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Gravitational waves: Einstein vindicated once again and another Nobel prize booked

On Feb. 11, 2016, the detection of gravitational waves was announced by researchers of LIGO (1,  LIGO – the Advanced Laser Interferometer Gravitational-Wave Observatory). Using their twin giant laser interferometer detectors in Livingston, Louisiana/USA, and in Hanford, Washington/USA, scientists claim to have measured ripples in space-time produced by a collision between two black holes, a merger of two black holes about 1.3 billion light-years distant from Earth.

The discovery of gravitational waves is a confirmation of Einstein’s general theory of relativity because the property of these black holes exactly matches with what Einstein predicted 100 years ago.

The discovery is certainly a hot candidate for a Nobel prize winner. BBC (2) wrote: „The first direct detection of gravitational waves is without doubt one of the most remarkable breakthroughs of our time“.

One of the most important scientific consequences of detecting a black-hole merger would be confirmation that black holes really do exist. Previously their existence was based on circumstantial evidence only.

According to Davide Castelvecchi (3), contributing editor for Scientific American magazine, a couple of further cosmic questions can be tackled, such as

DO GRAVITATIONAL WAVES TRAVEL AT THE SPEED OF LIGHT?

IS SPACE-TIME MADE OF COSMIC STRINGS?

ARE NEUTRON STARS RUGGED?

WHAT MAKES STARS EXPLODE?

HOW FAST IS THE UNIVERSE EXPANDING?

Einstein’s general theory of relativity predicts that any accelerating large mass should produce tiny ripples in space time. The effect is very weak and therefore it was not possible to measure it previously. Only the biggest masses, moving under the greatest accelerations, are expected to warp their surroundings to any appreciable degree. Now, the collision of black holes would radiate gravitational energy at the speed of light.

The Advanced LIGO interferometers have been searching for this tiny effect for over a decade, gradually improving the sensitivity of their equipment, their experiments would need to detect disturbances as small as a fractions of the width of an atom.

The recorded data fits perfectly with the modeled expectation for this type of black hole merger, which was picked up almost simultaneously by two widely separated LIGO facilities, ruling out measurement errors.

Further reading:

1.  Gravitational waves: 6 cosmic questions they can tackle
2. BBC: Gravitational waves, a triumph for big science
3. Scientific American:  Gravitational Waves: 6 Cosmic Questions They Can Tackle