Schematic of Gravitationally-bound, Inwardly-spiralling Neutron Stars About to Merge. Perimeter Institute.
GRAVITY WAVES AND LIGHT BOTH OBSERVED TO TRAVEL AT THE SAME SPEED
Mike Priaro, P.Eng.
First uploaded October 20, 2017.
On August 17, 2017 a gravitational wave displaying the signature of a merger of two neutron stars was observed by both the U.S. Laser Interferometer Gravitational-Wave Observatory (LIGO) and the newly-operational European Gravitational Observatory (VIRGO) in Italy.
Conceptualization of Gravitational Waves Resulting from Neutron Star Merger.
After alerting many telescopes around the world to focus on a patch of sky 130 million light years away in the Hydra constellation, a radiation source that was determined to be the same as the gravitational wave source was found.
The gravitational waves, ripples in space-time predicted by Albert Einstein, and the electromagnetic radiation travelled across the universe for 130 million years and arrived two seconds apart.
Logically, it took a little time for the energy of the neutron star merger, which immediately generated gravity waves, to create detectable electromagnetic waves, i.e, light, infrared, and gamma rays, by heating up the surrounding ejected matter and gas enough for it to be visible 130 million light years away.
That showed for the first time ever that both gravity waves and electromagnetic waves travel at the same speed, that of light, as predicted by Einstein.
Gravitational waves were first observed directly by LIGO in 2015 – 100 years after they were predicted in 1915 by Einstein in his theory of General Relativity.
Observations of merging black holes have as yet been unable to find any associated source of electromagnetic radiation perhaps because by definition, no light can escape a merged black hole, because its location could not be determined with enough accuracy for telescopes, and perhaps because the black hole mergers were much more distant.
It is known that the merger of two neutron stars is accompanied by immense gamma ray, infra-red, and optical electromagnetic radiation sufficient to result in a kilonova – second only to a supernova in optical brightness.
Astrophysicists believe that the radioactive decay of isotopes of the heavy elements produced, and ejected at about 20 percent of the speed of light, as a result of the violent merger of two neutron stars, each having a density of 100,000,000,000,000,000 kg/m3, powers the kilonova's distinctive thermal "glow".
Einstein's theory of General Relativity is based on continuous fields of space-time and gravity that seem to control the unimaginably large-scale physical structure of the universe that we can observe, 13.8 billion light years in radius, and perhaps the entire universe which scientists deduce to be at least 46 billion light years in radius. That said, most of the observable universe appears to be in the form of dark matter and dark energy – the nature of which are both a mystery to science at this time.
The structure of the unimaginably small world described by quantum mechanics and the Standard Model of particle physics is, in stark contrast, discontinuous and is effectively controlled by a sub-atomic scale constant known as Planck's constant, one of the smallest constants known. It defines discrete energy levels that any particle or wave can have as quanta of energy. Furthermore, the forces that hold the nucleus, as well as its constituent particles, together are carried by other particles.
While Quantum Field Theory incorporates Einstein's work on Special Relativity, there is no known relationship between General Relativity and the quantum mechanics of the sub-atomic world though both were effectively discovered by one man – Albert Einstein.
But because both gravity waves and electromagnetic radiation have now been shown to travel at the same speed, the speed of light which is 299,792,458 metres/second, there must therefore be an underlying connection between gravity and the large-scale structure of the universe and the quantum mechanical structure of the sub-atomic world.
Why the speed of light appears constant everywhere, why it has that particular value, and what the connection is between the large-scale structure of the universe and the structure of the sub-atomic world are mysteries that Albert Einstein, and all physicists since, have worked to explain – but with no success so far.
Mike Priaro
Calgary
403-281-2156
