4 | NewScientist | 29 June 2013

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GETTING computers to think like humans is tough but what about the opposite? A new mathematical framework gets humans to think like machines in order to harness the power of automated proof-checking.

The framework provides the possibility of proofs that can’t be wrong and so wouldn’t need to be laboriously checked by people. It could also be the first step towards computers making their own mathematical leaps.

Today, mathematics is based on set theory, the study of collections of objects. But this doesn’t suit computers, because although all mathematical objects can be expressed as sets, logical

statements cannot. Instead, automated proof-checking software uses type theory, in which objects and statements both count as types. To build this

Go mathemachines! capability into the normal work of mathematicians, Vladimir Voevodsky of the Institute for Advanced Study in Princeton, New Jersey, and his colleagues have created a 600-page instruction manual on how to shift from sets to types (bit.ly/HoTTBook).

Team member Andrej Bauer of the University of Ljubljana, Slovenia, points out that a proof of the long-standing abc conjecture published last year still hasn’t been verified by other mathematicians – a problem that simply wouldn’t exist if the proof was expressed in type theory.

Balmy ArcticWHEN Alaska had a cold snap recently, Sarah Palin quipped: “Global warming my gluteus maximus” on her Facebook page.

The 49th state’s former governor has not yet responded to Alaska’s latest temperature swing: recording-breaking heat. Talkeetna, north of Anchorage, recorded 36 °C on 17 June, and three other towns posted record temperatures.

Eugene Petrescu, a National Oceanic and Atmospheric Administration scientist in

Anchorage, says that a sharp south turn by the jet stream in May trapped Alaska in currents of cold air from the Arctic. More recently, it veered north, bringing bubbles of warm tropical air from the south and causing the present heatwave. “It has eased a bit, but it’s going to happen again next week,” Petrescu says, adding that there is too little data to say if climate change is to blame.

But he also said global warming is having an impact on Alaska’s ice cover, particularly in the north, where average temperatures rose by 1.7 °C between 2000 and 2010.

Staring at the sunIT’S not usually a good idea to stare at the sun – unless you’re a $181-million telescope, that is.

NASA’s Interface Region Imaging Spectrograph (IRIS) will be launched this week to probe an underappreciated aspect of the sun – the region between the star’s surface and its sizzling corona, the plasma layer that envelops it.

Little is known about what happens here. “IRIS will fill crucial gaps in our understanding of what

–More floods to come–

–Dark glasses not required–

A human-made disasterALMOST 20,000 people are stranded and at least 1000 confirmed dead in the wake of extreme floods in northern India. Poor local planning and a destructive approach to development in the Himalayas have left the region vulnerable to floods and landslides – which will only get worse under climate change.

“The current devastation is largely man-made,” says Maharaj Pandit, head of the department of environmental studies at the University of Delhi. He blames “rampant unauthorised and mindless building” on the Himalayan flood plains, and deforestation. Cutting down trees loosens up the soil on mountainsides, making landslides more likely.

In addition, the government has earmarked 292 dams for construction

in the Himalayas, which involves diverting rivers and increasing industrial traffic – all of which further destabilises soil. Moreover, in heavy rain, dam operators release more water to safeguard their structure. “Delhi, for instance, was flooded because the Hathnikund barrage in upstream Haryana released more water,” says Pandit.

Bhupendra Nath Goswami of the Indian Institute of Tropical Meteorology warns that the rapid bursts of heavy rain behind this flood are increasingly likely to happen. “The frequency of extreme rain events is increasing over the Indian continent.”

It’s not clear whether this flood is linked to global warming, but climate change does mean that such events are likely to happen more frequently.

“In this new framework, proofs couldn’t be wrong and so wouldn’t need to be checked by people”

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role the interface region plays in powering the corona,” says IRIS mission scientist Jeffrey Newmark.

On 26 June, an aircraft carrying a rocket with the telescope inside will launch from Vandenberg Air Force Base in California, and will release its payload 12 kilometres up. The rocket will then carry the telescope to its orbit, some 660 kilometres above Earth’s surface.

IRIS will track short-lived jets of plasma, which the IRIS team hope will help explain why the corona, at 1 million kelvin, is so much hotter than the surface, at a mere 6000 K.

Trio of alien planetsALIENS could be watching aliens watching aliens. That’s a realistic prospect now that three potentially habitable planets – a record – have been glimpsed orbiting the same star.

Earlier studies had suggested that a nearby star, Gliese 667C, had three planets, only one of which might support life. But the very presence of multiple planets made their precise number hard to tease out.

Now Guillem Anglada-Escudé of the University of Göttingen in Germany and his colleagues have reanalysed the original data and added some new observations. They found evidence for up to seven worlds, including three rocky planets where temperatures should suit life (Astronomy & Astrophysics, in press). The three are close enough to each other that any intelligent life there with the ability to build rockets could visit the neighbours in just one to two months.

In 2010, two of the paper’s authors were praised and then criticised when they claimed to have found the first potentially habitable rocky planet around the star Gliese 581 – a discovery others were unable to confirm. Anglada-Escudé is not worried: “We made sure to be very careful this time.”

Green pay-offGO GREEN, get rich. Firms that become environmentally friendly will profit the most.

“Companies that adapt quickest to the new environmental realities are the likeliest to thrive,” says Kaveh Zahedi of the United Nations Environment Programme.

In a report released this week, UNEP identified the threats and opportunities posed by environmental degradation to 10 business sectors. Threats include disrupted supply chains, for example. But a changing environment offers new areas to

expand into, such as creating more resilient products that withstand severe weather. It also provides more opportunities to gain customers by offering sustainable products.

Last year, researchers compared 180 companies and found that the more environmentally friendly businesses were more profitable in the long run than their less-sustainable competitors.

“Companies that adapt quickest to the new environmental realities are the likeliest to thrive”

IT’S a golden age for spying. The subsea fibre-optic cables that carry telephone and internet traffic are a technological marvel – and a gift to intelligence agencies. The cables make landfall at just a handful of locations, meaning vast quantities of data can be sucked out at one site and, according to Edward Snowden, the prolific US National Security Agency whistleblower, that is what British intelligence has been doing for the last 18 months.

In a leak to The Guardian newspaper on 22 June, Snowden said the UK Government Communications Headquarters in Cheltenham is siphoning data from at least 200 fibre-optic telecommunications cables – including many of the

transatlantic subsea cables that hit British shores at Bude in Cornwall. The tapping project, known as Tempora, allows phone calls to be monitored, as well as emails on offshore American-hosted webmail services such as Gmail, Yahoo and Outlook.

“It is astonishing access they are getting with Tempora,” says Eric King of pressure group Privacy International in London. “Every piece of data that leaves the UK, and every piece of international data that flows through the UK – which is 99 per cent of the world’s communications – is available to them.”

King and colleagues predicted as much in 2011 when they published a list of providers of subsea cable-tapping technology.

Cable hotspots a gift for UK spies

–Bude: prime site for snoopers–

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Light-bulb starThe oldest known relative of starfish looked like a light bulb. Fossils of a bulbous animal called Helicocystis moroccoensis have been discovered in rocks 510 million years old. Five grooves spiralled around the bulb to the mouth at the top (Proceedings of the Royal Society B, DOI: 10.1098/rspb.2013.1197).

Solar silver liningYou might think the best place for solar panels in the US would be in sunny California, but that’s not the case. Solar panels would cut more greenhouse gas emissions in cloudier states like Nebraska, provided they are close to coal-fired power plants and can compete with them for business (PNAS, doi.org/m29).

Landmark decisionWomen in the UK with a family history of certain cancers will be offered tamoxifen and raloxifene by the National Health Service as a protection against breast cancer under new guidelines. The drugs can reduce the incidence of cancer by up to 40 per cent in people at increased risk. A five-year course could prevent breast cancer in 1 of every 42 women taking it.

Europeans take heartThe number of people dying from heart disease in Europe has halved over the last 30 years, thanks mainly to reductions in smoking (European Heart Journal, DOI: 10.1093/eurheart/eht159). Heart disease is still Europe’s biggest killer, however, and the increased rate of diabetes and obesity is raising death rates among the young, warn the authors.

BigBrain mappedThe most detailed map of the brain ever made, called BigBrain, should lead to a more accurate picture of how its different regions function. It was created by embedding a 65-year-old woman’s brain in wax, before slicing it into more than 7400 sections and imaging it (Science, doi.org/m3b).

For daily news stories, visit newscientist.com/news

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