Planet’s Glow May Shine Light on Possible Life

Earthshine is the sunlight that is reflected off Earth and reflected back by the moon, and while it may seem like this is simply just a pretty glow to be seen from other positions of the universe, some astronomers believe the shines of exoplanets could speak wonders about its potential for life.

These glows emitted by planets display imprints of the chemicals present in their atmospheres and the materials on the surface (as plants and rocks do not reflect light similarly). However, with their parent stars’ shines being infinitely brighter, detecting minuscule variations in glow within an exoplanet poses a dilemma.

By using a large telescope to examine our own polarized earthshine, Michael Sterzik and colleagues of the European Southern Observatory in Santiago, Chile, were able to distinguish the polarized light of planets from the unpolarized stars filling the sky. Through this team’s testing, they were able to confirm the technique’s accuracy, as their results concluded that Earth had “light signatures of oxygen, ozone and water, as well as an increase in reflected wavelengths characteristic of vegetation.” With even larger telescopes pointed outward, looking for these characteristics among exoplanets should be a viable possibility.

A life-and-death struggle fueled by a simple drop of water is captured in a photograph by Michael Zach at the University of Wisconsin-Stevens Point.

Zach brought microbes to life by adding water to a salt sample he had found near Death Valley, thus dissolving the sample’s crystals. As the water evaporated, crystals began to reform, creating the prism-like colors captured in this winning picture from the 2009 International Science and Engineering Visualization Challenge.

But the desert-dwelling microbes were able to survive by excreting molecules that helped prevent crystal growth—an adaptation that allows the microbes to escape a salty death trap.

“Invisibility Cloak” Breakthrough Made

Researchers have “cloaked” a three-dimensional object, making it invisible from all angles, for the first time. However, the demonstration works only for waves in the microwave region of the electromagnetic spectrum. It uses a shell of what are known as plasmonic materials; they present a “photo negative” of the object being cloaked, effectively cancelling it out.

In the image above “microwaves can be seen being blocked and scattered without (L), and reconstructed (R) with the cloak”

Read More

Harnessing Light’s Full Spectrum: Scientists Claim Solar Power Breakthrough

Chemists at Ohio State University say they have produced a next-generation material that not only absorbs the full spectrum of sunlight, but also make makes the electrons generated more easy to capture.

The hybrid material — a combination of electrically conductive plastic and metals like molybdenum and titanium — is the first of its kind to capture the full solar spectrum, according to Malcolm Chisholm, one of the authors of the paper describing the research, which appears in Proceedings of the National Academy of Sciences. Solar panels in use today capture only a small fraction of the energy contained in sunlight.

The material generates electricity just like other solar cell materials do: light energizes the atoms of the material, and some of the electrons in those atoms are knocked loose.

Ideally, the electrons flow out of the device as electrical current, but this is where most solar cells run into trouble. The electrons only stay loose for a tiny fraction of a second before they sink back into the atoms from which they came. The electrons must be captured during the short time they are free, and this task, called charge separation, is difficult.

In the new hybrid material, electrons remain free much longer than ever before.

This fruit fly is part of an experiment to uncover how insects navigate thousands of miles during migration, or even find their way from flower to flower in the front yard. The “bars” of light demarcate a light-emitting diode (LED) flight arena, but what really holds the fly in is a magnetic field (he’s glued to a metal pin, allowing him to move naturally within the field but keeping him in place). 

The outcome of this bizarre set-up is the discovery that fruit flies look to the sky to keep their bearings. In naturally polarized light, the flies had no trouble staying on course. But when researchers altered the light polarization patterns, the flies got discombobulated. That means that as long as a bit of sunlight makes its way to the fly’s eye, it can use the patterns in light to get where it’s going. 

Day 18: Interesting Facts About Argon
Atomic Symbol: Ar; Atomic Number: 18; Atomic Mass: 39.948 

1. Argon is the third most abundant element in our atmosphere, composing .93% by volume, and is created when potassium decays within the earth’s crust.
2. It’s produced industrially by the fractional distillation of liquid air in a cryogenic air separation unit; a process that, due to their differing boiling points, separates liquid nitrogen from argon and liquid oxygen. Using this process, about 700,000 tonnes of argon are produced worldwide annually.
3. Argon emits light when electrically excited, making it useful in light bulbs, lasers, plasma globes, fluorescent tubes, and photo tubes. In addition, its inert properties make it useful in countless other ways, which include aiding the manufacture stainless steels, process of arc welding and cutting, thermal insulation of windows, production impurity-free silicon crystals, blanketing reactive substances, and even serving as the filling for some high-end car tires and scuba dry-suits.
4. In 2000, scientists produced the first known compound containing the inert element: argon fluorohydride (HArF). However, it has no practical uses since it decomposes in temperatures above minus 246°C, or 411°F.

Image: Argon Laser.

Red-Green and Blue-Yellow: The Stunning Colors You Can’t See

Try to imagine reddish green — not the dull brown you get when you mix the two pigments together, but rather a color that is somewhat like red and somewhat like green. Or, instead, try to picture yellowish blue — not green, but a hue similar to both yellow and blue.

Is your mind drawing a blank? That’s because, even though those colors exist, you’ve probably never seen them. Red-green and yellow-blue are the so-called “forbidden colors.” Composed of pairs of hues whose light frequencies automatically cancel each other out in the human eye, they’re supposed to be impossible to see simultaneously.

The limitation results from the way we perceive color in the first place. Cells in the retina called “opponent neurons” fire when stimulated by incoming red light, and this flurry of activity tells the brain we’re looking at something red. Those same opponent neurons are inhibited by green light, and the absence of activity tells the brain we’re seeing green. Similarly, yellow light excites another set of opponent neurons, but blue light damps them. While most colors induce a mixture of effects in both sets of neurons, which our brains can decode to identify the component parts, red light exactly cancels the effect of green light (and yellow exactly cancels blue), so we can never perceive those colors coming from the same place.

Almost never, that is. Scientists are finding out that these colors can be seen — you just need to know how to look for them.

Read More

A festive glow emanates from the South Pole and BICEP (Background Imaging of Cosmic Extragalactic Polarization) telescopes at the Amundsen-Scott South Pole Station in Antarctica. Red lights minimize light pollution while still allowing staff and researchers to see while walking around the facility during the six months of darkness here. The South Pole telescope is used, in part, to explore dark energy, the mysterious phenomenon suspected to be responsible for the acceleration of the expansion of the universe.

A female Closterocerus coffeellae, a wasp collected in Colombia, looks drab against a white background and shines against black. Researchers at Lund University in Sweden have discovered that the insect species – hymenoptera wasps and diptera flies – they’ve been studying for decades reflect light off their wings in rainbow-like patterns. The effect is a bit like oil on water, but these patterns are permanent, suggesting they may play a role in insect communication. The wings of the flies and wasps are transparent, but they reflect about 20 percent of the light that hits them, the researchers found. It’s this light that creates the shining patterns, just like a thin film of soap or oil on water creates a rainbow-colored glare.

In a world with two or three suns, plants might turn black, according to a new research study. It’s not because the extra suns would fry the vegetation to a crisp; rather, the plants’ color might change depending on how much of the visible light spectrum they absorbed for energy. In a multi-star system, plants depending on dim red dwarf stars for energy might evolve to absorb all colors of light. The result? Plants that appear black as night to the human eye.