First electric car race to zoom off on Saturday
Formula E will be a laboratory for new technology, according to motor sport great Alain Prost, while Bruno Senna said drivers will face a “lottery” when electric car racing kicks off in Beijing Saturday.
The nephew of Ayrton Senna was speaking Friday as he prepared to line up against the son of four-time Formula One champion Prost, rekindling one of the greatest rivalries in motorsport.
The pair will be competing in the first-ever Formula E race, in the shadow of the Bird’s Nest stadium in the Chinese capital.
Formula E has received high-profile backing from the likes of Hollywood star Leonardo DiCaprio and British tycoon Richard Branson, and some believe it represents an environmentally-friendly future for motor sports.
http://phys.org/news/2014-09-electric-car-saturday.html
Particle detector finds hints of dark matter in space
Researchers at MIT’s Laboratory for Nuclear Science have released new measurements that promise to shed light on the origin of dark matter.
The MIT group leads an international collaboration of scientists that analyzed two and a half years’ worth of data taken by the Alpha Magnetic Spectrometer (AMS)—a large particle detector mounted on the exterior of the International Space Station—that captures incoming cosmic rays from all over the galaxy.
Among 41 billion cosmic ray events—instances of cosmic particles entering the detector—the researchers identified 10 million electrons and positrons, stable antiparticles of electrons. Positrons can exist in relatively small numbers within the cosmic ray flux.
An excess of these particles has been observed by previous experiments—suggesting that they may not originate from cosmic rays, but come instead from a new source. In 2013, the AMS collaboration, for the first time, accurately measured the onset of this excess.
The new AMS results may ultimately help scientists narrow in on the origin and features of dark matter—whose collisions may give rise to positrons.
http://phys.org/news/2014-09-particle-detector-hints-dark-space.html#jCp
Online classes really do work, according to study
The findings have just been published in the International Review of Research in Open and Distance Learning, in a paper by David Pritchard, MIT’s Cecil and Ida Green Professor of Physics, along with three other researchers at MIT and one each from Harvard University and China’s Tsinghua University.
“It’s an issue that has been very controversial,” Pritchard says. “A number of well-known educators have said there isn’t going to be much learning in MOOCs, or if there is, it will be for people who are already well-educated.”
But after thorough before-and-after testing of students taking the MITx physics class 8.MReVx (Mechanics Review) online, and similar testing of those taking the same class in its traditional form, Pritchard and his team found quite the contrary: The study showed that in the MITx course, “the amount learned is somewhat greater than in the traditional lecture-based course,” Pritchard says.
A second, more surprising finding, he says, is that those who were least prepared, as shown by their scores on pretests, “learn as well as everybody else.” That is, the amount of improvement seen “is no different for skillful people in the class”—including experienced physics teachers—”or students who were badly prepared. They all showed the same level of increase,” the study found.
http://phys.org/news/2014-09-online-classes.html#jCp
New solar cells serve free lunch
Qi’s new method uses what he calls hybrid deposition to create perovskite solar cells, made from a mixture of inexpensive organic and inorganic raw materials. In addition, his solar cell is about a thousand times thinner than a silicon solar cell, and therefore uses far less material. Qi estimates that for the same price, he could either buy raw materials to build 1000 square meters of his solar cell, or he could buy about 20 wafers of crystallized silicon, to build 0.16 square meters of traditional solar panels. “Silicon is not rare,” Qi explains, “but processing silicon requires expensive equipment and sophisticated steps demanding high temperature, vacuum, or high pressure, and that makes crystallized silicon very expensive.” In contrast, the hybrid deposition process uses less energy to produce a solar cell at a far lower temperature. In fact, Qi envisions manufacturing the new solar cells using a low-cost printing process. The process would deposit the materials onto thin sheets of PET plastic very quickly to make large quantities of cheap solar cells. Qi does not yet know the limits of his hybrid cells, but optimists in his field hope that they could reach 20% efficiency. This means that that the solar cells will convert 20% of the energy they absorb from the sun into usable energy, which is comparable to the best silicon solar panels on the market.
The extremely thin perovskite cell that Qi and his lab designed measures merely 135 nanometers and reaches an efficiency of 9.9%. Because these films are semitransparent, Qi hopes to use them on windows, as a sort of lightweight set of blinds. “It will be a window and at the same time it will be a solar cell,” he says. “Some of the light could go through and the rest will be absorbed. Then, a certain percentage of the absorbed light will be converted to electricity.”
http://phys.org/news/2014-09-solar-cells-free-lunch.html#jCp
