Leafy and Weedy Sea Dragon
Sea dragons are some of the most ornately camouflaged creatures on the planet. Adorned with gossamer, leaf-shaped appendages over their entire bodies, they are perfectly outfitted to blend in with the seaweed and kelp formations they live amongst.Endemic to the waters off south and east Australia, leafy and weedy sea dragons are closely related to seahorses and pipefish. Leafies are generally brown to yellow in body color with spectacular olive-tinted appendages. Weedies have less flamboyant projections and are usually reddish in color with yellow spots.
Sea dragons have very long, thin snouts; slender trunks covered in bony rings; and thin tails which, unlike their seahorse cousins, cannot be used for gripping. They have small, transparent dorsal and pectoral fins that propel and steer them awkwardly through the water, but they seem quite content to tumble and drift in the current like seaweed. Leafies grow to a length of about 14 inches (35 centimeters), while the slightly larger weedies can grow up to 18 inches (46 centimeters) long.
Sea dragons survive on tiny crustaceans such as mysids, or sea lice. It is not known if they are preyed upon by other animals. They are, however, frequently taken by divers seeking to keep them as pets. In fact, such takings shrank their numbers so critically by the early 1990s that the Australian government placed a complete protection on both species. Pollution and habitat loss have also hurt their numbers, and they are currently listed as near threatened. Source:http://animals.nationalgeographic.com/animals/fish/sea-dragon/
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How do erasers erase?
You probably don't think about pencils and erasers much in today's world of digital and mobile access to everything; while it's undeniable that the No. 2 pencil and the SAT have a long history together, pencils don't really come up much outside of standardized testing anymore. But despite our devotion to our devices, Americans still use more than 2 billion pencils every year [source: Lunsford].
Contrary to popular belief, pencils aren't really made with lead, and haven't been since Roman scribes wrote on papyrus -- that's a common pencil myth. So if you chew on your pencils, rest assured you won't become ill from lead poisoning (although that's not a free pass to snack on a No. 2). Today's pencils are made with graphite, water and clay (which is used as a binder), and pencil lead has been made this way since Nicolas-Jacques Conté invented the mixture in 1795 [source: Ritter]. They weren't topped with an eraser tip, though, until about a century later. And it's this companion to the pencil, the eraser, that we're interested in here.
Erasers eradicate pencil markings by lifting graphite from the paper you've written on. As you write, particles of graphite from your pencil mingle with and cling to particles in the fiber of the paper. Here's the science: Modern erasers are almost always made from petroleum-based synthetic rubber compounds, typically polyvinyl chloride (they're no longer made from natural latex rubber, which is an allergen for some people). Because the particles in the polymer that make up an eraser are stickier than paper, those graphite particles get stuck to the eraser instead. Some erasers are stickier than others and absorb graphite particles more easily, giving you a cleaner, less-abrasive result.
Believe it or not, one of the very first erasers used was moist bread. Let's talk about how far erasers have come since the days of day-old bread, next.
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Did Dinosaurs Get The Flu?
It’s very hard to figure out when the influenza virus first started making animals sick. Studies of the history of major human epidemics suggest the flu has been around for at least a thousand years. “The certainty diminishes as we go further back into the past,” says David Morens, of the National Institute of Allergy and Infectious Diseases. “We can say for certain that influenza has been around since 1918 because we have the 1918 virus. Before that time, we have to speculate or make an educated guess.”
By looking for clues in contemporary accounts of disease outbreaks, Morens has concluded, with 95 percent certainty, that humans were getting the flu as far back as 1510 A.D. His confidence drops to about 80 percent for epidemics dating to the 800s. “Maybe the 590 A.D. epidemic was influenza,” he says, “but when we go back further than that, it’s just ‘Who knows?’”
Meanwhile, virologists have tried to find the genetic origins of influenza. Michael Worobey of the University of Arizona compares the genomes of influenza viruses with those of similar viruses that have been sequenced, in an effort to draw up a kind of evolutionary tree for pathogens. According to this method, the flu shares an ancestor with something called the infectious salmon anemia virus.
How long ago did the influenza and the salmon virus separate? That’s tricky. Viral genomes change more rapidly than an animal’s, in part because they don’t waste time fixing replication errors. “It’s like writing an e-mail really fast with your eyes closed and then sending it,” says Worobey. “Flu viruses accumulate a lot of mutations.”
At the same time, some key parts of a virus genome are very stable. Worobey helped identify relatives of HIV, for example, that had evolved in isolation off the coast of Africa over the course of 10,000 years. Even after all that time, their genomes still look very much the same. Scientists have also found evidence of an HIV-related virus that became embedded in the genome of the ferret eight million years ago.
No one has found similar evidence of ancient influenza. But could its ancestor— the one it shares with the salmon virus—have gone back to the dinosaurs? “For that, I don’t have even a gut feeling,” Worobey says. “It’s just kind of wide open.”
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Why do we say 'bless you' or 'gesundheit' when people sneeze?
Many people have become accustomed to saying "bless you" or "gesundheit" when someone sneezes. No one says anything when someone coughs, blows their nose or burps, so why do sneezes get special treatment? What do those phrases actually mean, anyway?Wishing someone well after they sneeze probably originated thousands of years ago. The Romans would say "Jupiter preserve you" or "Salve," which meant "good health to you," and the Greeks would wish each other "long life." The phrase "God bless you" is attributed to Pope Gregory the Great, who uttered it in the sixth century during a bubonic plague epidemic (sneezing is an obvious symptom of one form of the plague).
The exchangeable term "gesundheit" comes from Germany, and it literally means "health." The idea is that a sneeze typically precedes illness. It entered the English language in the early part of the 20th century, brought to the United States by German-speaking immigrants.
Virtually every country around the globe has its own way of wishing sneezers well. People in Arabic countries say, "Alhamdulillah," which means, "praise be to God." Hindus say, "Live!" or "Live well!" Some countries have special sneezing responses for children. In Russia, after children are given the traditional response, "bud zdorov" ("be healthy"), they are also told "rosti bolshoi" ("grow big"). When a child sneezes in China, he or she will hear "bai sui," which means, "may you live 100 years."
For the most part, the various sneeze responses originated from ancient superstitions. Some people believed that a sneeze causes the soul to escape the body through the nose. Saying "bless you" would stop the devil from claiming the person's freed soul. Others believed the opposite: that evil spirits use the sneeze as an opportunity to enter a person's body. There was also the misconception that the heart momentarily stops during a sneeze (it doesn't), and that saying "bless you" was a way of welcoming the person back to life.
We now know that sneezing is a reflex action and is most often the sign of something relatively benign, such as a cold or allergy. A sneeze also can be provoked by being outside in the sunlight or from smelling a strong odor. Still, we persist in the custom of saying "bless you" or "gesundheit," mainly out of habit and common courtesy.
Source: http://people.howstuffworks.com/sneezing.htm
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Flying Fish
Flying fish can be seen jumping out of warm ocean waters worldwide. Their streamlined torpedo shape helps them gather enough underwater speed to break the surface, and their large, wing-like pectoral fins get them airborne.
Flying fish are thought to have evolved this remarkable gliding ability to escape predators, of which they have many. Their pursuers include mackerel, tuna, swordfish, marlin, and other larger fish. For their sustenance, flying fish feed on a variety of foods, including plankton.
There are about 40 known species of flying fish. Beyond their useful pectoral fins, all have unevenly forked tails, with the lower lobe longer than the upper lobe. Many species have enlarged pelvic fins as well and are known as four-winged flying fish.
The process of taking flight, or gliding, begins by gaining great velocity underwater, about 37 miles (60 kilometers) per hour. Angling upward, the four-winged flying fish breaks the surface and begins to taxi by rapidly beating its tail while it is still beneath the surface. It then takes to the air, sometimes reaching heights over 4 feet (1.2 meters) and gliding long distances, up to 655 feet (200 meters). Once it nears the surface again, it can flap its tail and taxi without fully returning to the water. Capable of continuing its flight in such a manner, flying fish have been recorded stretching out their flights with consecutive glides spanning distances up to 1,312 feet (400 meters).
Flying fish are attracted to light, like a number of sea creatures, and fishermen take advantage of this with substantial results. Canoes, filled with enough water to sustain fish, but not enough to allow them to propel themselves out, are affixed with a luring light at night to capture flying fish by the dozens. There is currently no protection status on these animals.
Source:http://animals.nationalgeographic.com/animals/fish/flying-fish/
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Mendenhall Ice Caves
It may seem as if these pictures were taken from another planet,but they are actually shots of the Mendenhall Glacier which stretches 12 miles. It is located in Mendenhall Valley, approximatelyanother 12 miles from downtown Juneau in the southeast are the U.S.state of Alaska. The mammoth glacier and its immediate landscape area is protected as the 5,815-acre Mendenhall Glacier Recreation Area, a federally-designated unit of the Tongass National Forest.
The 19 kilometer long Mendenhall Glacier is an extraordinary
delight for both adventurous seekers as well as photographers such as Kent Mearig who goes beneath the glacier to capture its one-of-a-kind ice caves.
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First water plume seen firing from Jupiter moon Europa
Images from the Galileo spacecraft, which orbited Jupiter from 1995 to 2003, revealed a cracked and chaotic surface dominated by dark ridges and faults. This hinted that Europa has a relatively thin crust in which fissures sometimes open up and let water escape from a subsurface ocean. Similar rifts on Saturn's icy moon Enceladus shoot spectacular water geysers. But the Galileo probe did not spot any plumes in action on Europa, and later efforts also came up empty.
Now images taken by the Hubble Space Telescope have revealed a large cloud of hydrogen and oxygen – most likely in the form of water vapour – extending from the moon's south pole. A model suggests that it is a plume 200 kilometres high that is spouting 3000 kilograms of water per second.
"This is a big discovery," says Cynthia Phillips at the SETI Institute in Mountain View, California, who was not involved in the find but had looked for plumes with Galileo. "If there are plumes erupting, there's got to be liquid water, and it's got to be pretty close to the surface."
Source:http://www.newscientist.com/article/dn24743-first-water-plume-seen-firing-from-jupiter-moon-europa.html
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Is The Universe A Hologram? Physicists Say It's Possible
A team of physicists has provided some of the clearest evidence yet that our Universe could be just one big projection.In 1997, theoretical physicist Juan Maldacena proposed that an audacious model of the Universe in which gravity arises from infinitesimally thin, vibrating strings could be reinterpreted in terms of well-established physics. The mathematically intricate world of strings, which exist in nine dimensions of space plus one of time, would be merely a hologram: the real action would play out in a simpler, flatter cosmos where there is no gravity.
Maldacena's idea thrilled physicists because it offered a way to put the popular but still unproven theory of strings on solid footing — and because it solved apparent inconsistencies between quantum physics and Einstein's theory of gravity. It provided physicists with a mathematical Rosetta stone, a 'duality', that allowed them to translate back and forth between the two languages, and solve problems in one model that seemed intractable in the other and vice versa. But although the validity of Maldacena's ideas has pretty much been taken for granted ever since, a rigorous proof has been elusive.
In two papers posted on the arXiv repository, Yoshifumi Hyakutake of Ibaraki University in Japan and his colleagues now provide, if not an actual proof, at least compelling evidence that Maldacena’s conjecture is true.
In one paper, Hyakutake computes the internal energy of a black hole, the position of its event horizon (the boundary between the black hole and the rest of the Universe), its entropy and other properties based on the predictions of string theory as well as the effects of so-called virtual particles that continuously pop into and out of existence. In the other, he and his collaborators calculate the internal energy of the corresponding lower-dimensional cosmos with no gravity. The two computer calculations match.
“It seems to be a correct computation,” says Maldacena, who is now at the Institute for Advanced Study in Princeton, New Jersey and who did not contribute to the team's work.
Regime change
The findings “are an interesting way to test many ideas in quantum gravity and string theory”, Maldacena adds. The two papers, he notes, are the culmination of a series of articles contributed by the Japanese team over the past few years. “The whole sequence of papers is very nice because it tests the dual [nature of the universes] in regimes where there are no analytic tests.”
“They have numerically confirmed, perhaps for the first time, something we were fairly sure had to be true, but was still a conjecture — namely that the thermodynamics of certain black holes can be reproduced from a lower-dimensional universe,” says Leonard Susskind, a theoretical physicist at Stanford University in California who was among the first theoreticians to explore the idea of holographic universes.
Neither of the model universes explored by the Japanese team resembles our own, Maldacena notes. The cosmos with a black hole has ten dimensions, with eight of them forming an eight-dimensional sphere. The lower-dimensional, gravity-free one has but a single dimension, and its menagerie of quantum particles resembles a group of idealized springs, or harmonic oscillators, attached to one another.
Nevertheless, says Maldacena, the numerical proof that these two seemingly disparate worlds are actually identical gives hope that the gravitational properties of our Universe can one day be explained by a simpler cosmos purely in terms of quantum theory.
This story originally appeared in Nature News.
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Salar de Uyuni
Salar de Uyuni or Salar de Tunupa is a true blue paradise. This salt island 12,500 km ² is located in the highlands of southwestern Bolivia at over 3658 meters altitude. Who is now more than 10 000 years, it offers spectacular scenery and is one of the most beautiful places on the planet.
The Salar de Uyuni was created when a prehistoric lake dried up and left a salty crust behind. When it rains, the salty crust becomes a giant mirror.
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