When I returned a few days later to see if the water had disappeared, I was shocked to see the glass had been moved! Again! This time, Sally of the cleaning service had noticed the glass and thought it was left over from a party. She picked it up and washed it in the kitchen, placing it in the rack to dry. How difficult is it to do this simple experiment?? After more than 50 years, the result was exactly the same. I could not prove that water left in a glass will disappear in a few days.