Category - Science

For the first time ever, scientists found molecular oxygen on a comet

Washington Post, By Rachel Feltman, October 28

For the first time ever, molecular oxygen has been found on a comet. Comet 67P/Churyumov–Gerasimenko, currently being orbited by the European Space Agency’s Rosetta spacecraft, is the subject of a study published Wednesday in Nature. According to ESA researchers, the oxygen present in the comet’s surrounding gasses has likely been there since the formation of the comet.

“It is the most surprising discovery we have made so far, because oxygen was not among the molecules expected in a cometary coma,” the University of Bern’s Kathrin Altwegg said at a news conference Tuesday held by Nature. Altwegg, one of the new study’s authors, is in charge of Rosetta’s ROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis). This instrument is used to “sniff” out the atmospheric composition of the comet.


“We all went a little bit into denial,” she said. The result was so unexpected that the team wanted to be absolutely certain that the oxygen wasn’t the result of some kind of instrumentation failure or contamination. But the oxygen, Altwegg explained, “follows the comet very well.” The team has observed that oxygen levels are higher close to the comet, and disappear as the instrument pulls away.


But no current models of the solar system’s formation would allow for molecular oxygen to get locked away inside a comet. Oxygen is highly reactive, so it’s always been assumed that any molecular oxygen present would bond with the abundantly available hydrogen. The researchers were shocked to see that oxygen could “survive” in its molecular form for billions of years.

‘Zeno effect’ verified—atoms won’t move while you watch

PhysOrg, By Bill Steele, October 23

One of the oddest predictions of quantum theory – that a system can’t change while you’re watching it – has been confirmed in an experiment by Cornell physicists. Their work opens the door to a fundamentally new method to control and manipulate the quantum states of atoms and could lead to new kinds of sensors.

The experiments were performed in the Utracold Lab of Mukund Vengalattore, assistant professor of physics, who has established Cornell’s first program to study the physics of materials cooled to temperatures as low as .000000001 degree above absolute zero. The work is described in the Oct. 2 issue of the journal Physical Review Letters

Graduate students Yogesh Patil and Srivatsan K. Chakram created and cooled a gas of about a billion Rubidium atoms inside a vacuum chamber and suspended the mass between laser beams. In that state the atoms arrange in an orderly lattice just as they would in a crystalline solid.,But at such low temperatures, the atoms can “tunnel” from place to place in the lattice. The famous Heisenberg uncertainty principle says that the position and velocity of a particle interact. Temperature is a measure of a particle’s motion. Under extreme cold velocity is almost zero, so there is a lot of flexibility in position; when you observe them, atoms are as likely to be in one place in the lattice as another.

The researchers demonstrated that they were able to suppress quantum tunneling merely by observing the atoms. This so-called “Quantum Zeno effect”, named for a Greek philosopher, derives from a proposal in 1977 by E. C. George Sudarshan and Baidyanath Misra at the University of Texas, Austin,, who pointed out that the weird nature of quantum measurements allows, in principle, for a quantum system to be “frozen” by repeated measurements.

Hidden no more

One of the weirdest bits of physics is proved beyond doubt (almost)

The Economist, October 24

In the 1930s Albert Einstein was greatly troubled by a phenomenon that came from quantum theory. Entanglement, as it is called, forever intertwines the fates of objects such as subatomic particles, regardless of their separation. If you measure, say, “up” for the spin of one photon from an entangled pair, the theory suggests that the spin of the other, measured an instant later, will surely be “down”—even if the two are on opposite sides of the galaxy. This was anathema to Einstein and others: it looked as if information was travelling faster than light, a no-no in the special theory of relativity. Einstein was quotably derisive, calling the idea “spooky action at a distance”. But after 80 years of physicists’ fretting, a cunning experiment reported this week proves that such action is in fact how the world works.

To save physics from the spooky, Einstein invoked what he called hidden variables (though others might describe them as fiddle factors) that would convey information without breaking the universal speed limit. It took until 1964, though, to tame this woolly idea into testable equations. John Bell, a British physicist, worked out the maximum effect hidden variables could have on a given test. Any influence beyond that, his equations suggested, must be down to spooky action. The Bell inequality, as it became known, sparked decades of clever experiments—sending entangled photons or atoms hither and thither with detectors triggered by this or that—each designed to catch nature out, to banish hidden variables once and for all.


Ronald Hanson of the University of Delft and his colleagues, writing in Nature, describe an experiment that starts with two electrons in laboratories separated by more than a kilometre. Each emits a photon that travels down a fibre to a third lab, where the two photons are entangled. That, in turn, entangles the electrons that generated the photons. The consequence is easily measured particles (the electrons) separated by a distance that precludes any shifty hidden-variable signalling.

Over 18 days, the team measured how correlated the electron measurements were. Perhaps expectedly, yet also oddly, they were far more so than chance would allow—proving quantum mechanics is as spooky as Einstein had feared.

Also: Sorry, Einstein. Quantum Study Suggests ‘Spooky Action’ Is Real.

Under a Farmer’s Field: A Woolly Mammoth in Michigan

New York Times, By Nicholas St. Fleur, October 2

Buried beneath a Michigan farmer’s soy field were the butchered remains of a woolly mammoth. Paleontologists think that the skull, tusks, jaws and other parts that they uncovered on Thursday were stored there by early humans in a primitive fridge more than 10,000 years ago.

Last Monday James Bristle, the farmer, came across what he thought was a fence post while digging in his yard, only to discover that it was actually a rib, according to The Ann Arbor News. He contacted researchers from the University of Michigan to investigate, and together they unearthed the prehistoric beast.

Daniel Fisher, a paleontologist who led the dig, said the mammoth most likely roamed the area 11,700 to 15,000 years ago, and was around 40 years old when it died.

In addition to the skull and tusks, the team also recovered vertebrae, a pelvis, shoulder blade pieces and one kneecap. Missing from the find were most of the mammoth’s fore and hind limbs, which the team presumed were either buried elsewhere or had already been eaten.

NASA to hold urgent press conference to announce major science finding from Mars

News.Com.Au, By Matthew Dunn, September 28

Speculation that NASA’s Curiosity Rover has found life on Mars has been thrown into overdrive with the space agency announcing an urgent press conference.

In a press release, NASA said it would be holding a conference to detail “a major science finding from the agency’s ongoing exploration of Mars”.

This is not the first time NASA has used a press conference to announce a groundbreaking discovery, with the space agency doing the same earlier this year to reveal it had discovered the Earth-like planet Kepler-452b.

Jim Green, director of planetary science at NASA, and Michael Meyer, lead scientist for the Mars Exploration Program, will be leading the announcement.

Researchers Apply For Permission To Alter DNA Of Human Embryos

Some say gene editing shouldn’t be performed on human embryos until its effects are better understood.

The Huffington Post, By Sam Levine, September 18

The first British researchers have applied for permission to alter the DNA of human embryos to better understand the reason women have miscarriages, amid a broader debate over whether the testing is appropriate.

Earlier this year, Chinese scientists became the first in the world to modify human embryos. Researchers from the Francis Crick Institute are the first to seek permission to use the technique in Great Britain, where it is currently illegal except for research purposes.

The researchers hope to better understand the key genes involved in the first stages of fertilization and ultimately to determine the reason some women miscarry, according to The Guardian. The embryos, which are donated by couples who have a surplus after IVF treatment, would be destroyed after the research is completed. They cannot legally be studied for longer than two weeks.

Homo Naledi, New Species in Human Lineage, Is Found in South African Cave

New York Times, By John Noble Wilford, September 10

Acting on a tip from spelunkers two years ago, scientists in South Africa discovered what the cavers had only dimly glimpsed through a crack in a limestone wall deep in the Rising Star Cave: lots and lots of old bones.

The remains covered the earthen floor beyond the narrow opening. This was, the scientists concluded, a large, dark chamber for the dead of a previously unidentified species of the early human lineage — Homo naledi.

The new hominin species was announced on Thursday by an international team of more than 60 scientists led by Lee R. Berger, an American paleoanthropologist who is a professor of human evolution studies at the University of the Witwatersrand in Johannesburg. The species name, H. naledi, refers to the cave where the bones lay undisturbed for so long; “naledi” means “star” in the local Sesotho language.

In two papers published this week in the open-access journal eLife, the researchers said that the more than 1,550 fossil elements documenting the discovery constituted the largest sample for any hominin species in a single African site, and one of the largest anywhere in the world. Further, the scientists said, that sample is probably a small fraction of the fossils yet to be recovered from the chamber. So far the team has recovered parts of at least 15 individuals.

“With almost every bone in the body represented multiple times, Homo naledi is already practically the best-known fossil member of our lineage,” Dr. Berger said.

PBS Nova: Dawn of Humanity – to air this Wednesday, September 16th
National Geographic: New Human Ancestor Discovered: Homo naledi (Exclusive Video)
National Geographic: This Face Changes the Human Story. But How?
Washington Post: The caves that tell the story of humankind, including the latest, Homo naledi
Washington Post: A squeeze down a narrow crack, and then an amazing discovery

…and in other news, Boing Boing: National Geographic sold to Rupert Murdoch

Quantum ‘spookiness’ passes toughest test yet

Experiment plugs loopholes in previous demonstrations of ‘action at a distance’, against Einstein’s objections — and could make data encryption safer.

Nature, By Zeeya Merali, August 27

It’s a bad day both for Albert Einstein and for hackers. The most rigorous test of quantum theory ever carried out has confirmed that the ‘spooky action at a distance’ that the German physicist famously hated — in which manipulating one object instantaneously seems to affect another, far away one — is an inherent part of the quantum world.

The experiment, performed in the Netherlands, could be the final nail in the coffin for models of the atomic world that are more intuitive than standard quantum mechanics, say some physicists. It could also enable quantum engineers to develop a new suite of ultrasecure cryptographic devices.

“From a fundamental point of view, this is truly history-making,” says Nicolas Gisin, a quantum physicist at the University of Geneva in Switzerland.

First almost fully-formed human brain grown in lab, researchers claim

The Guardian, By Helen Thomson, August 18

Research team say tiny brain could be used to test drugs and study diseases, but scientific peers urge caution as data on breakthrough kept under wraps.

An almost fully-formed human brain has been grown in a lab for the first time, claim scientists from Ohio State University. The team behind the feat hope the brain could transform our understanding of neurological disease.

Though not conscious the miniature brain, which resembles that of a five-week-old foetus, could potentially be useful for scientists who want to study the progression of developmental diseases. It could also be used to test drugs for conditions such as Alzheimer’s and Parkinson’s, since the regions they affect are in place during an early stage of brain development.

The brain, which is about the size of a pencil eraser, is engineered from adult human skin cells and is the most complete human brain model yet developed, claimed Rene Anand of Ohio State University, Columbus, who presented the work today at the Military Health System Research Symposium in Fort Lauderdale, Florida.

Previous attempts at growing whole brains have at best achieved mini-organs that resemble those of nine-week-old foetuses, although these “cerebral organoids” were not complete and only contained certain aspects of the brain. “We have grown the entire brain from the get-go,” said Anand.

Farming Had an Earlier Start, a Study Says

New York Times, By Sindya H. Bhanoo, July 27

Farming may have originated 23,000 years ago, thousands of years earlier than previously thought, according to a new study.

Researchers discovered a large number of seeds at an ancient hunter-gatherer site known as Ohalo II on the shore of the Sea of Galilee in Israel. Many of the seeds had scars, a mark that distinguishes domesticated species from wild forms.

Additionally, about 150,000 plant remains were retrieved from the site, comprising more than 140 species. The mix included 13 known weeds, as well as edible cereals like wild emmer, barley and oats.