Students attend a live class taught by the Shenzhou-13 crew members at the China Science and Technology Museum in Beijing on December 9 (XINHUA)
A close-up shot of a spinning top marks the beginning of the long-awaited class. The top floats in mid-air, spinning like it will never stop. A hand appears on the screen and grabs the top as the camera zooms out to reveal the face of Wang Yaping, a female taikonaut with a ponytail and smiling face. "Welcome to space class," she says.
Wang's greeting came from inside China's Tiangong space station to an audience of hundreds of millions on Earth, who watched the class via a live webcast on December 9. The class was taught to a total of 1,420 primary and middle school students in five classrooms around China. These students, from Beijing, Nanning City in Guangxi Zhuang Autonomous Region, Wenchuan County in Sichuan Province, as well as Hong Kong and Macao special administrative regions, were able to communicate directly with the taikonauts and ask questions in real time. Others could watch the class online.
Wang introduced the other two crew members of the Shenzhou-13 spaceship that carried them to the space station, Zhai Zhigang, who performed China's first space walk in 2008, and Ye Guangfu, who is in space for the first time. Both assisted Wang with her experiments during the class.
The second space class
It is the second time for Wang to host a space class. Eight years ago, together with two other taikonauts on the Shenzhou-10 spacecraft, she delivered the country's first live space class in China's experimental space lab Tiangong-1 to over 60 million teachers and schoolchildren across China.
On that visit, Wang spent 15 days in space; this time, she will be in space for more than six months. Leaving Earth on October 16, Wang and her colleagues arrived at the space station on the same day, almost two months before the class took place.
The "classroom" is a lot larger than the previous one. The living and working area for taikonauts in the Tianhe core module is over three times that in Tiangong-1.
At the beginning of the new class, Wang first gave the audience a tour of the living area, including the bedrooms and toilet, a fully functional kitchen with a microwave, a water dispenser and a mini-refrigerator.
"As there is no gravity here, blood flows upward to the head. That is why our faces look a bit swollen," Wang said. "It will affect our health, and we must do exercises to stay healthy." Wang then demonstrated how to work out in space with a treadmill and a spin bike.
She showed the working area in which the crew members conduct their scientific experiments, where the trio then demonstrated several tests under zero-gravity conditions.
The first experiment was to compare the growth and shape of cells in artificial gravity and zero-gravity to study the differences under these conditions.
Following that, Ye demonstrated how the astronauts turn around in zero gravity. It's hard to do and it took him several attempts to complete his move. "The loss of gravity makes movements simple on Earth very difficult in space," Wang said.
Wang then used a table tennis ball to demonstrate how the lack of gravity causes a loss of buoyancy. The ball, which floats on the water's surface on Earth, sank with a push in Wang's experiment. Experiments concerning water were the main content of Wang's class. Wang made a water film by dipping a small metal ring into a bag filled with water. She then put a pink flower made of folded paper on the film. The flower "blossomed" as the paper unfolded.
Wang added more water to the film, growing it into a ball of water, which she used to conduct an optics experiment using water refraction. She then injected some blue liquid into the ball and finally added an effervescent tablet, which produced many bubbles within the object.
More to come
The water film and water ball were not new for audience members who watched the space class in 2013. "The main target audience of the space class is primary and middle school students, so the principle in designing experiments is to ensure they're simple and straightforward but deliver profound scientific knowledge," Wang Yanlei, Director of the China Astronaut Research and Training Center, told China Central Television.
Water is a common substance on Earth and is also a necessity in space, hence a good choice for the experiments in space classes, Wang Yanlei explained. "This time, we added more content to the experiments by using the water film and ball to make them more vivid."
The curriculum was made public in advance. Members of the public were welcome to submit their questions and suggestions regarding the class. The students watching in the five classrooms were all provided with the same experimental tools as those in space in order to compare the different results on Earth and in space.
The class lasted about 45 minutes. The spinning top was frequently featured during the class. The crew made it spin and remain in the air during the intervals between the experiments.
"It reminds me of the ending of the movie Inception, when a top was left spinning on a table," Qiu Changle, a Beijing resident told Beijing Review. "It indicates in the movie that if the top keeps spinning and never stops, the man is still in the dream."
Dreams were also a topic raised by one student. "Do you have dreams in space? Are the dreams different from those you had on Earth?"
"I do have dreams in space and the dreams are no different from those on the ground," Wang said. "If there is any difference, it's that every time I wake up from my dreams and see myself bound in a sleeping bag in space, I feel like I am still in a dream."
China will launch a space science education brand, "Tiangong Class"—the first of its kind, to make full use of the Chinese space station's educational capacity, according to the China Manned Space Agency, and more space lectures of various forms will be delivered from the Chinese space station in the future.
"The abundant educational resources of the orbiting outpost have provided unique advantages when it comes to encouraging the public, especially the young, to get involved in science and space exploration," Wang Yanlei said.
(Print Edition Title: No Gravity, All Gravitas)
Copyedited by G.P. Wilson
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