When travelers return from a journey, they usually hope to bring back some souvenirs, photos and maybe a slightly different perspective on the world.
But, they may be bringing something more harmful back with them as well. Not only did tourists bring back genes that rendered their gut bacteria resistant to antibiotics, it took as little as two days for it to happen, according to the results of a study presented recently at a conference of the American Society for Microbiology. Read More
She can tell you how to bring an aircraft out of a stall, but has no memory of her marriage. She can explain an arpeggio, but doesn’t remember the tune to “Happy Birthday.” She can detail the steps to remove excess paint from a watercolor painting, but fails to recognize “Starry Night”.
Lonni Sue Johnson is teaching scientists new things about our brains, after losing a critical part of hers. Infected in 2007 with a form of encephalitis, Johnson would end up losing her hippocampus, much of her medial cortex and parts of other brain regions to the disease. While her lucidity survived the illness, much of her memory did not. The regions of the brain she lost play a crucial role in making new memories and recalling old ones. She now suffers from severe amnesia that has painted over large swathes of her life, including a decade of marriage and a career as an illustrator that saw her work featured on the cover of the New Yorker multiple times.
She nevertheless displays talents, such as the ability to recall particular facts, that puzzle researchers. Recent research by a Johns Hopkins psychologist suggests that Johnson’s condition may hint at nuances of memory formation and recall that researchers have until now overlooked. Read More
We can’t — yet — directly see black holes, making finding one of these elusive beasts hard, especially since a great majority of them are dormant. But researchers at the University of Maryland, NASA Goddard, and the University of Michigan recently caught one of these sleeping giants waking up to slurp on a big snack: a passing star. Read More
Gun deaths dropped in Australia following a massive buyback program and tighter gun laws, according to a new study published Wednesday. However, the scientists say they can’t decisively prove a connection.
Researchers from the University of Sydney compared firearm deaths both before and after the 1996 Port Arthur Massacre, when a gunman killed 35 people and wounded 23 others. That mass shooting prompted Australian legislators to take action, launching a firearm buyback program and significant restrictions on some kinds of semi-automatic rifles and shotguns. They also added harsh penalties for those breaking the law. Read More
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.”