Physics

If you’ve ever wondered about the ultimate fate of the universe, Lawrence Krauss and Robert Scherrer have some good news - sort of. In a paper published online on April 25 in the journal Physical Review D, the two physicists show that matter as we know it will remain as the universe expands at an ever-increasing clip. That is, the current status quo between matter and its alter ego, radiation, will continue as the newly discovered force of dark energy pushes the universe apart.

A Georgia Tech research team has discovered that water exhibits very different properties when it is confined to channels less than two nanometers wide – behaving much like a viscous fluid with a viscosity approaching that of molasses. Determining the properties of water on the nanoscale may prove important for biological and pharmaceutical research as well as nanotechnology. The research appears in the March 15 issue of the journal Physical Review B.


Georgia Tech physicists have discovered that water behaves differently when its compressed in nano-sized channel. In these small spaces water behaves much like a solid, exhibiting high viscosity and organizing itself into layers.

By utilizing ideas developed in disparate fields, from earthquake dynamics to random-field magnets, researchers at the University of Illinois have constructed a model that describes the avalanche-like, phase-slip cascades in the superflow of helium.

Just as superconductors have no electrical resistance, superfluids have no viscosity, and can flow freely. Like superconductors, which can be used to measure extremely tiny magnetic fields, superfluids could create a new class of ultra-sensitive rotation sensors for use in precision guidance systems and other applications.

n experiment called "shining light through walls" would seem hard to improve upon.

But University of Florida physicists have proposed a way to do just that, a step they say considerably improves the chance of detecting one of the universe's most elusive particles, a candidate for the common but mysterious dark matter.

Penn State researchers will soon provide he first demonstration of a fundamentally new method for measuring a particular quantum property of individual atoms. "This method allows us to directly and precisely measure the phase shifts that result when ultracold atoms collide, in a way that is independent of the accuracy-limiting density of the atoms," says Kurt Gibble, an associate professor of physics and principal investigator of the Penn State University research team that developed the method.


Schematic of the Experiment. We collide a clock atom with atoms in another state (labeled |4, 4>).

Two weeks ago, I read several articles on proposed wireless power transfer, e.g. on CNN News or this older one from Physorg. Since I find the idea to have power transmitted wirelessly for home use really exciting, I tried to dig into the topic, you can read the full text here. A brief summary of what I found:

For the past three years a satellite has circled the Earth, collecting data to determine whether two predictions of Albert Einstein's general theory of relativity are correct.

Researchers have successfully applied X-ray scattering techniques to determine how dissolved metal ions interact in solution.

These findings will help researchers better understand how metal ions, such as those found in nuclear waste and other industrial processes, behave in the environment.


Researchers at the Department of Energy's Argonne National Laboratory and the University of Notre Dame have successfully applied X-ray scattering techniques to determine how dissolved metal ions interact in solution. Credit: Argonne National Laboratory

Through photosynthesis, green plants and cyanobacteria are able to transfer sunlight energy to molecular reaction centers for conversion into chemical energy with nearly 100-percent efficiency. Speed is the key - the transfer of the solar energy takes place almost instantaneously so little energy is wasted as heat. How photosynthesis achieves this near instantaneous energy transfer is a long-standing mystery that may have finally been solved.


Sunlight absorbed by bacteriochlorophyll (green) within the FMO protein (gray) generates a wavelike motion of excitation energy whose quantum mechanical properties can be mapped through the use of two-dimensional electronic spectroscopy.

Scientists of the MiniBooNE [1] experiment at the Department of Energy's Fermilab [2] today (April 11) announced their first findings. The MiniBooNE results resolve questions raised by observations of the LSND [3] experiment in the 1990s that appeared to contradict findings of other neutrino experiments worldwide.