Sisyphus’s train set

Ready to rock and roll

THE easiest way to squirrel electricity away in times of plenty, for use when it is scarce, is to pump water uphill with it. Such pumped storage is widely employed where local geography and hydrology permit, but it does need two basins, at different heights, to act as reservoirs, and a supply of water to fill them. At least one of the basins is likely to have to be artificial. The two must be connected by a tunnel that lets water flow between them. And the tunnel must house turbines attached to electrical devices that can do double duty—as motors to turn the turbine blades when they are pushing water from the lower reservoir to the upper one, and as generators when the blades are rotated in the opposite direction by an aqueous downrush after the upper sluices are opened.

Where geography does not favour pumped storage, though, the search is on for alternatives. These range from giant batteries, via caverns filled with compressed air, to huge flywheels made of carbon-fibre composites. But one firm looking into the matter eschews all these. It has stuck with the logic of pumped storage, which is to move…Continue reading
Source: Economist

By Jove!

IN 1543 Nicolaus Copernicus proposed, in a mathematically rigorous way, that the Earth is not the centre of the universe, and thus that all things do not revolve around it. In fact, only the Moon does so. Seven decades later Galileo Galilei provided more direct proof of Earth’s lack of specialness. He looked at Jupiter through a primitive telescope and found that the planet had four moons of its own.

Four centuries after Galileo’s discovery, it remains impossible to understand the solar system without understanding Jupiter. The sun accounts for 99.8% of the solar system’s mass. But Jupiter, which is more than twice as massive as the other seven planets put together, makes up most of the rest. Its heft shapes the orbits of the other planets, the structure of the asteroid belt and the periods of many comets. And the four moons observed by Galileo (seen to the left-hand side of Jupiter in the picture above) have proved merely the biggest members of an entire solar system in miniature: at the moment Jupiter has 67 known satellites.

The picture was taken on June 21st by Juno, a probe belonging to NASA, America’s…Continue reading
Source: Economist

Telling it like it is

VINGT-ET-UN, known to Americans as blackjack, is a card game in which players must decide whether the value of the two-card hand they are dealt is likely to be enough to beat the dealer’s unseen hand, or whether they should risk going bust by adding to it, one card at a time, as they seek to get as close as possible to a permitted maximum of 21 points. (Court cards are worth ten; aces score either one or 11, at the holder’s discretion.)

Making constant calculations is thus an essential part of this game—a fact that Kevin Holmes, a psychologist at Colorado College, in Colorado Springs, has used to test his hypothesis that such calculation will cause players to give away, by their eye movements, the sorts of hand they have. As he reports in Psychonomic Bulletin and Review, it turns out that they do.

Dr Holmes knew from studies by others that when people are asked to perform a mental calculation and then to point to the location of the answer on an unmarked horizontal line (known as a number line) whose left-hand end represents a numerical value, such as zero, and whose right-hand end represents a larger one,…Continue reading
Source: Economist

Addressing the world

LAST year, a brush fire threatened the home of Ganhuyag Chuluun Hutagt, who lives in Mongolia’s capital, Ulaanbaatar. Instead of giving the fire brigade his address, though, Mr Ganhuyag had to guide them to the blaze by describing a series of landmarks along the way. That was because, like most buildings in Mongolia, his house does not have an address. Road names and building numbers are so sparse there that fewer than 1% of Mongolians do. But Mr Ganhuyag, who is on the board of the country’s post office, Mongol Post, proposes to do something about it.

Thanks to his urging, Mongol Post is adopting an ingenious new system of addresses that can locate any place in the country—and, indeed, in the world. Instead of house number, street name, town, province and so on, or the unwieldy co-ordinates of latitude and longitude, this system, the brainchild of Chris Sheldrick, boss of What3Words, a firm based in London, divides the Earth’s surface into nine-metre-square blocks. Each block is then given names consisting of trios of randomly selected, unrelated words. One patch of Siberia, for example, is called, in English,…Continue reading
Source: Economist

Palaeontology

This photograph is of part of a bird wing preserved in amber from northern Myanmar. It dates from 99m years ago, during the Cretaceous period, and is described in this week’s Nature Communications by Lida Xing of China University of Geosciences, in Beijing, and her colleagues. It is one of two wings, the first known to have been preserved in amber, that her team discovered. Both belonged to juveniles of a group called the Enantiornithes that had claws on their wings (one such is marked with an arrow), probably to help them grip trunks and branches when they climbed trees.

Source: Economist

Halting the hate

AMERICAN officials referred to Anwar al-Awlaki as a senior recruiter for al-Qaeda. After being connected to numerous terrorist attacks, in 2011 he became one of the first United States citizens to be killed by an American drone. Yet Awlaki’s online lectures continue to inspire Islamic extremists nearly five years after his death. His videos are thought to have helped radicalise those responsible for the attack this month on a gay nightclub in Orlando, for the shootings in 2015 at the Inland Regional Centre in San Bernardino and for the Boston Marathon bombings in 2013.

Once such extremist videos appear online they never disappear. YouTube removed hundreds of Awlaki’s videos in 2010. But a search of the platform reveals thousands of copies remain in circulation. Now a new technology promises to help prevent extremist videos from spreading on the internet.

The technique, known as “robust hashing”, was developed by Hany Farid at Dartmouth College in Hanover, New Hampshire, working in partnership with Microsoft. In essence, it boils down a photograph, video or audio file into a unique numeric code.

To generate a code for a…Continue reading
Source: Economist

Flight compass

About to head north

WHETHER it is a herd of gazelle, a court of kangaroos or a crash of rhinos, the sight of a group of animals turning from a predator and bolting in unison in the same direction is one of the most majestic in nature. It is also one of the least understood. Now a group of researchers think they have come up with the reason why such animals seem instantly to know which way to run and not crash chaotically into one another: they use a sort of compass.

To investigate this, Petr Obleser, a PhD student at the Czech University of Life Sciences in Prague, and his supervisor, Hynek Burda, studied roe deer commonly found on hunting grounds in South Bohemia and West Moravia in the Czech Republic. That some animals have an innate awareness of Earth’s magnetic field is well known: many use it to guide their migration. Herdsmen and hunters have also long observed that grazing animals often tend to align themselves facing either north or south, which the researchers suspected was in readiness to escape in either of those directions should a threat emerge.

And that is largely what the roe deer did, Mr Obleser,…Continue reading
Source: Economist

Monsooner or later

FARMERS throughout the ages have gleaned clues about the weather from the natural environment. Animal movements and the colour of the sky have been considered augurs. For one of the world’s most important weather events, India’s monsoon, forecasting methods are becoming rather more refined. About half of the country’s population—600m people—depend upon the rain it brings. Scientists want a better understanding of the processes by which the Indian Ocean interacts with the atmosphere, and underwater robots can help in their quest.

Monsoon climates typically have two distinct seasons: wet and dry. In India the rainy onslaught begins when moist air is carried northwards from the Indian Ocean during the summer. The winds transporting it come from an area of high atmospheric pressure in the southern Indian Ocean, and cross the equator before raging over the land. As the air gathers moisture during the journey, atmospheric convection forms storm clouds which arrive first in southern India around early June (as they did this year). The monsoon creeps north and west, showering Pakistan about a month later. By September it is in retreat and it is normally gone by December.

Information about when and where the monsoon will arrive is important for farmers, especially as almost two-thirds of India’s fields lack irrigation systems. The expected arrival of…Continue reading
Source: Economist

What the deuce, Watson?

WHEN the 2016 Wimbledon Championships start on June 27th millions of tennis fans will begin posting on social networks such as Twitter, Facebook and Instagram about everything from the matches to the attire, hairdos and headbands of their favourite players. The contest’s organiser, the All England Lawn Tennis Club (AELTC), would quite like to know what the hottest topics are. So it is using a powerful computer to find out.

That computer is Watson, an IBM machine which in 2011 famously won the American TV quiz “Jeopardy!” and nowadays resides as a cloud-computing service. The idea, says Alexandra Willis, the AELTC’s digital supremo, is to use its machine learning and natural language-processing techniques to discover the most pressing topics of conversation among the vast output from fans. Knowing that, the club’s editorial team—which provides content for Wimbledon’s mobile app, its website and its video feeds—can respond quickly with relevant articles, posts, tweets, statistics and images.

The computer system is capable of analysing vast amounts of unstructured text and inferring meaning from it. It has also been trained…Continue reading
Source: Economist

Pulling the plug on robocalls

DWINDLING necessity aside, one of the more compelling reasons to ditch the telepone landline—and rely instead on a mobile-phone connection—is the annoying number of robocalls these days. Consumer Reports, a product-testing puiblication based in New York, reckons unsolicited telephone calls made by automatic dialing machines now comprise over a third of all calls to American homes. Worse, the majority are not just annoying telemarketing messages, but scams aimed at tricking the unwary into parting with personal information or cash. According to Consumer Reports, Americans lose $350m a year as a result of telephone fraud. The elderly are particularly vulnerable, and often the scammers’ main target.

Every month, some 200,000 Americans complain bitterly to the Federal Trade Commission (FTC) or the Federal Communications Commission (FCC) that robocalls are ruining their life, especially at meal time. (The FTC regulates telephone landlines, while the FCC oversees wireless communications.) The Telephone Consumer Protection Act of 1991 restricts unsolicited telemarketing practices using automated dialing equipment and prerecorded…Continue reading
Source: Economist