I am proudly one of Jon’s 42 postdoctoral students, and I can attest that he was a wonderful mentor. Probably, his best quality as an advisor was his ability to discover and develop the potential of each of his students, while doing whatever was at his hand to promote our professional careers. Unquestionably, Jon left his trademark in all of us. It was impossible to work with him without learning, as his vast knowledge would inexorably force you to expand yours. He was such an excellent communicator that we all ended up trying to mimic him. Even during his more technical talks, he included anecdotes, quotes and cartoons, managing to catch the attention of anyone in the room. His great talk about Pi was without any doubts my favorite.
Jon involved me in one of the most fun projects I ever worked on, and gave me the opportunity of collaborating with his brother Peter and David Bailey. Among other things, we created a huge and beautiful picture of Pi based on its first 100 billion base-4 digits. The picture went viral. I love that he chose this picture as the background image for his webpage.
Besides being an enthusiastic, inspiring and tireless researcher, he was a jovial person who only seemed to perceive the positive aspects in each individual. Perhaps these are the main reasons why we all feel so sorrow about his early departure. We miss you, Jon. [Francisco J. Aragon Artacho, University of Alicante, Spain]