Phys.org provides the latest news on physics, materials, nanotech, science and technology.
Updated: 3 days 21 hours ago
Countless times a day, seabirds dive-catch prey from the ocean, boats enter the water from dry land, and seaplanes touch down gently amid the waves. The phenomenon of objects entering water is commonplace, yet a full understanding of the physics of water entry remains elusive, especially as it pertains to instances where a solid object enters a body of water that contains other solid objects, such as a gull diving into a rocky patch of sea.
Ordinary sound waves—small oscillations of density—can propagate through all fluids, causing the molecules in the fluid to compress at regular intervals. Now physicists have theoretically shown that in one-dimensional quantum fluids not one, but two types of sound waves can propagate. Both types of waves move at approximately the same speed, but are combinations of density waves and temperature waves.
An international team of scientists has discovered a new, exotic form of insulating material with a metallic surface that could enable more efficient electronics or even quantum computing. The researchers developed a new method for analyzing existing chemical compounds that relies on the mathematical properties like symmetry that govern the repeating patterns seen in everyday wallpaper.
A pair of physicists at Aix-Marseille University has offered a possible way to measure the speed of our own galaxy more accurately as it moves through space. In their paper published in the journal Physical Review Letters, Julien Bel and Christian Marinoni describe their theory and how it might be tested.
A team that includes nuclear physicists, a machine-learning researcher and an NC State mathematician has created a new approach for narrowing down huge calculations – such as those involved in quantum physics – by focusing on a single, predictive parameter. This approach, dubbed the eigenvector continuation, could prove useful in solving other scientific and engineering problems where the calculations are simply too large for computer memory to handle.
Studying the photochemistry, or chemical results of light, has shown that ultraviolet radiation can set off harmful chemical reactions in the human body and, alternatively, can provide "photo-protection" by dispersing extra energy. To better understand the dynamics of these photochemical processes, a group of scientists irradiated the RNA base uracil with ultraviolet light and documented its behavior on a picosecond timescale.
In a Proceedings of the National Academy of Sciences (PNAS) "Special Feature" paper published online June 26, Lawrence Livermore National Laboratory (LLNL) and University of Michigan researchers reported on recent experiments and techniques designed to improve understanding and control of hydrodynamic (fluid) instabilities in high energy density (HED) settings such as those that occur in inertial confinement fusion implosions on the National Ignition Facility (NIF).
Magnets have fascinated humans for several thousand years and enabled the age of digital data storage. They occur in various flavors. Ferrimagnets form the largest class of magnets and consist of two types of atoms. Similar to a compass needle, each atom exhibits a little magnetic moment, also called spin, which arises from the rotation of the atom's electrons about their own axes. In a ferrimagnet, the magnetic moments point in opposite directions for the two types of atoms (see panel A). Thus, the total magnetization is the sum of all magnetic moments of type 1 (M1) (blue arrows) and type 2 (M2) (green arrows). Due to the opposite direction, the magnitude of the total magnetization is M1-M2.