Science and technologyбез даты Текст источника в новой вкладке

 
 
1. For artificial intelligence to thrive, it must explain itselfЧт., 15 февр.[−]

SCIENCE fiction is littered with examples of intelligent computers, from HAL 9000 in “2001: A Space Odyssey” to Eddie in “The Hitchhiker’s Guide to the Galaxy”. One thing such fictional machines have in common is a tendency to go wrong, to the detriment of the characters in the story. HAL murders most of the crew of a mission to Jupiter. Eddie obsesses about trivia, and thus puts the spacecraft he is in charge of in danger of destruction. In both cases, an attempt to build something useful and helpful has created a monster.

Successful science fiction necessarily plays on real hopes and fears. In the 1960s and 1970s, when HAL and Eddie were dreamed up, attempts to create artificial intelligence (AI) were floundering, so both hope and fear were hypothetical. But that has changed. The invention of deep learning, a technique which uses special computer programs called neural networks to churn through large volumes of data looking for and remembering patterns, means that technology which gives... Continue readingКомментарии


2. Computer programs recognise white men better than black womenЧт., 15 февр.[−]

SOFTWARE that recognises faces has bounded ahead in recent years, propelled by a boom in a form of artificial intelligence called deep learning (see article). Several firms now offer face recognition as a commercial service, via their respective clouds. The ability to recognise in faces such things as an individual’s sex has improved too, and this is also commercially available.

The algorithms involved have, however, long been suspected of bias. Specifically, they are alleged to be better at processing white faces than those of other people. Until now, that suspicion has been unsupported by evidence. But next week, at Fairness, Accountability and Transparency, a conference in New York, Joy Buolamwini of the Massachusetts Institute of Technology will present work which suggests it is true.

Ms Buolamwini and her... Continue readingКомментарии


3. Home-made drones now threaten conventional armed forcesЧт., 08 февр.[−]

AN ATTACK on Russian forces in Syria on January 5th by 13 home-made drones is a good example of “asymmetric” warfare. On one side, exquisite high-tech weapons. On the other, cheap-as-chips disposable robot aircraft. Ten of the drones involved attacked a Russian airbase at Khmeimim. The other three went for a nearby naval base at Tartus. Rather than being quadcopters, the most popular design for commercial drones, the craft involved in these attacks (some of which are pictured above) resembled hobbyists’ model aircraft. They had three-metre wingspans, were built crudely of wood and plastic, and were powered by lawnmower engines. Each carried ten home-made shrapnel grenades under its wings.

According to the Russian Ministry of Defence, which has so far refused to say who it thinks was responsible for the attack, the drones were guided by GPS and had a range of 100km. The electronics involved were off-the-shelf components, and the total cost of each drone was perhaps a couple of thousand dollars.... Continue readingКомментарии


4. How too much fructose may cause liver damageЧт., 08 февр.[−]

FRUCTOSE is the sweetest of the natural sugars. As its name suggests, it is found mainly in fruits. Its job seems to be to appeal to the sweet tooths of the vertebrates these fruit have evolved to be eaten by, the better to scatter their seeds far and wide. Fructose is also, however, often added by manufacturers of food and drink, to sweeten their products and make them appeal to one species of vertebrate in particular, namely Homo sapiens. And that may be a problem, because too much fructose in the diet seems to be associated with liver disease and type 2 diabetes.

The nature of this association has been debated for years. Some argue that the effect is indirect. They suggest that, because sweet tastes suppress the feeling of being full (the reason why desserts, which come at the end of a meal, are sweet), consuming foods rich in fructose encourages overeating and the diseases consequent upon that. Others think the effect is more direct. They suspect that the cause is the way fructose is metabolised. Evidence clearly supporting either hypothesis has, though, been hard to come by.

This week, however, the metabolic hypothesis has received a boost from a study published in Cell Metabolism by Josh Rabinowitz of Princeton University and his colleagues. Specifically, Dr Rabinowitz’s work suggests... Continue readingКомментарии


5. Searching for lithium deposits with satellitesЧт., 08 февр.[−]

CORNWALL, a rugged peninsula that forms Britain’s south-western extremity, has a history of mining going back thousands of years. Its landscape is dotted with the ruins of long-closed tin and copper mines, along with mountains of spoil from the extraction of china clay (also known as kaolin), a business that still clings to life today. Now, though, prospectors are back on the ground. Or, rather, they aren’t. Instead, they are peering down from space. And what they are searching for is not tin, nor copper nor kaolin, but a material that has come into demand only recently: lithium.

The high-flying prospectors in question are a group led by Cristian Rossi, an expert on remote sensing, which has been organised under the auspices of the curiously named Satellite Applications Catapult, an innovation centre backed by the British government. The plan is to use satellites already in orbit to detect and map geological and botanical features that might betray the presence of subterranean lithium. Though satellite prospecting of this sort has been... Continue readingКомментарии


6. The Falcon Heavy’s successful flight is another vindication for Elon MuskСр., 07 февр.[−]

IT WAS not the most powerful launch ever seen at the Kennedy Space Centre’s Pad 39A; almost half a century ago the Apollo programme’s mighty Saturn V made use of it. But if the Falcon Heavy that took off from 39A on February 6th could boast only half the thrust of those bygone giants, its successful maiden voyage still proved it the most powerful rocket in the world today, as well as the most technologically advanced.

Elon Musk, the founder of SpaceX, the firm which built the Falcon Heavy, had been frank about the possibility that the launch might fail, possibly spectacularly. The prospect of fireworks helped to entice the biggest crowd of spectators at Cape Canaveral since the heyday of the Space Shuttle, and an audience of half a million to a live webcast.

After a delay caused by strong winds the assembled spectators witnessed a balletic display of technological prowess. Most rockets are one-use wonders, all their components falling into the sea or burning up in the atmosphere once their payloads are in orbit. SpaceX,... Continue readingКомментарии


7. New evidence in the search for Amelia EarhartВт., 06 февр.[−]

JULY 2nd of last year marked the 80th anniversary of the disappearance of Amelia Earhart, a pioneering aviatrix (pictured above), and her navigator Fred Noonan over the Pacific Ocean, as they attempted a circumnavigation of the globe in a twin-engined Lockheed Electra monoplane. The many theories about the pair’s demise, aired once more on that occasion, fall into two broad groups: they crashed into the sea and drowned, or they crashed onto Nikumaroro, a remote island, where they perished from hunger. An American forensic anthropologist has new evidence that greatly increases the likelihood of their having suffered the second fate.

Nikumaroro, one of the Phoenix Islands, is an inhospitable place and was uninhabited at the time of the Electra’s disappearance in 1937. Three years later, though, a working party found a human skull and partial skeleton there. Nearby was a part of a shoe they judged to be a woman’s, and a box manufactured in around 1918 that was designed to contain a sextant. The bones were removed to a medical school in Fiji... Continue readingКомментарии


8. A strange fossil spider. Or maybe notПн., 05 февр.[−]

THE picture above is of one of the five known specimens of Chimerarachne yingi, a newly discovered arthropod that lived 100m years ago, during the Cretaceous period. It is preserved in amber and was found in the Hukawng Valley amber mines in northern Myanmar. It, and one of the other specimens, are described in a paper that has just been published in Nature Ecology and Evolution by Wang Bo of the Nanjing Institute of Geology and Palaeontology, in China, and his colleagues.

Dr Wang thinks Chimerarachne yingi is a spider, albeit an unusual one in that it has a tail. Two further specimens are reported simultaneously in a different paper in the same journal, by a team led by Huang Diying, a colleague of Dr Wang in Nanjing, and Gonzalo Giribet of Harvard University. They think the critter is part of an extinct group, related to but different from spiders, called the Uraraneida, of which tails are characteristic.

Dr Wang points to the... Continue readingКомментарии


9. Preventing passengers in autonomous cars from feeling queasyЧт., 01 февр.[−]

EXPECTATIONS are high, among those boosting the idea of self-driving cars, that people will be able to do other things, such as reading, working on a laptop or having a nap, when riding in such a vehicle. But for many that is an unlikely prospect. Apart from those who have no intention of even getting into an autonomous car, which currently amounts to some 23% of Americans, another 36% would be willing to ride but would not take their eyes off the road, according to a study published in 2014 by the University of Michigan. Some of those people will be looking out of the window because it helps to avoid nausea, dizziness and vomiting, particularly if they are among the 5-10% of the population who regularly experience the unpleasant symptoms of motion sickness.

Help, though, is at hand. The selfsame authors of the Michigan study, Michael Sivak and Brandon Schoettle, who both work for the university’s Transportation Research Institute, have just been awarded a patent for a device that... Continue readingКомментарии


10. An idea from the past may make a Severn barrage practicalЧт., 01 февр.[−]

COMPARED with solar and wind energy, which are booming, tidal power is an also-ran in the clean-energy stakes. But if you did want to build a tidal power station, there are few better sites than the estuary of the River Severn, in Britain. Its tidal range, the difference in depth between high and low tides, of around 15 metres is among the largest in the world.

Engineers and governments have been toying with the idea since at least 1925. But none of the proposed projects has materialised. Price is one objection. A study by Britain’s National Infrastructure Commission, published last year, reckoned that tidal energy might cost between ?216 and ?368 ($306-521) per MWh of electricity by 2025, compared with ?58-75 for seagoing wind turbines and ?55-76 for solar panels. Environmentalists also worry that any plant would alter the tides it was harnessing, making life harder for wildlife.

As he describes in a paper just published in the Proceedings of the Royal Society, though, an engineer called Rod Rainey... Continue readingКомментарии


11. Genes play a role in the likelihood of divorceЧт., 01 февр.[−]

THAT the children of divorced parents are more likely, when they grow up, to get divorced themselves is well known. What is not known is how much this tendency is the result of nurture (with children manifesting, in later life, behaviours learned from their parents), and how much it is caused by nature (with children inheriting from divorced parents the sorts of genes that lead to marriage-breaking behaviour). That genes are important has, though, now been confirmed by a study published in Psychological Science by Jessica Salvatore and Kenneth Kendler of the Virginia Institute for Psychiatric and Behavioural Genetics.

To explore the role of genes Dr Salvatore and Dr Kendler turned to the Swedish national registries. These databases store, for all residents of Sweden, information on sex, year of birth, year of death, marital status, criminal activity, education and alcohol abuse. They also contain details of both the biological and the adoptive parents of adopted... Continue readingКомментарии


12. A new type of solar cell is coming to marketЧт., 01 февр.[−]

SOMETIMES it takes a while for the importance of a scientific discovery to become clear. When the first perovskite, a compound of calcium, titanium and oxygen, was discovered in the Ural mountains in 1839, and named after Count Lev Perovski, a Russian mineralogist, not much happened. The name, however, has come to be used as a plural to describe a range of other compounds that share the crystal structure of the original. In 2006 interest perked up when Tsutomu Miyasaka of Toin University in Japan discovered that some perovskites are semiconductors and showed particular promise as the basis of a new type of solar cell.

In 2012 Henry Snaith of the University of Oxford, in Britain, and his colleagues found a way to make perovskite solar cells with an efficiency (measured in terms of how well a cell converts light into electric current) of just over 10%. This was such a good conversion rate that Dr Snaith immediately switched the direction of Oxford Photovoltaics, a firm he had co-founded to develop new... Continue readingКомментарии



 
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