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Posted: March 6, 2007
Military contractor trying to build quantum radar
(Nanowerk News) They designed an exploding cigar to kill Fidel Castro and hired fortune-tellers to fight the cold war. Now the US military is taking its war on terror where even Albert Einstein feared to tread - into the baffling world of quantum mechanics. Lockheed Martin, a main US defence contractor, thinks it can exploit research on the fringes of theoretical physics to build the ultimate radar, which could see through anything, from buildings to solid earth.
The company has designed and patented a scanner based on the principle of quantum entanglement - a far out concept, even by the weird standards of the quantum world. It says the device could penetrate any type of defence, to identify hidden weapons and roadside bombs from hundreds of miles away.
Quantum entanglement says that two particles can be joined so that whatever happens to one must also happen to its partner, however far apart they are.
Einstein called it "spooky action at a distance". Lockheed Martin prefers: "Quantum radar is capable of providing information about targets that cannot be provided using classical radar systems."
European patent number EP1750145 describes "radar systems and methods using entangled quantum particles". It says such a device could "visualise useful target details through background and/or camouflaging clutter, through plasma shrouds around hypersonic air vehicles, through the layers of concealment hiding underground facilities, [and find] IEDs [improvised explosive devices], mines and other threats - all while operating from an airborne platform". It could also be mounted on a satellite.
Filing a patent does not mean that the company has the know how to build such a system - British Rail famously patented a nuclear fusion-powered flying saucer in the 1970s - but Lockheed Martin is known to be experimenting with sensors based on quantum entanglement, also known as ghost imaging.
In theory entangled particles could be used to reveal details of objects they have never interacted with. If one particle bumped into an aircraft its twin would react in the same way, even if it never left the laboratory. Work out a way to read that behaviour, and an image could be built up, even with no information being directly transmitted from the target.
The Lockheed Martin patent envisages a different use for entanglement. Current radar systems become less useful as range increases, because the frequencies needed to transmit over long distances are less sensitive. According to the patent this problem can be removed by entangling light at different frequencies and then sending them out together as a bundle.
It says: "Entangled radar waves can combine one or more particles with a relatively high frequency for resolution, with one or more particles at a lower frequency for more effective propagation." The radar beam could then "propagate through different types of mediums and resolve different types of target".
Analysing the return signal would reveal the "location, speed, direction of travel, distance to target, target image, target size, target area, target volume, target dimensions, target cross-section, target surface roughness and target material composition", the patent claims.
However, others are sceptical. Brian Cox, a physicist at Manchester University, has discussed the patent with colleagues. "The consensus at Manchester is that this is just not right," he said. "The quantum mechanics is wrong, I don't know what that says about US defence contractors."