Tiangong No.1 Handwritten Newspaper

As a national space laboratory, China Space Station is also an important space science education base, which contains rich educational resources and has special advantages in encouraging the public, especially young people, to carry forward the scientific spirit and love the space industry.

"Tiangong Classroom" is a series of launches through the construction and on-orbit operation of China Space Station, combined with manned missions. The lecture will be held by China astronauts as "space teachers", with young people as the main target, and the world will cooperate with each other.

The experiment of "ice and snow" in space is actually the process of nucleation and crystallization of supersaturated sodium acetate solution, in which heat will be released. The crystallization of supersaturated solution usually needs external disturbance, and the mystery of this experiment is that the rod is stained with crystal powder to provide condensation nuclei for supersaturated sodium acetate solution, and then sodium acetate trihydrate crystals are precipitated.

Microgravity environment and liquid surface tension are the main reasons for the formation of liquid bridge. The liquid bridge in daily life is not easy to be detected. For example, when washing hands, two fingertips occasionally form a liquid column of several millimeters, and then pull it far away, which will collapse under the action of gravity. On the space station, astronauts can easily demonstrate a liquid bridge hundreds of times larger than the ground, which is impossible to see on the ground.

Why is the weightless environment of the space station called "microgravity"? In fact, although the space station has a weightless environment, it has not escaped from the gravity of the earth. In an orbit about 400 kilometers from the earth, the gravity on the space station is about 88% of the ground. 5%, not significantly smaller than the ground. The space station can form a microgravity environment because of its very high flight speed. At this time, gravity becomes an appropriate centripetal force, which makes the space station orbit around the earth. But the earth is not a uniform sphere and the speed of the space station is not constant, so the environment in the space station is "microgravity" rather than "zero gravity".