The physics of espionage

As the 23rd Bond movie, Skyfall, hits cinemas, we take a look at the physics behind spying.

Daniel Craig as James Bond

Premiering on 26 October, Skyfall, the 23rd film in the official James Bond franchise, sees the reintroduction of MI6’s gadgetmaster, known only as Q. Innovative gizmos have long been a staple of the series, with rocket belts, lasers hidden in wristwatches, and stun-guns concealed in mobile phones helping get 007 out of some tight spots when on Her Majesty’s secret service.

Many of them are a little far-fetched, and have been criticised by physicist and science-communicator Neil deGrasse Tyson for taking rather too much creative licence (to kill) with the laws of nature. But while Hollywood occasionally stretches credibility way past its elastic limit, there’s plenty of real physics involved in spying.

From Russia Greece With Love
During the second world war, British forces had more than ten thousand personnel operating behind enemy lines – the fabled Special Operations Executive. But communicating with their handlers back home put them in danger, as their signals gave away their locations to Axis spycatchers.

Radio antennas that are particularly direction-sensitive will see a peak in the strength of a received signal when pointed directly towards the source of a transmission. Using two different antennas placed in widely separated positions, the exact position of a broadcasting secret agent can be worked out by triangulation – a simple application of trigonometry.

Modern technology can work around this problem by compressing a long message and sending it as a “burst transmission” lasting a second or less. Even if such a signal is detected, they’re typically too short to work out a source direction accurately.

Direction-finding is now more commonly used to locate pirate radio broadcasts than to uncover espionage activity.

Live and Let Die
Material produced as a byproduct in nuclear reactors used for peaceful purposes can be turned to far more nefarious ends.

In 2006, the radioactive isotope polonium-210 – produced in nuclear powerplants by bombarding bismuth with neutrons – was implicated in the death of the former KGB employee Alexander Litvinenko.

Because polonium emits alpha radiation, which isn’t very penetrative, it’s only especially dangerous if ingested or inhaled, allowing for easy transport, without harming those carrying it, until it’s ready for use – it can even make it through airport security. Unlike in the case of most chemical poisons, the onset of the symptoms of radiation sickness is delayed, allowing time for the assailants to escape. Polonium was also thought to be a hard substance to detect when ingested, although this ultimately proved not to be the case.

Unusually high levels of polonium have also been detected on the possessions of the former president of the Palestinian National Authority, Yasser Arafat, who died in 2004.

(Golden) Eyes in the sky
The same space-based technology that is used to peer out into the cosmos and investigate the origins of the universe can be used to look down instead of up.

They’re typically used for high-resolution photography of areas of particular interest – such as the location of runways on hostile airfields that are going to be taken out of action – and to monitor for compliance with treaties on nuclear test bans.

The transfer of technology works both ways. In the US, the National Reconnaissance Office recently gifted two telescopes that would have been used in spy satellites to NASA. Though they currently have no instrumentation, they’re expected to be about as powerful as the Hubble Space Telescope.

For Your Eyes Only
Technology presented in film as the latest must-have for a secret agent might instead have real-life civilian uses – not saving the world, but saving an expensive paint-job on your car.

Die Another Day, the 2002 flop that was the last to feature Pierce Brosnan as Bond, featured an Aston Martin equipped with a kind of cloaking device that rendered it invisible. The premise was that the car was embedded with cameras that took images from one side and projected them on the other.

Although criticised for being too unbelievable even for a Bond film, the technology is on the cusp of possibility, as has been shown by Mercedes Benz. But rather than being used to develop an invisible car – for which, given the chances of someone crashing into it, the cost of insurance would scare the living daylights out of you – it’s been adapted to improve road safety instead.

Toyota have developed a version of their Prius that takes an image of what’s behind the car and projects it onto the rear seats, effectively making the back of the vehicle transparent and providing for much easier parking in tight spaces, and eliminating blind spots when reversing. Drivers will get a better look at what’s behind their car, rather than a view to a kill.



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