By Rebecca Boyle, Inside Science
-- When light bulbs colonize our homes, humans get much less sleep.
It's an intuitive idea, but a new study measures this effect in a real-life situation for the first time by examining hunter-gatherers in Argentina.
Communities with access to electric lighting have shifted their bedtimes to later in the evening, curtailing a normal night of shuteye.
"When you have access to electricity, you can decide when you turn the lights off, and that resets your biological clock," said Horacio de la Iglesia, a biologist at the University of Washington, in Seattle, who led the study.
Scientists have developed the first liquid nanoscale laser and it's tunable in real time, meaning you can quickly and simply produce different colors, a unique and useful feature. The laser technology could lead to practical applications, such as a new form of a "lab on a chip" for medical diagnostics.The laser's color can be changed in real time when the liquid dye in the microfluidic channel above the laser's cavity is changed.
In a recent study, scientists have presented a new technique that significantly reduces the halo effect that is generated when using multi-focal. contact and intra-ocular, lenses and looking at bright point sources in dark conditions.
Presbyopia is a result of natural aging and stems from a gradual thickening and decrease in elasticity of the lens inside the eye. Corrective lenses used to address presbyopia often lead to a halo effect. This is basically a glow or color light pattern observed when looking at a bright source of light in front of a dark background.
It is mostly experienced at night when people see halos around street lamps and car headlights, and it can make driving at night unsafe or even impossible in extreme cases.
Light is a useful tool for quantum communication, but it has one major disadvantage - it travels at the speed of light and sometimes things need to be kept in place, or at least slowed down.
Like with trains all sharing a track, you can't have one express line with no brakes for very long.
A team researchers has demonstrated they can put the brakes on light, and not in some arcane quantum system but rather in glass fiber networks we are already using today. By coupling atoms to glass fibers light was slowed down to train speed - 90 miles per hour - and they even managed to bring the light to a complete stop and to retrieve it again later.
Most people don't realize that light can take different shapes. In the fundamental mode, light energy is most intense at the center and gradually fades towards the edge of the beam.
Light also has higher order modes. For example, the energy pattern can look like a donut, with most of the energy contained in a ring, and none in the hole or middle. Scientists create higher order modes by shining light through crystals and in recent years passing light along optical microfibers or nanofibers to manipulate particles has gained popularity in research labs because it could some day have applications in physics and biology.
Modern life and inadequate exposure to natural light during the day combined with overexposure to artificial light at night is believed by some to be harmful to the body's natural sleep/wake cycle.
One of those who contends so is University of Connecticut cancer epidemiologist Richard Stevens. "It's become clear that typical lighting is affecting our physiology. But lighting can be improved. We're learning that better lighting can reduce these physiological effects. By that we mean dimmer and longer wavelengths in the evening, and avoiding the bright blue of e-readers, tablets and smart phones."
Though every month we read about some new advance in artificial intelligence, how much progress is really being made? Neuromorphic computing has created software and electronic hardware that mimic brain functions and signal protocols but, like economic models that successfully predict the past, they have only slightly improved the efficiency and adaptability of conventional technology and are not really making bold advances.
Since they were pioneered by Robert Hooke 350 years ago, microscopes have been extending our vision. In the 21st century, scanning electron microscopy (SEM) and confocal microscopy, which uses a pinhole to remove out-of-focus light and allows 3D structures to be built from multiple images, have pushed the boundaries of resolution.
Quantum mechanics tells us that light can behave simultaneously as a particle or a wave, but researchers haven't been able to capture both natures of light at the same time; the closest we have come is seeing either wave or particle at different times.
When UV light hits a metal surface, it causes an emission of electrons. Albert Einstein explained this "photoelectric" effect by proposing that light - thought to only be a wave - is also a stream of particles. Even though a variety of experiments have successfully observed both the particle- and wave-like behaviors of light, they have never been able to observe both at the same time.
French artist Paul Gauguin has had quite the resurgence - having a painting sell for nearly $300 million will do that - but the artist noted for his colorful paintings of Tahitian life was also a highly experimental printmaker.
The techniques and materials Gauguin used to create his unusual and complex graphic works are little studied but a team from Northwestern University and the Art Institute of Chicago used a simple light bulb, an SLR camera and computational power to uncover new details of Gauguin's printmaking process -- how he formed, layered and re-used imagery to make 19 unique graphic works in the Art Institute's collection.