Moths and insects cluster around lights at night. Why?
Buildings at the 1893 World’s Columbian Exposition in Chicago, illuminated by George Westinghouse’s alternating current.
Field Museum Library/Wikipedia
Indoor plant factories have high energy costs since LEDs replace the sunlight outdoor plants get for free. Scientists found a way to dial back how much light is needed by breaking it into tiny bursts.
Gravity helps stars to form.
UNIMAP / L. Piazzo, La Sapienza – Università di Roma; E. Schisano / G. Li Causi, IAPS/INAF, Italy
Gravity exists because the universe is full of ‘stuff’ – here’s how it came to be.
The crests (bright) and troughs (dark) of waves spread out after they were produced. The picture applies to both light and sound waves.
Titima Ongkantong
Most people are familiar with lasers. But what about a laser made with sound rather than light? A couple of physicists have now created one that they plan to use for measuring imperceivable forces.
The sea is blue because of the way water absorbs light, the way particles in the water scatter light, and also because some of the blue light from the sky is reflected.
Flickr/Fiona Paton
Photons stream from the sun and interact with all matter on Earth. Depending on what the light touches, some of the photons will get absorbed or soaked up. And some will bounce back.
A cross section of a fractal pattern, created by a laser in the Wits Structured Light Laboratory.
Wits University
Despite the primacy of Christmas in American culture, the visibility of Hanukkah in pop culture reminds Jews that they have their own holiday in which they can take pride.
Anish Kapoor made “Cloud Gate”, a giant bean-shaped mirror in Chicago. Visitors play with the light in the city and its surroundings, where our future lays.
What could a ‘relativistic camera’ capture on the way to Alpha Centauri?
ESA/NASA
An astronomer suggests an idea to piggyback on the ambitious Breakthrough Starshot project that aims to send nano spacecraft to Alpha Centauri at a major fraction of the speed of light.
Section of a tumor observed with an optical microscope. The two white forms with brown borders are blood vessels. Inside, gold nanoparticles accumulate against their walls.
Mariana Varna-Pannerec (ESPCI)
Gold can be used to make jewelry, but also to fight cancer. Several clinical trials are currently underway in the United States where patients are being treated with gold nanoparticles.
In 1954, three scientists observed a paradox to which they gave their name: the Fermi-Pasta-Ulam recurrence. Now, fibre optics are on the way to finally providing an explanation.
About a century ago, we didn’t even know that galaxies existed.
Mai Lam/The Conversation NY-BD-CC
Pretty much as soon as we understood what galaxies were, we realised they are all moving away from each other. And the ones that are further away are moving faster. In short, the universe is expanding.