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.
A team has undertaken what they call the most comprehensive examination of skyglow - variations in the radiance of the night sky
- ever done and found remarkably large variations in artificial night sky brightness at the different observation sites.
Light became popular because it allowed us to extend the day - and electricity meant people could read a book without falling asleep and setting themselves on fire. But the introduction of light into the nighttime environment is one of the most striking changes humans have made to the Earth’s physical environment, and it is associated with several unintended negative consequences. One example is skyglow, the artificial brightening of the night sky.
A collaboration of researchers have experimentally produced Möbius strips from the polarization of light, confirming a theoretical prediction that it is possible for light's electromagnetic field to assume this peculiar shape.
Möbius strips are easy to create, of course. Millions of school children do it in classrooms every year by taking a strip of paper, twisting it once and joining up the ends. That's it, you have created a Möbius strip: a three dimensional structure that has only one side.
But finding Möbius strips occurring naturally is another issue.
Engineers in Austria have given us a blessing and a curse - they have created a giant laser system that sends beams in different directions, which makes them visible from many different angles.
The angular resolution is so fine that the left eye is presented a different picture than the right one, creating a 3D effect.
By: Charles Q. Choi, Inside Science
(Inside Science) - A laser could be created with air in a practical way, a new advance that could one day be used to help spot explosives or pollutants from afar, researchers say.
Laser light is generated by pumping energy into atoms or other objects. A chain reaction can occur in which energized atoms all stimulate each other to give off laser light.