Today marks a new era in cosmology, astronomy, and astrophysics. The main page of the Einstein Papers Project website reports, “Gravitational waves do exist, as has been announced today with great joy by the scientists of the LIGO collaboration, after more than two decades of intensive experimental work.”

The cosmic breakthrough, which proves Einstein’s 100 year old prediction, has resulted in a tremendous response across the scientific community and social media. Scientific websites everywhere are already debating the meaning of the discovery, the #EinsteinWasRight hashtag has been bantered about on Twitter; You Tube featured a live announcement with over 80,000 people tuning in to watch (check it out at 27 minutes).

Princeton University Press authors **Jeremiah Ostriker** and **Kip Thorne** had a bet about gravitational wave detection in the 80s. Today when we contacted him, Ostriker, author of Heart of Darkness, was ebullient:

“The LIGO announcement today and the accompanying papers are totally persuasive. We all believed that Einstein had to be right in predicting gravitational waves, but to see them, so clean and so clear is marvelous. Two independent instruments saw the same signal from the same event, and it was just what had been predicted for the in-spiral and merger of two massive black holes.

A quarter of a century ago I had a bet with Kip Thorne that we would not see gravitational waves before the year 2000 – and I won that bet and a case of wine. But I did not doubt that, when the sensitivity of the instruments improved enough, gravitational waves would be found. Now the skill and perseverance of the experimentalists and the support of NSF has paid off.

Hats off to all!!!”

But was Einstein always a believer in gravitational waves? **Daniel Kennefick**, co-author of The Einstein Encyclopedia says no:

“One hundred years ago in February 1916, Einstein mentioned gravitational waves for the first time in writing. Ironically it was to say that they did not exist. He said this in a letter to his colleague Karl Schwarzschild, who had just discovered the solution to Einstein’s equations which we now know describe black holes. Today brings a major confirmation of the existence both of gravitational waves and black holes. Yet Einstein was repeatedly skeptical about whether either of these ideas were really predictions of his theory. In the case of gravitational waves he soon changed his mind in 1916 and by 1918 had presented the first theory of these waves which still underpins our understanding of how the LIGO detectors work. But in 1936 he changed his mind again, submitting a paper to the Physical Review called “Do Gravitational Waves Exist?” in which he answered his own question in the negative. The editor of the journal responded by sending Einstein a critical referee’s report and Einstein angrily withdrew the paper and resubmitted it elsewhere. But by early the next year he had changed his mind again, completely revising the paper to present one of the first exact solutions for gravitational waves in his theory. So his relationship with gravitational waves was very far from the image of the cocksure, self-confident theorist which dominates so many stories about Einstein. Because of this, he would have been thrilled today, if he were still alive, to have this major confirmation of some of the most esoteric predictions of his theory.”

Here at Princeton University Press where we recently celebrated the 100th anniversary of Einstein’s theory of general relativity, the mood has been celebratory to say the least. If you’d like to read the Einstein Papers volumes that refer to his theory of gravitational waves, check out Document 32 in Volume 6, and Volume 7, which focuses on the theory. Or, kick off your own #EinsteinWasRight celebration by checking out some of our other relevant titles.

*Traveling at the Speed of Thought: Einstein and the Quest for Gravitational Waves
*by Daniel Kennefick

*Relativity: The Special and the General Theory, 100th Anniversary Edition*

by Albert Einstein

*The Meaning of Relativity: Including the Relativistic Theory of the Non-Symmetric Field
*by Albert Einstein

*Einstein Gravity in a Nutshell
*by A. Zee

*The Road to Relativity: The History and Meaning of Einstein’s “The Foundation of General Relativity” Featuring the Original Manuscript of Einstein’s Masterpiece
*by Hanoch Gutfreund & Jürgen Renn.

*The Curious History of Relativity: How Einstein’s Theory of Gravity Was Lost and Found Again
*by Jean Eisenstaedt

** An Einstein Encyclopedia**

by Alice Calaprice, Daniel Kennfick, & Robert Sculmann

*Gravitation and Inertia
*by Ignazio Ciufolini & John Archibald Wheeler

*Einstein’s Jury: The Race to Test Relativity
*by Jeffrey Crelinsten

*What Does a Black Hole Look Like?
*by Charles D. Bailyn

*Dynamics and Evolution of Galactic Nuclei
*by David Merritt

*The Global Nonlinear Stability of the Minkowski Space (PMS-41)
*by Demetrios Christodoulou & Sergiu Klainerman

*Modern Classical Physics: Optics, Fluids, Plasmas, Elasticity, Relativity, and Statistical Physics
*by Kip S. Thorne & Roger D. Blandford

*The Collected Papers of Albert Einstein, Volume 7: The Berling Years: Writings, 1918-1921
*by Albert Einstein