When tilted downhill, a pile of grain starts flowing at an angle θstart that is larger than the angle θstop at which it stops. That hysteresis is an important feature of the behavior of earthquakes, landslides, and industrial flows. But despite the many years researchers have investigated granular flows (see the article by Anita Mehta, Gary Barker, and Jean-Marc Luck, Physics…
A chameleon can alter the color of its skin so it either blends into the background to hide or stands out to defend its territory and attract a mate. The chameleon makes this trick look easy, using photonic crystals in its skin. Scientists, however, have struggled to make a photonic crystal “smart skin” that changes…
Superhard materials can slice, drill and polish other objects. Now, science is opening the door to the development of new materials with these seductive qualities. Researchers have used computational techniques to identify 43 previously unknown forms of carbon that are thought to be stable and superhard — including several predicted to be slightly harder than…
With apologies to “Spinal Tap,” it appears that black can, indeed, get more black. MIT engineers report today that they have cooked up a material that is 10 times blacker than anything that has previously been reported. The material is made from vertically aligned carbon nanotubes, or CNTs — microscopic filaments of carbon, like a…
In 2011 Peter Kalmus calculated the carbon emissions associated with his personal and professional activities for his previous year as a postdoc at Caltech. The climate scientist at NASA’s Jet Propulsion Laboratory found that his air travel to two international and half a dozen domestic conferences accounted for more than two-thirds of his annual emissions.…
Warren Pickett is a distinguished professor in the department of physics at the University of California, Davis. Mikhail Eremets is a research physicist at the Max Planck Institute for Chemistry in Mainz, Germany. Physics Today 72, 5, 52 (2019); https://doi.org/10.1063/PT.3.4204
Jeffrey Moran is an assistant professor of mechanical engineering at George Mason University in Fairfax, Virginia. Jonathan Posner is a joint professor of mechanical and chemical engineering and an adjunct professor in family medicine at the University of Washington in Seattle. Physics Today 72, 5, 44 (2019); https://doi.org/10.1063/PT.3.4203
Over the next 10–20 years, motor vehicles and trains powered by carbon-free hydrogen fuel cells could become commonplace. With limits on greenhouse gas emissions looming and with their streets choked with exhaust, Japan and other energy-importing East Asian nations are already searching abroad for sources of readily usable hydrogen. Physics Today 72, 5, 28 (2019); https://doi.org/10.1063/PT.3.4200
The scientists from Scripps Research Institute in California were able to expand the genomes in bacteria with two synthetic base pairs. These bacteria are now able to produce up to 172 amino acids in comparison to the 20 amino acids the genome naturally produces. Date:November 28, 2018 Source:Scripps Research Institute Link: https://www.sciencedaily.com/releases/2018/11/181128082729.htm