What Is That Floating There?
The above image shows a tall narrow class cylinder siting on the table in a lab. The cylinder is completely filled with a clear liquid and sealed tightly with a flexible membrane, which was done using a neoprene glove and a rubber band. Inside the cylinder, there is second glass container that appears to be floating upside down (opening facing downward) and resting against the rubber membrane that is covering the top of the cylinder.
What is the likely explanation for this setup?