人类太空授课珍贵画面上新！冰墩墩太空“再就业”成为了……

来源：央视新闻，新华社作者：21ST 日期: 2022-04-20

全球顶流冰墩墩的

“退休生活”什么样？

昨天

大家发现“墩墩”已经实现

太空“再就业”！

图源：央视新闻

“天宫课堂”第二课

于3月23日下午开讲

神舟十三号乘组航天员

翟志刚、王亚平、叶光富

在中国空间站进行太空授课

助教“冰老师”在

太空抛物实验中

狠狠秀了几个空翻

第二课的一个个太空实验

更是干货满满

↓↓↓

这次太空授课活动在中国科技馆

设地面主课堂

在西藏拉萨、新疆乌鲁木齐

设2个地面分课堂

航天员还通过视频通话形式

与地面课堂师生进行互动交流

The second live class from China's space station was held in the afternoon of Mar. 23, delivered by Shenzhou-13 crew members Zhai Zhigang, Wang Yaping and Ye Guangfu to students on Earth.

Wang, assisted by the other two crew members, conducted several scientific experiments, such as the crystallization of supersaturated solution, a liquid bridge demonstration, water-oil separation and throwing objects under the zero-gravity condition, amazing numerous students on Earth.

They also had real-time Q&A with the students via video call, according to the China Manned Space Agency.

The primary ground classroom was at the China Science and Technology Museum. Classrooms were also set up in Lhasa of Southwest China's Tibet autonomous region, Urumqi of Northwest China's Xinjiang Uygur autonomous region.

太空“冰雪”实验

这个“冰球”有点热

在“四季如春”的中国空间站里

王亚平制作了一颗

晶莹剔透的“冰球”

——液体球结晶

手摸这个“冰封”的小球

竟然还有点热热的感觉

这是什么原理？

图源：央视新闻

In the first experiment of the class, Wang used a bag of supersaturated sodium acetate solution to demonstrate its crystallization in micro-gravity.

After Wang squeezed the solution from the bag, it became a transparent fluid ball floating in front of the camera. Wang used a small stick covered with crystal nuclei to touch the fluid ball and it quickly became crystallized.

"It looks like an ice ball, but as I touch it, I can feel that it's warm," Wang told the class.

其实这是因为乙酸钠溶液

在温度较高的水中的溶解度非常大

很容易形成过饱和溶液

在这种溶液里只要有

一丁点的结晶和颗粒

就能迅速打破它的稳定状

析出大量晶体

同时还会释放出大量热量

王亚平将过饱和乙酸钠溶液

挤出一个液体球

再用一根沾有晶体粉末的棉棒

触碰了这个小球

由此得到了这个

外观像“冰球”的“热球”

The space teacher explained that the solubility of sodium acetate in water of higher relative temperature is very high, and it very easily forms a supersaturated solution. Just a small trace of crystal nuclei causes the sodium acetate to crystallize, releasing a lot of heat.

“液桥”演示实验

液体在什么情况下能搭桥？

地面重力环境下

水的表面张力微不足道

那么在太空的微重力环境下

液体的表面张力有多强？

图源：央视新闻

在微重力环境下

液体的张力足以维持住

两个物体之间的水

因此航天员可以徒手

搭建一座“液桥”！

The taikonauts conducted liquid bridge experiment to display the surface tension in space.

水油分离实验

叶光富秒变“人工离心机”

地面上

水和油混合后自然分层

那么在空间站里

水和油会自然分层吗？

王亚平用力摇晃一个

装有水和油的瓶子

让水油充分混合

时间一分一秒过去

瓶中仍然没有变化

油滴依旧均匀分布在水中

图源：央视新闻

Another micro-gravity experiment showed how to separate oil from water in space.

When Wang asked for a method of separating water and oil in space, a student from Beijing suggested swinging the bottle in a circle. Wang's teammate Ye Guangfu tried the method and succeeded in separating the two.

叶光富前来助力

抓着系在瓶上的细绳甩动瓶子

“人工离心机，启动！”

数圈后水油明显分离

油在上层，水在下层

瓶子高速旋转时的离心作用

使得浮力重新出现了！

冰墩墩成“天宫课堂”助教

全球“顶流”晋升宇宙“顶流”

太空抛物实验中

来了一位特殊的助教：冰墩墩

在太空中抛出冰墩墩

会和地面上一样向下坠落吗？

一试便知！

图源：央视新闻

憨态可掬的“墩墩”

此时姿态格外轻盈

接连秀出几个“空翻”

画出了几条漂亮的直线

原来这是牛顿第一定律

所描述的现象

在空间站中

冰墩墩被抛出后

几乎不受外力影响

保持近似匀速直线运动

Wang used a toy of Bing Dwen Dwen, the popular mascot of the 2022 Beijing Winter Olympic Games, to display how objects fly in a weightless environment.

网友见到压轴出场的“墩墩”

纷纷表示想念：

“难怪墩儿还没到我手上

原来是去太空出差了！”