I’m way behind in my blog reading. Here’s a little optics something from ZapperZ:
Can a dog bowl start a fire? Test shows idea does hold water

A Bellevue Fire Department investigator said earlier this week that he suspects a house fire started when a partially filled glass bowl, resting in a wire stand on the home’s deck, concentrated the sun’s rays like a magnifying glass.

Reminiscent of the snow globes that were recalled for their similar qualities of refraction.