For more than a century, Einstein's theory of general relativity has shaped our understanding of gravity, space and time. But is it the complete picture? Could gravitational waves from colliding black holes reveal something his famous equations cannot explain?

When two black holes collide, something extraordinary happens. The newly formed black hole begins to ring, almost like a bell. But instead of sound, it sends gravitational waves through spacetime, carrying clues about its mass, spin – and perhaps the limits of Einstein's theory.

In this episode of IDA Space Talks, we welcome Lorena Magaña Zertuche from the Centre of Gravity at the Niels Bohr Institute, where she studies gravitational waves and black hole mergers.

We explore how scientists detect incredibly tiny changes in spacetime, why supercomputers are needed to solve Einstein's equations, and how black holes can even be kicked out of their own galaxies.

We also discover gravitational wave memory – the remarkable idea that a passing gravitational wave can leave a permanent fingerprint on the universe.

So far, Einstein's theory has passed every test. But Lorena and her colleagues are searching for cracks.

What if black holes are trying to tell us something Einstein never knew?