The CSUSM Department of Mathematics 2023 Reid Lecture hosts Professor Ami Radunskaya of Pomona College. She will deliver a talk titled "Uncertainty: The Mathematics of What We Don't Know." Over the past few centuries, the theory of probability has been developed to quantify possibilities and to help human beings make decisions with incomplete knowledge. More recently, this theory has been refined to include predictions based on chaotic dynamical systems, as well as providing a measure of our belief in future events, based on observed data.