This one is something I kept meaning to do on multiple occasions but never was ready when it occurred to me.  Boiling a pan of water, I am always fixated on the patterns that show up as shadows on the bottom of the pan as the heat affects the water by differing amounts resulting in convection flows across the pan.  This is the sort of thing that only oddballs like me find fascinating.  I finally thought to have the camera close to hand when boiling some water and got some footage of the patterns as they swirled.  I was quite pleasantly surprised that the lens didn’t steam up during this.  No doubt Nancy looked at me with that puzzled expression that has appeared many times after decades of knowing me!