On a recent trip to Six Flags, we took a break from rides to see the otter show. As we watched the man swim with the otters, it looked like his head was not attached to his body. The reason: Refraction.
As the light from his body passes from the water to the glass (or Plexiglas), it refracts. But as the light from his head passes from air to glass it refracts more, because the change in density is greater.
I guess we really do have a lifestyle of learning: take a break from rides to learn about otters – then take a break from watching otters play to learn about refraction. It was a fun day.