Good news for diabetics! This experiment in space has so many benefits...

Expert of this article: Yang Chao, PhD in Chemistry, University of Chinese Academy of Sciences

Reviewer of this article: Li Xueyang, Postdoctoral Fellow, Dalian Institute of Chemical Physics, Chinese Academy of Sciences

This afternoon, China's space station's "Tiangong Classroom" launched its second space teaching activity, continuing to adopt the method of dialogue between the ground and the earth.

Each space experiment is both interesting and full of practical information.

Even our lovely Bing Dwen Dwen went to space and was "forced" to become a teaching tool just to explain this important law to you!

If you still can't memorize it, then I'll be sorry to Teacher Bing who works in the space business!

What strange things happened after Bing Dwen Dwen was thrown out?

In the space parabolic experiment, teacher Wang Yaping used the popular Bing Dwen Dwen as a teaching tool. With a light push, she made Bing Dwen Dwen do several backflips easily. If she had let go of the Bing Dwen Dwen on the ground, it would have fallen to the ground long ago.

Then Teacher Wang gently threw Bing Dwen Dwen in one direction. Again, Bing Dwen Dwen did not fall "down" like it did on the ground, but moved forward at a nearly uniform speed in the direction of throwing. Why is that?

This is explained by Newton's first law, which is also called the law of inertia. Do you remember the definition in our junior high school physics textbook? All objects always remain at rest or in uniform linear motion when there is no external force acting on them.

When Bing Dwen Dwen is thrown in one direction, the gravity of the earth and other celestial bodies provide the centripetal force for uniform circular motion. This centripetal force makes Bing Dwen Dwen and the space station revolve around the earth, but from the space station, with the space station as the reference system, Bing Dwen Dwen has basically no acceleration. Since Bing Dwen Dwen has forward inertia, it can approximate uniform linear motion. If no force is applied to Bing Dwen Dwen during the release process, Bing Dwen Dwen will remain stationary.

Why did Professor Wang Yaping always emphasize in her course that it is "approximately" uniform linear motion? This is because although the Tiangong is in space, it is still affected by other forces inside the space station.

For example, the air in the space station will exert a very small backward resistance on Dun Dun when Bing Dwen Dun moves forward. This is air resistance. If the space station is "long" enough, Bing Dwen Dun's speed will gradually decrease during the forward movement (which may last for a long time), and eventually it will remain relatively stationary with the space station.

Does the Moon appear bigger and brighter when viewed from space?

Would the moon appear larger if we were closer to it in space than we are on Earth?

No, the moon is 380,000 kilometers away from the earth, while the Chinese space station is only 400 kilometers away from the earth. This distance is negligible compared to 380,000 kilometers. Therefore, the moon is the same size when viewed from the space station and from the earth.

But without the interference of atmosphere and clouds, the moon seen on the space station will be clearer and brighter!

The moon as seen from Earth (Source: Photographed by the author)

What benefits can a weightless environment bring to humans?

In a weightless environment, substances can be mixed more evenly

Just like the water-oil mixing experiment done by Professor Wang Yaping, water and oil cannot be mixed evenly on Earth, and will be separated into layers due to different densities under the action of gravity.

In a weightless environment, the mixture can be blended evenly, allowing the creation of special alloys that would be impossible on the ground.

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In weightless conditions, crystals grow more uniformly

The "Protein Crystal Growth in Space" experiment is an important scientific research project in the world's manned space activities.

Due to the influence of gravity on the ground, it is extremely difficult to produce pure and large protein crystals. However, under the weightless conditions in space, protein crystals can grow purer and larger than on Earth.

Experiments to promote the growth of protein crystals, such as the crystallization of insulin, have also been carried out on the International Space Station. The insulin crystals grown in space are of high quality and can form hexameric insulin crystals that are different from insulin monomers. Compared with monomeric insulin, hexamer can gradually dissolve after injection to deliver the monomer into the blood. This provides potential for the development of new insulins with slower delivery rates, which is of great significance for better treatment of diabetics.

Insulin grown on Earth and insulin grown in space (Source: doi.org/10.1016/0022-0248(96)00325-9)

Microgravity metallurgy yields metals with novel properties

Humans have been smelting metals for thousands of years, and with the development of aerospace technology, metal smelting has gradually begun in space.

Space metallurgy, also known as cosmic metallurgy, is the smelting of metals in the specific ultra-high vacuum and weightless space environment of a spacecraft. Various interferences caused by gravity can be eliminated to obtain metals with novel properties.

In 1969, the Soviet Union completed welding and alloy melting and solidification experiments under space microgravity conditions on the Soyuz 6 spacecraft, creating the history of human space metallurgy. Under microgravity conditions in outer space, surface tension and diffusion become the main controlling factors. Under microgravity conditions, density differences will not produce gravity sedimentation or buoyancy caused by buoyancy, so bubbles in the liquid will not move upward due to buoyancy. For example: foam metal materials have received widespread attention due to their low density and strong impact absorption capabilities.

Space dream, Chinese dream,

The world is paying attention and looking up to it.

The starry sky is bright and Shenzhou is shining.

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