“Einstein’s gravitational theory, said to be the greatest single achievement of theoretical physics, resulted in beautiful relations connecting gravitational phenomena with the geometry of space,” said the great Caltech physicist Richard Feynman. For all its vast voids, the universe is rippling with ghostly gravitational waves produced by extreme astrophysical phenomena, vibrating the fabric of space-time, like the ringing of a cosmic bell.
Did primordial Black holes –described as “the gates of hell, the end of spacetime, paradoxical, intriguing, frightening” by the Event Horizon Telescope scientists who imaged the now iconic black hole the size of our solar system at the heart of monster elliptical galaxy M87— exist during the cosmic Dark Age following the Big Bang, before the formation of the first stars?
Astronomers have spotted a distant pair of titanic black holes each with a mass more than 800 million times that of our sun headed for a collision in a galaxy roughly 2.5 billion light-years away. The supermassive black holes (inset above) are lit up by warm gas and bright stars that surround the objects. The finding improves estimates of when astronomers will first detect gravitational waves emanating from the black hole pair “a million times louder than those detected by LIGO.”
Arguably the most important Cosmological discovery ever made, Hubble’s Constant, is that our universe is expanding. Its stands, observes the Harvard -Smithsonian Center for Astrophysics, along with the Copernican Principle — that there is no preferred place in the universe, and Olbers’ paradox — that the sky is dark at night, as one of the cornerstones of modern cosmology.