FB Water flow in 3 bottles: Physics education and concept #experiment

https://www.facebook.com/share/v/1KSquUoDR7/

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A comment says: "Gravity is forcing the water in the middle bottle down. This displaces the air in the left bottle, forcing it into the right bottle. This displaces the air in the right bottle, pushing the water out of the right bottle into the middle bottle. Gravity is the pump. It will continue to do this until one of two things happens. All the water dumps into the left bottle. Or, if you keep adding water, until the left and midd"