Improved security, surveillance and data tools are helping to make the world safer.So how can we keep up the momentum? –By Tom Gash



FOR DECADES, POLITICIANS HAVE BEEN PERPET-uating two big myths about crime. Those on the right have argued that only ever-tougher prison terms will deter would-be wrong-doers. Those on the left have argued that crime will only fall when we reform society and reduce poverty and inequality. In fact, crime has fallen dramatically over the past 20 years, not due to reforms traditionally advocated by politicians, but due to the technological change which has made it harder to commit crime.

In many developed countries, crime has halved overall, with precise drops varying from country to country. Some crime types have fallen particularly rapidly: car crime, for example, has more than halved across developed countries, and in the UK, is at one-sixth of early 90s levels. Much of this shift is a result of the slow spread of central locking and electronic immobilisers – with countries that forced manufacturers to deploy these technologies soonest experiencing the quickest and most dramatic crime drops.

Credit- and debit-card fraud has not dropped in absolute terms – but in terms of the amounts stolen as a proportion of total card spend it has fallen dramatically in many countries. Here, falls have been greatest where chip-and-PIN technology is widely used.Murder rates have fallen by over a third in the US and, at first glance, it is hard to think that technology might be involved in the shift. A study led by University of Massachusetts professor Anthony Harris found that US to test Einstein’s theory of general relativity at the event horizon itself,” Doeleman says.
Of course, Einstein’s theory of general relativity has been repeatedly confirmed at every turn, most recently by the Advanced Laser Interferometer Gravitational-wave Observatory’s measurement of the gravitational waves produced when two black holes merge. What new information could an image of the event horizon offer? One area of uncertainty is what’s known as the information paradox.

“The information swallowed by a black hole is seemingly lost completely,” says Doeleman. “If you burn an encyclopaedia, an advanced civilisation could still reconstitute it and the information it contained. But if you throw it into a black hole it seems it’s just gone. Quantum-mechanically that doesn’t make sense, so understanding where the information goes is a mystery.

But there are ways that the quantum states inside the black hole might manifest outside of it, so it’s a mystery we may be able to address.” Even the existence of black holes shouldn’t be taken for granted. The evidence for them may be strong, but it’s still indirect enough to allow for other possibilities, and nowhere do Einstein’s theories produce stranger and more unintuitive results than at the event horizon. “Einstein himself disavowed black holes for many years,” Doeleman points out.

“He thought that something would prevent the catastrophic gravitational collapse of matter. But if he’s right, and if this object is a black hole, then the shape of its shadow should conform to the no-hair theorem, which says that you can characterise a black hole by just its mass and its spin. If what we actually see is an irregular shape, then we’d have to look at scenarios in which it’s either not a black hole, or that Einstein was wrong. But I always say: you never bet against Einstein.”