Category Physics

In principle, nothing that enters a black hole can leave the black hole. This has considerably complicated the study of these mysterious bodies on which generations of physicists have debated ever since 1916, the year their existence was hypothesized as a direct consequence of Einstein’s Theory of Relativity. There is, however, some consensus in the scientific community on the fact that black holes possess an entropy, because their existence would otherwise violate the second law of thermodynamics. In particular, Jacob Bekenstein and Stephen Hawking have suggested that the entropy – a measure of the inner disorder of a physical system – of a black hole is proportional to its area and not to its volume, as would be more intuitive...

A photograph (left) shows the experimental set-up used to confirm the existence of the Bloch wave resonance, which was first predicted theoretically. An illustration (right) shows the interior of the experimental device, called a hollow periodic waveguide, which consists of two corrugated metallic plates separated by a variable distance of about one inch, and the upper plate can slide with respect to the lower. When researchers shot microwaves between the plates through the air, they were able to control which wavelengths of microwaves were allowed through by varying the position of the upper plate. Credit: Lab of Victor Pogrebnyak/University at Buffalo

Imagine a device that is selectively transparent to various wavelengths of light at one moment, and opaque to them the next, following a m...

(Colour online) Pre- and post-video test scores by age group (Study A). Values shown are means ± standard errors. All pre-test to post-test improvements were statistically significant (paired t-tests, p < .001 for each)

Does “edutainment” such as content-rich music videos have any place in the rapidly changing landscape of science education? A new study indicates that students can indeed learn serious science content from such videos. The study, titled ‘Leveraging the power of music to improve science education’ and published by International Journal of Science Education, examined over 1,000 students in a 3-part experiment, comparing learners’ understanding and engagement in response to 24 musical and non-musical science videos.

The central findings were that
(1) across ages and g...

Hybrid solar and wind harvesting cells on the top of this model house collect enough energy to light it up inside. Credit: American Chemical Society

The “Internet of Things” could make cities “smarter” by connecting an extensive network of tiny communications devices to make life more efficient. But all these machines will require a lot of energy. Rather than adding to the global reliance on fossil fuels to power the network, researchers report on a single device that harvests wind and solar energy appears in the journal ACS Nano.

Hybridized nanogenerator, including a solar cell (SC) and a triboelectric nanogenerator (TENG), that can individually/simultaneously scavenge solar and wind energies, which can be extensively installed on the roofs of the city buildings...