I'm really shocked and saddened to hear of Andy's death. He and I had not been in direct contact for several years, although every year I thought "must meet again, this year", but we'd stayed connected on LinkedIn (which is how I learned of his passing) and there I had watched with interest as every now and again his job-title changed to something more senior, as he deservedly took on ever more responsibility for his colleagues and his students. It always made me smile to see him taking another upward step, because I remember our first meeting so clearly, because he simply fizzed. 

One day in late 2011 I got an email from Andy, totally out of the blue because he and I had never met or interacted before. Somehow he'd decided that I would be useful to visit Denbigh to give a talk to pupils from his school, and he explained he was allowing anyone else in the local community who was interested to come along too. My invite was to be the next one of a series of external speakers, scientists from various fields. His letter mentioned several previous speakers who I knew, and although it was quite a bit of a drive to get there something about the engaging and enthusiastic way he'd phrased the letter made me want to say yes so I accepted, and in Feb 2012 I drove over from Bristol to visit Denbigh School and to meet Andy. 

It couldn't have been a warmer welcome from Andy: he had such enthusiasm and clearly put so much thought and effort into arranging that series of science lectures from external speakers. He'd attracted an interesting audience for my talk who asked some great questions, and both before and after my talk Andy just seemed to bubble and fizz and spark with passion for what he was doing. I remember, as I drove away, thinking how much I wish that there had been a teacher like Andy at my school when I was young; I remember thinking that the Denbigh community was very lucky to have someone like him serving them; and I remember thinking that he would go far. 

He invited me back several times, but other commitments too often got in the way. I always wanted to come back and do it again. Sometimes you don't need to know someone for long to get a sense of who they are. I'm really sorry to learn that his time here has ended; my condolences to his family and friends and everyone else who will miss him. 

Dave Cliff, University of Bristol.