Taking inspiration from sand and oil hourglass toys, we filled the airspace in our prototype mirror with sand and oil. First, it was filled with sand, but the finest sand particles clung to the mirror and made it hard to see through. We thought the oil would help clarify the mirror, but we're probably not using the right oil or liquid, because it fuses with the sand particles. We're not sure what kind of liquid is used in those toys, but we need to figure out a different way to let the sand through so that the mirror can still be perceived.
