Yeah I know its probably not close enough to Halloween or anything but I always thought this episode was funny. In the costume episode Sheldon goes as the "Doppler effect" and I also thought of a nerdy costume. Its called the refractive light costume. It would be a white shirt, rainbow hair, rainbow suspenders, black overalls and rainbow wrist bands. The joke is that rainbows are made out of refractive light. Therefore being a rainbow would show you are representing refractive light. What are some nerdy costume ideas you can think of? Not to be confused with reflective like a mirror which is bouncing it.