
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.