There are two sides to the work of Emeritus Professor Vaughan Pratt: the pioneering mathematical theorist and thought-leader and the problem solver tackling everything from self-driving cars to climate change.
Talk to anyone with even a passing knowledge of the evolution of computer systems and they will be aware of key concepts that Professor Pratt has been instrumental in developing, and carry his name: Pratt certificates of primality, the Pratt parser and the Knuth-Morris-Pratt algorithm that substantially streamlined the search for patterns in computer data.
Professor Pratt is also well known for building what was the world's smallest webserver back in 1999, which fit into a matchbox.
His remarkable work is being recognised in this year's prestigious University of Sydney Alumni Awards, where he will be awarded the Alumni Award for Innovation and Entrepreneurship. The award recognises Professor Pratt's role as a forward-thinker leader in his field and celebrates his visionary thought leadership.
Professor Pratt's fascination with science started early. By the age of 13 he was building radios and oscilloscopes with parts from army surplus stores. At 15 he moved onto theoretical physics, which led, eight years later, to his graduation from the University of Sydney with double honours in pure mathematics and physics. It was in the Physics Department that he discovered the emerging subject of computing, which would become a major part of his life's work.
"I found computing so extraordinarily different from the other physics departments that I fell in love with the subject," Professor Pratt said.
"I designed, built and demonstrated a computer that could play 'noughts and crosses' capable of only winning or drawing, although at the time I knew nothing about how real computers worked or how to program them."
In 1976 he invented Dynamic Logic, a method of reasoning about computer programs. The richness of this idea has seen it used in linguistics and philosophy. It has had a recent resurgence in the design of high-speed digital electronics.
In the early 1980s, when computer technology was rapidly evolving from a corporate and government tool into a device almost every home would eventually have, Professor Pratt helped to found one of the most influential computer companies, Sun Microsystems. In 1980 he became the unofficial faculty leader of the highly influential Sun workstation project, developing a modular computer system that gave rise to various commercial products.
In 2006 he was a member of the Stanford team that created Stanley, a self-driving car that won the DARPA high-speed desert driving competition.
Professor Pratt traces his current work on climate change and debunking the fallacies of climate-change denialism back to his university days. In the 1960s, he was taught about the greenhouse effect and he was unhappy to see so much of that information later ignored or misrepresented in the media.
"He is an outstanding computer scientist, innovator and entrepreneur who has had a wide impact on the world through his work. He has achieved the remarkable combination of outstanding academic achievement, with research that has had wide use and huge impact in the world, and commercial success. This award recognises and celebrates these achievements," Kay said.