Image: "The Fixer" from "The Future is Now," by Josan Gonzales -

Computers, algorithms, and artificial intelligence have touched every aspect of our society, from science, to communication, to the justice system. But despite their enormous power, computers have fundamental limits — problems that no program can solve, and thorny issues in fairness and human rights. During this 26th year of the popular Ulam Lecture Series, SFI Professor Cristopher Moore looks at two sides of computation — the mathematical structures that make problems easy or hard, and the growing debate about fairness in algorithmic predictions.

These two lectures are self-contained, and can be enjoyed together or separately.

Lecture I, Monday, September 24, 7:30 p.m.— Easy, Hard, and Impossible Problems: The Limits of Computation

Every day we ask computers to solve problems for us — to find the fastest route across town, the shape a protein folds into, or a proof for an unsolved mathematical question. For all these problems, the space of possible solutions is vast. Why is it that for some problems, we can quickly zoom in on the solution, while for others it’s like looking for a needle in a haystack? What is it about the structure of a problem that makes it easy, or hard, or even impossible to solve? Moore will draw analogies between computation and evolution, and take us from simple puzzles to the heights of universal computation, Turing’s halting problem, and the nature of mathematical truth and creativity.

Lecture II, Tuesday, September 25, 7:30 p.m.— Data, Algorithms, Justice, and Fairness

Algorithms are being used today to predict whether defendants will show up for court, whether they should be released on bail, and whether they will be good citizens if they are given parole. How accurate are these algorithms? What data are they based on? And how fair are they to different groups of people? Over the past few years, a controversy has erupted over the issue of algorithmic fairness — whether these algorithms treat some groups of people differently than others. In this second lecture, Moore will lead us through how these algorithms work, what data they are based on, and how “fairness” and “accuracy” are slippery terms. Can decisions made by AIs be explained to the humans affected by them? What recourse do we have if we disagree with them? Will algorithms help us move forward to a better future, or will they encode and enshrine the biases of the past?


Cristopher Moore is a Professor at the Santa Fe Institute where he works on problems at the interface of mathematics, computer science, and physics. The co-author of The Nature of Computation (Oxford University Press), a classic textbook in modern mathematics, Moore has also written more than 150 scientific papers on topics ranging from quantum computing to the theory of social networks.

Moore is an elected fellow of the American Association for the Advancement of Science, the American Physical Society, and the American Mathematical Society.

SFI's Stanislaw Ulam Memorial Lecture Series honors the memory of the late theoretical mathematician Stanislaw Ulam.

Read the Q&A with Julia Goldberg and Cris Moore in The Santa Fe Reporter (September 19, 2018)

SFI’s 2018 Community Lecture Series is supported by Thornburg Investment Management, with additional support provided by The Lensic Performing Arts Center and the Enterprise Holdings Foundation.

See all upcoming SFI events