Black holes rank among the most mysterious and exotic objects in the universe. Each of these weird misfits, whose gravitational pull exceeds even light’s capacity to escape, distorts the space-time continuum that surrounds it. They give up their identity only when another object — a star or gas cloud, for example — comes too close. As the black hole’s gravity pulls in material, the gas becomes superheated and emits copious amounts of electromagnetic radiation.
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