General relativity has scored yet another impressive success. Measurements on a double pulsar system 2000 light-years away have confirmed Albert Einstein's theory to within 0.05%, providing the most precise test made so far. The measurements, led by Michael Kramer of the University of Manchester's Jodrell Bank Observatory, are based on more than two years of observations made of the double pulsar system PSR J0737-3039A/B since its discovery by many of the same team in 2004 (see CERN Courier March 2004 p12).

The work takes earlier single pulsar measurements a step further as the radio beacons of two pulsars provides much more detailed data. The data constrain alternatives to general relativity in a region where gravitational fields are strong, with pulsars only about 20 km across but with masses larger than the Sun.

Further reading

M Kramer et al. 2006 Science 314 97.