Black holes are elusive, but not rare. Like nocturnal creatures perfectly camouflaged for night, they are exceedingly difficult to detect.
Some come out of hiding by devouring a nearby star or other nearby material, which glows in a superheated whirlpool as it falls past the black hole’s point of no return.
Sometimes two black holes twirl ever-closer to each other until a final collision produces gravitational waves, the ripples in spacetime like those recently measured for the first time by the Laser Interferometer Gravitational-wave Observatory.
But these are uncommon events. What about the many other black holes believed to be hurtling alone through our galaxy? Without such cataclysms, they remain invisible to us here on Earth, neither emitting nor reflecting light.
But they may soon emerge from the shadows thanks to research led by Avery Broderick, Associate Faculty member at Perimeter Institute and the University of Waterloo, and PhD student Mansour Karami. … (Perimeter)