A super-powered neutrino generator could in theory be used to instantly destroy nuclear weapons anywhere on the planet, according to a team of Japanese scientists.

If it was ever built, a state could use the device to obliterate the nuclear arsenal of its enemy by firing a beam of neutrinos straight through the Earth. But the generator would need to be more than a hundred times more powerful than any existing particle accelerator and over 1000 kilometres wide.

"It is really quite futuristic," Alfons Weber, a neutrino scientist at Oxford University, UK, told New Scientist. "But the maths and physics seems to be right."

John Cobb, another researcher at Oxford University, cautions: "It might be technically feasible, given massive investment, but there are still unsolved problems."