Renowned computer scientist and mathematician Gregory Chaitin spoke to a nearly full house in the Paul Martin Centre yesterday afternoon.
This was the third stop on a six-stop tour of Ontario, which saw him at Western on Friday and the Perimeter Institute on Monday.
He will speak again today at the Institute for Quantum Computing before leaving Waterloo for his final two stops in Toronto.
Chaitin is professor emeritus at IBMโs Thomas J. Watson Research Center and is most notable for his discovery of omega โ a real number which can be defined but not computed.
Chaitinโs work is well-known in a number of disciplines, with implications in the fields of mathematics, computer science, philosophy, physics and biology.
If his credentials arenโt enough indication of his status as a great thinker, his presence in the room confirmed it.
Chaitin pulled off the disheveled genius look with ease, sporting mismatched clothing and a noticeable lack of footwear.
He delivered the difficult material as accessibly as he could, but at times it seemed as if he forgot other people were in the room.
Many times the audience waited curiously as he paused to look up at the ceiling, lost in thought, before deciding on an amusing metaphor for whatever he was trying to explain.
His absent-minded persona suitably matched the subject matter that he grapples with.
Yesterdayโs talk, entitled โHow Real Are Real Numbers?โ, did not shy away from the abstract.
Chaitin advanced the idea that math is full of things that we cannot know and cannot calculate.
The existence of omega, Chaitin argued, proves the existence of random truths in mathematics โ truths that have no reason for existing.
Chaitin admitted that for those focused on the practical world, his work on omega is of little value, calling pure math a โplay worldโ that does not deal with messy reality.
Nonetheless, he argued that the basic idea that even in math โGod plays diceโ might force us to take a step back and question what we know, and can know, in any discipline.