清香讲堂 | 仰望星空，有趣的太空现象及地面模拟漂浮实验
本文已收录到News专题
- 学术荣誉 | 牛津大学编程思维挑战赛，清香学子初战告捷
- 学术荣誉｜清香学子夺取全国青少年科技教育成果展示大赛多枚奖项并晋级全国赛！
- 清香讲堂 | 仰望星空，有趣的太空现象及地面模拟漂浮实验
- 喜报 | 教育部白名单赛事，清香学子再夺金！
星空充满着人类伟大的梦想，苍穹承载着中华民族崇高的追求，从火箭成功发射到人类登月，再到太空站的建立和运营等等，中国的飞天之路是不断让梦想成为现实的漫漫征途，一代代航天人和科学家仰望星空、勇攀高峰，他们不断克服太空环境中的各种极端条件，为了飞跃九天的梦想艰苦卓绝地奋斗，他们努力突破各项技术难关，连战连捷的飞天奇迹不仅写就了天空梦圆的英雄史诗，也树立了激荡人心的精神丰碑。
The starry sky is full of great dreams of mankind, and the dome of the sky carries the noble pursuit of the Chinese nation. From the successful launch of rockets to the moon landing of mankind to the establishment and operation of space stations and so on, China’s road to the sky is a long journey that keeps making dreams a reality, and generations of astronauts and scientists have been looking up to the stars and scaling the peaks, overcoming all kinds of extreme conditions in the space environment and striving hard and desperately to make a leap to the sky for the sake of their dream, and striving to break through the various technological barriers to not only succeed in ascending into the space, but also set up a spiritual monument that stirs up the hearts of the people.
为了普及航天知识，培养同学们对科学、对宇宙的热爱和向往，3月10日晚，清香特别邀请到清华大学航天航空学院高云峰教授，为同学们开展了一堂别开生面的科学讲座，通过有趣的太空现象及地面模拟漂浮实验，带领同学们一起穿越时空，领略神奇的太空课堂。
In order to popularize space knowledge and cultivate students’ love and desire for science and the universe, THISDL invited Professor Gao Yunfeng from the School of Aeronautics and Astronautics of Tsinghua University on the evening of March 10 to conduct a unique science lecture for students, leading them to travel through time and space and appreciate the magical space classroom through interesting space phenomena and ground simulation floating experiments.
高云峰教授任清华大学航天航空学院教授，长期从事航天航空方面的教学和研究。出版著作 10 多部、论文 100 多篇、专利 2 项。高教授积极参与太空授课的方案论证、道具原型设计等工作，与中央电视台《走进科学》栏目合作，策划并拍摄了一系列地面模拟失重实验。
Prof. Gao is a professor at the School of Aeronautics and Astronautics, Tsinghua University, and has long been engaged in teaching and research in aerospace and aviation. He has published more than 10 books, 100 papers and 2 patents. Prof. Gao is actively involved in the program demonstration and prototype design of props for space lectures, and has planned and filmed a series of ground-based simulated weightlessness experiments in cooperation with CCTV’s “Into Science” program.
讲座伊始，高教授与同学们分享了太空与地面明显的区别。区别之一是漂浮现象，这也是太空中最明显的现象。在宇宙空间，人可以在空中漂浮，也可以轻易搬动在地面上难以搬动的物体，太空中会出现漂浮现象的主要原因是失重。
At the beginning of the lecture, Prof. Gao shared with the students the obvious differences between space and the ground. One of the differences is the floating phenomenon, which is also the most obvious phenomenon in space. In space, people can float in the air and can easily move objects that are difficult to move on the ground. The main reason for the floating phenomenon in space is weightlessness.
众所周知，地球附近的物体都受地球引力作用。在距离地面很近、范围很小时，引力通常称为重力。飞船及内部物体绕地球运动时，仍受地球的引力作用。但是物体在飞船中为什么会失重呢？此刻同学们发出了大大的疑问？
Objects in the vicinity of the Earth are subject to the Earth’s gravitational pull. At very close and small ranges from the ground, the gravitational force is usually called gravity. A spaceship and the objects within it are still subject to the Earth’s gravitational force as they move around the Earth. But why are objects weightless in a spaceship? At this moment the students are asking the question?
高教授耐心解释：“失重并不是物体失去重力。”为了让同学们更清晰地理解这一概念，高教授用橡皮筋和小球给同学们演示了一个小实验，用橡皮筋连着小球，当小球转动的时候，橡皮筋会被拉长。高教授表示：“物体做圆周运动时需要向心力，而橡皮筋只有伸长了，才能产生向心力。人们利用这个特点可以发展出很多杂技，比如电视中常见到的水流星表演，杯子转动时在倒立位置水不会洒出来。”高教授用杯子和水作为简易道具为同学们现场演示了这一现象，通过实验同学们看到，如果转动速度较大，使得重力成为水做圆周运动的向心力，则水不会洒出。
Prof. Gao patiently explained, “Weightlessness is not the loss of gravity of an object.” In order to let the students understand this concept more clearly, Prof. Gao used a rubber band and a small ball to demonstrate a small experiment to the students, using a rubber band attached to a small ball, when the ball rotates, the rubber band will be stretched. Prof. Gao said, “The object needs centripetal force to do circular motion, and the rubber band can only produce centripetal force when it is stretched. People use this feature can develop a lot of acrobatics, such as the water meteor show often seen on TV, the cup turns in the upside down position water will not spill.” Professor Gao site with a cup and water as a simple props for students to demonstrate the phenomenon, through the experiment students see, if the rotation speed is greater, so that gravity becomes the centripetal force of the water to do circular motion, the water will not spill.
通过这些简单、常见的现象，高教授引导同学们思考物体在飞船中产生失重现象的原因，同学们顿时恍然大悟：飞船绕地球飞行时，地球对飞船产生引力，飞船做圆周运动需要向心力。如果引力大小等于向心力，则飞船内部处于失重状态。
Through these simple, common phenomena, Professor Gao guided the students to think about the reasons for the weightlessness of objects in the spaceship, and the students suddenly realized: when the spaceship flies around the Earth, the Earth produces gravitational force on the spaceship, and the spaceship needs centripetal force to do circular motion. If the size of the gravitational force is equal to the centripetal force, the spacecraft is in a state of weightlessness.
随后，高教授通过视频与同学们分享了太空与地面的第二个明显区别：在太空失重环境下，水珠会自动收缩成一个圆球。为什么水在太空中会变成水球呢？高教授表示：“这是因为液体的表面张力。表面张力，是液体表面层由于分子引力不均衡而产生的作用力，导致液体表面是曲面。在太空中，引力被离心力抵消，表面张力的作用就明显了。如果没有其他限制，水珠不管多大，最终会收缩成水球。”
Prof. Gao then shared with the students through a video the second obvious difference between space and the ground: in the weightless environment of space, a water droplet will automatically shrink into a ball. Why does water turn into a water ball in space? Prof. Gao said, “This is because of the surface tension of the liquid. Surface tension, which is the force on the surface layer of a liquid due to the imbalance of molecular gravity, causes the surface of the liquid to be curved. In space, where the gravitational force is canceled out by the centrifugal force, the effect of surface tension becomes apparent. If there were no other limitations, water droplets, no matter how big, would eventually contract into water spheres.”
高教授也在讲座现场与同学们一起观看了几项有趣的太空实验视频，真实而有趣的太空实验令同学们捧腹大笑又惊喜无比。通过太空中的单摆实验、宇航员空中转体实验、乒乓球在水中的悬浮实验，同学们更深刻地理解了失重环境下物体运动特性；通过太空中的水膜演示、水球演示、水球+泡腾片演示、水膜+纸花实验，同学们更直观地领悟了失重环境下液体表面的张力特性。
Prof. Gao also watched several interesting videos of space experiments with the students at the lecture site, and the real and interesting space experiments made the students laugh and surprised. Through the single pendulum experiment, the astronaut’s aerial rotation experiment, and the levitation of ping-pong ball in water, the students gained a deeper understanding of the characteristics of object movement under weightlessness; through the water film demonstration, water balloon demonstration, water balloon + effervescent tablets demonstration, and the water film + paper flower experiment, the students more intuitively comprehended the characteristics of the tension of the surface of the liquid under the weightless environment.
观看视频后，高教授语重心长地说到：“航天技术的发展实现了人类飞天的梦想。2013年6月20日，我国进行了首次太空授课，中国航天员王亚平在300 公里高度的轨道上对6千万中小学生进行了科学实验直播。太空授课旨在激发广大中小学生对宇宙、对科学的热爱和向往，它是中国和平利用太空资源的一次展示，也是我国综合国力和航天技术的一次集中展示。”
After watching the video, Prof. Gao said in a heartfelt manner, “The development of space technology has realized the dream of human beings to fly to the sky. on June 20, 2013, China conducted the first space lecture, in which the Chinese astronaut Wang Yaping broadcasted live science experiments to 60 million primary and secondary school students in an orbit at an altitude of 300 kilometers. Space lectures are aimed at inspiring the love and yearning of primary and secondary school students for the universe and science, and it is a demonstration of China’s peaceful use of space resources, as well as a focused display of China’s comprehensive national strength and space technology.”
同时，地面模拟漂浮实验对于航天事业的发展是非常必要的，如何在地面创造失重的环境更是值得人类思考的。在地面，自由落体可以造成失重现象，失重飞机可以模拟几分钟的失重环境，水中也可以模拟失重环境。高教授曾亲身参与过相关模拟实验，在水中做1：1的空间站模型，帮助宇航员练习出舱和太空行走。高教授表示：“在地面模拟太空失重环境中的现象，还是有很多困难，但是通过努力，可以得到近似的定性结论，这是其重要的意义和价值所在。”
At the same time, ground simulation of floating experiments is very necessary for the development of the space industry, and how to create a weightless environment on the ground is even more worthy of human thought. On the ground, free fall can cause weightlessness, weightless airplanes can simulate weightless environment for a few minutes, and water can also simulate weightless environment. Prof. Gao said, “There are still a lot of difficulties in simulating the phenomena in the weightless environment in space on the ground, but through the efforts, we can get approximate qualitative conclusions, which is its important significance and value.”
随后，高教授向同学们展示了自己为中学生设计的比赛项目——地面模拟飞船的交会对接，并鼓励同学们可以充分运用清香校园丰富的实验室资源，用各种材料自己设计制作简易飞船的对接模型，让科学走进生活，让抽象的理论知识更具体化。
Afterwards, Prof. Gao showed the students the competition project he designed for secondary school students – the ground simulation of spacecraft rendezvous and docking, and encouraged them to make full use of THISDL’s abundant laboratory resources to design and make their own simple spacecraft docking models with various materials, so as to let science come into life and make the abstract theoretical knowledge more concrete.
最后，讲座在阵阵掌声中落下帷幕。寓教于乐、通俗易懂的科学课堂让在场的每一位同学都受益匪浅，飞天梦的种子悄悄萌芽在同学们的心中。伟大的航天人和科学家们克服重重困难，为探索宇宙的奥秘和人类的发展不断努力，让我们向航天人与科学家致敬，坚守理想不断向未知迈进，探寻属于自己的那片星空。
Finally, the lecture came to an end with a burst of applause. The entertaining and easy-to-understand science class benefited every student in the audience, and the seed of the dream of flying quietly sprouted in the hearts of the students. The great astronauts and scientists have overcome many difficulties to explore the mysteries of the universe and the development of mankind, so let’s pay tribute to the astronauts and scientists, adhere to the ideals and keep moving towards the unknown, and explore the starry sky that belongs to ourselves.
