The WashU Physics Department is excited to invite the public to our Saturday Science series, an engaging and interactive set of lectures designed to spark curiosity and explore the wonders of science. Whether you're a science enthusiast or simply looking for a fun and educational activity, these events offer a hands-on way to dive into the world of physics.

Fall 2026

What are the Laws Governing the Evolution of The Law? 
Saturday, October 17 | James Holehouse

The Laws governing society are becoming increasingly complex. Each year tax returns become more difficult to fill out. More forms, more exceptions, more hours spent reading small print. In sports, with every subsequent season more rules are introduced. Each year more time is spent deliberating holding calls, more tactics are developed to expose new laws, and more time is spent with commentators debating the ins-and-outs of increasingly nuanced situations. Many people find this increase in bureaucracy excessive, appealing to the joy of simpler times. However, as society evolves so must how society is regulated—but is bureaucratic growth really necessary? 
In this talk, using case studies from governance, sports, and biology, I will paint a picture of how and why bureaucracies increase in size and complexity as they evolve. This picture attempts to unify descriptions of regulatory architectures across all scales of life, pointing towards a universal Science of Regulation. Using this science, I will then suggest how principles from cell biology could help to better regulate society.

Pulsars, the Lighthouses of the Cosmos
Saturday, October 24 | Alex Chen

Pulsars are rapidly rotating remnants of stars after they reach the end of their lifecycle. They possess some of the strongest magnetic fields known in the universe, and their densities are so high that their cores contain exotic states of matter that we still do not quite understand. I will give an overview on these extreme objects, and explain how we can use their pulsation to understand how the universe works.

How Do Unreliable Cells Build a Reliable Embryo?
Saturday, October 31 | Tony Tsai

Fishing for the Principles of Self-Organization in Development
Have you ever watched a marching band or a drone show? Hundreds of individuals coordinate their movements to create patterns and shapes far larger than themselves. Such performances require intricate planning and remarkably precise execution.
Now imagine making the challenge harder. What if some members of the marching band occasionally lose their way, cannot move properly, or fail to communicate with their neighbors? Could the group still produce the same beautiful pattern every time?
This is the remarkable engineering problem that embryos solve every day. Millions of cells must collectively build tissues with reproducible shapes and patterns, even though individual cells experience noisy signals, move unpredictably, and constantly exchange neighbors. Somehow, remarkably reliable structures emerge from surprisingly unreliable components.
How is such reliability possible?
In this talk, we will explore classic and modern ideas in Developmental Biology about how cells build an embryo. We will introduce classic paradigms in embryo development, and some new insights (including work from my lab) that refine our current view. We will discuss pros and cons of different strategies when collectives of individuals need to build structures larger than themselves. 

When Tiny Crystals Make Big Surprises
Saturday, November 7 | Xi Wang

What if we could build new materials the way we build with LEGO, one incredibly thin layer at a time?
Scientists can now work with crystals that are only one or a few atoms thick. When we stack these tiny sheets, rotate them, or place different materials together, surprising things can happen. Electrons may move in completely new ways, materials can become magnetic, and light can behave differently. A small twist between two layers can sometimes change the properties of the whole material.
We will take a journey into a world far too small to see with our eyes. We will explore how scientists make these tiny materials, how we discover what is happening inside them, and how simple ideas like stacking and twisting can create entirely new behavior. Along the way, we will see how playing with materials at the scale of atoms is opening new possibilities for understanding our quantum world and for technologies of the future.