It is my sad duty to report that our colleague Jonathan Borwein, Laureate Professor of Mathematics at the University of Newcastle, Australia, has passed away at the age of 65. He is survived by his wife Judith and three daughters. For details on his funeral and for making donations to a scholarship fund in his name, see the obituary below.

What can one say about Jon’s professional accomplishments? Adjectives such as “profound,” “vast” and “far-ranging” don’t really do justice to his work, the sheer volume of which is astounding: 388 published journal articles, plus another 103 articles in refereed or invited conference proceedings (according to his CV, dated one day before his death). The ISI Web of Knowledge lists 6,593 citations from 351 items; one paper has been cited 666 times. The Google Citation Tracker finds over 22,048 citations.

But volume is not the only remarkable feature of Jon’s work. Another is the amazing span of his work. In an era when academic researchers in general, and mathematicians in particular, focus ever more tightly on a single specialty, Jon ranged far and wide, with significant work in pure mathematics, applied mathematics, optimization theory, computer science, mathematical finance, and, of course, experimental mathematics, in which he has been arguably the world’s premier authority.

Unlike many in the field, Jon tried at every turn to do research that is accessible, and to highlight aspects of his and others’ work that a broad audience (including both researchers and the lay public) could appreciate. This was, in part, behind his long-running interest in Pi, and in the computation and analysis of Pi — this topic, like numerous others he has studied, is one whose wonder and delight can be shared with millions.

This desire to share mathematics and science with the outside world led to his writing numerous articles on mathematics, science and society for the Math Drudge blog, the Conversation and the Huffington Post. He was not required to do this, nor, frankly, is such writing counted for professional prestige; instead he did it to share the facts, discoveries and wonder of modern science with the rest of the world.

Jon was a mentor par excellence, having guided 30 graduate students and 42 post-doctoral scholars. Working with Jon is not easy — he is a demanding colleague (as the present author will attest), but for those willing to apply themselves, the rewards have been great, as they become first-hand partners in ground-breaking work.

There is much, much more that could be mentioned, including his tireless and often thankless service on numerous committees and organizational boards, including Governor at large of the Mathematical Association of America (2004–07), President of the Canadian Mathematical Society (2000–02), Chair of the Canadian National Science Library Advisory Board (2000–2003) and Chair of the Scientific Advisory Committee of the Australian Mathematical Sciences Institute (AMSI).

But Jon was more than a scholar. He was a devoted husband and father. He and Judi have been married for nearly 40 years, and they have three lovely and accomplished daughters. They have endured some incredible hardships, but Jon has made some equally incredible sacrifices on their behalf. Jon has also been devoted to his own father and mother, often collaborating on research work with his father David Borwein (also a well-known mathematician), and following the work of his mother, a scholar in her own right.

I myself am at a loss of what to say at Jon’s passing. What can I say? I have collaborated with Jon for over 31 years, with over 80 papers and five books with Jon as a co-author. Thus my personal debt to Jon is truly enormous. My work will forever be connected with (and certainly subservient to) that of Jon’s. I am humbled beyond measure and grieve deeply at his passing.

Jon’s passing is an incalculable loss to the field of mathematics in general, and to experimental mathematics in particular. Jon is arguably the world’s leading researcher in the field of experimental mathematics, and his loss will be very deeply felt. We will be reading his papers and following his example for decades to come.

#### Jonathan Borwein’s obituary

BORWEIN, Jonathan Michael, August 2, 2016 at age 65. Jon Borwein, Laureate Professor at the University of Newcastle, FRSC, FAAAS, FBAS, FAustMS, FAA, FAMS, FRSNSW passed away suddenly at 12:32 a.m. on August 2 during a stint as Distinguished Scholar in Residence at Western University in London, Ontario.

An innovative and prolific mathematician of international renown, he is survived by his parents, Bessie and David Borwein of London; his adoring wife Judith, three daughters Naomi, Rachel, and Tova; five grandchildren Jakob Joseph, Noah Erasmus, Skye, Zoe and Taj; siblings Sarah and Peter; sister-in-law Jennifer Moore.

The funeral will take place at Logan Funeral Home, 371 Dundas Street, London, Ontario at 1:00 pm on Wednesday August 10, 2016 with a visitation period from noon to 1:00 pm. In lieu of flowers, friends and colleagues may wish to donate to a scholarship fund being set up in Jonathan’s name. For information on how to donate contact Judith.Borwein@gmail.com.