“For all the history, we have looked into the sky and seen starlight. That is really how our love affair with the universe began,” says Nergis Mavalvala, an astrophysicist at MIT who has dedicated her entire career to gravitational waves, phenomena that trace its conception to Albert Einstein’s revolutionary General Relativity equations. Mavalvala was speaking on The Space Show, to Becky Ferraria, a VICE Motherboard reporter.
Further in the program, Mavalvala explains what gravitational waves are and why they are so important to us. She also dives into the nostalgia of the day when her team made the discovery of the G-waves public. Gravitational waves are ripples in spacetime that appeared in Einstein’s equations of general relativity. General relativity is Einstein’s revolutionary theory of gravitation that explains the motion of objects using a geometric understanding of space-time, a concept that unifies time with space. It implies that time, just as space, is relative and not absolute.
In 1916, when Einstein introduced the theory of general relativity, on which most of modern physics is essentially founded, gravitational waves appeared in his equations. He discarded them saying that these waves would be “vanishingly small” and nearly impossible to detect. 100 years later, scientists at Laser Interferometry Gravitational-Wave Observatory detected the first gravitational waves in 2016.
Mavalvala was one of the members of the core LIGO team that made the discovery. According to Mavalavala, we are being hit and our bodies are fluctuating with these gravitational waves all the time, but because we are very subtle, we are not able to perceive them. When a gravitational wave passes through us, it changes or ripples the distances between objects. These changes are at the scale of 10-18 of a metre. LIGO, using laser beams, is able to detect these subtle changes in distances, hence, it detect gravitational waves, which are coming from the acceleration of massive bodies such as neutron stars and black holes.
Talking about why these waves are important to us, Mavalvala has a glimmer of fascination in her eyes. She explains that these waves tell us how nature has assembled our universe and where is our place in it.