Category Physics

One of the CRESST detector modules. When illuminated with ultraviolet light, the scintillating inner shield glows brightly.

Highest sensitivity detector ever for very light dark matter elementary particles. The origin of matter in the universe has puzzled physicists for generations. Today, we know that matter only accounts for 5% of our universe; another 25% is constituted of dark matter. And the remaining 70% is made up of dark energy. Dark matter itself represents an unsolved riddle.

Physicists believe that such dark matter is composed of (as yet undefined) elementary particles that stick together thanks to gravitational force. In a study recently published in EPJ C, scientists from the CRESST-II research project use the phonon-light technique to detect dark matter...

The new nanoscale manufacturing process draws zinc to the surface of a liquid, where it forms sheets just a few atoms thick. Credit: Xudong Wang

After 6 yrs of painstaking effort, Uni of Wisconsin-Madison materials scientists believe the tiny sheets of the semiconductor zinc oxide they’re growing could have huge implications for the future of a host of electronic and biomedical devices. Xudong Wang et al have developed a technique for creating nearly 2D sheets of compounds that do not naturally form such thin materials. Nanomaterials have unique electronic and chemical properties compared to identically composed materials at larger, conventional scales. Until now, they were limited to working with naturally occurring 2-D nanosheets eg graphene...

New tools for harvesting wind energy may soon look less like giant windmills and more like tiny leafless trees. A project at The Ohio State University is testing whether high-tech objects that look a bit like artificial trees can generate renewable power when they are shaken by the wind – or by the sway of a tall building, traffic on a bridge or even seismic activity.

Tree-like structures made with electromechanical materials can convert random forces – such as winds or footfalls on a bridge – into strong structural vibrations that are ideal for generating electricity. The technology may prove most valuable when applied on a small scale, in situations where other renewable energy sources such as solar are not an option...

Bernhard Rauer in the lab at TU Wien. Credit: Image courtesy of Vienna University of Technology, TU Vienna

When cold milk is poured into a hot cup of tea, a temperature equilibrium is reached very quickly ie thermalization. It plays a crucial role in cooling down gases to ultra-low temperatures. But surprisingly, even gases for which this effect is suppressed can be cooled. Scientists at TU Wien took a closer look at this phenomenon and found a special quantum-mechanical kind of cooling at work.

“The particles that make up a liquid or a gas have different energies,” says Professor Jörg Schmiedmayer (TU Wien). The distribution of these energies depends on the temperature. The hotter the gas, the higher the number of particles with high energies...