Nergis Mavalvala
From a Karachi classroom to the team that first heard two black holes collide
Nergis Mavalvala was born in Lahore in 1968 and grew up in Karachi, in a Parsi family that thought girls should study whatever they wanted. She liked taking things apart and fixing bicycles. A teacher lent her books, and at 18 she went to Wellesley College in Massachusetts with a scholarship, arriving in a country where she knew no one.
At MIT she did her doctorate under Rainer Weiss, who had been trying since the 1970s to build an instrument sensitive enough to detect gravitational waves, the ripples in space itself that Einstein had predicted and doubted could ever be observed. The instrument, LIGO, had to measure changes in length far smaller than a proton over a distance of four kilometres. Many physicists considered it a waste of money. Mavalvala's work was on the parts that make such precision possible: keeping mirrors still, and finding ways around the noise of the laser light itself.
For years the detectors ran and saw nothing. In September 2015, a few days after an upgraded LIGO was switched on, both instruments recorded the same signal: the last fraction of a second of two black holes merging more than a billion years ago. The announcement in 2016 was one of the great moments in modern physics.
She became the first woman to lead MIT's School of Science in 2020. She is openly gay and has spoken about how few people from her background she saw in physics when she started.