ScienceDirect.com | Search through over 10 million science, health, medical journal full text articles and books. Extinguish a fire by blasting it with sound. Sandrine Ceurstemont, editor, New Scientist TV Forget blasting out your favourite tunes, you could now use speakers to put out a fire. A new video from the US Defense Advanced Research Projects Agency (DARPA) shows how to extinguish burning fuel by trapping it in an acoustic field generated by surrounding speakers.
By using specific frequencies, a fire is killed in a two-pronged attack. First, sound increases the air speed, thinning the layer where combustion occurs and thus making it easier to disrupt the flame. But the acoustics also disturb the surface of the fuel which increases vaporisation, widening the flame and cooling its overall temperature. Whereas typical firefighting techniques disrupt chemical reactions involved in combustion, DARPA has been looking at approaches like this one that exploit physics. If you enjoyed this post, watch a knitted suit resist 1000 ˚C flames or see how to fight a fire in space. Meteorite Hunter Discovers New Mineral | Wired Science.
Hidden within a rock from space is a mineral previously unknown to science: panguite. The new mineral was found embedded in the Allende meteorite, which fell to Earth in 1969. Since 2007, geologist Chi Ma of Caltech has been probing the meteorite with a scanning electron microscope, discovering nine new materials, including panguite. Ma and his team have determined that panguite was one of the first solid materials to coalesce in our solar system, roughly 4.567 billion years ago.
The mineral’s name is a reference to Pan Gu, a primitive, hairy giant from Chinese mythology who separated yin and yang with a swing of his enormous axe, thereby creating the Earth and sky. Panguite’s primordial nature means that it was actually around before the Earth and other planets formed, meaning it can help scientists learn more about the conditions in the cloud of gas and dust that gave rise to our solar system.
Image: Chi Ma/Caltech. Magnets in a copper pipe. Scientists capture the shadow cast by a single atom. A team of researchers at Griffith University has managed to stretch the capabilities of microscopy to its ultimate limit. Culminating a five-years effort, the scientists have obtained a digital image of the shadow cast by a single atom, in a development that might soon lead to important advances in scientific observations ranging from the very big to the very small. Holding an atom in place long enough to take its picture has been within our technological grasp for some time. This is done by isolating the atom inside a chamber and holding it still through electrical forces, a method known as a radiofrequency Paul Trap (named after Wolfgang Paul, who shared the Nobel Prize in Physics in 1989 for this work).
The researchers trapped single ytterbium ions using this technique and exposed them to a very specific frequency of laser light. Under this light, the atom's shadow was cast onto a detector and then captured by a digital camera. Intricate, often invisible land-sea ecological chains of life threatened with extinction around the world. Douglas McCauley and Paul DeSalles did not set out to discover one of the longest ecological interaction chains ever documented. But that's exactly what they and a team of researchers -- all current or former Stanford students and faculty -- did in a new study published in Scientific Reports. Their findings shed light on how human disturbance of the natural world may lead to widespread, yet largely invisible, disruptions of ecological interaction chains. This, in turn, highlights the need to build non-traditional alliances -- among marine biologists and foresters, for example -- to address whole ecosystems across political boundaries.
This past fall, McCauley, a graduate student, and DeSalles, an undergraduate, were in remote Palmyra Atoll in the Pacific tracking manta rays' movements for a predator-prey interaction study. Palmyra is a unique spot on Earth where scientists can compare largely intact ecosystems within shouting distance of recently disturbed habitats. 10 Mind-Blowing Discoveries This Week | Environment. Photo Credit: Sabino Parente/Shutterstock.com July 20, 2012 | Like this article? Join our email list: Stay up to date with the latest headlines via email. We’ve talked about this before. And I don’t mean to minimize your troubles. 1. This week saw a lot of encouraging news on the disease-eradication front: the FDA approval of Truvada , the first HIV preventative drug and the possibility that a peptide in spider venom -- specifically that of the Chilean rose tarantula -- could thwart the progression of muscular dystrophy.
Did I lie? Most cases occur in South Sudan and people who get it try to stem the pain of the exit by putting their feet in water -- and guess what happens? But through the efforts of the Carter Center and other groups the guinea worm is on its way out…of the world. “We are approaching the demise of the last guinea worm who will ever live on earth,” says former US president Jimmy Carter, namesake of the Carter Center.
One thing’s for sure. 2. Lone wolves are overrated. Wolves are highly competent – relatively more so than the criminals we often refer to as lone wolves. Psychologist Knut Sturidsson thinks the term is inappropriate for the human oddballs who commit atrocities. (Photo: Colourbox) This week the Swede Peter Mangs was charged with the murder of three people and the attempted murder of a dozen others in Malmö. Mangs and the Norwegian mass murderer Anders Behring Breivik and lots of other extreme and violent criminals are often called lone wolves by the media, law enforcers and researchers.
What does that actually mean? According to psychologist Knut Sturidsson of the Karolinska Institute in Stockholm, the image of a single wolf on the prowl misses the mark: “I don’t think the concept really covers the essential character of these criminals,” he says. “The term lone wolf gives associations of a fairly competent criminal, one with authority, prowess and knowledge. Lone wolf − or stray mutt? Don’t jump to conclusions about insanity Knut Sturidsson. Cavity Waves: Displaced-Water "Pineapple" Wins Fluid Dynamics Competition: Scientific American Gallery.
When a rock, an Olympic diver or any other object hits the water, an air cavity forms behind it. Fluid dynamicists study the shapes of these cavities and how they change and close over time. When a disk with 20 petals was pulled through a tank of water, it created the cavity shown in this striking set of images. The disk moved at a constant speed of one meter per second. The air cavity pinched off just 200 milliseconds after the disk entered the water, a little before picture (e) in the diagram.
In order to study cavities created this way, researchers record video at 10,000 frames per second and analyze it frame by frame. Oscar Enriquez of the Physics of Fluids group at the University of Twente in the Netherlands studied the pineapple-shaped cavity for his master's thesis project. He and his collaborators, Ivo Peters, Stephan Gekle, Laura Schmidt, Devaraj van der Meer and Detlef Lohse then entered these images into the Gallery of Fluid Motion competition in 2010. —Evelyn Lamb.