Relativity theory verified yet again — BBC
Astronomers who discovered two pulsars in a pas de deux have used the massive dancers to test Albert Einstein’s theory of gravitation — general relativity.
Big shocker! Einstein got it right.
Pulsars are neutron stars, huge collapsed stars compacted by their own gravity into objects only a few miles across. Matter falling into the pulsars radiates intense beams of energy, which, if the rapidly rotating stars are pointing in the Earth’s direction, resemble lighthouse beacons.
The twin pulsars are both pointing their beams toward Earth, providing astrophysicists a “laboratory” to check Einstein’s prediction that gravity slows down time and warps space.
By monitoring the pulses’ arrival at Earth, the team was able to measure how the beams from each neutron star were being disturbed as they passed through the curved space-time near their companion.
“We see their orbits edge-on, so what happens is that one pulsar will eclipse the other,” explained co-researcher Dr Duncan Lorimer from West Virginia University, Morgantown, US.
“We can measure the signal from the [far] pulsar so precisely that we can see the delay of the signal as its beam passes through the curved space-time of the pulsar sitting in the way; the signal has to travel an extra distance. It’s called ‘Shapiro delay’,” he told BBC News.
The team found this delay to be close to 90 millionths of a second and the ratio of the observed and predicted values to be 1.0001, plus or minus 0.0005 - a precision of 0.05%.
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