An unusual moment where Mark could not control himself

Usually, it is not difficult to find people disagreeing when someone without reservation is characterized as kind, respectful, thoughtful, calm, and similar favorable traits, but I strongly doubt anybody disagreeing could be found in case of Mark. I was in Zurich all the time Mark was there, and Malcolm describes Mark in the crossfire between the two ”collaborating” research groups very well. Of course, rivalry was not only at the top – there were lieutenants too, and often more intra- than inter-group crossfire, but Mark elegantly manoeuvred his way and nobody had a problem with him.
Mark is sometimes credited for DQF COSY, but that was not his contribution in the highly cited 1983 BBRC paper. In the downtown group we were somewhat ignorant of practical issues, and pure-absorption peakshapes along with phase-sensitive display was not of much relevance over absolute-value display of 2D spectra. We had only thought of MQF COSY for eliminating solvent and other signals plus reduction of dominant diagonal peaks in COSY spectra. On the other hand, in the group up the hill high resolution and pure-absorption cross peaks were gaining interest, but conventional COSY had the problem of large dispersive tails from diagonal peaks interfering with nearby cross peaks. Then Mark being at both places had the insight to see that DQF COSY solved that problem and he thus opened the door and eyes to the value of pure-absorption peakshapes and phase-sensitive spectral display in multidimensional NMR spectroscopy in general. That trend really took off with Mark as the problem solver.
Mark had invited me to be on several of his papers after what I considered only minor contributions, so I felt it was time to return some of that by inviting him to be part of the z filter project. The z filter is easy to understand without much theory, and Mark and I had drafted a manuscript without any equations and given it to Ernst for his perusal. Simplicity is a great thing but if something can be described at a higher theoretical level Ernst likes to do that. Thus, when the draft came back with his revisions it was no surprise that equations had been added, but it was the introduction to them that made Mark crack up. I had never believed I would see Mark laugh as much as he did when he read ”In more scholarly terms, …”. That was just an immensely funny wording to him, and apart from scientific contributions it is the first moment that comes to mind when I think of Mark.
It is great to have known you, Mark.
Ole