In my Introduction to Political Methodology class we talk about optical illusions. When we use the scientific method we rely on empirical observation and replicability, so with optical illusions as a jumping off point, we talk about what it means to observe something, the importance of replicating methods, and how our biases and brains can sometimes get in the way of what it is we think we know. After many semesters of looking at optical illusions I have gotten very good at seeing the illusions. However, I ran across this one today and it is just puzzling the shit out of me. I can't make my brain see it at all. Can you? I'm losing sleep over this.