Light

In summer months sunlight comes with an unwanted side order of heat. Now, researchers have developed windows that can change color automatically when heated by sunlight, to keep buildings cool – and to top it off, they’re solar panels as well.

Physicists in Germany have measured the shortest timespan ever recorded. The team measured the time it takes for a photon of light to travel the length of a hydrogen molecule, and found it to occur in just trillionths of a billionth of a second.

One method of 3D printing involves selectively exposing liquid resin to ultraviolet (UV) light, causing that resin to harden into a solid. Now, scientists have developed a new resin that works with safer, more energy-efficient visible light.

Three years ago, scientists from the University of Arizona reported that exposure to green light appeared to reduce neuropathic pain in rats. Now, the researchers believe that such light could also be used to treat migraine headaches in humans.

Scientists have created a new class of laser beam that appears to violate long-held laws of light physics. Known as “spacetime wave packets,” these lasers follow different rules of refraction, which could lead to new communication technologies.

The Linac Coherent Light Source (LCLS) is an extremely powerful X-ray laser – and now it's about to get even more powerful. The second generation of the instrument has now achieved first light, with scientists demonstrating fine control of the beam.

Despite the name, black holes often shine very bright in the sky, due to their hot glowing corona. Now, astronomers have been puzzled to watch a black hole’s corona suddenly vanish – and if that wasn’t weird enough, it reappeared a few months later.

Scientists have discovered ultra-black fish that absorb almost all light that hits them, allowing them to effectively hide in the deepest, darkest parts of the ocean. The find could help inform future advances in optical and camouflage technology.

Astronomers have observed a bright flash of light from space, which appears to have come from a collision between two black holes. And that’s surprising, considering that black holes are famously dark objects.

Radio waves travel poorly through the water, which makes it difficult for divers or submersibles to wirelessly transmit information to the surface. Scientists are trying to change that, though, by developing an underwater version of Wi-Fi.

When it comes to regular photovoltaic panels, the fewer shadows that are cast upon them, the better. An experimental new device, however, actually generates electricity via the contrast between shadows and light on its surface.

A breakthrough from an international team of researchers raises hopes of a new, targeted approach to regenerative medicine, demonstrating how violet light can be used to switch on a drug and promote growth in highly selective areas.