The Milky Way's black hole may be spinning at top speed

Our galaxy's centre may contain an exceptional cosmic spinning top – a black hole that seems to be spinning almost as fast as possible. Michael Janssen at Radboud University in the Netherlands and his colleagues were studying the black hole at the Milky Way's centre, Sagittarius A*, using the data gathered by a network of observatories collectively known as the Event Horizon Telescope (EHT). To deal with the complexity of the data, they turned to artificial intelligence. First, they used well-known mathematical models to simulate about a million black holes – which was itself a computational feat that required millions of hours of supercomputer time. Then they used these simulations to train a type of AI called a neural network, enabling it to determine a black hole's traits based on observational data. Finally, they fed the AI the data about Sagittarius A* that EHT had collected throughout 2017.