大象传媒

The universe is silent no longer - physicists at the LIGO observatory have detected gravitational waves.

LIGO, the Laser Interferometer Gravitational-wave Observatory, with its giant laser beam arms totalling 5 miles across the remote Hanford desert, is the largest lab on the surface of the planet. It was constructed in the Columbia Basin region of south-eastern Washington specifically to detect gravitational waves - ripples in the fabric of space-time along with its sister detector in Louisiana.

First predicted a century ago by Einstein in his theory of general relativity, gravitational waves are produced by exotic cosmic events, such as when two black holes collide. Scientists have hunted for them for decades with increasingly sensitive equipment. The laser beam tubes of the observatory have now proved sensitive enough to detect the signal from deep space as small as a thousandth the diameter of a proton.

Claudia Hammond examines this week鈥檚 momentous discovery and we hear in detail from Aleem Maqbool who travelled to LIGO in Hanford just before the switch on last September to scrutinise the cutting-edge technology and aspirations of this 鈥渘ew ear on the universe鈥� which has to be of almost unimaginable sensitivity to enable detection of some of the universe's most dramatic events and hear the universe in a whole new way.

(Photo caption: Inspecting LIGO's optics for contaminants 漏 Advanced LIGO)

The Science Hour was presented by Claudia Hammond

Producer: Adrian Washbourne