ريتشارد دوكنز's Blog, page 574
January 29, 2016
Signs of Modern Astronomy Seen in Ancient Babylon
Photo credit: Trustees of the British Museum/Mathieu Ossendrijver; NASA
By Kenneth Chang
For people living in the ancient city of Babylon, Marduk was their patron god, and thus it is not a surprise that Babylonian astronomers took an interest in tracking the comings and goings of the planet Jupiter, which they regarded as a celestial manifestation of Marduk.
What is perhaps more surprising is the sophistication with which they tracked the planet, judging from inscriptions on a small clay tablet dating to between 350 B.C. and 50 B.C. The tablet, a couple of inches wide and a couple of inches tall, reveals that the Babylonian astronomers employed a sort of precalculus in describing Jupiter’s motion across the night sky relative to the distant background stars. Until now, credit for this kind of mathematical technique had gone to Europeans who lived some 15 centuries later.
“That is a truly astonishing find,” said Mathieu Ossendrijver, a professor at Humboldt University in Berlin, who describes his archaeological astronomy discovery in an article on Thursday in the journal Science.
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Moon was produced by a head-on collision between Earth and a forming planet
Photo credit: Christelle Snow/UCLA
By Science Daily
The moon was formed from a violent, head-on collision between the early Earth and a ‘planetary embryo’ called Theia approximately 100 million years after the Earth formed, almost 4.5 billion years ago.
Scientists had already known about this high-speed crash, which occurred almost 4.5 billion years ago, but many thought the Earth collided with Theia (pronounced THAY-eh) at an angle of 45 degrees or more — a powerful side-swipe (simulated in this 2012 YouTube video). New evidence reported Jan. 29 in the journal Science substantially strengthens the case for a head-on assault.
The researchers analyzed seven rocks brought to the Earth from the moon by the Apollo 12, 15 and 17 missions, as well as six volcanic rocks from the Earth’s mantle — five from Hawaii and one from Arizona.
The key to reconstructing the giant impact was a chemical signature revealed in the rocks’ oxygen atoms. (Oxygen makes up 90 percent of rocks’ volume and 50 percent of their weight.) More than 99.9 percent of Earth’s oxygen is O-16, so called because each atom contains eight protons and eight neutrons. But there also are small quantities of heavier oxygen isotopes: O-17, which have one extra neutron, and O-18, which have two extra neutrons. Earth, Mars and other planetary bodies in our solar system each has a unique ratio of O-17 to O-16 — each one a distinctive “fingerprint.”
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World’s Grandest Canyon May Be Hidden Beneath Antarctica
Photo credit: Stewart Jamieson
By Shannon Hall
Tucked beneath East Antarctica’s vast ice sheet is a frozen world, complete with subglacial lakes, rivers, basins, volcanoes and mountains. But roughly 91 percent of Antarctica—nearly twice the size of Australia—is unmapped, and the largest unsurveyed region on the icy continent is a region called Princess Elizabeth Land. Now a team of geologists has scoured that area to reveal a massive subglacial lake and a series of canyons, one of which—more than twice as long as the Grand Canyon—could rank as Earth’s largest. The findings indicate the ice sheets are less stable than previously thought, and could be strongly affected by climate change.
Stewart Jamieson from Durham University in England and his colleagues made the discovery by looking for subtle changes in the ice sheet’s surface shapes, developed as a result of ice flowing over diverse topography. For years geologists have thought that hidden features could subtly sculpt the surface above, leaving ghostly hints in the ice. An unwrinkled ice sheet, for example, might reveal a buried subglacial lake whereas an undulating one might signal a hidden mountain range. So with satellite images of such surface features as a guide, Jamieson and his team used ice-penetrating radio waves—which bounce back as echoes, like radar–to help map the topography underneath.
Their analysis, recently published in Geology, reveals a subglacial lake covering as much as 1,250 square kilometers (making it the second-largest subglacial lake in Antarctica by length after Lake Vostok) and a series of canyons that extend a kilometer deep and 1,100 kilometers across. It is a tantalizing first glance at such an uncharted region, says Dustin Schroeder of Stanford University, who was not involved in the study.
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God’s Own Party
Photo credit: Shutterstock
By Herb Silverman
I don’t think that politicians in our secular country should be quoting the Bible to make their case for legislation. That’s why I half agree with Virginia Rep. Dave Brat, the GOP lawmaker who famously upset former House Majority Leader Eric Cantor in a 2014 Republican primary. Here’s the half with which I disagree. Brat said that it’s fine for Republicans to quote the Bible, but not for Democrats to do so. He continued, “Our side, the conservative side, needs to re-educate its people that we own the entire [biblical] tradition.” What especially drew Brat’s ire was President Obama’s reasons for allowing Syrian refugees to enter our country, which included a biblical reference from James 1:27 about looking after widows and orphans.
If politicians can’t provide good evidence-based reasons to support an issue, they shouldn’t rely on an ancient pre-scientific book written by bigoted, misogynistic, homophobic, intolerant, superstitious men. I understand why politicians often pander to people who prefer black and white theocratic decisions. After all, political pandering is bi-partisan. Brat, however, goes too far. Although I find his comments mildly amusing, if I were a Christian I’d be incensed by the way Brat is giving Christians a bad name (or worse name, depending on your point of view).
Some Republicans say we need to take our country back, but they usually don’t specify where or from whom. Perhaps they want to take our country back from a black president, or from Democrats. But they are not saying we need to take our government back, so perhaps they want to take our country back to the bad old days before we adopted civil rights legislation, equal rights for women and other minorities, and social programs that helped people in need.
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Elon Musk Says He Will Reveal How He Plans To Get To Mars This Year
Photo credit:
Musk was speaking at the StartmeupHK Festival in Hong Kong. YouTube
SpaceX CEO Elon Musk has made no secret of his desire to get humans to Mars. He has hinted at doing so with something called the Mars Colonial Transporter (MCT) in the past. But despite previously saying he would reveal what this is in 2015, nothing materialized.
What We’re Reading
NCSE moved offices this week, which left less time than usual for reading. But the fact that all our books and computers are in boxes didn't keep me or my colleauges from getting caught up in some good reads.
“The Toughest Scene I Wrote: How Drew Goddard Made Physics Fun in The Martian.” Vulture, 1/26/16 — Kevin Lincoln talked with Drew Goddard, screenwriter for The Martian, about the challenge of getting the science right in a Hollywood blockbuster. In the end, the toughest scene to write was solved not by fighting the way scientists talk and nitpick, but by building it right into the script. It’s exactly the sort of thing Randy Olsen would’ve written, exploring the interplay between good storytelling and good science.
Accepting, Understanding, Teaching, and Learning (Human) Evolution: Obstacles and Opportunities, American Journal of Physical Anthropology, January 2016 — A fantastic review article by Briana Pobiner on the pedagogy of human evolution. She concludes, "Despite the potentially controversial topic of human evolution, growing research is demonstrating that a pedagogical focus on human examples is an effective and engaging way to teach core concepts of evolutionary biology."
"We're the Only Animals with Chins, and No One Knows Why," The Atlantic, January 28, 2016 — Of all animals extinct or extant, only humans have chins. What do we have them for? What selective pressure resulted in the chin? Was it that we constantly punched each other in the face? This delightful article explores and tentatively rejects this and other hypotheses for why humans have chins. (We also read Yong's follow-up, which emphasizes that "No, Really, Other Animals Don't Have Chins.")
"Climate Deal’s First Big Hurdle: The Draw of Cheap Oil," The New York Times, January 25, 2016 — Considering the prospects for the Paris climate deal, the Times reports that falling gasoline prices could sink the deal.
"The Zika virus foreshadows our dystopian climate future," The Guardian, January 25, 2016 — Bill McKibben explains how the consequences of Zika virus are, like so many other climate change related phenomena, such as smog and sea level rise, disproportionately affecting poor countries. It is a stark and important reminder that out of sight should not be out of mind.
"To Lions, Zebras Look Mostly Gray…So Why Are They Stripey?," The Atlantic, January 26, 2016 — In his usual delightful way, Ed Yong explains new research that suggest the old “they’re striped so they confuse lions” theory is not valid (note: it’s also teleological!). The new hypothesis is that stripes defend against disease-carrying biting flies. But as with everything in science, it might not be that simple, there is some evidence that at least one other selection pressure is at play, too.
"Sitting Ducks: Why Millions of Arctic Seabirds Are in Danger," Audubon, January-February 2016 — "Scientists worry that seabirds are especially sensitive to the threats of climate change, ocean acidification, commercial fishing, and shifts in marine ecosystems—threats that are only expected to intensify in the coming years," writes Scott Weidensaul.
NASA Satellites Capture Superstorm Jonas From The Skies
Photo credit:
NASA
While the inches upon inches of snow caused joy, inconvenience and tragedy to millions of people on the East Coast, NASA’s satellites were up above and taking full advantage of their front-row view.
NHS To Begin Offering Hand Transplants
Photo credit:
A successful double hand transplant in France, 2013. Philippe Desmazes/Getty Images
Patients right across the U.K. will soon be able to get hand transplants on the National Health Service (NHS). The publicly funded procedures will be offered at the Leeds Teaching Hospital in the north of England, and it is expected that between two and four transplants will be performed each year. The new hands will be warm to the touch and be able to move with much greater dexterity than can currently be offered with prosthetics.
Male Mice Can Reproduce Without Y Chromosomes
Photo credit:
Mice don't need Y chromosomes to father litters like these. Igor Stramyk/Shutterstock
Mice whose Y chromosomes have been replaced with just two genes are still able to father offspring, demonstrating the unexpected complexity of reproductive genetics.
Man’s Persistent Hiccups Turned Out To Have A Rather Horrifying Cause
Photo credit:
Arrows show tumor and associated cystic structure. © 2016 by the BMJ Publishing Group Ltd
Surprising someone who has the hiccups sometimes helps these thoroughly irritating diaphragm spasms go away, but unfortunately for one man, the surprise was that his persistent hiccups were down to a tumor.
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