Gravitational wave observations are set to expand the frontiers of our knowledge of the cosmos. But there was a time when physicists had doubted their existence, until the maverick physicist Richard Feynman settled the debate with an ingenious thought experiment.
Gravitational waves are ripples in the gravitational field, just as light waves are ripples in the electromagnetic field. They interact with matter very weakly, making them both famously hard to detect and invaluable sources of information about the universe. Gravitational waves produced billions of years ago are virtually undistorted when they reach us, giving us perfect snapshots of the cataclysmic events that created them. We will peer much further and deeper into the cosmic past when we start ‘seeing’ the universe in gravitational waves.
