Everything we can see with our naked eyes is the result of tiny particles that we cannot see doing something complex. The experiences of our daily lives; from the ice cooling your glass of water to the display on our phones, are due to tiny things in nature interacting to create the world around us. What happens when the microscopic traits don’t match the macroscopic behaviors? Are solids, liquids, and gases as simple as we think, or is there a regime in between? Why is light sometimes a wave and sometimes a particle? Does size and shape matter? Do these questions even matter for our daily lives? This class considers how the organization and collective behaviors of small particles gives rise to the world we live in, and wrestles with how we treat ideas when the microscopic and macroscopic worlds do not coincide.