With a lot of skillful maneuverings, a team of researchers have finally found a way to image a molecule. The portrait of pentacene, an organic molecule consisting of five benzene rings, shows off the chemical bonds between the carbon and hydrogen atoms.
It may seem a somewhat surprising first, since atoms have been imaged for decades. The earliest pictures of individual atoms were captured in the 1970s by blasting a target – typically a chunk of metal – with a beam of electrons, a technique known as transmission electron microscopy (TEM)…. But strange though it might seem, imaging larger molecules at the same level of detail has not been possible – atoms are robust enough to withstand existing tools, but the structures of molecules are not [New Scientist].
In the new study, published in Science, researchers used an atomic force microscope to image the molecule in unprecedented resolution. The measurement requires extremes of precision. In order to avoid the effects of stray gas molecules bounding around, or the general atomic-scale jiggling that room-temperature objects experience, the whole setup has to be kept under high vacuum and at blisteringly cold temperatures [BBC News]; 5 Kelvin, to be exact. Rather than relying on an optical system to produce pictures, atomic force microscopes use a probe that narrows to an atomic-scale tip, and measures the forces of attraction between the tip and the molecule’s components.
A prehistoric armadillo-like animal swung its tail like a baseball bat, taking advantage of the “sweet spot” the same way tennis and baseball players do today, according to a study published in the journal Proceedings of the Royal Society B.
The tail sported spikes at a specific location that allowed the mammals, known as glyptodonts, to deliver a strong blow while minimizing the risk of harming the tail, the researchers found; spiny-tailed dinosaurs may have used the same mechanism. Known as the “sweet spot” today in sports like baseball, this so-called “center of percussion” helps athletes avoid wrist injuries. “The center of percussion is a point where you can deliver a very powerful blow with a baseball bat, a tennis racket, a sword, an axe or any hand-held implement, but the forces against your hands are almost zero” [Discovery News], said lead author Rudemar Ernesto Blanco. The glyptodont, which went extinct about 8,000 years ago after its emergence about 2.5 million years ago, would have swung its tail about 15 meters per second–about as fast as a modern-day tennis player swinging his or her racket.
Physicists in Washington State and Louisiana recently spent two years hunting for the mysterious gravitational waves first predicted by Einstein, but detected nothing: zilch, zero, nada, nary a ripple. But that “null result” is itself of great value, researchers say, because it tells them where to look for the waves next. The findings are a nice reminder that scientific progress isn’t always about the dramatic discovery; it’s often a long, careful process of testing hypotheses, analyzing results, and heading back to the drawing board.
Einstein’s theory of general relativity states that every time mass accelerates — even when you rise up out of your chair — the curvature of space-time changes, and ripples are produced. However, the gravitational waves produced by one person are so small as to be negligible. The waves produced by large masses, though, such as the collision of two black holes or a large supernova explosion, could be large enough to be detected [SPACE.com].
Beyond those large disturbances, the universe is thought to be filled with small disturbances left over from the rapid period of expansion that followed the Big Bang, in a phenomenon known as the stochastic (meaning randomly distributed) gravitational wave background. If the expansion of the newborn universe had produced strong gravity waves, the physicists working at the two Laser Interferometer Gravitational-wave Observatory (LIGO) centers would have detected them. Since they found nothing, researchers have determined that smaller waves were produced, which they’ll need more sensitive instruments to detect. Says study coauthor Vuk Mandic: “We now know a bit more about parameters that describe the evolution of the universe when it was less than one minute old” [Sky & Telescope].
The next big leap in computing power may come from a surprising source: the genetic code. Researchers at IBM have found a way to use DNA strands as the scaffolding on which to place carbon nanotubes, creating tiny microchips that could eventually be more efficient and cheaper to produce than today’s silicon chips. To keep pace with Moore’s Law, which postulates that the number of transistors on an integrated circuit will double every two years, chip makers have to squeeze an increasing number of transistors onto every chip [Wired.com]. The new process offers an entirely different route to miniaturization.
Microchips are used in computers, cell phones and other electronic devices…. Right now, the tinier the chip, the more expensive the equipment. [An IBM spokesman] said that if the DNA origami process scales to production-level, manufacturers could trade hundreds of millions of dollars in complex tools for less than a million dollars of polymers, DNA solutions, and heating implements [Reuters].
Stephen Hawking, the world’s leading theoretical physicist, was among a group of 16 to receive the Presidential Medal of Freedom, the highest civilian award. The medal honors those who have significantly contributed to world peace, U.S. security or other endeavors.
Pres. Barack Obama presented the award, lauding Hawking’s immense contributions in spite of his physical disability due to a neurological disorder. “From his wheelchair, he has led us on a journey to the farthest and strangest reaches of the cosmos. In so doing, he has stirred our imagination and showed us the power of the human spirit,” [Sky News], Obama said of Hawking as he placed the medal around his neck. Besides his contributions to the field of physics through his research on topics like black holes and cosmology, Hawking, 67, is also the author of the best-selling science book A Brief History of Time.
The motion of jellyfish and other sea creatures might mix the oceans just as much as the winds and tides do, according to a study published in Nature. The study’s findings provide support for a theory called Darwin drift, which was developed by Charles Galton Darwin (the grandson of the Darwin). The theory holds that a body moving through water brings along some of the wet stuff.
To test the theory of Darwin drift, researchers first modeled the motion of swimming organisms in a lab, using liquids of various viscosities, or levels of internal resistance. They found that bodies drag more liquid along with them when the liquid is thicker. This effect can be significant; in fact, when marine plankton-sized objects moved a couple of body lengths forward in the most viscous liquids, they carried with them up to four times their volume in liquid. Next the researchers monitored jellyfish as they swam through clouds of dye in a lake on the Pacific island of Palau. A trail of dye followed each animal, as Darwin’s mechanism would predict. Using a laser-equipped camera, the team then measured the dye’s movement and the stirring of suspended particles in the animal’s wake [Nature News]. The scientists found that the mechanism proposed by Galton Darwin provided for 90 percent of the mixing between the water and the dye.
Scientists now know how the iridescent green scarab beetle’s shell get its iridescent hue: A molecular arrangement that reflects light, with the reflected light’s magnetic field oriented like a corkscrew, according to a study published in Science.
The beetles don’t appear green due to pigments, which give flowers and plants their colors. Instead, they get their hue from structural color, or molecular structures that reflect light in a certain manner–the same way birds and butterflies do. Light hitting the shell is reflected by the microstructures, and these reflections create an electric field that forms a clockwise helix. Humans cannot see this property — known as left-handed circular polarization — but can see a green hue [ScienceNews]; some organisms, however, can actually see circular polarization itself. The molecular structure consists of three shapes: pentagons, hexagons, and seven-sided heptagons.
The pitter-patter of raindrops on your umbrella is caused by raindrops of all different sizes, and now physicists have a new explanation for how those raindrops form. A pair of researchers used a high-speed camera (video below the jump) to watch a single drop of water fall and change shape over the course of six-hundredths of a second, and found that the shattering of single raindrops after they leave clouds is enough to explain the wide variety of drop sizes [Science News].
Previously, the leading theory to explain the diversity of raindrops had been that raindrops grow as they gently bump into each other and coalesce. Meanwhile, more forceful collisions break other drops apart into a scattering of smaller droplets. All this action would explain the wide distribution of shapes and sizes [ScienceNOW Daily News]. But lead researcher Emmanuel Villermaux says he questioned that theory, with its supposition of frequent collisions. Real raindrops are so sparse, he said, that it is likely a drop would “fall on its own and never see its neighbours” [BBC News].
In the past century, jockeys have helped their horses race about six percent faster, thanks to a position on the horse known as the “monkey crouch.” This elevated, squatting stance minimizes the work the horse must do to propel his rider forward, according to a study published in Science.
To analyze the movement of the horse and jockey while racing, scientists attached sensors to the saddle and the jockey’s belt. They found that when a horse runs, it also moves up and down, bringing the jockey along with it. The rider can therefore weigh the horse down or, in the case of the monkey crouch, he can isolate himself from the horse’s motions, and therefore minimize his effect on the horse’s movement. When seated upright, riders act much like sandbags, weighing down the horse and incurring increased mechanical and metabolic costs. But in the crouched … position, a jockey can move relative to the horse and minimize this forward-backward and up-and-down movement [Scientific American].
The sandfish lizard appears to “swim” like a fish through sand, but how exactly the animal does it has long puzzled biophysicists. Now, a study published in Science reveals that the four-legged creature really does swim through sand like it would in water by retracting its legs and undulating its body.
To examine the lizard’s movement, researchers had to peek underground. They did this using X-ray imaging, and found that once the lizard, or skink, has dived beneath the sand, it doesn’t paddle. “When started above the surface, the animals dive into the sand within half a second. Once below the surface, they no longer use their limbs for propulsion — instead, they move forward by propagating a traveling wave down their bodies like a snake,” said study leader Daniel Goldman [LiveScience]. This movement was surprising because previous magnetic resonance imaging studies seemed to suggest that the lizards pushed themselves along using their legs.
Astronomers have caught sight of two stars that went kaboom only 2.5 billion years after our universe was created in the Big Bang, and say that ancient explosions are the oldest and most distant supernovas ever discovered. Researchers plan to use the new technique used to identify these supernovas to find other stars that blew up in the universe’s early days, which may aid our understanding of how the universe was seeded with heavy elements.
Only a few lightweight elements – hydrogen, helium, and lithium – are thought to have been created in the big bang; all others were forged over time in the nuclear furnaces of stars and in supernovae. Since the spectrum of light from a supernova reveals the chemical composition of the exploding star, observing many such explosions would allow astronomers to trace out a chemical history of the universe [New Scientist]. Heavier metals eventually gathered in the clouds of dust that surrounded young stars, and sometimes formed parts of rocky planets like Earth.
The European Space Agency’s Planck observatory has reached its operating temperature of a mere tenth of a degree above the lowest temperature theoretically possible given the laws of physics, known as absolute zero. That means it’s ready for its mission: Observing the oldest light in the universe, known as the cosmic microwave background, or CMB, to create the clearest picture yet of what the young universe looked like.
Although scientists have achieved temperatures closer than this to absolute zero in the laboratory, the spacecraft is likely the coldest object in space. Such low temperatures are necessary for Planck’s detectors to study the Cosmic Microwave Background by measuring its temperature across the sky. Over the next few weeks, mission operators will fine-tune the spacecraft’s instruments. Planck will begin to survey the sky in mid-August [SPACE.com], and the first batch of data is expected to be released next year. Planck was launched May 14 and will observe the CMB from a spot more than 930,000 miles from Earth.
Astronomers believe they’ve found something never before detected in the universe: a black hole of intermediate size. And while that may not sound thrilling to the layman, researchers are thrilled by the discovery of the so-called “Hyper-Luminous X-ray Source 1,” which is poised at the edge of galaxy ESO 243-49. Astronomers are excited because they’ve seen plenty of small black holes and large black holes, but experts had questioned whether a medium-sized variety could exist. These middleweights, at about 500 times the mass of the sun, could represent a missing link between common stellar black holes, created by the death of a single star, and the supermassive variety that can pack the mass of millions or even billions of suns [SPACE.com].
Astronomers explain that small black holes, between three and 20 times the mass of the sun, are created when big stars collapse and leave behind a gravitational pull strong enough to block nearby light rays. Researchers have speculated that super-massive black holes result from the successive fusion of many smaller black holes. But without finding evidence of a medium-size hole, it was a tough theory to prove [Wired.com]. Supermassive black holes are of particular interest because they lurk at the hearts of most galaxies, and may play an important role in galaxy formation.
Computers powered by frickin’ laser beams just came a step closer. Light-based, or photonic, computers would theoretically be much faster and smaller than the electronic computers we use today, but researchers have had a hard time putting theory into action. Now, a new study has shown that two laser beams can be harnassed to turn a single molecule into a transistor. However, the specialized conditions necessary for the trick to work mean that computer stores won’t have photonic sections anytime soon.
Conventional computers are based on transistors, which allow one electrode to control the current moving through the device and are combined to form logic gates and processors. The new component achieves the same thing, but for laser beams, not electric currents. A green laser beam is used to control the power of an orange laser beam passing through the device [New Scientist]. In the study, published in Nature, the green beam could make the orange beam either weak or strong, which is analagous to an electronic transistor turning a current on or off.
Scientists have found a way to safely store notoriously dangerous white phosphorus on the atomic scale: in a cage made of atoms that can only be unlocked by a specific molecule, according to a study published in the journal Science.Containing white phosphorus, a tetrahedral formation of phosphorus atoms, will be useful because the molecule readily reacts if it comes into contact with air.
It’s not surprising, then, that it is often used in military campaigns to create smokescreens to mask movement from the enemy, as well as an incendiary in bombs, artillery and mortars [ScienceDaily]. White phosphorus is also an essential ingredient in many plant fertilizers and weed killers, so the ability to safely transport and store the molecule would also be an asset for those industries.
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With a lot of skillful maneuverings, a team of researchers have finally found a way to image a molecule. The portrait of pentacene, an organic molecule consisting of five benzene rings, shows off the chemical bonds between the carbon and hydrogen atoms.
A prehistoric armadillo-like animal swung its tail like a baseball bat, taking advantage of the “sweet spot” the same way tennis and baseball players do today, according to a 
Physicists in Washington State and Louisiana recently spent two years hunting for the mysterious gravitational waves first predicted by 
The next big leap in 
Scientists now know how the iridescent green scarab 
The pitter-patter of raindrops on your umbrella is caused by raindrops of all different sizes, and now physicists have a new explanation for how those raindrops form. A pair of researchers used a high-speed camera (video below the jump) to watch a single drop of water fall and change shape over the course of six-hundredths of a second, and found that the shattering of single raindrops after they leave clouds is enough to explain the wide variety of drop sizes [
In the past century, jockeys have helped their 
The sandfish 
Astronomers have caught sight of two stars that went kaboom only 2.5 billion years after our universe was created in the 
The European Space Agency’s 
Astronomers believe they’ve found something never before detected in the universe: a 
Computers powered by frickin’ laser beams just came a step closer. Light-based, or photonic, computers would theoretically be much faster and smaller than the electronic 
Scientists have found a way to safely store notoriously dangerous white phosphorus on the atomic scale: in a cage made of atoms that can only be unlocked by a specific molecule, according to a 
