Address at "Ripples in Spacetime: Our New Window on the Universe"

February 23, 2016
Thomas F. Rosenbaum

In 1752, Benjamin Franklin wrote to Peter Collinson of the Royal Society and described his famous experiment in Letter XI of Observations on Electricity:

"As soon as any of the thunder clouds come over the kite, the pointed wire will draw the electric fire from them, and the kite, with all the twine, will be electrified, and the loose filaments of the twine will stand out every way, and be attracted by an approaching finger. And when the rain has wet the kite and twine, so that it can conduct the electric fire freely, you will find it stream out plentifully from the key on the approach of your knuckle. At this key the phial may be charged; and from electric fire thus obtained, spirits may be kindled, and all the other electric experiments may be performed…"

The "sameness of the electric matter with that of lightening," as Franklin would put it, is old hat to us today, as is the familiar image of a key on a kite in a thunderstorm. Yet, 260 years ago, it was a beautiful and unexpected demonstration of the link between heavenly phenomena and terrestrial experience, made real through meticulous experimentation and rich and detailed observations.  It also came with the satisfying bonus that the trapped fire in the Leiden jar could be used as a source for further electric research.

On September 14, 2015 LIGO recorded the whisper of two black holes coalescing far across the universe and back in time, connecting the heavens and the earth for our own day. It was a glorious statement about scientific persistence and discovery, and a wonderful example of how the right mix of people and technology can change the world. The LIGO effort captures the essence of our dreams for Caltech. We want to be the place that takes risks when the scientific and technological payoffs can be large, and have the resolve and ingenuity to succeed. The signature of the gravitational waves picked up by LIGO is an image as redolent for the 21st century as the kite and key flying in a thunderstorm was for the 18th.

A good deal of the news coverage focused on LIGO proving Einstein right. There is a pleasing aspect to the confluence of theory and experiment, 1915 and 2015, but this misses the most profound aspect of the discovery.  We have opened a new window on the universe and we are positioned for further surprises emanating from the cosmos.

In the aphoristic venue for which Franklin also was famous, he instructed that "Energy and persistence conquer all things." We celebrate this evening the thousands of researchers who held on to an extraordinary vision over four decades until it could be realized. We hear the universe in a different key because of their energy and persistence.