The Thunder of Gravity in the Cosmos

In 1916, Albert Einstein predicted the existence of gravitational waves—vibrations in spacetime that travel at the speed of light and are produced by the most cataclysmic events in the universe, such as the collision of black holes. Over the past 45 years, scientists have been developing ever-more-sensitive detectors, which are now capable of measuring these distortions from hundreds of millions of light years away. On September 14th, two of those detectors—as part of the Laser Interferometer Gravitational-wave Observatory, or LIGO—picked up the gravitational vibrations of a pair of massive black holes from a billion years ago.

On Wednesday, March 9, at 8 p.m. in Beckman Auditorium, Caltech professor of physics Rana Adhikari will describe how our understanding of the quantum physics of the very, very small has allowed us to explore the gravitational physics of the very, very large. Admission is free.

What do you do?

I am an experimental physicist. My overarching obsession is to use experiments to reveal the true nature of the universe.

We have been learning about the universe through precision experiments in the laboratory and by pushing the limits of astronomical instruments for many years. The recent discovery of gravitational waves from a binary black hole merger allows us to observe the warping of spacetime. This is a chance for us to use quantum physics to extend our knowledge of Einsteinian gravity.

Why is this important?

Our knowledge of how the universe really works comes to us when we as a people make a bold step by measuring something about nature much better than ever before. The upgraded LIGO detectors have radically expanded our view of the universe. For the first time, humanity is able to receive signals from across the universe made entirely by gravity. The dark side of the universe is being revealed for the first time.

How did you get into this line of work?

I've had great teachers and mentors! Doing laboratory work in physics and chemistry has always been the most fun thing to do and I was amazed that it is possible to do that for a living. Where else is 'unlocking the secrets of the universe' part of the job description?