Alpha, which aims to loft tens of thousands of lightweight, inflatable modules into space. Once there, they will be assembled into a huge bell-shaped structure that will use mirrors to concentrate energy from the sun onto solar panels. The collected energy would then be beamed down to ground stations on Earth using microwaves, providing unlimited, clean energy and overnight reducing our reliance on polluting fossil fuels. The snag? It is unproven technology and he estimates it will take at least $15 B – $20 B to get his project off the ground.

 

Mankins initially had research funding from an advanced concepts arm at Nasa, but that money dried up in September 2012; hence his continuing search for a benefactor. “I can’t think of a better solution than to find somebody who is very wealthy, very visionary and willing to make this happen,” he says.

 

But not everyone shares Mankins’ optimism. Space-based solar power (SBSP) is a topic that divides the scientific world into extremes. On one side are people like Mankins who believe it is the only solution to our ever increasing energy demands, whilst on the other is a sizeable chunk of the scientific community who believe any money put into solar power should remain firmly on the ground.

 

SBSP has its roots in the 1941 short story Reason, by Isaac Asimov, which depicts a space station – run by robots – collecting energy from the sun to distribute to Earth and other planets. No further thought was given to the idea until the late 1960s, when aerospace engineer Peter Glaser began to investigate its potential. In the following decades, various concepts were put forward but none took off. At the same timeNasa and the US Department of Energy also became involved, funding bits and pieces of research and commissioning reports into its feasibility. Most of these concluded that SBSP was too “high risk” and too costly.

 

But in recent years, SBSP has once again begun to attract attention with projects emerging in the US, Russia, China, India and Japan, amongst others. All are driven by increasing energy demands, soaring oil and gas prices, a desire to find clean alternatives to fossil fuels and by a burgeoning commercial space industry that promises to lower the cost of entry into space and spur on a host of new industries.

 

“SBSP is the ultimate energy source for the world and eventually it’s going to replace nearly everything else,” says Ralph Nansen of US-based advocacy group Solar High, with some of the characteristic hyperbole that defines both sides of the SBSP debate. “I don’t think there’s any doubt that within the next century we will be getting the majority of our power from space. It’s just a question of when.”

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