4th April 2011 – Einstein’s Last Legacy: Detecting Wrinkles in Space-Time

Associate Professor Andrea Lommen of Franklin & Marshall College and Dr Ben Stappers of Jodrell Bank study millisecond pulsars. These are dead stars with about the mass of our sun, collapsed down to about the size of Knutsford (10km across), and spinning about as fast as your kitchen blender. The fastest pulsar known, PSR J1748-2446ad, spins on its axis 716 times each second.

Pulsars are very accurate clocks, meaning they are predictable – at the same level that atomic clocks are predictable.  You can think of pulsars as a collection of clocks distributed throughout the galaxy. Anything that could disturb time, such as a perturbation in space-time, will effect the clocks. Pulsars are so predictable that we may be able to detect such a disturbance by observing pulsars.

Where would a space-time perturbation come from?

Rotating pairs of massive black holes eventually coalesce into a single hole as they radiate gravitational radiation (a prediction of Einstein’s General Theory of Relativity) and Gravitational Waves propagate as a ripple in the fundamental structure of space-time.

It turns out that we think the Universe is filled with gravitational radiation (a travelling space-time disturbance) but no one has measured it yet. This radiation is created, for example, any time two black holes finally coalesce into a massive black hole. This radiation that we seek to detect is exceedingly weak – a million times less energetic than that in the cosmic microwave background radiation which, itself, is a billion times weaker than that in a household oven. Maybe, eventually, they might detect the echo of the Big Bang still echoing round the universe after 14 billion years.

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