Ever wondered what’s inside a black hole? Or what happens when you try to travel at the speed of light? In this class, we’ll give a brief tour of the postulates of relativity, and some surprising results that follow. Make yourself shorter or make time run slower? Turn red flags green or the other way around? While we won’t get to go faster than the speed of light or travel to the past, we will get to learn about clocks, rulers, light and gravity, and maybe even what’s really at the center of a black hole.