Optics

Experiments on individual photons conducted by physicists from the Faculty of Physics at the University of Warsaw (FUW) and the Faculty of Applied Physics and Mathematics at the Gdansk University of Technology (PG), have revealed yet another bizarre feature of the quantum world.

When a quantum object is transmitted, its quantum property, whether it behaves as a wave or as a particle, appears to depend on other properties that at first glance have nothing to do with the transmission, they argue.

Thermoelectric materials were discovered in the 19th century and have the remarkable property that heating them creates a small electrical current - but adopting them to the 21st century has been a challenge. 

Researchers have developed a new concept for a microscope that would use neutrons,  subatomic particles with no electrical charge,
to create high-resolution images
instead of the more traditional beams of light or electrons.

Among other benefits, neutron-based instruments have the ability to probe inside metal objects, such as fuel cells, batteries, and engines, even when in use, and learn details of their internal structure. Neutron instruments are also uniquely sensitive to magnetic properties and lighter elements that are important in biological materials.

Researchers recently used a laser to accelerate electrons at a rate 10 times higher than conventional technology in a nanostructured glass chip smaller than a grain of rice, an advance that could dramatically shrink particle accelerators for science and medicine.

 Because it employs commercial lasers and low-cost, mass-production techniques, the researchers believe it will set the stage for new generations of "tabletop" accelerators.

At its full potential, the new "accelerator on a chip" could match the accelerating power of SLAC's 2-mile-long linear accelerator in just 100 feet, and deliver a million more electron pulses per second.

If you want to see Aurora Borealis (the northern lights) in 3-D with your SLR cameras, and even determine the altitude where electrons in the atmosphere emit the light that produces aurora,  Ryuho Kataoka from the National Institute of Polar Research in Tokyo, Japan can show you how.

Kataoka came up with an idea for a new method to measure the height of aurora borealis after working on a 3D movie for a planetarium. They used two digital single-lens reflex (SLR) cameras set 8 km apart.

A new type of camera allows scientists to take sharper images of the night sky than ever before.  It combines a telescope with a large diameter primary mirror is being used for digital photography at its theoretical resolution limit in visible wavelengths – the light that the human eye can see.

The design team has been developing this technology for more than 20 years at observatories in Arizona, most recently at the Large Binocular Telescope, and has now deployed this latest version in the high desert of Chile at the Magellan 6.5-meter telescope.

Light traveling in a vacuum is the ultimate speed demon, moving at about 700 million miles per hour.

Matter cannot exceed the speed of light - unless, perhaps, there is a speed bump in light's path. Researchers from  France's Université de Nice-Sophia Antipolis and China's Xiamen University have embedded dye molecules in a liquid crystal matrix to throttle the group velocity of light back to less than one billionth of its top speed. The team says the ability to slow light in this manner may one day lead to new technologies in remote sensing and measurement science. 

Researchers have measured light emitted by photoluminescence from a nanodiamond levitating in free space. 

Their paper describes how they used a laser to trap nanodiamonds in space, and – using another laser – caused the diamonds to emit light at given frequencies.

The experiment, led by Nick Vamivakas, an assistant professor of optics at the University of Rochester, demonstrates that it is possible to levitate diamonds as small as 100 nanometers (approximately one-thousandth the diameter of a human hair) in free space, by using a technique known as laser trapping.  Specifically, nitrogen vacancy (NV) photoluminescence (PL) from a nanodiamond suspended in a free-space optical dipole trap.

Of the estimated 20,000 genes humans have, only a fraction are turned on at any given time. It depends on the cell's needs, which can change by the minute or hour.

Determining what those genes are doing means using tools that can manipulate their status on similarly short timescales and that is now possible with technology developed by the Eli and Edythe L. Broad Institute of Harvard and MIT. It can rapidly start or halt the expression of any gene simply by shining light on the cells.

The advance in optogenetics, which uses proteins that change their function in response to light, is possible because researchers adapted light-sensitive proteins to either stimulate or suppress the expression of a specific target gene almost immediately after the light comes on.

X-ray experiments have found chemical traces of the original 'dinobird' Archaeopteryx and dilute traces of plumage pigments in a 150 million-year-old fossil.

Only 11 specimens of Archaeopteryx have been found, the first one consisting of a single feather. Until a few years ago, researchers thought minerals would have replaced all the bones and tissues of the original animal during fossilization, leaving no chemical traces behind, but two studies have turned up more information about this 'dinobird' and its plumage.