Remembering Erwin Hahn 1921 - 2016

Thursday, September 22, 2016

Erwin Hahn, Professor Emeritus of Physics and dedicated educator for more than 70 years, passed away on Tuesday, September 20, 2016. He was 95.

Born in Sharon, Pennsylvania on June 9, 1921, Erwin grew up in Sewickley, being the seventh child of Hungarian/German Jewish immigrants. Hahn received his BS in Chemistry in 1943 from Juniata College and afterwards completed a year of graduate studies in Physics at Purdue University. He continued his studies in Physics at University of Illinois, earning his MS in 1947 and his PhD in 1949.

Prof. Hahn had several interesting possibilities for a career, among them the US Navy, movies, and music. Luckily he decided a career in science in the magnetic resonance and optics area. Prof. Hahn created pulsed NMR sequences with which he discovered the spin echo and the first recording of nuclear free induction decay due to free precession, all of which are of monumental significance to many areas of science. The occurrence of echoes and other time reversal phenomena has important implications in the statistical physics of processes which appear to approach equilibrium, and were the first manifestation of the Loschmidt-Boltzmann Paradox. The prominent use of spin echoes and gradient echoes in Magnetic Resonance Imaging (MRI) is one of the most significant developments in medical diagnostics history.

Prof. Hahn also obtained the first nuclear quadrupole resonance echoes in solids and co-authored a definitive and widely quoted text on nuclear quadrupole resonance spectroscopy. In the area of laser physics, Hahn and co-workers predicted and demonstrated ‘‘self-induced transparency,’’ in which coherent optical pulses of particular shapes and areas propagate unattended through an otherwise resonantly absorbing medium, a type of an optical soliton.

Alexander Pines, Professor of Chemistry at UC Berkeley said, "The contributions of my mentor and dear friend Erwin to science are phenomenal. He did so many creative and beautiful things, a fraction of any one of which could serve each of us for a lifetime. The Hahn Echo changed the very foundations of spectroscopy and diagnostic imaging. We have lost a giant and our world will never be the same." (see this link for more information:

David Feinberg, Professor of Neuroscience at UC Berkeley and president of Advanced MRI Technologies said, “The transformative changes made by Erwin Hahn to NMR instrumentation, his discovery of spin echo, gradient echo refocusing, diffusion and velocity phase encoding are the foundation of modern day MRI. The world has lost a genius physicist.”

Prof. Hahn joined the Department of Physics at UC Berkeley as an Assistant Professor in 1955, becoming a full professor in 1961 and then an emeritus in 1991. From 1982-1983, he was the Chairman of a special ad hoc committee to improve the Physics preliminary examination. From 1985 to 1986, he was a Research Professor of the Miller Institute for Basic Research at UC Berkeley. In 1991, he received the Berkeley Citation for his dedication to the department and the University, as well as his contributions to magnetic resonance and optics. Professor Hahn received the 2016 Gold Medal from the International Society for Magnetic Resonance in Medicine (ISMRM) in early May. The award, ISMRM's highest honor, was given to Professor Hahn for his creation of pulsed magnetic resonance and processes of signal refocusing which are essential to, and the foundation of, modern-day MRI and magnetic resonance in general. Beyond Hahn’s famous published works, he has always been a brilliant, provocative, and entertaining lecturer, raconteur, and teacher.

The support which Erwin received from his spouses during his two long marriages was incalculable. He was married twice, to Marian Ethel Failing in 1944 and, after her death in 1978, to Natalie Woodford Hodgson in 1980. Erwin Hahn is survived by his widow Natalie Hahn, his children David, Deborah and Katherine, his stepchildren Welles and Elisabeth, his grandchildren Andrew and Christopher Hahn and Cecilia Caruso, and his great-grandchildren Owen, Hudson and Ethan Hahn.

A memorial for Erwin Hahn will be held on Thursday, December 1, 2016 at the Faculty Club on the UC Berkeley campus. Guests may begin gathering at 4:00 p.m. in the lobby area and Howard Room where there will be displays of photographs and memorabilia pertaining to Erwin's personal and professional life. The presentations will begin at 5:00 p.m. in the Great Hall.

Donations may be made in honor of Professor Hahn to the Hahn Graduate Fellowship in Physics.


Important Links

View photos of Professor Erwin Hahn

Visit the memories page, and share your memories of Professor Erwin Hahn

View Professor Hahn's last lecture, July 20 2015

Watch a video of Professor Hahn's speach at the 2013 ICOLS Conference

Read "Erwin@90", a tribute to Erwin L. Hahn on the occasion of his 90th birthday, co-authored by Dimitry Budker and Jean-Claude Diels

Read "The Transformative Genious of Erwin Hahn", and interview by David A. Feinberg