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Black holes are regions in space with such strong gravity that nothing, including light, can escape once it crosses the event horizon. They were first described by Albert Einstein's theory of general relativity, which posits that massive objects warp space and time. The center of a black hole is a singularity of infinite density, surrounded by an event horizon beyond which nothing can return. Black holes come in various sizes, with stellar ones formed from collapsed stars and supermassive ones found at galaxy centers having masses millions or billions of times that of the Sun. While direct observation is impossible due to black holes' light-trapping nature, scientists have inferred their presence through gravitational effects on surrounding matter and light. Research into black holes has provided insights into space, time, and fundamental physics, captivating both scientists and the general public. In 2019, the first direct image of a black hole was captured by the Event Horizon Telescope, showing the event horizon of a supermassive black hole at the center of Messier 87 galaxy.