This year sees the retirement of Dr. E. J. (John) Parkes. His Final Honours Waves course is running one more time, and he is now an Honorary Research Fellow — which means that we will be seeing more of him, for he is as passionate about research as ever, saying to *DoF* that it is ridiculous to assume that just because of retirement an area that interested one for close to 40 years would suddenly stop being exciting. Dr. Parkes will be long remembered by students for his meticulous and crystal-clear course materials, and not only by students: many of his fellow academics use and reuse his lecture notes, examples and exercises. In addition, he has been a devoted and effective advocate of disabled students’ rights.

No description of John can hope to be complete without mentioning his love of music. He is a trumpet player and jazz connoisseur. He is proud of co-founding the Strathclyde University Big Band in 1978, since when he has co-organized it and played in it. He intends to continue with this activity.

Scientifically, much of Dr. Parkes’ work has been on nonlinear evolution equations and, in particular, integrable systems: these are PDEs, such as the world-famous Korteweg–de Vries equation, that have an infinite number of conserved quantities and exhibit a variety of patterns, of which perhaps the best known are solitons and multi-solitons. Solitons are travelling waves that can collide with each other without any change of shape, like the proverbial ships that pass in the night (but hopefully do not collide). He is interested in exact solutions, which abound in integrable systems, and has developed efficient methods for finding such solutions and examining their properties. Some of his papers are citations classics and he has an enviably high *h*-factor of 19. For comparison, mathematics papers have on average one citation each; one of Dr. Parkes’, with Dr. Brian Duffy, has over 437 citations according to the Web of Knowledge database! (If you want to know more about citations, including *h*– and other factors, see the International Mathematical Union report on the subject.)

Dr. Parkes kindly answered some of our questions.

**Q**: Which scientists do you admire?

**EJP**: Newton, Einstein, Dirac, and of the more modern ones, Martin Kruskal and Roger Penrose. Their work has the qualities I like most in mathematics: beauty, elegance, and economy. Dirac and Einstein were captivated by the belief that the fundamental equations of physics must be beautiful; Penrose is well-known for believing that a beautiful mathematical idea has a much greater chance of being correct than an ugly one. These notions have strengthened my belief in an omnipotent Creator and have also led me to be a mathematical Platonist: that is, I believe that mathematical concepts exist prior to our knowledge of their existence, so that they are discovered rather than invented.

**Q**: What would your message be to today’s Strathclyde undergraduates?

**EJP**: I wish them to learn in the spirit of discovery, to revel in the beauty of concepts, results, patterns and connections.

**Q**: Why do so many integrable systems have exact solutions?

**EJP**: I do not think anyone knows the answer to that, but the same equations appear again and again in different contexts, which again is elegant and economical; and somehow it makes sense that such ubiquitous equations should have solutions that one can write down in closed form and examine.

**Q**: What is your favourite jazz album?

**EJP**: I will give a clichéd answer: Miles Davis’ *Kind of Blue*. It appeared in 1959, when I was just starting to be interested in jazz, and so by chance it was one of the first albums I bought. I have been living with this album for more than fifty years. Miles Davis’ trumpet solos on *Kind of Blue* have the perennial beauty and elegance of the best of work in science, and seem to me as fresh and wonderful now as when I heard them for the first time.

Please join *DoF* in wishing John a healthy, productive, and very musical retirement!