Grand Canyon could be much older than thought
|Dating of rock erosion pegs the ancient chasm as 70 million years old
By Alexandra Witze
Rock of ages it may be, but the Grand Canyon’s age itself is under fire. New work suggests the iconic chasm was already in place 70 million years ago — making it far older than commonly believed.
By most geologists’ definition, the Grand Canyon proper emerged between 5 million and 6 million years ago, as the Colorado River flowed across and eroded its way through layer after layer of rock. Evidence for this age comes from, among other things, great piles of washed-out gravel at the canyon’s western end that appeared around that time.
But the new study, reported online November 29 in Science, looks instead at the chemistry of rocks exposed throughout the canyon. Rocks get cooler as erosion strips away the material above them. That cooling is chemically preserved in several ways, including in helium within the mineral apatite.
Our Minds Can Only Handle Four Chunks Of Information At A Time
For the last 50 years, psychological lore has held seven as a “magic” number when it comes to the number of items of information the mind can cope with before confusion sets in.
A new analysis from the University of New South Wales challenges this long-held view, suggesting the magic might actually be in the number four.
American psychologist George Miller published a paper in 1956 in the influential journal Psychological Review. The paper, “The Magical Number Seven, Plus or Minus Two. Some Limits on Our Capacity for Processing Information,” argued that the mind could cope with a maximum number of only seven chunks of information at a time. Since publication, the paper has become one of the most highly cited psychology articles. Psychology Review says the paper is the most influential of all time.
UNSW professor Gordon Parker, however, says that his re-analysis of Miller’s experiments shows that Miller missed the mark by a wide margin.
Printed robot moves with a beat
|Tiny device created with a 3-D printer employs heart cells to make it move
By Rachel Ehrenberg
Fueled by the rhythmic beating of rat heart cells, a soft-bodied robot the size of a grain of rice chugs across a Petri dish. Designed with drafting software on a computer, the bot’s blueprints were brought to life with a 3-D printer at the University of Illinois at Urbana-Champaign.
3-D printers create objects by depositing layer upon layer of a material other than ink, ultimately building a 3-D object from the bottom up. To create the bot, the printer squirts out a layer of liquid hydrogel — a gelatinous mix of water and inert, meshlike molecules — and then stiffens up each layer of the bot’s body with a laser. The bot’s curved “leg” was then seeded with a mix of rat fibroblast and heart cells, which spontaneously contract. After about three days, the cell layer became a synchronized beating sheet whose contractions propelled the springboardlike bot forward.
The beauty of printing the bots, says study leader Rashid Bashir, is it allows for tweaking designs and ingredients until, for example, the bots’ legs are just sticky enough to skip forward. Similar bots may one day serve as traveling sensors that detect chemicals in the environment. “By using cells to build biological machines we may solve problems,” Bashir says. Bashir and colleagues describe the feat online November 15 in Scientific Reports.
E-Ink Case Turns the Back of Your Phone Into a Second Screen
|By Tim Maly
Do you own a smartphone? Flip it over. What do you see? Maybe there’s a hole for a camera, a company logo, and some FCC disclaimers? Do you see the cool design of a case you bought for it? Either way, it’s essentially inert. But for Greg Moon and Yasha Behzadi, it was an opportunity to do some clever design.
“We both like strong imagery, and we were running with the idea of electronic, persistent visual personalization in a physical object,” says Moon, and the pair had been throwing around ideas for what that could be. “We were walking back from lunch, musing, ‘Where is there a big, flat piece of real estate that we could visually configure?’”
Behzadi first realized the answer: the back of a phone. From there, they created popSLATE, a case for the iPhone 5 with an e-ink screen. The innovative device is being launched on IndieGoGo today.
The e-ink screen that popSLATE uses is the next generation of screens that are at the core of e-readers like Amazon’s Kindle or the Kobo. Like all e-ink screens, it only consumes power when the display is changed. This allows for an always-on ambient visual interface.
Shrinking polar ice caused one-fifth of sea level rise
|Comprehensive analysis quantifies ice sheet loss in Greenland and Antarctica
By Erin Wayman
Scientists now have one polar ice study to rule them all. An international team of researchers has compiled 20 years of data from 10 satellite missions to create the most comprehensive assessment to date of Greenland’s and Antarctica’s shrinking ice sheets.
And the verdict: Between 1992 and 2011, the Greenland ice sheet lost 2,940 billion metric tons of ice while the Antarctic ice sheet shed 1,320 billion metric tons. All that water raised the sea level by an average of 11.1 millimeters, accounting for one-fifth of sea level rise over that period, the team reports in the Nov. 30 Science.
The findings are a good starting point for making improved predictions of future sea level increases. “Our estimates of ice sheet mass loss are the most reliable to date,” says study coleader Andrew Shepherd of the University of Leeds in England.
Over the last 15 years, scientists have reported a wide range of sometimes-conflicting estimates of how the polar ice sheets are changing. Many studies suggest that more ice is now lost each year through melting and calving icebergs than is added by annual snowfall. But some research indicates ice losses and gains actually balance out. The disparities stem from three different satellite methods used to evaluate ice sheet mass. And these studies have looked at different regions of the ice sheets over different, usually brief, intervals, says Richard Alley, a glaciologist at Penn State University.
Gulf spill harmed small fish, studies indicate
|Effects vary but dire impacts seen with some very low exposures
By Janet Raloff
LONG BEACH, Calif. — Two years after BP’s Deepwater Horizon well blowout, laboratory studies are finally offering clues to the spilled oil’s impact on sea life. Brief, very low exposures to oil were capable of killing many fish embryos and hatchlings, new studies show. Those that survived often exhibited major deformities that would diminish an animal’s fitness.
Affected species ranged from the young of large open-ocean denizens, such as tuna, to minnow-sized coastal homebodies — the tiny fish that serve as lunch for everyone bigger. Researchers shared their findings in mid-November during a symposium at the Society of Environmental Toxicology and Chemistry’s annual meeting.
Among oil constituents that most threaten sea life are polycyclic aromatic hydrocarbons, or PAHs. Through a process known as weathering, lighter-weight chemicals evaporate off of fresh oil, rendering what’s left progressively heavier and sludgy. New chemical analyses show that weathering reduces oil’s propensity to shed PAHs into water, finds Damian Shea of North Carolina State University in Raleigh. The bottom line, he concludes: Weathering reduces oil toxicity.
Auditory test predicts coma awakening
|Patients whose sound discrimination improved in 48 hours eventually awoke
By Tanya Lewis
A coma patient’s chances of surviving and waking up could be predicted by changes in the brain’s ability to discriminate sounds, new research suggests.
Recovery from coma has been linked to auditory function before, but it wasn’t clear whether function depended on the time of assessment. Whereas previous studies tested patients several days or weeks after comas set in, a new study looks at the critical phase during the first 48 hours. At early stages, comatose brains can still distinguish between different sound patterns,. How this ability progresses over time can predict whether a coma patient will survive and ultimately awaken, researchers report.
“It’s a very promising tool for prognosis,” says neurologist Mélanie Boly of the Belgian National Fund for Scientific Research, who was not involved with the study. “For the family, it’s very important to know if someone will recover or not.”
A team led by neuroscientist Marzia De Lucia of the University of Lausanne in Switzerland studied 30 coma patients who had experienced heart attacks that deprived their brains of oxygen. All the patients underwent therapeutic hypothermia, a standard treatment to minimize brain damage, in which their bodies were cooled to 33° Celsius for 24 hours.
Homicide spreads like infectious disease
|Health & Medicine
Homicide moves through a city in a process similar to infectious disease, according to a new study that may give police a new tool in tracking and ultimately preventing murders. Using Newark, N.J., as a pilot case, a team of Michigan State University researchers led by April Zeoli successfully applied public health tracking methods to the city's 2,366 homicides between 1982 and 2008. They found the killings were not randomly located but instead followed a pattern, evolving from the city's center and moving southward and westward over time.
Like a flu bug that spreads to susceptible groups such as children and the elderly, homicide clusters in Newark -- often fueled by gangs and guns -- spread to areas consisting largely of poor and minority residents. Over time, the concentration of homicides effectively disappeared from one area and settled in another.
"By using the principles of infectious disease control, we may be able to predict the spread of homicide and reduce the incidence of this crime," said Zeoli, public health researcher in MSU's School of Criminal Justice.
Glimpse at early universe finds expansion slowdown
|BOSS project looks at acceleration rate before dark energy hit the gas
By Andrew Grant
New measurements have captured the universe’s expansion when it was slowing down 11 billion years ago, before a mysterious entity called dark energy took over and began spurring the cosmos to expand faster and faster. The measurements, reported online November 12 at arXiv.org, are an important step toward understanding what dark energy is and how it works.
About 15 years ago, astronomers discovered that the universe’s expansion is accelerating by cataloging spectacular stellar explosions called type Ia supernovas. Because each explosion emits almost exactly the same amount of light, astronomers can use a supernova’s observed brightness to determine its distance, and then measure its redshift, or how much its light is stretched, to determine how fast the supernova is moving away from Earth. Astronomers Adam Riess of Johns Hopkins University, Saul Perlmutter of the University of California, Berkeley and Brian Schmidt of Australian National University shared the 2011 Nobel Prize for their work using this technique to reveal that the universe’s expansion is currently accelerating and has been for the last 5 billion years or so.
But as bright as supernovas are, they are difficult to see deep in the cosmos, at distances corresponding to the time when the universe was only a few billion years old. So an international team of scientists with the Baryon Oscillation Spectroscopic Survey, or BOSS, employs a different method. They use the 2.5-meter Sloan telescope at New Mexico’s Apache Point Observatory to collect light produced by feasting supermassive black holes that thrived a couple billion years after the dawn of the universe 13.7 billion years ago.
First-ever hyperspectral images of Earth's auroras
|Astronomy & Space
Hoping to expand our understanding of auroras and other fleeting atmospheric events, a team of space-weather researchers designed and built NORUSCA II, a new camera with unprecedented capabilities that can simultaneously image multiple spectral bands, in essence different wavelengths or colors, of light. The camera was tested at the Kjell Henriksen Observatory (KHO) in Svalbard, Norway, where it produced the first-ever hyperspectral images of auroras -- commonly referred to as "the Northern (or Southern) Lights" -- and may already have revealed a previously unknown atmospheric phenomenon. Details on the camera and the results from its first images were published November 29 in the Optical Society's (OSA) open-access journal Optics Express.
Auroras, nature's celestial fireworks, are created when charged particles from the Sun penetrate Earth's magnetic field. These shimmering displays in the night sky reveal important information about the Earth-Sun system and the way our planet responds to powerful solar storms. Current-generation cameras, however, are simply light buckets -- meaning they collect all the light together into one image -- and lack the ability to separately capture and analyze multiple slivers of the visible spectrum. That means if researchers want to study auroras by looking at specific bands or a small portion of the spectrum they would have to use a series of filters to block out the unwanted wavelengths.
Study Shows US College Students Suck At Math
When it comes to texting and updating Facebook, our U.S. culture has an edge on all other societies, but mathematics is a different story altogether. A new research paper looked at how U.S. students fared in comparison to other nations, and found that our national math IQ is lacking.
In the study, U.S. college students were presented with a number line, ranging from -2 to 2, and were asked to pinpoint the location of 0.7 and 13/8. They found that just 21 percent of students answered the equation correctly.
When the students were asked whether a/5 or a/8 was greater, only 53 percent answered correctly. The authors believe that many of the participants could’ve been just guessing, since 36 percent were unable to explain why one was bigger.
The researchers said that since much of math education is just following formulas, students are incapable of tracking problems only slightly different than ones that they have encountered.
A student was asked in the study whether it was possible to check if 462 + 253 = 715. The student correctly answered that you could subtract 253 from 715, but when he was asked whether one could also do 715 – 462, the student “did not think so.”
Another set of questions checked to determine whether students would take advantage of relationships between problems to find easy solutions. These students were asked to solve the following problems: 10 × 3 = ; 10 × 13 = ; 20 × 13 = ; 30 × 13 = ; 31 × 13 = ; 29 × 13 = ; and 22 × 13 = .