A. Riotto

The universe began with the Big Bang and subsequent inflation — a rapid expansion. Alan Guth suggested that in some regions this growth never stopped. They remained ‘underbaked’ pockets of eternal expansion forever.

Two non-spinning black holes at the moment of merger give birth to gravitational waves — ripples in the very fabric of spacetime, captured by instruments developed with the help of Kip Thorne.

A light beam approaches a black hole not head-on, but at a glancing angle. If the angle is just right, the light neither falls in nor escapes: it starts looping around, like a figure skater circling the rim of a funnel. This narrow track is the photon ring. It acts like a lens, repeatedly reflecting the image of everything that falls into the hole.

Drop a pebble into a pond, and ripples spread across the water. Something similar happens when a black hole merges with another: it emits gravitational waves that resemble the fading ring of a bell.