We already knew that noise pollution invades the Mariana Trench, but it seems that another, more dangerous, form of pollutant has entered the deepest place on Earth as well.
Researchers from the University of Aberdeen went to arguably the most removed place on the planet and still found traces of chemical pollutants in creatures living miles below the ocean surface, as Nature reports. Speaking at a conference in Shanghai in early June, the scientists presented evidence of both PCB’s and another class of toxic chemical called polybrominated diphenyl ethers (PBDE’s) in small crustaceans gathered from the deeps. Read More
Chameleons present an intriguing puzzle for biologists. From their bulging eyes to their color-swapping skin, they possess a host of unique adaptions. Now, another piece of their mysterious physiology has come to light.
Researchers from France and Belgium have discovered how chameleons hang on to their prey once they’ve snatched it with their tongues. A chameleon’s tongue can be up to twice its body length — over two feet in some cases — and operates something like an arrow fired from a bow. Using elastic tissues, chameleons launch their tongues toward prey at accelerations of up to 20 feet per second. If judged perfectly, their tongue grabs unfortunate insects or small lizards at the apex of the shot and drags it into their mouth. Read More
A wide-ranging aerial study of archeological sites in Cambodia reveals a Khmer empire that was larger and more sophisticated than previously thought.
By attaching a Lidar scanning system to helicopter skids, Damian Evans, the leader of the Cambodian Archaeological Lidar Initiative (CALI), peered beneath 734 square miles of dense rainforest canopy to map the topography of the ground beneath. He found dozens of new sites that were previously invisible to archaeologists, and significant evidence of large-scale human endeavors to shape the land. Evans discovered a network of roads between settlements, quarries and diverted rivers, in addition to swathes of ancient settlements that had previously eluded archaeologists. His work significantly expands the scale and emphasizes the interconnectedness of the ancient empire, which was the largest in the world at its height in the 12th century. Read More
Take a good look, because once this squirming lump of golden fur dives back into the ground, you probably won’t see it again for a long time.
The adorable creature is a northern marsupial mole, Notoryctes caurinus, known more commonly by its aboriginal name, karrkaratul. It was found by rangers affiliated with the Tjamu Tjamu Aboriginal Corporation during an expedition to the outback last week, after it scurried across the road in front of their vehicle. The crew stopped for a quick photo shoot before returning it to its subterranean habitat. Some of the younger rangers had never even seen the creature before.
Karrkaratul are so rare that fewer than ten are seen a decade, as National Geographic reports. They are thought to be endangered, although so little is known about them that their status is largely a mystery. They are descended from marsupials, and actually have no common ancestors with other moles, making them a prime example of convergent evolution. Their sleek fur and streamlined bodies allow them to move quickly through earth, a job made easier with two shovel-like paws and a hardened forehead that acts as a kind of battering ram. The blind marsupials dine mostly on insects and larvae, and can live their whole lives underground, which explains why they are so rarely spotted on the surface.
As a 2000 paper published in the Australian Journal of Zoology explains, these moles can lower their body temperatures significantly, similar to a reptile, in order to match the heat of the sand and conserve energy. Their metabolic rate is so low, in fact, that they don’t even need to dig out a tunnel, instead surviving on the wisps of air that seep in through tiny gaps in the sand.
In 2014, Discover reported on an equation that purported to lay out key variables that determine how happy we are. It said, in a nutshell, lower your expectations if you want to be happier.
But the pursuit of happiness is far more complicated than simply expecting nothing, so it’s no surprise that the “happiness equation” has since grown. Now, on top of lowering your expectations, you might want to avoid scrolling through your Facebook newsfeed comparing yourself to other smiling faces. It turns out other people’s happiness is now part of that equation.
Chad Hanna was enjoying a quiet Christmas night with family in rural western Pennsylvania when he got the text message. He sprang for his phone, surprising his in-laws. Then he grabbed his laptop and flew up the stairs to an empty bedroom.
The cosmos had quietly gifted scientists with a second gravitational wave, dubbed GW151226, from two black holes that collided 1.4 billion light-years away. The signal from those black holes — one 14 solar masses and the other eight — showed the final dozens of death spirals before the pair smashed together with such intensity that a mass equal to our sun radiated out as gravitational waves. That announcement came Wednesday at the American Astronomical Society meeting in San Diego.
At the time of the second detection, scientists working on the Laser Interferometer Gravitational-wave Observatory (LIGO) were already confident they had the historic first signal in the bag. But that knowledge remained a closely guarded secret, even as rumors trickled out to media outlets around the world.
So Hanna couldn’t explain his strange behavior.
“My family had no idea what was going on,” says Hanna, a LIGO scientist from Pennsylvania State University. “In fact, they didn’t really know that much about what I do for a living. Until recently it was pretty esoteric and not something that the public at large had any experience with.”
When the drama subsided, he seized the opportunity to play a practical joke.
“The rest of our holiday vacation I led them to believe that I may or may not be on a top-secret government mission to protect the world from alien invaders,” he says. ”The truth was only slightly less interesting.”
As Hanna’s family and the rest of the world learned in February, gravitational waves are ripples in the fabric of space-time. And because gravity is the weakest of the four fundamental forces, only the most extreme cosmic events like supernovas, spinning neutron stars and colliding black holes generate detectable waves.
When gravitational waves move across LIGO’s twin detectors in Louisiana and Washington state, extremely sensitive equipment employs lasers to catch the waves’ tiny stretches and squeezes of space-time.
The first historic chirp of two colliding black holes, detected September 14, had come as a surprise. Scientists predicted their first signal would come from merging neutron stars, which were thought to be more common than colliding black holes. And the first black holes LIGO “saw” collide were more massive than models predicted, packing 36 and 29 times the sun’s mass. Earthly observations had never turned up such monsters.
The gravitational wave from this enormous pair leapt out of LIGO’s data, confirming Albert Einstein’s general relativity, or theory of gravity, with a signal that stood tall above the noise. This second gravitational wave signal was weaker.
“The first detected signal was very loud, so loud that it was possible to see the waveform in the data stream by naked eye,” Marco Cavaglià, a University of Mississippi astronomer and assistant LIGO spokesman. “In this second detection the signal is buried in the noise.”
LIGO relied instead on a technique called matched filtering. The process works much like the phone app Shazam, which allows users to identify a song title and artist by recording a sample of what they’re listening to and matching it to the service’s catalog. Similarly, LIGO’s supercomputer is constantly searching for signals that match any of its hundreds of thousands of templates for merging black holes and other astrophysical phenomena.
“The basic idea is it’s easier to find something if you know exactly what you’re looking for,” says Hanna.
The second signal also wasn’t the only other gravitational wave LIGO scientists saw during their first advanced observing run. A third signal, too weak to label a formal detection, is now giving insights about how often black holes collide in our universe.
“The best guess we have is that binary black holes merge in our universe at the rate of a few per hour,” says LIGO scientist Jolien Creighton of the University of Wisconsin-Milwaukee.
Assuming LIGO’s early data are not exceptional, scientists will soon piece together the first black hole census. Extrapolating from these mergers to the larger universe beyond what LIGO can see, the team calculates that a few binary black holes should merge every hour in the cosmos.
“It does imply that we should have tens of detections over the next few years, and hundreds through the end of the decade,” says Hanna. “That’s enough to do some pretty significant astronomy. That’s a big population.”
LIGO scientists say they’ve now reported all observed gravitational waves from merging black holes that happened in their first advanced observing run. However, they’re still analyzing the data in search of merging neutron stars. That research could bring new surprises in the coming months.
The early detections do hint at a bigger find still waiting out there — a persistent background of gravitational wave signals streaming over Earth from mergers all over the cosmos.
“With these detections we have evidence that the stochastic background is higher than what we previously expected and is potentially measurable once Advanced LIGO and Advanced Virgo will be operating at their design sensitivity,” Cavaglià says. That should happen in the coming years.
The next frontier for gravitational waves is to study their sources with electromagnetic radiation immediately after a LIGO detection. There were some tantalizing results after the historic first gravitational wave signal, when NASA’s Fermi gamma-ray telescope also saw something that might possibly have been related in the same general region of the sky. Other telescopes turned their gaze and saw nothing.
But the LIGO collaboration stumbled with that step on its second signal, giving scientists a lesson in overcoming the bureaucracy of their enormous collaboration.
Hanna and other LIGO scientists received text alerts almost instantaneously on Christmas night and then quickly rallied to analyze the signal. But the next step wasn’t automated.
LIGO is supposed to tip off hundreds of scientists working on more than 60 partner teams so they can try and train their telescopes onto the source, which could have come from anywhere across a vast region of the sky.
The holiday timing proved a perfect storm that stopped the team from notifying the larger astronomy community right away.
The collaboration hasn’t changed its policies yet, but the expansive team hopes to have new procedures in place by the time LIGO starts its second advanced run later this summer.
“In the future we want to make this much more streamlined,” Hanna says. “This was our first run.”
Drinking coffee isn’t going to give you cancer, but the way you drink it might.
Those are the findings of 23 scientists from 10 countries who reviewed roughly 1,000 studies looking at the long-debated link between drinking coffee and getting certain types of cancer. They found no basis for the claims that your daily cuppa will give you cancer — if anything, it might protect against tumors — but they did find a potential link between extremely hot beverages and certain types of cancer. They published their findings in The Lancet on Wednesday after meeting at the World Health Organization’s International Agency for Research on Cancer in Lyon, France, back in May. Read More
A peculiar new molecule hovering within a star-forming dust cloud in deep in space could help explain why life on Earth is the way it is.
The cloud, called Sagittarius B2, resides near the center of the Milky Way, and it’s there that researchers from the California Institute of Technology discovered an organic element that displays a key property shared by all life. Propylene oxide is the first element discovered outside of our solar system to exhibit chirality, or the presence of two distinct, mirror-image forms. Many complex molecules have this property, including myriad organic molecules necessary for life. The chemical formula of these two versions is exactly the same, but the structure is flipped.
All life on Earth is composed of chiral molecules, and the versions organisms use, either right- or left-handed, determines fundamental properties of their biology. For example, all living things only use the right-handed form of the sugar ribose to form the backbone of DNA, giving it that the signature twist. You can think of molecular handedness by picturing gloves — hence the “handed terminology”. The gloves, or molecules, may look similar, but you could never put a left-handed glove on your right hand.
Ignoring the chirality of the molecules that we put in our bodies can have deadly consequences. The drug thalidomide, used in the mid-20th century as a sedative for pregnant women, turned out to cause terrible birth defects if taken at the wrong time. It turned out that thalidomide was made up of chiral molecules — some were left-handed and others were right-handed. One version would act as a sedative, while the other would lead to birth defects.
The fact that we are made up of molecules that look one way and and not the other has long presented a near-ontological question for researchers. The various building blocks of life here, sugars and amino acids, all share chirality with each other —sugars are all right-handed and amino acids are all left-handed — what’s called homochirality. While just one version may exist here on Earth, both right and left-molecules are possible. It isn’t known how life on this planet chose its preferred molecular handedness.
The question for researchers now is whether molecules on Earth are inherently better suited for life, or if chirality is a product of pure chance. It could be that conditions in the universe favor one form of organic molecules over the other — it has been suggested that the way that photons or electrons are polarized could preferentially destroy one form of a molecule over another.
“[It] provides us with a lab to try and test theories about the role chiral molecules played in the origins of life on earth and elsewhere in the galaxy,” says Brandon Carroll, a PhD candidate at Caltech and coauthor of the paper.
The researchers found traces of propylene oxide in Sagittarius B2 with the help of two radio telescopes, one in West Virginia and one in Australia. Every molecule emits radio waves in a unique frequency as it moves through space, which serves as an invisible signature. Using radio telescopes, researchers detect these emissions and match the wave frequency to known spectra. Using this method, the Caltech researchers determined that Sagittarius B2 contains significant amounts of propylene oxide, an organic chemical often used to manufacture plastics here on Earth.
While this propylene oxide is not used by any organic lifeforms here on Earth, it does prove that finding chiral molecules beyond our solar system is possible. They couldn’t determine which form of the molecule was present in Sagittarius B2, but the researchers say that it may be possible to determine handedness in the future by exploiting differences in how polarized light passes through the cloud.
We have previously found chiral organic molecules on comets and asteroids from our solar system, but scientists wanted to discover the presence of such molecules beyond our backyard. Our entire solar system was likely formed from a cloud of dust and gas much like Sagittarius B2, and the chirality of the molecules that went on to form the Earth, and eventually us, determined some of the most basic features of Earthly life. Discovering chiral molecules elsewhere is an important step toward elucidating the role that chirality plays in creating life and guiding its development.
This post has been updated to clarify that amino acids and sugars display different handedness.
Bombay night frogs have added a new chapter to the Anuran Kama Sutra.
There are roughly 6,600 species of Anurans – frogs and toads –worldwide, but for all that variety, these amphibians stick to one of six mating positions when it’s time to make more frogs and toads. But Bombay night frogs, Nyctibatrachus humayuni, aren’t like other frogs; instead, mating couples wriggle into a newly discovered, seventh sex position that researchers christened the “dorsal straddle”.
Don’t be surprised if this one soon appears in the Urban Dictionary.
Here’s a quick primer on the recently minted seventh mating position: The male straddles the female while grasping onto a leaf or a twig – on occasion, his hand may rest on her hand or arm. He then thrusts his hips, releases his sperm onto the female’s back and hops away. After that, she deposits her eggs and arches her back, funneling the sperm onto the clutch of eggs between her legs. She remains motionless while fertilization occurs.
And that’s the dorsal straddle in a nutshell. That’s not to be confused with the head straddle, which is the move preferred by mantellid frogs. The name speaks for itself.
A research team led by University of Delhi professor S.D. Biju observed the novel mating position while studying Bombay night frogs for 40 nights between 2010 and 2012 in the dense forests located near Humbarli village in Maharashtra, India. The team published its findings Tuesday in the open-access journal PeerJ.
In most frog species, males release sperm and females release eggs simultaneously while locked in an embrace, called amplexus. Staying together is thought to increase the odds of reproductive success, and males in most frog species fertilize eggs by clasping onto the female’s waist or her armpits. Bombay night frogs don’t embrace, and egg-laying and fertilization occurs after the male hops away. These two behaviors make the dorsal straddle unique.
Interestingly, the frogs hit a 100 percent fertilization rate, based on samples researchers gathered. Males, the researchers hypothesize, grab hold of a leaf or twig rather than the female to reduce the risk of falling off their perch.
For most frog couples, their dorsal straddling simply fueled the food chain. During researchers’ observation period, a snake gobbled up 80 percent of the egg clutches. It’s the first time a snake was observed eating frog eggs in India, according to researchers.
The genus Nyctibatrachus is endemic to the Western Ghats of India, and includes 28 known species, many of which were only recently described. Scientists still don’t know much about this particular branch of the frog family tree, but several studies have noted interesting reproductive behaviors in Nyctibatrachus species. The froggy Kama Sutra will likely grow as scientists learn more about them.
But time isn’t on researchers’ side, however. Species of Nyctibatrachus are particularly threatened by human activities, so knowing how they mate is key to building effective conservation efforts. More studies “exploring the unique and diverse (behavior) in Nyctibatrachus frogs are, therefore, badly needed,” Biju’s team wrote in its paper.
And, in case you’re interested, researchers put together a video of Bombay night frogs’ twist on fertilization.
Calling a person a birdbrain isn’t the insult to intelligence it used to be. Sure, bird brains are small, but, according to a new study, their surprising intellect might arise from packing more neural connections into a smaller package.
Some birds excel at tasks believed to require “higher thought,” such as planning for the future, using tools and recognizing themselves in mirrors. Birds accomplish these challenges at a level that matches or exceeds primates’ problem-solving skills, despite having brains that are several times smaller. Researchers in the past suggested that bird brains are wired in a completely different way than primates’, a theory that was disproved two years ago in a study examining pigeon brains. Instead, birds might be living proof that big things come in small packages. Read More