In the video, we saw the experiment that the water film became a big water balloon because of the property of water.

Wang Yaping also demonstrated the experiment of water film tension. The experiment of water film becoming a big water ball is due to the nature of water surface tension. This experiment also uses the principle of surface tension. When astronauts continue to inject water into the water film, the water will be evenly distributed around the water film and gradually form water balloons.

The surface tension of liquid has an important application in space activities. In the weightless environment, the liquid fuel interface and gas interface in the spacecraft propellant tank are no longer stable, which may lead to liquid migration, gas-liquid mixing and other phenomena, resulting in the normal supply of propellant. Therefore, scientists have created a surface tension tank, which uses surface tension to promote the flow of liquid propellant.

Space experiment

At the China Space Station, astronaut Ye Guangfu demonstrated the study of cell growth and development under weightlessness. Wang Yaping invited the students in the ground class to put table tennis in a glass of water like himself. Table tennis on the earth will float on the water, but table tennis in space will float in the water, because buoyancy is related to gravity, and it will almost disappear in the microgravity environment of the space station.

After that, Wang Yaping also demonstrated the water film tension experiment, water polo optics experiment and effervescent tablet experiment in turn to guide students to explore the principle of liquid surface tension and convex lens imaging.