Stephen Hawking gets it right again

About this episode

Gravitational waves show two black holes merge just how Hawking predicted. Plus, a space mission without a target. And a Space probe without a confirmed budget. In January 2025 the LIGO gravitational wave observatories witnessed two distant black holes spinning into each other. In the ten years of LIGO’s operations, that’s not a first. But the instruments have been improved to such an extent that this time some very important predictions of General Relativity and out understanding of black holes could be tested. As Birmingham University’s Alberto Vecchio says, the elegant simplicity of the mathematics of black holes has passed a test, in particular Stephen Hawking’s prediction that the surface area of merging black holes can only be increased. Space craft have met comets before. But because spaceflight takes so long to plan and fund, we’ve only sent them to comets with human-lifetime orbital periods so far, because we know when they’re arriving. ESA wants to meet one we’ve never seen before, one that has never or seldom been in close to the sun, and never been barbecued and seared by the radiation. Colin Snodgrass of the University of Edinburgh explains the plan to launch and par