Archive for the ‘Science’ Category
2009
“The Opportunity rover has come across an odd-shaped, large, dark rock, about 0.6 meters (2 feet) across on the surface of Mars, which may be a meteorite. The rover team spotted the rock called “Block Island,” on July 18, 2009, in the opposite direction from which it was driving. The team then had the rover do a hard right (not really, but you know what I mean) and backtrack some 250 meters (820 feet) to study it closer. Oppy has been studying the rock with its alpha particle X-ray spectrometer to get composition measurements and to confirm if indeed it is a meteorite…
Block Island really does have a meteorite-like look to it. Stu suggested on his blog that it looks like several meteorites found on Earth, such as one of the Derrick Peak meteorites found in Antarctica, shown below. The Derrick Peak meteorites are iron meteorites, and about 27 were found in one location in Antarctica. Researchers believe they all came from one meteor shower…”
source universetoday.com
“The giant star Betelgeuse churns out gas bubbles that match its own size — and that’s how it can shed an entire solar mass in 10,000 years. That according to the sharpest-ever images of Orion’s second-brightest star, released this week by the European Organisation for Astronomical Research in the Southern Hemisphere (ESO)…
Betelgeuse, the second brightest star in the constellation of Orion (the Hunter), is a red supergiant, one of the biggest stars known, and almost 1,000 times larger than our Sun. It is also one of the most luminous stars known, emitting more light than 100,000 Suns. Red supergiants still hold several unsolved mysteries. One of them is just how these behemoths shed such tremendous quantities of material — about the mass of the Sun — in only 10,000 years. With an age of only a few million years, Betelgeuse is already nearing the end of its life and is soon doomed to explode as a supernova. When it does, the supernova should be seen easily from Earth, even in broad daylight.”
source: universetoday.com
“Engineers at the Charles Stark Draper Laboratory in Cambridge, MA, are developing a guidance, navigation, and control system for lunar landings that includes an onboard hazard-detection system able to spot craters, slopes, and rocks that could be dangerous to landing craft. In the Apollo missions of 40 years ago, astronauts steered the lander to a safe spot by looking out the window; the lander itself “had no eyes,” says Eldon Hall, a retired Draper engineer and one of the original electronics designers for Apollo’s navigation computer.
That meant there were some close calls with Apollo, says Tye Brady, the technical director for lunar landing at Draper, who demonstrated his team’s automated-landing and hazard-avoidance technology at last week’s celebration of the 40th anniversary of Apollo 11…”
source: technologyreview.com
“Dr. Dean Ransom, AgriLife Research wildlife ecologist in Vernon, has conducted a study of the roadrunner’s ecology and habitat for the past four years. Using radio telemetry and studying more than 50 nests, he and his staff have researched home range, habitat use, nesting ecology and dispersal of young since 2006. The roadrunner is fairly common across the southwestern U.S., but very little is known about the bird, Ransom said. As their name suggests, roadrunners spend most of their time walking and running along the ground, but are capable of flight when pressured. ‘It’s not graceful, but it works,’ he said.
Roadrunner behavior is somewhat unique, Ransom said. They are monogamous and likely mate for life. Also, the male helps in all facets of nesting and feeding the young, including incubating the eggs at night. Nesting activity begins in early April, he said. The nest typically is located in a tree or shrub, about 3-5 feet high, and usually in dense brush not far from an edge, such as a fence line or ranch road.Such nest placement allows ease of movement to and from the nest, quick escape from predators and open areas to hunt and forage for lizards and snakes that bask in the bare dirt, Ransom said.
Most nests are well hidden and difficult to find, he said. They are generally in the crook of a large single-trunk tree, using the main branch of the trunk for stability. The nest is a flat-platformed shallow bowl with the outer rim lined with fairly large twigs and resembles a large mockingbird nest. Roadrunners lay about four eggs on average per nest, but the clutch size can range as high as 10, Ransom said. In the larger clutches, many of the young don’t survive and older nestlings have been documented eating their younger siblings…”
source: eurekalert.org
“Artificial photosynthesis has yet to be cracked, but electrical engineers in the US think that synthetic leaves could be used to generate electricity in a different way – by sweating. Natural leaves constantly lose water through evaporation in a process called transpiration, which draws water from the roots to the very top of even the tallest trees. The new synthetic leaves also lose water through evaporation to create that mechanical water pump effect, and use it to generate power…
Michel Maharbiz at the University of California, Berkeley, working with colleagues at the University of Michigan and MIT, built their leaves from glass wafers shot through with a branching network of tiny water-filled channels arranged like the veins of a leaf. The smaller channels extend to the edge of the plate and have open ends that allow water to evaporate, drawing fluid along the leaf’s central stem at a rate of 1.5 centimetres per second.The researchers added metal plates to the walls of the central stem and connected them to a circuit. The charged plates and the water within the stem create a sandwich of two conducting layers separated by an insulating layer – in effect, a capacitor.The leaf is transformed into a source of power by periodically interrupting the water flowing into the leaf with air bubbles. Thanks to the different electrical properties of air and water, every time a bubble passes between the plates the capacitance of the device changes and a small electric current is generated, which passes to an external circuit where it’s used to pump up the voltage on a storage capacitor. ‘We use the mechanical energy in the liquid flow to change the capacitance and add energy to the capacitor,’ says Maharbiz…”
source: newscienties.com
“Neurons can protect themselves against infection with HIV, new research has demonstrated. They owe their hardiness to a protein called FEZ-1, made uniquely by neurons, and which appears to lock out the virus. The finding raises the possibility of new treatments to thwart HIV by using gene therapy or drugs to activate production of the same protein in cells other than neurons – especially the white blood cells most vulnerable to infection.
Mojgan Naghavi of University College Dublin, Ireland, along with her colleagues Juliane Haedicke and Craig Brown, established the protective effects of FEZ-1 by blocking production of the protein in human neurons. When they did this, the neurons became vulnerable to infection. Likewise, they successfully blocked the usual infections in other types of brain cells, such as microglia, by engineering them to manufacture FEZ-1…”
source: newscientist.com
“A SECOND look at sunspot drawings from the 1700s has clarified a puzzling episode in the sun’s history, and could lead to more accurate forecasts of dangerous solar outbursts.
The sun sometimes hurls clouds of plasma our way, which can fry satellites and knock out power grids on EarthMovie Camera. The outbursts are most common during solar maxima, when the dark blemishes of sunspots appear in greatest abundance on the sun.
Although there is an average of 11 years between solar maxima, predicting the exact timing and height of each peak is difficult as there is little historical data to plug into models. About two dozen solar cycles have occurred since reasonably complete records began. Now an analysis of historic sunspot drawings suggests that this patchy record had omitted a solar cycle from the late 1700s…”
source: newscientist.com
“A new study by psychologists at the University at Buffalo and the F. W. Olin College of Engineering finds that in the aftermath of national trauma, the ability to make sense out of what happened has implications for individual well-being and that the kinds of stories people tell about the incident predict very different psychological outcomes for them.
The study, “The Political is Personal: Narrating 9/11 and Psychological Well-Being,” is by Jonathan M. Adler, Ph.D., assistant professor of psychology at Olin, and Michael J. Poulin, Ph.D., assistant professor of psychology at UB.
‘Understanding the stories people tell about national events provides a unique opportunity to understand how individual well-being is linked to the state of the society,’ Poulin explains…”
source: buffalo.edu
“An invasion led by artificially intelligent machines. Conscious computers. A smartphone virus so smart that it can start mimicking you. You might think that such scenarios are laughably futuristic, but some of the world’s leading artificial intelligence (AI) researchers are concerned enough about the potential impact of advances in AI that they have been discussing the risks over the past year. Now they have revealed their conclusions.
Until now, research in artificial intelligence has been mainly occupied by myriad basic challenges that have turned out to be very complex, such as teaching machines to distinguish between everyday objects. Human-level artificial intelligence or self-evolving machines were seen as long-term, abstract goals not yet ready for serious consideration.
Now, for the first time, a panel of 25 AI scientists, roboticists, and ethical and legal scholars has been convened to address these issues, under the auspices of the Association for the Advancement of Artificial Intelligence (AAAI) in Menlo Park, California. It looked at the feasibility and ramifications of seemingly far-fetched ideas, such as the possibility of the internet becoming self-aware…”
source: newscientist.com
“The laboratory for photovoltaics of the University of Luxembourg has produced its first thin film solar cells made from compound semiconductors, already reaching a 12 percent efficiency.
Thin film solar cells are considered the next generation of solar cells and are expected to be considerably cheaper because they need much less material and energy in their production than today’s photovoltaic modules.
Researchers around the globe are racing to develop efficient thin film solar cells. The solar cells made in Luxembourg are based on a semiconductor made of copper, indium, gallium and selenium (CIGS) and made by a process with the potential for highest performance. Furthermore, the scientists of the University of Luxembourg produced another solar cell based on a new cheaper material, which does not contain the costly indium, and made by a low cost galvanic process. This solar cell has reached an efficiency of 3.2 percent. This is already close to the world record: the worldwide best cell based on this new material and prepared by a similar low cost process shows an efficiency of 3.4 percent…”
source: compoundsemi.com
“A liquid plume is spewing from Saturn’s icy moon Enceladus — but is it coming from heated ice on the surface, or a liquid ocean underneath?
Analysis of the plume’s chemistry, detailed in the Cassini (CICLOPS) image above and reported in Nature this week, may put the debate to rest.
Lead author Jack Hunter (J.H.) Waite, of the Southwest Research Institute in San Antonio, Texas and his colleagues say ammonia detected in the jets from Enceladus’ south pole provides the strongest evidence yet for the existence of liquid water beneath the surface.
A previous paper led by Frank Postberg of the University of Heidelberg in Germany, published in Nature just last month, reported the discovery of salts in E-ring particles derived from the plume, also suggestive of a liquid reservoir.”
source: universetoday.com
“A new genetic engineering technique could make it as easy to rewrite a genome as it is to read it.
Using the process, which grafts pieces of synthetic DNA into the genomes of dividing cells, researchers generated 15 billion different genomic patterns in just three days. The process would normally take years, and could eventually be used to produce industrial chemicals, drugs, fuel and anything else that comes out of bacteria.
‘Automated sequencing really advanced the way we can read genetic information. We hope automated genome engineering will advance the way we write genetic information,’ said Harris Wang, a Harvard University biophysicist.
Earlier methods of manipulating genomes involved a painstaking biological cut-and-paste process, with target genes removed, tweaked and reinserted, one at a time. Alternatively, bioengineers could use a mutagen that turned genomes to hash.
But Wang and George Church — a co-author of the study, and a pioneer in DNA synthesis, genome sequencing and all-purpose biotechnological wizardry — want to speed that process up.
Their technique, known as Multiplex Automated Genome Engineering, or MAGE, starts with single-stranded pieces of DNA, custom synthesized to fit on target sections of a genome. In a microscopic remix of the famous Dr. Frankenstein movie scene, a target cell is then jolted with energy, opening holes in its membrane. The DNA flows inside. When the cell divides, it uses the new DNA in copying itself.”
source: wired.com
“There’s a growing chorus of calls to send astronauts to Mars rather than the moon, but critics point out that such trips would be long and gruelling, taking about six months to reach the Red Planet. But now, researchers are testing a powerful new ion engine that could one day shorten the journey to just 39 days.
Traditional rockets burn chemical fuel to produce thrust. Most of that fuel is used up in the initial push off the Earth’s surface, so the rockets tend to coast most of the time they’re in space.
Ion engines, on the other hand, accelerate electrically charged atoms, or ions, through an electric field, thereby pushing the spacecraft in the opposite direction. They provide much less thrust at a given moment than do chemical rockets, which means they can’t break free of the Earth’s gravity on their own.
But once in space, they can give a continuous push for years, like a steady breeze at the back of a sailboat, accelerating gradually until they’re moving faster than chemical rockets.
Several space missions have already used ion engines, including NASA’s Dawn spacecraft, which is en route to the asteroids Vesta and CeresMovie Camera, and Japan’s spacecraft Hayabusa, which rendezvoused with the asteroid Itokawa in 2005.”
source: newscientist.com
“Nanoparticles are being developed to perform a wide range of medical uses – imaging tumors, carrying drugs, delivering pulses of heat. Rather than settling for just one of these, researchers at the University of Washington have combined two nanoparticles in one tiny package.
The result is the first structure that creates a multipurpose nanotechnology tool for medical imaging and therapy. The structure is described in a paper published online this week in the journal Nature Nanotechnology.
‘This is the first time that a semiconductor and metal nanoparticles have been combined in a way that preserves the function of each individual component,’ said lead author Xiaohu Gao, a UW assistant professor of bioengineering.
The current focus is on medical applications, but the researchers said multifunctional nanoparticles could also be used in energy research, for example in solar cells…”
source: eurekalert.com
“Since fears of manmade global warming — and potential legislation or regulations of carbon dioxide emissions — are based mostly upon the output of climate models, it is important for people to understand the basics of what climate models are, how they work, and what their limitations are…
Generally speaking, a climate model is a computer program mostly made up of mathematical equations. These equations quantitatively describe how atmospheric temperature, air pressure, winds, water vapor, clouds, and precipitation all respond to solar heating of the Earth’s surface and atmosphere. Also included are equations describing how the so-called “greenhouse” elements of the atmosphere (mostly water vapor, clouds, carbon dioxide, and methane) keep the lower atmosphere warm by providing a radiative ‘blanket’ that partly controls how fast the Earth cools by loss of infrared to outer space…”
source: drroyspencer.com