Albert Einstein rejected the idea that black holes might exist
The closest known black hole, called 1A 0620-00, is 3,000 lightyears away. You know our nearest stellar neighbour is 4.2 light-years away
When the Event Horizon Telescope shared an image of M87*, a supermassive black hole 55 million light-years away
If you replaced the Sun with a black hole of the same mass, nothing would happen but, it would be a lot colder, and the planets would stay in the same orbits
They are not wormholes (or Einstein-Rosen bridges), providing shortcuts between different points in space, once you’re in a black hole, you can’t leave
Stellar-mass black holes can be created when two neutron stars merge, two black holes can merge to make a larger one