"I don't feel old," the late great American comic Bob Hope, who lived to be a hundred, once cracked. "I don't feel anything until noon. Then it's time for my nap."

Like Hope, the clan of sixty-somethings toasted at the university's annual retirement dinner two weeks ago bantered heartily about old age, creaky joints and the body's demands for regular lie-downs. But for many, rest is the furthest thing from their minds.

There are those, of course, who are severing their formal ties with UCT. But for the likes of Oliver Young and Nicolaas Klassen that just means they now have the time to dedicate themselves to their other loves. Young, who wraps up 34 years at the university, including 30 with the Department of Mathematics and Applied Mathematics, is breezing his way through a series of soccer coaching qualifications.

Klassen, a handyman for most of his 38 years at UCT, is keeping his hand in by fixing all the things around the house he couldn't get to before. He's also throwing himself into the charity work he's long been doing with his church.

Some academics are also moving, even if it's just office. In the science faculty, three world-class researchers will remain affiliated to the university - Distinguished Professors George Ellis (mathematics and applied mathematics) and Brian Warner (astronomy), and Professor Luigi Nassimbeni (chemistry).

Colleague Associate Professor Peter Dunsby said he first met Ellis at the University of Colorado at Boulder in 1989. "It was his absolute focus on the present and achieving new research goals that drew me to work with him, first as a student at Queen Mary College, London, and then later as a colleague at UCT.

"George's approach to science, and indeed much of his other work, appears to be driven by three key principles. Firstly, forget the current trends, look at the body of evidence and find the simplest solution that fits. He is clearly a devoted follower of Occam's razor, despite his occasional unshaven appearance.

"His versatility has also resulted in him being lovingly referred to as the 'distinguished professor of very applied mathematics' by many of his colleagues and friends – I suppose one thing will change. His title will be a little bit longer. George will no longer be 'the distinguished professor of very applied mathematics', he will be the 'emeritus distinguished professor of very applied mathematics'."

Associate Professor Susan Bourne of the Department of Chemistry said one needed a map to track Nassimbeni's students, many of whom had established themselves at high levels in industry and academia: Mike Taylor, head of explosives research at AECI; Anita Coetzee, an application scientist with the instrument manufacturer Bruker Nonius; and Janet Scott, deputy director of the Centre for Green Chemistry at Monash University. Two of the chemistry department's UCT Fellows, Professors Allen Rodgers and Mino Caira, did their PhDs under Nassimbeni.

"Luigi's colleagues have always wondered why he has such a high number of women among his grad students. It's true that crystallography has historically attracted a relatively high number of women, but I think Luigi deserves some credit. Without doubt – Luigi values the different perspectives and voices that women bring to the research effort."

Professor Tony Fairall of the Department of Astronomy described Warner as "one of the most distinguished scientists to have made his home on South African soil". "He has remarkable eyesight. With only a mild telescopic aid he has been able to monitor the most minute of brightness fluctuations of cataclysmic variable stars. His musical ability has lead him to listen to their tones and overtones, and thus to decipher the nature of these extreme celestial objects.

"What a pity then, after a mere 32 years at UCT, and having sent so many disciples into the world, that he has to retire. But that is not a problem, for the heartbeat of such superstars, overtones and all, will continue to beat. And all he needs to stay at UCT is an office down the hallway."

For Associate Professor Geoffrey Haresnape, who is staying on as a research associate in his beloved Department of English Language and Literature, growing old lends itself to greater reflection on mortality, according to HOD Professor Stephen Watson. In testimony Watson suggested that, at the retirees' dinner, vice-chancellor Professor Njabulo Ndebele read from Confessions of a Veteran Bird Watcher. In this poem, penned by Haresnape, an aged twitcher spies on a voluptuous nymph gambolling in the water with her boyfriend. "Wrinkled and old foot,/I watch from this bench./You've started up/Unpensionable pulses in my head./Rejoicing in your juice,/I realise it's not nice to be dead."

Bob Hope couldn't have said it better.