I'm John Liebman, Jo's brother in law, and I am honored to have this opportunity to share with you memories of a Leon that many of you never had the chance to know.

It's hard to imagine two more different individuals than Leon and me. When we first met, I was a newly-minted lawyer just three years out of military service, and Leon was an established professor of science with prodigious musical talent teaching at a leading university. We both had become members of a remarkable family by marriage and went on to develop a close relationship marked by many happy gatherings and other interactions, despite the fact that the Knopoffs were often away on sabbaticals and we lived in the East for five years. Looking back, I think that the core of our friendship was founded on our time together hiking in the Sierra Nevada.

Our first foray together into the Sierras took place in 1960 or 1961. The four of us – Jo, Leon, Marilyn and I – climbed from South Lake to Long Lake, and dined that evening on freeze-dried or dehydrated meat balls, rice, fresh trout and (God help me) hot watermelon Jello. That was to be the first of many hikes and, as it turned out, an integral part of a relationship that endured for five decades. I am so grateful that Leon and I were able to improve our menus on those occasions. Through those many years, I learned much more from Leon than he learned from me – how to reconstitute those awful dehydrated meatballs, how to pace myself at high elevations (the "Sierra step"), and what I was actually seeing as we worked our way up and down steep mountain trails: hanging lakes, geological formations of all sorts, and telltale signs of earthquake activity. It was a postgraduate education in natural history that you can't get in a classroom. That first hike was followed by many others that we enjoyed with Jo, our children and their friends and of which I have memories that will stay with me for the rest of my life. There were many bear stories – there always are – but we'll skip those in the interest of time.

Our families also shared a home at Lake Arrowhead for twenty years, and produced mighty feasts at Thanksgiving, Christmas, the Fourth of July, and Labor Day – and on other occasions as well. Marilyn and I brought up to the lake house a rickety upright piano that refused to stay in tune, but Leon was unfazed and coaxed wonderful music from that poor relic on many evenings. Those years became part of the foundation of the strong friendships among our children that will last for their entire lives. Our home at Arrowhead was a gathering place for so many of our children's friends as well – some of whom found love and peace among us where they had none other. I did manage to get Leon to try mountain biking at Arrowhead – just once – and I'm not sure that he ever forgave me for that. But we hiked all over hell and gone in those mountains, too – San Jacinto, San Gorgonio, and dozens of local trails. Leon knew most of them by heart and his joy in being there was contagious.

While Leon and I were as different as night and day in many ways, we found plenty to share and enjoy together. I treasure the memory of our friendship. Shalom, dear Leon.