How Does a Submarine Sink and Rise? Soda Bottle Diver | Cartesian Diver Physics Experiment

How Can a Submarine Sink and Rise? Cartesian Diver Hello. I’m Dr. Bruce Denardo here in the Physics Lecture Demonstrations Laboratory at the Naval Postgraduate School in Monterey, California. How can a submarine sink or rise? One way is to change the amount of water in the ballast tanks. But how does this cause sinking or rising? We can understand the behavior by considering a simple physics demonstration called a Cartesian diver. Submarine showing air vents, water intake, and double hull which serves as the ballast tank. Demo Here is our Cartesian diver apparatus. It is a flexible clear 2- liter soda bottle with an inverted glass test tube inside. The test tube is open, and it contains some air. The yellow tape around the tube and cork at the top of the bottle allow the test tube to be clearly seen in a classroom. The bottle is filled with water and securely capped. There is enough air to make the test tube float. Without the air, it will sink. There are different ways that