A Bit More Detail

Assorted Personal Notations, Essays, and Other Jottings

Posts Tagged ‘science

[LINK] “Is There a Kraken in Kraken Mare? What Kind of Life Would We Find on Titan?”

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At Universe Today, Paul Patton speculates about plausible biochemistries for life on Titan.

Could there be life on Saturn’s large moon Titan? Asking the question forces astrobiologists and chemists to think carefully and creatively about the chemistry of life, and how it might be different on other worlds than it is on Earth. In February, a team of researchers from Cornell University, including chemical engineering graduate student James Stevenson, planetary scientist Jonathan Lunine, and chemical engineer Paulette Clancy, published a pioneering study arguing that cell membranes could form under the exotic chemical conditions present on this remarkable moon.

In many ways, Titan is Earth’s twin. It’s the largest moon in the solar system and bigger than the planet Mercury. Like Earth, it has a substantial atmosphere, with a surface atmospheric pressure a bit higher than Earth’s. Besides Earth, Titan is the only object in our solar system known to have accumulations of liquid on its surface. NASA’s Cassini space probe discovered abundant lakes and even rivers in Titan’s polar regions. The largest lake, or sea, called Kraken Mare, is larger than Earth’s Caspian Sea. Researchers know from both spacecraft observations and laboratory experiments that Titan’s atmosphere is rich in complex organic molecules, which are the building blocks of life.

All these features might make it seem as though Titan is tantalizingly suitable for life. The name ‘Kraken’, which refers to a legendary sea monster, fancifully reflects the eager hopes of astrobiologists. But, Titan is Earth’s alien twin. Being almost ten times further from the sun than Earth is, its surface temperature is a frigid -180 degrees Celsius. Liquid water is vital to life as we know it, but on Titan’s surface all water is frozen solid. Water ice takes on the role that silicon-containing rock does on Earth, making up the outer layers of the crust.

The liquid that fills Titan’s lakes and rivers is not water, but liquid methane, probably mixed with other substances like liquid ethane, all of which are gases here on Earth. If there is life in Titan’s seas, it is not life as we know it. It must be an alien form of life, with organic molecules dissolved in liquid methane instead of liquid water. Is such a thing even possible?

It is, actually.

Written by Randy McDonald

October 3, 2015 at 3:59 am

[LINK] “Humans have more primitive hands than chimpanzees”

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Science does its readers a service in reporting new findings suggesting that chimpanzees cannot be taken to represent the original state of proto-humans, that this species also evolved over time. Michael Balter writes.

Humans and chimps diverged from a common ancestor perhaps about 7 million years ago, and their hands now look very different. We have a relatively long thumb and shorter fingers, which allows us to touch our thumbs to any point along our fingers and thus easily grasp objects. Chimps, on the other hand, have much longer fingers and shorter thumbs, perfect for swinging in trees but much less handy for precision grasping. For decades the dominant view among researchers was that the common ancestor of chimps and humans had chimplike hands, and that the human hand changed in response to the pressures of natural selection to make us better toolmakers.

But recently some researchers have begun to challenge the idea that the human hand fundamentally changed its proportions after the evolutionary split with chimps. The earliest humanmade stone tools are thought to date back 3.3 million years, but new evidence has emerged that some of the earliest members of the human line—such as the 4.4-million-year-old Ardipithecus ramidus (“Ardi”)—had hands that resembled those of modern humans rather than chimps, even though it did not make tools. And back in 2010, a team led by paleoanthropologist Sergio Almécija, now at George Washington University in Washington, D.C., began arguing that even earlier human relatives, dating to 6 million years ago—very soon after the human-chimp evolutionary split—already had humanlike hands as well. This even included the ability to press the thumb against the fingers with considerable force, a key aspect of precision gripping.

To get a grasp on what early hands really looked like, Almécija and his colleagues analyzed the thumb and finger proportions of a large number of living apes and monkeys, including modern humans. They then compared these to the hands of several extinct species of apes and early humans, including Ardi, the Neandertals, and the 2-million-year-old Australopithecus sediba from South Africa, which its discoverers controversially think might be a direct ancestor of humans. The sample also included the 25-million-year-old fossil ape known as Proconsul.

The team crunched the measurements from all these samples using sophisticated statistical methods designed to determine the course of hand evolution over time. The researchers found that the hand of the common ancestor of chimps and humans, and perhaps also earlier ape ancestors, had a relatively long thumb and shorter fingers, similar to that of humans today. (Gorillas, which spend most of their time on the ground and not in trees, have similarly shaped hands.) Thus, the human hand retains these more “primitive” proportions, whereas the elongated fingers and shorter thumbs of chimps, as well as orangutans, represent a more specialized and “derived” form ideal for life in the trees, the team reports today in Nature Communications.

Written by Randy McDonald

October 3, 2015 at 3:57 am

Posted in Science

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[LINK] “India’s Historic 1st Mission to Mars Celebrates 1 Year in Orbit at Red Planet”

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Universe Today’s Ken Kremer reports on the success of India’s mission to Mars.

India’s historic first mission to Mars is now celebrating one year orbiting the Red Planet and may continue working for years to come. During year one the spacecraft was highly productive, achieving its goals of taking hordes of breathtaking images and gathering scientific measurements to study Mars atmosphere, surface environments, morphology, and mineralogy.

The Mars Orbiter Mission, or MOM, is India’s first deep space voyager to explore beyond the confines of her home planets influence and successfully arrived at the Red Planet after the “history creating” orbital insertion maneuver on Sept. 23/24, 2014 following a ten month interplanetary journey from Earth.

The MOM orbiter was designed and developed by the Indian Space Research Organization (ISRO), India’s space agency, which is the equivalent of NASA.

“Mars Orbiter spacecraft marks one year of its life around the Red Planet today [Sept. 24, IST],” said ISRO. It was primarily designed as a technology demonstrator but is also outfitted with significant science instruments.

Written by Randy McDonald

September 29, 2015 at 2:10 am

Posted in Science

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[LINK] On recovering unique grape variants and developing their wines

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Andrea Vogt at The Telegraph wrote an interesting article syndicated to the National Post about the efforts of scientists to preserve endangered grape populations.

High on a windswept hillside on the Sicilian island of Pantelleria, vineyard workers are carefully harvesting a variety of Zibibbo grapes from vines at risk of extinction.

Also known as Muscat of Alexandria, because it is thought to have originated in the Egyptian city, the grape is used to make Passito wines, some of Italy’s most prized dessert wines.

For the past five years, scientists have been searching remote outposts across the Mediterranean basin for endangered strains of this ancient vine, carefully removing vines from overgrown estates and remote mountain tops in Spain, Italy, Greece and France and cultivating them on test plots on Pantelleria.

This month, the first fruits of their labour are being harvested from 2,117 vines scattered across the remote volcanic island, where the grape cultivation techniques used to produce Passito were inscribed last year on Unesco’s world heritage list.

“These biotypes are at risk of disappearing across the Mediterranean, but we believe that with careful cultivation, their genetic patrimony can help us enhance existing and new Zibibbo wines,” said the project’s lead scientist Attilo Scienza, professor of viticulture at the University of Milan.

Written by Randy McDonald

September 23, 2015 at 5:19 pm

[LINK] “This Tower Purifies a Million Cubic Feet of Air an Hour”

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Wired‘s Liz Stinson notes the actual deployment in the Netherlands of what fans of science fiction would call an atmosphere processor.

There’s a massive vacuum cleaner in the middle of a Rotterdam park and it’s sucking all the smog out of the air. A decent portion of it, anyway. And it isn’t a vacuum, exactly. It looks nothing like a Dyson or a Hoover. It’s probably more accurate to describe it as the world’s largest air purifier.

The Smog Free Tower, as it’s called, is a collaboration between Dutch designer Daan Roosegaarde, Delft Technology University researcher Bob Ursem, and European Nano Solutions, a green tech company in the Netherlands. The metal tower, nearly 23 feet tall, can purify up to 1 million cubic feet of air every hour. To put that in perspective, the Smog Free Tower would need just 10 hours to purify enough air to fill Madison Square Garden. “When this baby is up and running for the day you can clean a small neighborhood,” says Roosegaarde.

It does this by ionizing airborne smog particles. Particles smaller than 10 micrometers in diameter (about the width of a cotton fiber) are tiny enough to inhale and can be harmful to the heart and lungs. Ursem, who has been researching ionization since the early 2000s, says a radial ventilation system at the top of the tower (powered by wind energy) draws in dirty air, which enters a chamber where particles smaller than 15 micrometers are given a positive charge. Like iron shavings drawn to a magnet, the the positively charged particles attach themselves to a grounded counter electrode in the chamber. The clean air is then expelled through vents in the lower part of the tower, surrounding the structure in a bubble of clean air. Ursem notes that this process doesn’t produce ozone, like many other ionic air purifiers, because the particles are charged with positive voltage rather than a negative.

“The proposed technology, while not new, would need to be well demonstrated on a large scale in a highly polluted urban area,” says Eileen McCauley, a manager in the California Air Resources Board’s research division. She adds that there are concerns around efficacy and logistics like how often something like this would need to be cleaned. But Ursem himself has used the same technique in hospital purification systems, parking garages, and along roadsides. Still the tower is by far the biggest and prettiest application of his technology.

Written by Randy McDonald

September 23, 2015 at 5:15 pm

[CAT] On cats and their love (or otherwise) of their humans

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The Telegraph‘s Sarah Knapton reported on a study that might depress some.

Researchers at the University of Lincoln have concluded that cats, unlike dogs, do not need humans to feel protected.

Before cat lovers start despairing about their aloof pets, however, animal behaviourists said they should take the finding as a compliment. If cats stay, it means they really want to be there.

Daniel Mills, Professor of Veterinary Behavioural Medicine at the University of Lincoln’s School of Life Sciences, said: “The domestic cat has recently passed the dog as the most popular companion animal in Europe.

“Previous research has suggested that some cats show signs of separation anxiety when left alone by their owners, in the same way that dogs do, but the results of our study show that they are, in fact, much more independent than canine companions.

“It seems that what we interpret as separation anxiety might actually be signs of frustration.” To find out if cats needed their owner to feel secure, the researchers observed how 20 cats reacted when they were placed in an unfamiliar environment together with their owner, with a stranger or on their own.

At The Guardian, Fay Schopen argued otherwise, concluding in the end of a 25-point list that “maybe your cat doesn’t love you. At least, not in the way you think. There’s no need to anthropomorphise them. Cat love, I suspect, is deeper, truer and more mysterious than the human variety.”

I’m actually OK with that. Cats, whatever else they are, are not exactly human.

Written by Randy McDonald

September 12, 2015 at 5:32 pm

Posted in Popular Culture, Science

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[CAT] “Island’s Feral Cats Kill Surprisingly Few Birds, Video Shows”

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National Geographic‘s Carrie Arnold notes a recent environmental-impact study of feral cats suggesting that they tend to hunt relatively small animals lower on the food chain.

Cats, already the overlords of the Internet, also reign over Jekyll Island, a small barrier island off the coast of Georgia.

The island is home to 150 free-ranging cats, which is about one cat for every five people. While the feral felines can help control the numbers of rats, mice, and other animals considered pests, they can also prey on other local wildlife—including, most controversially, birds.

A 2013 study, for instance, estimated that free-ranging cats are responsible for killing billions of birds and mammals in the continental U.S. every year, including possibly up to 3.7 billion birds. The study sparked major debate among both bird and cat groups. The American Bird Conservancy has said “the carnage that outdoor cats inflict is staggering.”

Since Jekyll Island is a popular stopover for many migrating tropical birds, wildlife biologist Sonia Hernandez at the University of Georgia wanted to see whether the island’s feral cats were preying on birds.

Enter the KittyCam: A small, collar-mounted video camera that records life from a cat’s point of view. By putting KittyCam on 31 feral cats for a year, Hernandez and her team gathered many hours of footage that let them see exactly what the island’s felines did—and didn’t—catch.

Interview at the site.

Written by Randy McDonald

September 12, 2015 at 5:27 pm

Posted in Popular Culture, Science

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