Aug 13, 2015
Scientists from the University of California, Riverside, studied how ants tell each other apart in their colonies based on tiny, nearly undetectable changes in how other ants smell. The research, published today (Aug. 13) in the journal Cell Reports, revealed how much ants' sniffing abilities may have been underestimated.
Social insects, like ants, detect each other's smells using sensors in their antennae. It was initially thought that ants used these smells to distinguish between friends and foes, but the new study suggests the insects' abilities go further than this.
The researchers tested how the ants react to different odors by sticking tiny glass electrodes into single sensory hairs on the insects' antennae, which were then exposed to puffs of different hydrocarbons. The electrodes acted like sensors to show whether each antenna was responding and if the ant had recognized a smell. The researchers discovered that ants are highly sensitive to chemical changes, with sensory neurons able to respond to a variety of subtly different hydrocarbon odors.
The scientists were also curious about whether the ants understood the actual chemical compound. So in a second experiment, the researchers paired one hydrocarbon with a sugary reward and one with plain water.
"We found that the ants were really superb at being able to make way to the hydrocarbon that had originally been paired with the reward," said study lead author Anandasankar Ray, an associate professor of entomology at the University of California, Riverside. "It's a very unusual ability that I think is unique to social insects that live in large colonies."
As it turns out, ants are quite the connoisseurs when differentiating among body odors. The Camponotus floridanus ants in this study have more smell-sensing genes than humans do, the researchers said.
Ray said that although people may be able to train themselves to distinguish among subtle variations in odors, such as the "difference between, say, a pinot noir and a cabernet," human noses are not up to the standards of ant antennae. In fact, most animals would not be able to detect the hydrocarbons in the study as a smell at all, he added.
"I think what is unique to the ants is that they are able to discriminate these very low-volatility chemicals — these hydrocarbons, which humans cannot perceive," Ray told Live Science.
How volatile a compound is refers to how easily it boils and turns into a gas to be smelled. Shorter hydrocarbon chains have fewer bonds that need to break, so they turn into gas faster. The hydrocarbons on the ants have low volatility, meaning they have long chains and low levels of the chemical evaporate at room temperature to be sniffed.
Detecting such small doses requires a meticulous sense of smell, which may have evolved as a way for ants to navigate their complex social networks, the researchers said.
"Imagine that there are hundreds and thousands of these social insects in a colony," Ray said. "It's really critical for them to be able to tell the difference between major worker, a minor worker, a queen and different individuals within a colony, in order to be able to coordinate their social experience."
The researchers said they think low-volatility hydrocarbons fit the bill for detecting such differences, because ants interact with each other in close quarters. If the odors were strong, the ants would likely get confused, the researchers said. Ants get so close when they touch antennae and sniff each other, it is the equivalent of "shaking hands and exchanging business cards," Ray said.
"If they were using volatile odors to try to recognize their peers, it would be a real mess because these volatile odors would be all over the colony," Ray said. "It would overrun them."
Read more at Discovery News
Affectionately dubbed Pig Beach, the island is a hopping tourist destination. In exchange for food, the charismatic pigs take to the water to greet approaching boaters:
Another less whimsical theory suggests that the pigs were intentionally planted to attract tourists -- which, if you ask us, is pretty genius.
From Discovery News
Now an eagle has gotten into the drone-busting business, as you can see in this footage, which was shot by Melbourne Aerial Videos and placed on its Youtube channel.
"Eagle was fine -- she was massive, and used talons to 'punch' the drone out of the sky," Melbourne Aerial Videos wrote on its Youtube channel. The drone, however, had to go in for some surgery, according to ABC News.
As the old saying goes -- if you mess with the eagle, you get the talons. OK, that's not quite the saying, but this drone sure saw it that way.
From Discovery News
A scan of the wall texture in King Tutankhamun’s tomb reveals indentations or faint lines, which could suggest two hidden doors. Based on other aspects of the tomb’s geometry, it’s possible that Nefertiti is hiding behind the door, said Nicholas Reeves, an archaeologist at the University of Arizona who has proposed the theory of Queen Nefertiti’s secret tomb.
If Nefertiti’s tomb indeed lies undisturbed behind the wall, that would be big news.
“We could be faced for the first time in recent history with the intact burial of an Egyptian pharaoh in the Valley of the Kings,” Reeves told Live Science. “Goodness knows what that will tell us.”
However, other Egyptologists are skeptical, because the scratches on the wall are the sole indications of the queen’s burial.
King Tut’s tomb
King Tutankhamun (also spelled Tutankhamen), often dubbed the boy king, was an Egyptian pharaoh who rose to power in 1333 B.C., at the tender age of 10. His mother was Queen Nefertiti, and his father was Akhenaten. He died at age 20, possibly of malaria or bone abnormalities, and his rule could have been a footnote in Egyptian history if not for one thing: His gold-bedecked, opulently appointed tomb was discovered, mostly intact, by British archaeologist Howard Carter in 1922.
The boy king was buried in haste; bacterial traces suggest the paint had not even dried before he was sealed into the place. And his tomb is smaller than others in the Valley of the Kings, leading many experts to believe that his death was unexpected, and so his underlings had to scramble and put him in a makeshift tomb originally intended for someone else, Reeves said.
Reading between the lines
Over the years, throngs of tourists had damaged the tomb, so the Egyptian government commissioned a replica of King Tut’s tomb for tourists to visit. As part of that process, the reconstruction company Factum Arte took photographs and created scans of the wall’s textural surface.
Reeves was studying these scans when he noticed strange “echoes of features” beneath the plaster walls inside King Tut’s tomb. He noticed vertical lines on the west wall of the tomb. When he measured the dimensions of these lines, they corresponded to the dimensions of an existing doorway in a nearby wall. He speculated that someone had plastered over a hidden doorway in antiquity.
The layout of the tomb also suggested there should be a chamber at that spot. Another wall also had faint lines suggestive of another hidden doorway and wall partition.
In addition, Tutankhamun’s tomb is smaller than others in the Valley of the Kings, and to get to the chamber, one must turn right from the main corridor — a configuration typically used for Egyptian queens, not kings, whose chambers were off to the left, Reeves said.
“I think Tutankhamun’s tomb started off as the tomb of a queen, and that Tutankhamun was buried only later and buried in the outer part of the tomb,” Reeves said. The outer part of the tomb was quickly enlarged to make it a proper royal burial that could house the nest of shrines that was due to a pharaoh.
The real centerpiece tomb — that of Nefertiti — was never discovered because it was hidden by a “blind,” or a painted wall, he speculated.
Queen to king.
Many Egyptologists believe that after King Tut’s father, Akhenaten died, Nefertiti became a pharaoh, not just a queen. For instance, a female pharaoh appears in historical records at about the same time as any mention of Nefertiti disappears, said Aidan Dodson, an Egyptologist at the University of Bristol in the United Kingdom, who was not involved in the study.
If Nefertiti were indeed a “super queen” or female pharaoh, she might have been buried in what was originally planned as Akhenaten’s tomb, Reeves speculated.
Supporting this super-queen theory, the dimensions of the hidden doorways suggest her tomb was large enough to fit a nest of shrines — the fitting tribute for a pharaoh, Reeves said.
However, not everyone is convinced by Reeves’ hypothesis.
“It’s a very interesting observation that there are these traces; however, the jump to ‘and Nefertiti’s behind the wall’ — the logic just doesn’t follow at all,” Dodson told Live Science. “All we’ve actually got are a bunch of scratches on a wall,” Dodson said.
There’s no proof that there is a chamber behind the vertical lines, and even if there were, they could contain other items or people besides Nefertiti, he said. Some Egyptologists believe that Nefertiti’s mummy has already been found, and is sitting in the Egyptian Museum in Cairo, Dodson said. (A prior DNA analysis found that mummy could have been the mother of Tutankhamun, Dodson said.)
“I think it’s a very attractive idea, but I think the evidence for it is not very solid,” said Salima Ikram, a professor of Egyptology at the American University in Cairo, who was not involved in the study. “It’s rather a bold statement to say that behind painted parts of Tutankhamun’s tomb lies the tomb of Nefertiti.”
Read more at Discovery News
As part of a $34.5 million project, the city’s Department of Water and Power has released nearly 100 million of so-called “shade balls” into three local reservoirs in recent months. The layer of balls protects water from algae formation, dust, rain and wildlife.
Perhaps more importantly, the black balls also help to prevent evaporation. According to Los Angeles Mayor Eric Garcetti, the balls could conserve 300 million gallons of reservoir water each year — water that California desperately needs.
On a chemical level, the balls prevent the production of bromate, a suspected carcinogen. Bromate forms when naturally occurring bromite reacts with added chlorine and sunlight.
Shade balls will likely become a permanent fixture atop reservoirs. This particular batch will be deployed for decade, after which time they will be removed, recycled and replaced.
“LADWP’s innovative use of shade balls will protect our water supply and ensure that residents have access to clean, safe, and ready-to-drink water. As we work to ensure a more sustainable and resilient future for L.A., I look forward to more creative, trailblazing and cost-effective solutions,” Los Angeles Councilmember Felipe Fuentes, chair of the city’s Energy and Environment Committee, said in a news release.
From Discovery News
Aug 12, 2015
The 13th-century weapon was found in the River Witham in Lincolnshire, in the United Kingdom, in 1825. It now belongs to the British Museum, but is currently on loan to the British Library, where it's being displayed as part of an exhibit on the 1215 Magna Carta.
The sword looks fairly ordinary at first glance. Weighing in at 2 lbs., 10 ounces (1.2 kilograms) and measuring 38 inches (964 millimeters) long, the weapon is steel, with a double edge and a hilt shaped like a cross. But on one side of the sword is a mysterious inscription, made by gold wire that has been inlaid into the steel, which reads, "+NDXOXCHWDRGHDXORVI+."
What does this strange group of letters mean? No one knows for sure, according to the British Library, which recently posted information about the weapon on its website, along with a request for readers to help crack the seemingly incomprehensible code.
Is the message some kind of magical incantation, meant to empower the weapon's owner with mystical abilities during battle? Perhaps the inscription is a religious blessing, or maybe it's just the complicated signature of whoever forged the weapon. Those who read the British Library's blog post put these and many other theories forward regarding the sword's enigmatic message.
Dozens of commenters chimed in to help solve the mystery. And luckily, one of those commenters had a lot of insight into the history of inscribed swords in Europe. Marc van Hasselt, a graduate student of medieval studies at Utrecht University in the Netherlands, has studied similarly inscribed swords and said that these weapons were "all the rage" in 13th-century Europe. The British Library recently updated its blog post with more information from van Hasselt.
Many inscribed swords have been found in countries including Poland, France, Sweden, the Netherlands and the United Kingdom, making the River Witham sword "part of a large international family," according to van Hasselt.
In 2006, researchers from Uppsala University in Sweden (as well as several other institutions) started the Fyris Swords Project, a research project dedicated to figuring out the historical context in which these inscribed medieval swords were used.
The River Witham sword was forged in Germany, which was then the blade-making center of Europe, according to the British Museum. And pre-Christian Germanic tribesman inscribed runes onto their swords, axes and armor to "endow the items with magical powers," the Fyris Swords Project researchers wrote in a paper published in the journal Waffen- und Kostümkunde (Weaponry and Costumes) in 2009.
Such swords were likely owned by wealthy warriors, according to the British Museum, which speculates that the River Witham sword belonged to a knight or some other rich individual who rode into battle during the crusades of the late medieval period. The British Museum also suggests that such swords may have been a part of the ceremony in which a man became a knight and vowed to defend the church.
Even though historians are fairly certain why inscribed swords were popular in the medieval period and who owned them, they still aren't sure just what these swords actually say. Interpreting the inscriptions on the blades is like "trying to crack a mysterious code," according to the Fyris Swords Project researchers.
While historians aren't entirely sure what language the letters on the sword represent, they are fairly certain that the letters are a short-form version of Latin, according to van Hasselt, who said that Latin was the "international language of choice" in 13th-century Europe. The first two letters on the River Witham sword are ND, which van Hasselt said might be a kind of invocation that stands for "Nostrum Dominus (our Lord) or Nomine Domini (name of the Lord)."
The XOXcombination that follows could refer to the Holy Trinity of the Christian faith. And the two plus sign-shaped symbols before and after the inscription are likely Christian crosses, according to the Fyris Swords Project researchers.
This sort of speculation about what the sword's inscriptions might represent has been going on for more than a century (researchers have been publishing their interpretations of the inscriptions in the journal Waffen- und Kostümkunde since 1904). The variety of the letter sequences on the swords makes it clear that the inscriptions are not general statements (i.e., a standard blessing written out in short form). Quite the opposite is true, according to the researchers.
Read more at Discovery News
As Earth enters the sixth such concentrated annihilation of life over the last half-billion years, this could be bad news for humans, the researchers say.
The last major wipeout occurred 66 million years ago when a giant asteroid put a relatively quick end to the age of dinosaurs after their spectacular 150 million-year run.
By comparison, humans have been around for about one tenth of one percent of that time.
Outside of these moments of planetary upheaval -- each of which decimated 50 to 95 percent of life forms -- species tend to disappear at a steady "background" rate that has varied remarkably little.
During the previous big five extinction, however, that rate increased by at least 100-fold.
And that's about where we are today.
"Rates of extinction amongst modern animal groups are as high, if not higher, than those we see in the fossil records during times of mass extinction," comments Alexander Dunhill, a professor at the University of Leeds, and lead author of the study.
Most mass die-offs were associated with climate change, itself triggered by some cataclysmic event -- a massive, continental-scale rupturing of volcanoes in the case of the Triassic-Jurassic juncture 200 million years ago.
"Organisms are unable to adapt quick enough to rapidly changing conditions and thus become extinct," Dunhill said.
Looking at the fossil record of land-living animals around the Triassic-Jurassic event -- in which 80 percent of species ceased to exist -- Dunhill and colleague Matthew Wills asked whether geographically far-flung creatures fared better.
The answer, published in the peer-reviewed journal Nature Communication, was "no".
"Wider geographical range conferred greater resilience ... throughout most of the Triassic and Jurassic," the study concludes.
"However, this insurance weakened towards the end of the Triassic, and was imperceptible during the mass extinction itself."
Thus, the age of giant amphibious reptiles and crocodile-like creatures gave way to the dinosaurs, which in turn yielded to small mammals and birds when their time was up.
Read more at Discovery News
First things first, assuming you do have clear skies, meteor viewing requires no specialist equipment. All you need to do is to, well, look up. Of course, standing around in the dark looking up for long periods of time isn’t terribly good for your neck, so you can take your observing session up a notch and recline in a comfy chair or even just lie on the floor. It’s a social event! Invite your friends, family and neighbors and make a night of it.
However, although it’s the middle of summer in the Northern Hemisphere, sitting or laying still for long periods of time at night, depending on the weather, can still get chilly, so be sure to keep warm and lay on something soft.
So, Where to Look?
As I said, “up” is a good place to start, and so long as your eyes have adjusted to the dark, you shouldn’t have any problems spotting the Perseid meteors (or “shooting stars”) flash across the sky. But if you want to be even more pro, make sure you know where the constellation of Perseus is in the sky. Perseus can be found in the northeast between the bright star of Capella (that will be rising above the horizon after 11 p.m. local time) and the constellation Cassiopeia. SPACE.com has a handy night sky rendering that can help you track down Perseus.
Why Perseus? Well, that’s the reason why the Perseids are named after this constellation — it just so happens that the meteors from this particular shower at this time of year appear to originate in the general direction of Perseus. This is what is known as a “radiant” and all the other annual meteor showers throughout the year have been named after the constellation they appear to be radiating from. However, it is not necessary to stare directly at Perseus to see tonight’s Perseid meteors, just be aware they will be coming from that direction and sweeping directly overhead.
Now you know what direction they’ll be coming from and you know where to look (hint: “up”), what are the Perseids anyway?
The Perseid meteors are tiny grains of dust that originate from the periodic comet Swift-Tuttle. During the comet’s 133 year trundle around the sun, the ancient icy body has left a trail of dust and ice particles in its wake — much like a cometary contrail — looping around the sun. It just so happens that this trail of comet dirt crosses Earth’s orbit and, at this time in the Earth’s 365 day orbit around the sun, we hit the dust as regular as clockwork.
As Earth passes through the comet’s trail, these particles — called meteoroids — hit our atmosphere at high speed. With high velocity comes high gas pressure in front of each falling dust grain, triggering a phenomenon called “ram pressure.” This process compresses the air in front of the meteor, causing the atmospheric gases to rapidly heat up to over 3,000 degrees Fahrenheit (1,650 degrees Celsius). If the meteoroid is small, it is the ram pressure heating, not atmospheric friction (a common misconception) that vaporizes it, creating a bright, transient meteor and short-lived ionization trail. Bigger meteoroids may generate a bright streak of light as a meteor and then erupt as an even brighter “fireball,” the largest of which may even generate a bang that can be heard on the ground.
Which brings me to my next point…
What if it’s Cloudy?
A meteor’s ionization trail is usually all that remains of the vaporized comet dust that has impacted our atmosphere. Composed of ionized gas (atmospheric gas molecules that have lost or gained electrons), these trails rapidly dissipate, but they can be used to detect the frequency of meteors raining through the upper atmosphere (at around 60 miles in altitude). These ionized gases bounce radio waves back to Earth, a signal anyone with an FM radio set can detect, even if it’s cloudy. Check out astronomer Mark Thompson’s guide on how to do meteor spotting with a radio.
Of course, it’s not just by sight and radio that you can get involved in tonight’s Perseids peak; there’s always the internet.
During every meteor shower, various social media platforms, particularly Twitter, buzz with the #MeteorWatch hashtag. Connected to the UK-based MeteorWatch.org website, you can monitor the skies and report your meteor sightings from wherever in the world. Your meteor report is then logged and plotted on a dynamic map. For instructions on how to get involved, check out the MeteorWatch website.
Also, Slooh.com will be hosting a live online event for the Perseids tonight at 5 p.m. ET/8 p.m. PT, featuring professional astronomers and live feeds from their telescopes.
And of course, NASA will also be in on the action, covering the meteor shower live online with a webcast and expert guides. Many other astronomical and space organizations will be hosting their own events.
So, if you have clear skies tonight, get out there and enjoy the cosmic fireworks. The best time to see the meteors is after midnight in the early hours of Thursday morning (Aug. 13) as, like mosquitoes hitting a car’s windshield, the leading hemisphere of our planet will be rotating into the comet dust cloud at that time.
Read more at Discovery News
The black hole was discovered in the dwarf galaxy RGG 118. It's the smallest supermassive black hole discovered to date, but it still “weighs in” at a whopping 50,000 times the mass of our sun. However, it is less than half the mass of the next-smallest supermassive black hole discovered to date and 100 times less massive than the supermassive black hole that lives in the center of our galaxy.
As we’re comparing, RGG 118′s black hole is 200,000 less massive than the biggest supermassive black hole known to exist.
Size comparisons to one side, this latest black hole discovery is extremely important to astronomers trying to understand the perplexing evolutionary processes that dominate supermassive black holes, which are known to reside in the majority of galaxies, and how they relate to their host galaxy’s evolution.
“It might sound contradictory, but finding such a small, large black hole is very important,” said Vivienne Baldassare of the University of Michigan in Ann Arbor, in a NASA news release. “We can use observations of the lightest supermassive black holes to better understand how black holes of different sizes grow.”
RGG 118 was originally discovered by the Sloan Digital Sky Survey. Baldassare’s team used NASA’s Chandra X-ray Observatory and the 6.5-meter Clay Telescope in Chile to characterize the surprisingly small supermassive black hole. They were able to study the motion of cool gas in the center of RGG 118 in optical light using the Clay Telescope. They also zoomed in on the X-ray emissions from the hot, swirling gas in close proximity to the black hole using Chandra. Both of these measurements proved that RGG 118′s black hole acts in a similar way to other supermassive black holes in the centers of other galaxies.
The velocities of stars surrounding the black hole in the core of the galaxy also supported this finding.
One of the biggest mysteries in modern astrophysics is the existence of seriously massive, billion-solar mass supermassive black holes that must have existed in the universe less than a billion years after the Big Bang. Astronomers hope that through the discovery of this smaller example that black hole evolution models may be refined.
Read more at Discovery News
Aug 11, 2015
The unusual find at first seemed to the breeder like it would net him a tidy sum. But soon he realized the strange creature would neither eat nor take water, and he decided to give the snake to specialists at the Nanning Zoo.
The snake, pencil-thin, with a dark brown backside, still has yet to eat on its own, a Nanning Zoo official told the website. It is about 20 centimeters long and has been alive for 10 days, having shed its skin once, they noted.
Because each head has its own brain, the two halves can move independently, and Nanning Zoo experts say the two heads often come together, as if they are going to fight. But scientists there say that's because the typical cobra will move in an "S" shape, and the two heads will naturally butt.
The rare snake could conceivably grow to a typical Chinese cobra length of about 1.2 meters, but zoo doctors are unable to tell how much longer it might live if it doesn't begin to eat on its own, and they also worry about its potentially low resistance to infection.
From Discovery News
Findings published in this week’s Proceedings of the National Academy of Sciences, show that the Asteraceae family of flowering plants is much older than previously thought.
“It’s one of the few modern families of flowering plants that can be traced back to the Cretaceous,” says co-author and palynologist, Dr Ian Raine, of GNS Science in New Zealand.
Flowers of the Asteraceae family — such as daisies, sunflowers, chrysanthemums, dandelions, gerberas and lettuce — are characterised by inflorescences, or clusters of small tightly packed flower heads, which often form a larger composite flower.
“The Asteraceae were thought to be a rather highly evolved family and not to have appeared until well along the evolution of the flowering plants,” says Raine.
While the earliest flowering plants evolved 130 million years ago, to date the earliest known member of the Asteraceae family, was thought to have lived in Patagonia 47.5 million years ago.
As part of ongoing research into the family, lead author Dr Viviana Barreda of the Bernardino Rivadavia Natural Sciences Museum in Buenos Aires, and colleagues, have now pushed that timeline back by at least 20 million years.
They examined pollen grains extracted from 76 to 66 million-year-old sediments on the eastern side of the Antarctic Peninsula.
Based on the shape and surface sculpture of the pollen grains the researchers identified the grains as being from the species Tubulifloridites lillei.
This extinct species had previously been found in New Zealand and southern Australia in sediments of the same age, but researchers have only now confirmed it is an early member of the Asteraceae family.
The team show the pollen grains are similar to those from members of the Barnadesioideae subfamily of Asteraceae in South America. However they don’t yet know exactly what the flower would have looked like.
Barreda and colleagues argue that once this latest find is included in the family tree of flowering plants, this places the earliest Asteraceae as living at least 80 million years ago.
While today, there are only two flowering plants native to Antarctica, back in the Cretaceous the continent was part of Gondwana and would have been covered with temperate forests and roaming dinosaurs, says Raine.
Read more at Discovery News
The broken tablet, or stela, depicts the king’s head, adorned with a feathered headdress, along with some of his neck and shoulders. On the other side, an inscription written in hieroglyphics commemorates the monarch’s 40-year reign.
The stone tablet, found in the jungle temple, may shed light on a mysterious period when one empire in the region was collapsing and another was on the rise, said the lead excavator at the site, Marcello Canuto, an anthropologist at Tulane University in Louisiana.
The team found the broken stela while excavating the ancient ruins of El Achiotal, a site occupied between 400 B.C. and roughly A.D. 550. Though archaeologists had been excavating at the site for years, they only discovered the stone tablet while digging a trench that revealed a hidden chamber at the site. The room was a sanctuary or shrine, and was so small that researchers had to crouch to get inside.
The stela was broken so that the portion that likely once depicted the King’s body was missing. Some of the hieroglyphics were worn away. But based on the inscriptions that were legible, the stela seemed to be commemorating a king who was the fifth vassal of another king.
“He’s someone under another larger person. He has an overlord of his own,” Canuto told Live Science.
The stela was also dated using the Mayan calendar, though the date was partly rubbed off. Given the text that remains, the number could refer to one of four possible dates, but the likeliest is equivalent to A.D. 418. Because the stela was celebrating the king’s 40th year in power, the ruler likely ascended to the throne in A.D. 378, the researchers deduced.
The year 378 was a significant one for the Mayans.
“It is like a Waterloo date for the Mayan, or a July 4, 1776,” Canuto said.
At that time, several texts describe a political upheaval wherein the king of Teotihuacan, near modern-day Mexico City, came down to the majestic capital city of Tikal in what is now Guatemala and overthrew its leader. (Whether that leader was killed, committed suicide or was simply deposed isn’t clear from texts, Canuto said). The king of Teotihuacan then placed one of his own vassals on the throne.
Read more at Discovery News
Lending at least some plausibility to these hypothesis was the scientific consensus that the solar activity has been trending upwards in the 300 years since the Maunder Minimum that occurred between 1645 and 1715, when there was little sunspot activity. That has led some to argue that the Sun, rather than the burning of fossil fuels, has been the main driver of rising global temperatures.
But deniers will have a tougher time making the case now. The solar explanation for global warming is refuted by a new study just presented at the International Astronomical Union’s annual assembly in Hawaii, which fixes a discrepancy among historical records of sunspots.
The apparent upward trend of solar activity between the 18th century and the late 20th century has now been identified as a major calibration error in the Group Sunspot Number, one of the two systems for counting sunspot activity historically. (The other is the Wolf Sunspot Number.)
But now that the error has been fixed, scientists say that solar activity actually has remained relatively stable since the 1700s. That means that although fluctuations in solar weather can influence climate over shorter periods, the long-term trend is being caused by something else.
The Wolf system, which was developed back in 1856, is the oldest time series in solar terrestrial physics that’s still in use today. It counts both individual sunspots and sunspot groups. But in the mid-1990s, scientists began to question whether it was an accurate way to reconstruct the longer history of solar activity. In 1998, the Group Sunspot Number, a new index, was established. It was based in part based on sunspot measurements made by Galileo in 1612.
Read more at Discovery News
Just as the speed of light in a vacuum (c) and Planck’s constant (h) well-known universal constants, the gravitational constant (or simply “G“) has been long assumed to be constant everywhere throughout the cosmos. But how can we be sure?
In the past, scientists have bounced lasers off the moon to measure the Earth-moon distance, thereby arriving at a precise measure of G. But now, astronomers using the Green Bank Telescope (GBT) in West Virginia and the Arecibo Observatory in Puerto Rico have taken a long look beyond the solar system and recorded the steady flashes of radiation produced by a spinning neutron star, or pulsar, thousands of light-years away.
Pulsars are the cosmic clocks of our universe. They are ancient remnants of larger stars that have run out of fuel and gone supernova and now consist of extremely dense, degenerate matter less than 20 miles in diameter. Pulsars also possess powerful magnetic fields that can generate extremely collimated beams of radio emissions. Each time a pulsar spins, the polar beams may sweep in the direction of Earth, registering as a pulse — much like a lighthouse appears to flash in the distance.
By timing these pulses on the finest of scales, astronomers have come to see these objects as the most precise timekeepers in the universe, rivaling even the most advanced atomic clocks we have on Earth.
Now, through the study of one special pulsar called PSR J1713+0747, astronomers have arrived at the best, and most precise, measure of G outside the solar system.
“The uncanny consistency of this stellar remnant offers intriguing evidence that the fundamental force of gravity — the big ‘G’ of physics — remains rock-solid throughout space,” said astronomer Weiwei Zhu, formerly with the University of British Columbia in Canada, in a NRAO press release. “This is an observation that has important implications in cosmology and some of the fundamental forces of physics.”
Zhu is lead author of a new study accepted for publication in the Astrophysical Journal.
PSR J1713+0747 is an ideal “laboratory” to study some of the most fundamental quantities of space, time and relativity. For starters, it has a uniquely wide orbit around the white dwarf, taking 68 days for the pulsar to complete one orbit. It is also extremely bright, one of the brightest pulsars known. As pair orbit one another, an extremely tiny amount of energy is lost from the system, via gravitational waves — a phenomenon predicted by Einstein’s general theory of relativity.
Their wide and stable orbit means that this energy loss is extremely small and has a negligible impact on the orbit of the pulsar, making it a prime target for any gravitational observations. (A more compact orbit would cause more energy to be carried away from the system via gravitational waves, introducing errors in the measurements of the pulsar’s orbital characteristics.)
So, we can now precisely measure the gravitational nature of this star system — why does it matter?
The pulsar-white dwarf binary are located 3,750 light-years from Earth and the value of G derived over 21 years of radio observations almost exactly match the most precise measurements of G we’ve carried out in our solar system. Therefore, it appears (in this test at least) that G is constant throughout the known universe.
“Gravity is the force that binds stars, planets, and galaxies together,” said astronomer and co-author Scott Ransom, with the National Radio Astronomy Observatory (NRAO) in Charlottesville, Va. “Though it appears on Earth to be constant and universal, there are some theories in cosmology that suggest gravity may change over time or may be different in different corners of the Universe.”
“These results — new and old — allow us to rule out with good confidence that there could be ‘special’ times or locations with different gravitational behavior,” said astronomer and co-author Ingrid Stairs, also from the University of British Columbia in Canada. “Theories of gravity that are different from general relativity often make such predictions, and we have put new restrictions on the parameters that describe these theories.”
Read more at Discovery News
Aug 10, 2015
The country’s tabloid newspapers have had a field day, with headlines including: “Seagull stole my iPhone” (The Sun), “Moment killer seagull turns cannibal” (The Daily Mail) and “Psycho seagulls keep out illegals” (Daily Express).
Even the broadsheets have joined in, with The Sunday Times warning that “Gull gangs learn new tricks to steal your seafront snacks”.
The squawking menaces have always had a bad reputation as scavengers.
But the gulls are now apparently growing in audacity and rather than feeding on leftovers, are deliberately targeting people’s fish and chips, the battered haddock or cod combination traditionally eaten by holidaymakers, as they tuck in.
“They’ve been trained by terrorists, I’m sure,” said Cliff Faires, owner of a seafood kiosk in the historic south coast resort of Brighton.
A sign outside his Brighton Shellfish and Oyster Bar warns: “Seagulls will snatch your food. Please be aware. We don’t take any responsibility for this action.”
’Never been so bad’
Local witnesses described a common plan of attack used by the birds, whereby a lone assailant pounces on an unsuspecting diner, forcing them to drop their food. At this point, hordes of reinforcements arrive to feast on the spilled remains.
“They’ll eat everything except lemon and tabasco,” one added.
“I see gulls grabbing food from people three or four times a day, more when it’s sunny,” said Chris, who works at a fish-and-chip kiosk on Brighton pier.
“The worst thing I’ve seen is one landing on the head of an old lady who had a hot dog. She obviously dropped it and the same gull took it away really fast, the woman was terrified,” he told AFP.
“It’s never been as bad. This is the worst year,” said Jack Messenger, from the Sea Haze Bar, another beachfront restaurant.
“It’s probably best for us, because when the seagulls eat their food, they (the customers) come and get more,” he joked.
It is not only seaside towns that are suffering, with inland cities such as Bath and Bristol reporting problems.
Experts blame a combination of factors for this summer’s Hitchcockian events.
They include gulls becoming more accustomed to living close to humans and the birds being particularly aggressive in July when they have young in their nests.
Three pets have been pecked to death by seagulls in southwest England in recent months: a turtle, a chihuahua and a Yorkshire Terrier.
“Blood was coming out of his head. It was like a murder scene,” the Yorkshire Terrier’s owner Emma Vincent told reporters.
Hysteria ‘not justified’
Even Prime Minister David Cameron has swooped into the debate.
“I think a big conversation needs to happen,” he said. ”Reading the papers this morning about how aggressive the seagulls are now in St Ives, for instance, we do have a problem.”
It is forbidden to kill seagulls, so the only way to fight them is to destroy their eggs or release birds of prey to hunt them.
Tony Whitehead, spokesman for the Royal Society for the Protection of Birds, said he “didn’t think the hysteria is justified.”
“There is an issue… but to demonize the whole species off the back of a few incidents, I don’t agree with that,” he told AFP.
Read more at Discovery News
Noblella madreselva lives in the humid cloud forest near Cusco, Peru, probably only in the valleys right around where it was discovered, researchers report today (Aug. 6) in the journal ZooKeys. The frogs, which are not much bigger than jelly beans, can fit on the tip of a human finger. They're active during the day, and live in leaf litter on the forest floor.
Vanessa Uscapi, a biologist at the National University of Saint Anthony the Abbot in Cusco, Peru, discovered the new tiny frog in January 2011, but only now has it been officially described. She and her colleagues picked the name madreselva to honor conservation initiatives in the region: The word means "mother jungle" and is also the name of a nearby ecotourism lodge and a small valley where a group called Sircadia is trying to launch a sustainable eco-community.
N. madreselva has a dark-brown body with a darker patch on its head. Its belly is decorated with striking white marks. It's not the only recently discovered tiny frog with bold coloration; in June, researchers in Brazil announced the discovery of seven itsy-bitsy new frogs from rainforests in Brazil. Those frogs, all of which belong to the genus Brachycephalus, came in colors ranging from greenish-brown to bright orange and blue.
The smallest frog ever discovered hails from Papua New Guinea, and could perch quite comfortably on a penny. Frogs, of the genus Paedophryne, are less than half an inch long. The smallest species in the genus, Paedophryne amauensis, grows to be just 0.3 inches (7.7 millimeters), on average. It's not only the world's smallest frog, but also the smallest vertebrate discovered so far.
The newly discovered Peruvian frog likely has a very limited geographical range, making it vulnerable to the effects of deforestation and habitat loss, Uscapi and her colleagues said. Andean frogs are also at risk of a deadly chytrid fungus called Batrachochytrium dendrobatidis. This fungus has devastated frog populations worldwide. It causes the amphibians' skin to harden, disrupting their electrolyte balance and causing cardiac arrest. A December 2013 study in the journal Conservation Biology found that climate change in the Andes is increasing the area in which this fungus can thrive. Alessandro Catenazzi, one of the researchers on the team that discovered the new frog along with Uscapi, was an author of that 2013 study as well.
Read more at Discovery News
“Newer galaxies are simply putting out less energy than galaxies did in the past,” astronomer Mehmet Alpaslan, with NASA’s Ames Research Center in Mountain View, Calif., told Discovery News.
Older stars are fading out faster than new stars are forming, a trend that eventually will leave the universe a cold and lonely place. “At some point, all matter will eventually decay. We’re observing the lights slowly shutting down," Alpasian said.
“The timeline for all this to come to pass is very long, hundreds of trillions of years,” he added.
The study, released Monday at the International Astronomical Union conference in Hawaii, culminates a seven-year, international effort to measure both the distances and energy output of more than 200,000 galaxies.
Seven observatories, including Europe’s Visible and Infrared Survey Telescope for Astronomy (VISTA) and its VLT Survey Telescope, both at the Paranal Observatory in Chile, contributed to the study. Other data came from NASA’s Wide-field Infrared Survey Explorer (WISE) and its now-defunct Galaxy Evolution Explorer (GALEX) space telescopes, and European Space Agency’s retired Herschel space telescope.
“GAMA is the first survey to study a large number of galaxies and map the energy outputs over the range where most of the energy comes out,” lead scientist Simon Driver, with the University of Western Australia, wrote in an email to Discovery News.
Scientists have known since the late 1990s that the universe is slowly fading, but the GAMA study is the first to measure galaxies’ radiation across the spectrum. Measurements were made at 21 wavelengths, ranging from the far ultraviolet to the infrared.
“You’re probing a lot of different kinds of physics when you look at a lot of different energy,” Alpaslan said. “Having the homogeneous data set makes it a lot easier to fully understand what is going on in a galaxy across all these different kinds of physics.”
The decline in galaxies’ energy output coincides with the universe’s ever-increasing rate of expansion, which is due to a mysterious, anti-gravity force referred to as dark energy.
Read more at Discovery News
The findings suggest that vision problems may be an underreported effect of the mosquito-transmitted virus, which has spread in recent years from Africa and Asia to the Caribbean, Latin America and parts of the United States, the report’s authors said.
“Sight-threatening visual loss can be a late complication of infection with chikungunya,” said Dr. Abhijit Mohite, who treated the woman and co-authored the report of her case.
It is important that people with vision problems get treatment early, to prevent lasting vision loss, said Mohite, an ophthalmologist at the West Midlands Postgraduate Deanery and Queen’s Hospital in the United Kingdom.
Researchers first recognized chikungunya (chik-un-GUN-ya) in Tanzania in 1952. The name is based on an East African word that means “that which bends,” because people infected with the virus are often bent over with muscle and joint pain. Other symptoms include fever, headache, nausea, vomiting and rash, according to the case report, which was published online July 28 in the journal BMJ Case Reports.
In July 2014, a Florida man became the first person to get chikungunya in the United States, according to the Centers for Disease Control and Prevention. The disease is transmitted by two species of mosquito — Aedes aegypti and Aedes albopictus — that are recognizable by their black and white legs.
There is no vaccine or drug to treat the disease, but medications such as steroids can treat the symptoms, which include inflammation, said Dr. Aileen Marty, director of the Florida International University Health Travel Medicine Program and Vaccine Clinic, who was not involved in the case report.
The woman in the case was 69, and visited the Caribbean island of Grenada in July 2014. During her stay, she was bitten by mosquitoes, and developed a flu-like illness, fever, rash and joint pain. She also developed muscle weakness in her face, and received steroids from a local doctor to treat it, according to the study.
The woman returned home to the United Kingdom that August. Although her illness appeared to go away (except for lingering joint pain and stiffness), she began having trouble seeing with her right eye.
“Her main symptom was that she felt she could not see the lower half of her vision in the right eye,” Mohite told Live Science in an email. “This had come about only a day before she came to see us, and about three weeks after she returned from Grenada.”
At first, the woman’s central vision appeared fine, and she could see with normal acuity, 20/20 vision, with both eyes. However, as the doctors raced to diagnose her illness — testing her for HIV, syphilis, Lyme disease and dengue fever — her right optic nerve swelled and damaged her vision. Within days, she had 20/80 vision, and could read only to the third line down on the eye chart.
Two days after her initial visit, a blood test showed the woman had chikungunya. But the doctors still had to rule out other possible causes of her vision loss, such as another infection, inflammation, or a tumor pressing on the optic nerve or pathway, Mohite said.
After more tests ruled out these conditions, the doctors prescribed steroids to treat the woman’s optic nerve, which had swelled as part of her body’s inflammatory reaction to the virus, he said. “One of the main risks of high-dose steroids is that they can exacerbate an infection, if she had another infection somewhere else in the body. This is why we had to await all the other tests before we could start steroids, and this took six days.”
Treated too late?
However, during the six days that it took for the doctors to run all the tests and prescribe the steroids, about half of the nerve cells in woman’s optic nerve died, Mohite said.
The steroids decreased the inflammation, but couldn’t undo all of the damage.
“The steroids, unfortunately, were not started soon enough in our patient,” Mohite said. The vision loss was permanent.
Other doctors have noted eye problems in people infected with chikungunya, but this is the first known case of a woman in the United Kingdom developing this problem, Mohite said.
It’s unknown how often chikungunya infections may lead to eye problems, experts said.
Read more at Discovery News
Aug 9, 2015
The study, published in the journal Geology, examined an 18-square-mile chloride salt deposit (roughly the size of the city of Boulder) in the planet's Meridiani region near the Mars Opportunity rover's landing site. As seen on Earth in locations such as Utah's Bonneville Salt Flats, large-scale salt deposits are considered to be evidence of evaporated bodies of water.
Digital terrain mapping and mineralogical analysis of the features surrounding the deposit indicate that this one-time lakebed is no older than 3.6 billion years old, well after the time period when Mars is thought to have been warm enough to sustain large amounts of surface water planet-wide. Planetary scientists believe that the solar system formed approximately 4.6 billion years ago.
"This was a long-lived lake, and we were able to put a very good time boundary on its maximum age," said Brian Hynek, a research associate at the Laboratory for Atmospheric and Space Physics (LASP) at CU-Boulder and lead author of the study. "We can be pretty certain that this is one of the last instances of a sizeable lake on Mars."
Based on the extent and thickness of the salt, the researchers estimate that the lake was only about 8 percent as salty as Earth's oceans and therefore may have been hospitable to microbial life.
"By salinity alone, it certainly seems as though this lake would have been habitable throughout much of its existence," said Hynek, who is also an associate professor in the Department of Geological Sciences at CU-Boulder and director of the CU Center for Astrobiology. He noted, however, that other factors such as acidity levels were not included in the scope of the study.
From Science Daily
NOvA is on a quest to learn more about the abundant yet mysterious particles called neutrinos, which flit through ordinary matter as though it weren't there. The first NOvA results, released this week at the American Physical Society's Division of Particles and Fields conference in Ann Arbor, Michigan, verify that the experiment's massive particle detector -- 50 feet tall, 50 feet wide and 200 feet long -- is sitting in the sweet spot and detecting neutrinos fired from 500 miles away. Scientists have sorted through millions of cosmic ray strikes and zeroed in on neutrino interactions.
"People are ecstatic to see our first observation of neutrino oscillations," said NOvA co-spokesperson Peter Shanahan of the U.S. Department of Energy's Fermi National Accelerator Laboratory. "For all the people who worked over the course of a decade on the designing, building, commissioning and operating this experiment, it's beyond gratifying."
Researchers have collected data aggressively since February 2014, recording neutrino interactions in the 14,000-ton far detector in Ash River, Minnesota, while construction was still under way. This allowed the collaboration to gather data while testing systems before starting operations with the complete detector in November 2014, shortly after the experiment was completed on time and under budget. NOvA construction and operations are supported by the DOE Office of Science.
The neutrino beam generated at Fermilab passes through an underground near detector, which measures the beam's neutrino composition before it leaves the Fermilab site. The particles then travel more than 500 miles straight through Earth, no tunnel required, oscillating (or changing types) along the way. About once per second, Fermilab's accelerator sends trillions of neutrinos to Minnesota, but the elusive neutrinos interact so rarely that only a few will register at the far detector.
When a neutrino bumps into an atom in the NOvA detector, it releases a signature trail of particles and light depending on which type it is: an electron, muon or tau neutrino. The beam originating at Fermilab is made almost entirely of one type -- muon neutrinos -- and scientists can measure how many of those muon neutrinos disappear over their journey and reappear as electron neutrinos.
If oscillations did not occur, experimenters predicted they would see 201 muon neutrinos arrive at the NOvA far detector in the data collected; instead, they saw a mere 33, proof that the muon neutrinos were disappearing as they transformed into the two other flavors. Similarly, if oscillations did not occur, scientists expected to see only one electron neutrino appearance (due to background interactions). But the collaboration saw six such events, evidence that some of the missing muon neutrinos had turned into electron neutrinos.
Similar long-distance experiments such as T2K in Japan and MINOS at Fermilab have seen these muon neutrino to electron neutrino oscillations before. NOvA, which will take data for at least six years, is seeing nearly equivalent results in a shorter time frame, something that bodes well for the experiment's ambitious goal of measuring neutrino properties that have eluded other experiments so far.
"One of the reasons we've made such excellent progress is the impressive Fermilab neutrino beam and accelerator team," said NOvA co-spokesperson Mark Messier of Indiana University. "Having a beam of that power running so efficiently gives us a real competitive edge and allows us to gather data quickly."
Fermilab's flagship accelerator recently set a high-energy neutrino beam world record when it reached 521 kilowatts, and the laboratory is working on improving the neutrino beam even further for projects such as NOvA and the upcoming Deep Underground Neutrino Experiment. Researchers expect to reach 700 kilowatts early next calendar year, accumulating a slew of neutrino interactions and tripling the amount of data recorded by year's end.
Neutrinos are the most abundant massive particle in the universe but are still poorly understood. While researchers know that neutrinos come in three types, they don't know which is the heaviest and which is the lightest. Figuring out this ordering -- one of the goals of the NOvA experiment -- would be a great litmus test for theories about how the neutrino gets its mass. While the famed Higgs boson helps explain how some particles obtain their masses, scientists don't know yet how it is connected to neutrinos, if at all. The measurement of the neutrino mass hierarchy is also crucial information for neutrino experiments trying to see if the neutrino is its own antiparticle.
Read more at Science Daily