What is a Black Hole? | Explained in Under 10 Minutes

Nothing can escape them. Not matter, not light, not information. And yet we know they exist — because we can see what happens to everything around them.Emma opens with the basic physics: what a black hole actually is, why Einstein's equations predicted them decades before anyone believed they were real, and what the event horizon — the point of no return — means in practice. Neev takes on the strange truth about time near a black hole: general relativity says a clock at the event horizon would appear frozen to an outside observer, while to the person falling in, nothing unusual happens at all.Lewis brings in the landmark image — the 2019 photograph of the black hole at the centre of galaxy M87, 6.5 billion times the mass of our sun, captured by a telescope the size of the Earth. And then there's Sagittarius A*, the black hole at the centre of our own Milky Way, lurking 26,000 light-years away.Emma closes with the question that keeps physicists awake: what actually happens to information that falls in? Stephen Hawking spent the last decades of his life on that problem. We still don't have the answer.If you enjoyed this episode, please subscribe — and send your topic suggestions to [email protected]. We read every one.