China’s great leap forward in science

From elsewhere, April 19, 2018

Philip Ball writes:

I first met Xiaogang Peng in the summer of 1992 at Jilin University in Changchun, in the remote north-east of China, where he was a postgraduate student in the department of chemistry. He told me that his dream was to get a place at a top American lab. Now, Xiaogang was evidently smart and hard-working – but so, as far as I could see, were most Chinese science students. I wished him well, but couldn’t help thinking he’d set himself a massive challenge.

Fast forward four years to when, as an editor at Nature, I publish a paper on nanotechnology from world-leading chemists at the University of California at Berkeley. Among them was Xiaogang. That 1996 paper now appears in a 10-volume compendium of the all-time best of Nature papers being published in translation in China.

I watched Xiaogang go on to forge a solid career in the US, as in 2005 he became a tenured professor at the University of Arkansas. But when I recently had reason to get in touch with Xiaogang again, I discovered that he had moved back to China and is now at Zhejiang University in Hangzhou – one of the country’s foremost academic institutions.

For Xiaogang, it seems that America was no longer the only land of opportunity. These days, Chinese scientists stand at least as good a chance of making a global impact on science from within China itself.

The economic rise of China has been accompanied by a waxing of its scientific prowess. In January, the United States National Science Foundation reported that the number of scientific publications from China in 2016 outnumbered those from the US for the first time: 426,000 versus 409,000. Sceptics might say that it’s about quality, not quantity. But the patronising old idea that China, like the rest of east Asia, can imitate but not innovate is certainly false now. In several scientific fields, China is starting to set the pace for others to follow. On my tour of Chinese labs in 1992, only those I saw at the flagship Peking University looked comparable to what you might find at a good university in the west. Today the resources available to China’s top scientists are enviable to many of their western counterparts. Whereas once the best Chinese scientists would pack their bags for greener pastures abroad, today it’s common for Chinese postdoctoral researchers to get experience in a leading lab in the west and then head home where the Chinese government will help them set up a lab that will eclipse their western competitors. [Continue reading…]

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Filed Under: Science

Burning coal may have caused Earth’s worst mass extinction

From elsewhere, April 11, 2018

Dana Nuccitelli writes:

Recently, geologist Dr Benjamin Burger identified a rock layer in Utah that he believed might have formed during the Permian and subsequent Triassic period that could shed light on the cause of the Great Dying [the Earth’s deadliest mass extinction 252 million years ago].

During the Permian, Earth’s continents were still combined as one Pangea, and modern day Utah was on the supercontinent’s west coast. Samples from the end-Permian have been collected from rock layers in Asia, near the volcanic eruptions, but Utah was on the other side of Pangaea. Burger’s samples could thus provide a unique perspective of what was happening on the other side of the world from the eruptions. Burger collected and analyzed samples from the rock layer, and documented the whole process in a fascinating video:

 

Burger’s samples painted a grim picture of Earth’s environment at the end of the Permian period. A sharp drop in calcium carbonate levels indicated that the oceans had become acidic. A similar decline in organic content matched up with the immense loss of life in the oceans during this period. The presence of pyrite pointed to an anoxic ocean (without oxygen), meaning the oceans were effectively one massive dead zone.

Bacteria ate the oversupply of dead bodies, producing hydrogen sulfide gas, creating a toxic atmosphere. The hydrogen sulfide oxidized in the atmosphere to form sulfur dioxide, creating acid rain, which killed much of the plant life on Earth. Elevated barium levels in the samples had likely been carried up from the ocean depths by a massive release of methane.

Levels of various metals in the rock samples were critical in identifying the culprit of this mass extinction event. As in end-Permian samples collected from other locations around the world, Burger didn’t find the kinds of rare metals that are associated with asteroid impacts. There simply isn’t evidence that an asteroid struck at the right time to cause the Great Dying.

However, Burger did find high levels of mercury and lead in his samples, coinciding with the end of the Permian period. Mercury has also been identified in end-Permian samples from other sites. Lead and mercury aren’t associated with volcanic ash, but they are a byproduct of burning coal. [Continue reading…]

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Filed Under: Biology, Science

There’s no scientific basis for race — it’s a made-up label

From elsewhere, April 10, 2018

 

Elizabeth Kolbert writes:

In the first half of the 19th century, one of America’s most prominent scientists was a doctor named Samuel Morton. Morton lived in Philadelphia, and he collected skulls.

He wasn’t choosy about his suppliers. He accepted skulls scavenged from battlefields and snatched from catacombs. One of his most famous craniums belonged to an Irishman who’d been sent as a convict to Tasmania (and ultimately hanged for killing and eating other convicts). With each skull Morton performed the same procedure: He stuffed it with pepper seeds—later he switched to lead shot—which he then decanted to ascertain the volume of the braincase.

Morton believed that people could be divided into five races and that these represented separate acts of creation. The races had distinct characters, which corresponded to their place in a divinely determined hierarchy. Morton’s “craniometry” showed, he claimed, that whites, or “Caucasians,” were the most intelligent of the races. East Asians—Morton used the term “Mongolian”—though “ingenious” and “susceptible of cultivation,” were one step down. Next came Southeast Asians, followed by Native Americans. Blacks, or “Ethiopians,” were at the bottom. In the decades before the Civil War, Morton’s ideas were quickly taken up by the defenders of slavery.

“He had a lot of influence, particularly in the South,” says Paul Wolff Mitchell, an anthropologist at the University of Pennsylvania who is showing me the skull collection, now housed at the Penn Museum. We’re standing over the braincase of a particularly large-headed Dutchman who helped inflate Morton’s estimate of Caucasian capacities. When Morton died, in 1851, the Charleston Medical Journal in South Carolina praised him for “giving to the negro his true position as an inferior race.”

Today Morton is known as the father of scientific racism. So many of the horrors of the past few centuries can be traced to the idea that one race is inferior to another that a tour of his collection is a haunting experience. To an uncomfortable degree we still live with Morton’s legacy: Racial distinctions continue to shape our politics, our neighborhoods, and our sense of self.

This is the case even though what science actually has to tell us about race is just the opposite of what Morton contended. [Continue reading…]

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Filed Under: Anthropology, Humanity, Science

Science shouldn’t treat the undetectable as taboo

From elsewhere, April 6, 2018


Adam Becker writes:

The Viennese physicist Wolfgang Pauli suffered from a guilty conscience. He’d solved one of the knottiest puzzles in nuclear physics, but at a cost. ‘I have done a terrible thing,’ he admitted to a friend in the winter of 1930. ‘I have postulated a particle that cannot be detected.’

Despite his pantomime of despair, Pauli’s letters reveal that he didn’t really think his new sub-atomic particle would stay unseen. He trusted that experimental equipment would eventually be up to the task of proving him right or wrong, one way or another. Still, he worried he’d strayed too close to transgression. Things that were genuinely unobservable, Pauli believed, were anathema to physics and to science as a whole.

Pauli’s views persist among many scientists today. It’s a basic principle of scientific practice that a new theory shouldn’t invoke the undetectable. Rather, a good explanation should be falsifiable – which means it ought to rely on some hypothetical data that could, in principle, prove the theory wrong. These interlocking standards of falsifiability and observability have proud pedigrees: falsifiability goes back to the mid-20th-century philosopher of science Karl Popper, and observability goes further back than that. Today they’re patrolled by self-appointed guardians, who relish dismissing some of the more fanciful notions in physics, cosmology and quantum mechanics as just so many castles in the sky. The cost of allowing such ideas into science, say the gatekeepers, would be to clear the path for all manner of manifestly unscientific nonsense.

But for a theoretical physicist, designing sky-castles is just part of the job. Spinning new ideas about how the world could be – or in some cases, how the world definitely isn’t – is central to their work. Some structures might be built up with great care over many years, and end up with peculiar names such as inflationary multiverse or superstring theory. Others are fabricated and dismissed casually over the course of a single afternoon, found and lost again by a lone adventurer in the troposphere of thought.

That doesn’t mean it’s just freestyle sky-castle architecture out there at the frontier. The goal of scientific theory-building is to understand the nature of the world with increasing accuracy over time. All that creative energy has to hook back onto reality at some point. But turning ingenuity into fact is much more nuanced than simply announcing that all ideas must meet the inflexible standards of falsifiability and observability. These are not measures of the quality of a scientific theory. They might be neat guidelines or heuristics, but as is usually the case with simple answers, they’re also wrong, or at least only half-right. [Continue reading…]

Filed Under: Science

The ancient hunt in which the tracker’s skill united reason and imagination

By Paul Woodward, March 14, 2018

“The San people of the Kalahari desert are the last tribe on Earth to use what some believe to be the most ancient hunting technique of all: the persistence hunt; they run down their prey,” says David Attenborough:

 

“The hunter pays tribute to his quarry’s courage and strength. With ceremonial gestures that ensure that its spirit returns to the desert sands from which it came. While it was alive, he lived and breathed with it and felt its every movement in his own body, and at the moment of its death, he shared its pain. He rubs its saliva into his own legs to relieve the agony of his own burning muscles, and he gives thanks for the life he has taken so that he may sustain the lives of his family waiting for him back in their settlement.”

Louis Liebenberg, author of The Art of Tracking: The Origin of Science, argues that the rational skills required by the ancient tracker provided the basis of scientific reasoning.

The first creative science, practiced by possibly some of the earliest members of Homo sapiens who had modern brains and intellects, may have been the tracking of game animals…

In easy tracking terrain, trackers may follow a trail simply by looking for one sign after the other, but in difficult terrain this can become so time-consuming that they may never catch up with their quarry. Instead of looking for one sign at a time, the trackers place themselves in the position of their quarry in order to anticipate the route it may have taken. They then decide in advance where they can expect to find signs, instead of wasting time looking for them. To reconstruct an animal’s activities, specific actions and movements must be seen in the context of the animal’s whole environment at specific times and places…

Since tracks may be partly obliterated or difficult to see, they may only exhibit partial evidence, so the reconstruction of these animals’ activities must be based on creative hypotheses. To interpret the footprints, trackers must use their imagination to visualize what the animal was doing to create such markings. Such a reconstruction will contain more information than is evident from the tracks, and will therefore be partly factual and partly hypothetical. As new factual information is gathered in the process of tracking, hypotheses may have to be revised or substituted by better ones. A hypothetical reconstruction of the animal’s behaviors may enable trackers to anticipate and predict the animal’s movements. These predictions provide ongoing testing of the hypotheses.

Perhaps the most significant feature of creative science is that a hypothesis may enable the scientist to predict novel facts that would not otherwise have been known.

Implicit in this interpretation of tracking there is also a view of science broader than its conventional placement within the sphere of human rationality. From this perspective, reason and imagination work hand in hand.

Thus, when the hunter hypothesizes about the movements of his quarry, he is also engaging in a wild leap of imagination: he becomes the quarry by entering its mind and seeing the world through its eyes.

From this vantage point, there is no conquest or victory in the hunt. Hunter and hunted are one, inseparable in life and death.

This way of knowing non-human life, through a creative identification in which animal “spirits” are experienced, seems to be universal among indigenous peoples, strongly suggesting it is something we have lost rather than advanced above. In a most fundamental way, it signals the degree to which collectively our observational and empathic skills have withered as we withdrew from the natural world.

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Filed Under: Anthropology, Creativity, Indigenous Peoples, Science

Stephen Hawking, in his own words

From elsewhere, March 14, 2018

In memory of Stephen Hawking, who died on Wednesday at 76, the New York Times has gathered a selection of his quotes:

“Remember to look up at the stars and not down at your feet. Try to make sense of what you see and wonder about what makes the universe exist. Be curious. And however difficult life may seem, there is always something you can do and succeed at.”

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Filed Under: Astronomy, Science