Economist 9/25/14

1. Cupid, which runs subscription-based dating websites such as Cupid.com, UniformDating.com and LoveBeginsAt.com, announced £3m ($4.9m) in pre-tax losses for the six months ending June, an increase of 20% from the previous year.The problem is that Cupid’s lovebirds now seem to be going elsewhere to meet each other. Although the firm still manages to turn one in every 30 singletons visiting its websites into paying subscribers, the number of new users has dropped.In the American market alone, the revenues generated by dating apps will double within the next five years, predicts IBISWorld, a market-research firm. The leaders of the pack are Grindr, a location-dating app for gay men, and Tinder, a similar service for heterosexuals.The big problem for Cupid is that unlike dating websites, Grindr and Tinder are free.
2.  The headline projection in the Science study says the world’s population is likely to grow from 7.2 billion now to 9.6 billion in 2050 and to 10.9 billion in 2100 (not 12 billion). This projection is not new. It was first made by the UN itself in its 2012 estimates. (Before that, the UN had projected a population of 9.3 billion for 2050.Global population growth is slowing down, not stopping. The rise in the total from 5 billion to 6 billion took 12 years; so did the rise from 6 billion to 7 billion. But the rise from 9 billion to 10 billion looks likely to take 25 years and from 10 billion to 11 billion, roughly 45 years.. At the moment, the UN works out its main projection (called the medium variant) based on countries’ fertility rates and life expectancies, the most important determinants of population growth.
3. If you are looking for weapons against human pathogens, though, surely the best place to look is in the human microbiome itself, for this collection of bugs that live on people’s skins and in their guts (see article) are the ones most likely to have evolved chemicals designed to deal specifically with interlopers invading their human territory.Mohamed Donia of the University of California, San Francisco. Dr Donia and his colleagues have designed a piece of software that can scan DNA databases for genes which look as if they are involved in antibiotic production.The most useful products of all, though, could be drugs that can regulate the immune system.There is also the possibility of using bugs themselves as treatments.
4. Squeezing energy from nuclear fusion is an idea conceived in the 1950s, but yet to be born in a laboratory. Here is one way that might make it happen: gather an international consortium of the fusion-minded, including the European Union, America, China, India, Japan, Russia and South Korea.Conspire to build a 23,000-tonne doughnut-shaped vessel called a tokamak, that is wrapped with 80,000km of superconducting wire, all to contain the plasma magnetically and, for the first time, produce fusion energy continuously. Call it the International Thermonuclear Experimental Reactor; shorten the name to ITER.The most recently published schedule says the first plasma will be created in the vacuum vessel in 2020. That will now have to slip to 2023 or 2024.
5. There is not much difference between a death sentence in the jihadists’ “Islamic State” and in Saudi Arabia, a country seen as a crucial Western ally in the fight against IS. Both follow Hanbali jurisprudence, the strictest of four schools of traditional Sunni Islamic law. Dissidents in Raqqa, the Syrian town that is IS’s proto-capital, say all 12 of the judges who now run its court system, adjudicating everything from property disputes to capital crimes, are Saudis. The group has also created a Saudi-style religious police, charged with rooting out vice and shooing the faithful to prayers.. Still, in the space of just 18 days during the month of August, the kingdom of Saudi beheaded some 22 people, according to human-rights advocates. The spate of killings was surprising not only because it was so sudden—the kingdom carried out a total of 79 executions last year—but also because many of those killed were convicted of relatively minor offences, such as smuggling hashish or, strangely, “sorcery”.