Anyone who has ever had a glass of fizzy soda knows that bubbles can throw tiny particles into the air. But in a finding with wide industrial applications, Princeton researchers have demonstrated that the bursting bubbles push some particles down into the liquid as well.
"It is well known that bursting bubbles produce aerosol droplets, so we were surprised, and fascinated, to discover that when we covered the water with oil, the same process injected tiny oil droplets into the water," said Howard Stone, professor of mechanical and aerospace engineering at Princeton and the lead researcher for the project.
By zapping the air with a pair of powerful laser bursts, researchers at the Univ. of Arizona have created highly focused pathways that can channel electricity through the atmosphere.
The technique can potentially direct an electrical discharge up to 33 feet away or more, shattering previous distance records for transmitting electricity through air. It also raises the intriguing possibility of one day channeling lightning with laser power.
Manmade earthquakes, a side effect of some high-tech energy drilling, cause less shaking and in general are about 16 times weaker than natural earthquakes with the same magnitude, a new federal study found.
People feeling the ground move from induced quakes — those that are not natural, but triggered by injections of wastewater deep underground— report significantly less shaking than those who experience more normal earthquakes of the same magnitude, according to a study by U.S. Geological Survey geophysicist Susan Hough.
Physicists at the Univ. of York, working with researchers at the Universities of Birmingham and Genoa, have developed new technology to study atomic vibration in small particles, revealing a more accurate picture of the structure of atomic clusters where surface atoms vibrate more intensively than internal atoms.
Using new computer technology based on gaming machines, scientists were able to use a combination of molecular dynamics and quantum mechanics calculations to simulate the electron microscopy of gold particles. By modelling the atomic vibration of individual atoms in such clusters realistically, external atoms on the surface of the structure can be seen to vibrate more than internal atoms.
Laser physicists have found a way to make atomic force microscope probes 20 times more sensitive and capable of detecting forces as small as the weight of an individual virus.
The technique, developed by researchers in the Quantum Optics Group of the Australian National Univ.’s Research School of Physics and Engineering, hinges on using laser beams to cool a nanowire probe to -265 C.
The physical properties of the ultra-white scales on certain species of beetle could be used to make whiter paper, plastics and paints, while using far less material than is used in current manufacturing methods.
The Cyphochilus beetle, which is native to South-East Asia, is whiter than paper, thanks to ultra-thin scales that cover its body. A new investigation of the optical properties of these scales has shown that they are able to scatter light more efficiently than any other biological tissue known, which is how they are able to achieve such a bright whiteness.
Higgs Boson May Explain Earliest Expansion of the Universe
Fedor Bezrukov from the RIKEN BNL Research Center and Mikhail Shaposhnikov from EPFL propose that the Higgs boson may be responsible for the mode of inflation and shape of the Universe shortly after the Big Bang.
“There is an intriguing connection between the world explored in particle accelerators today and the earliest moments of the existence of the Universe,” explained Bezrukov.
NASA astronaut Reid Wiseman, Expedition 40 flight engineer, has installed Capillary Channel Flow (CCF) experiment hardware in the Microgravity Science Glovebox (MSG) located in the Destiny laboratory of the International Space Station. CCF is a versatile experiment for studying a critical variety of inertial-capillary dominated flows key to spacecraft systems that cannot be studied on the ground.
An international team of sky scholars, including a key researcher from Johns Hopkins, has produced new maps of the material located between the stars in the Milky Way. The results should move astronomers closer to cracking a stardust puzzle that has vexed them for nearly a century.
The maps and an accompanying journal article appear in today’s issue of the journal Science. The researchers say their work demonstrates a new way of uncovering the location and eventually the composition of the interstellar medium — the material found in the vast expanse between star systems within a galaxy.
Researchers at the Univ. of Tennessee Knoxville have made a novel discovery that may potentially protect the world from future collisions with asteroids.
The team studied near-Earth asteroid 1950 DA and discovered that the body, which rotates so quickly it defies gravity, is held together by cohesive forces, called van der Waals, never before detected on an asteroid.
Porphyrin molecules are essential to many biological processes, such as photosynthesis and respiration. Wilhelm Auwärter’s group is investigating these all-round talents at Technische Universität München. Normally, hydrogen attaches to the outer edges of the porphyrin core – named porphin, but other chemical entities can take the place of hydrogen, thereby changing the properties of the molecules.
Alissa Wiengarten, PhD student at the TUM Department of Physics, heats a porphin powder in a vacuum chamber. In the process, individual porphin molecules leave the collective and adhere to a silver surface, where they react with each other and assemble into small groups – all by themselves. Single molecules can desorb from the hot surface, while chains of two, three or more porphin units cannot. In this way the scientists were able to assemble chains of up to 90 porphin units.
Physicists at The Australian National Univ. (ANU) have created a tractor beam on water, providing a radical new technique that could confine oil spills, manipulate floating objects or explain rips at the beach.
The team, led by Horst Punzmann, discovered they can control water flow patterns with simple wave generators, enabling them to move floating objects at will. The team also experimented with different shaped plungers to generate different swirling flow patterns.
Computer Model Reveals Water’s ‘Split Personality’
Seemingly ordinary, water has quite puzzling behavior. Why, for example, does ice float when most liquids crystallize into dense solids that sink?
Using a computer model to explore water as it freezes, a team at Princeton Univ. has found that water’s weird behaviors may arise from a sort of split personality: at very cold temperatures and above a certain pressure, water may spontaneously split into two liquid forms.
Method Could Make Sub-wavelength Images at Radio Frequencies
Imaging and mapping of electric fields at radio frequencies (RF) currently requires the use of metallic structures such as dipoles, probes and reference antennas. To make such measurements efficiently, the size of these structures needs to be on the order of the wavelength of the RF fields to be mapped. This poses practical limitations on the smallest features that can be measured.
New theoretical and experimental work by researchers at the National Institute of Standards and Technology (NIST) and the Univ. of Michigan suggests an innovative method to overcome this limit by using laser light at optical wavelengths to measure and image RF fields. The new technique uses a pair of highly stable lasers and rubidium atoms as tunable resonators to map and potentially image electric fields at resolutions far below their RF wavelengths — though not below the much shorter wavelengths of the lasers.