Sliced light is how we communicate now. Millions of phone calls and cable television shows per second are dispatched through fibers in the form of digital zeros and ones formed by chopping laser pulses into bits. This slicing and dicing is generally done with an electro-optic modulator, a device for allowing an electric signal to switch a laser beam on and off at high speeds (the equivalent of putting your hand in front of a flashlight). Reading that fast data stream with a compact and reliable receiver is another matter. A new error-free speed-reading record using a compact ultra-fast component—640 Gbits/second (Gbps, or billion bits per second)—has now been established by a collaboration of scientists from Denmark and Australia.
Uniform and mottle patterns are what most people recognize as camouflage and those patterns function by resembling the background. True background matching is not simple, though, and Roger T. Hanlon and colleagues say they are making one of the first efforts to quantify camouflage body patterns.
Although they have begun to compare camouflage tactics in many animals — large primates, amphibians, reptiles, fishes, insects — they are currently focusing on the cephalopods, which include squid, octopus, and cuttlefish. Remarkably, these soft-bellied mollusks are able to dynamically produce all three classes of camouflage body patterns (termed uniform, mottled, and disruptive).
'Cloaking' devices bend electromagnetic waves, such as light, in such a way that it appears as if the cloaked object is not there. In the latest laboratory experiments by Duke researchers, a beam of microwaves aimed through the cloaking device at a "bump" on a flat mirror surface bounced off the surface at the same angle as if the bump were not present. Additionally, the device prevented the formation of scattered beams that would normally be expected from such a perturbation.
The underlying cloaking phenomenon is similar to the mirages seen ahead at a distance on a road on a hot day.
In 1609, 400 years ago, Galileo revolutionized humankind's understanding of our position in the Universe when he used a telescope for the first time to study the heavens and sketched radical new views of the moon and also discovering the satellites orbiting Jupiter.
To celebrate the International Year of Astronomy (IYA), which marks the anniversary of Galileo's discoveries, a group of astronomers and curators from the Arcetri Observatory and the Institute and Museum of the History of Science, both in Florence, Italy, are recreating the kind of telescope and conditions that led to Galileo's world-changing observations, reports January's Physics World.
Using a beam of light shunted through a tiny silicon channel, researchers have created a nanoscale trap that can stop free floating DNA molecules and nanoparticles in their tracks. By holding the nanoscale material steady while the fluid around it flows freely, the trap may allow researchers to boost the accuracy of biological sensors and create a range of new 'lab on a chip' diagnostic tools.
Light has been used to manipulate cells and even nanoscale objects before, but the new technique allows researchers to manipulate the particles more precisely and over longer distances.
Deriving plentiful electricity from sunlight at a modest cost is a challenge with immense implications for energy, technology, and climate policy. A paper in a special energy issue of Optics Express, describes a relatively new approach to solar cells: lacing them with nanoscopic metal particles. As the authors describe in the article, this approach has the potential to greatly improve the ability of solar cells to harvest light efficiently.
A team of astronomers from Europe and the US studied the "Einstein Cross", a famous cosmic mirage. This cross-shaped configuration consists of four images of a single very distant source. The multiple images are a result of gravitational lensing by a foreground galaxy, an effect that was predicted by Albert Einstein as a consequence of his theory of general relativity. The light source in the Einstein Cross is a quasar approximately ten billion light-years away, whereas the foreground lensing galaxy is ten times closer. The light from the quasar is bent in its path and magnified by the gravitational field of the lensing galaxy.
It may seem, at least to those of us who have been alive long enough to witness any of the advances in semiconductor technology, that computer power has been improving at breakneck speed. A quantum computer
, however - a theoretical type of computer that utilizes the states of atoms to store information instead of magnetic fields - may make our current conception of computing power completely obsolete. And now, new research into the storage and retrieval of quantum information has brought quantum computing one step closer to reality.
Researchers at Purdue University have developed a technique that uses a laser and holograms to precisely position numerous tiny particles within seconds, representing a potential new tool to analyze biological samples or create devices using nanoassembly.
The technique, called rapid electrokinetic patterning, is a potential alternative to existing technologies because the patterns can be more quickly and easily changed, said mechanical engineering doctoral student Stuart J. Williams.
It's an idea that has pervaded a huge amount of science fiction and fantasy stories, from Star Trek to Harry Potter, and there are few of us that would deny a couple of hours with one - but is an invisibility cloak actually possible? Although the lightweight, flowing cloak of Harry Potter may be impossible in the near future, scientists are quickly creating and studying new metamaterials - materials with a negative index of refraction - that are paving the way to making invisibility a reality.