Beverage bottles can also make "rockets": rural teachers light up the lamp of science for children
2024-08-18
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Yangcheng Evening News Omnimedia Reporter Tan Jiewen Intern Zhang Yuqia
"The first generation is the ordinary version of water rocket, the second generation is the 'recyclable' water rocket, the third generation is the 'hat-type' water rocket, and we are now starting to study the fourth generation 'clockwork catapult type'." Talking about water rockets, Zhang Jiantao opened up all of a sudden, and introduced the various "water rockets" he had studied like a treasure trove - this is a toy that uses air pressure to form a water spray effect and propel the bottle into the air, and is usually made of discarded beverage bottles.
There are not only water rockets that can fly 100 meters, but also air cannons and flying trash cans... At the No. 1 Primary School of Zhangguangmiao Town (hereinafter referred to as "Zhangguang No. 1 Primary School"), which is located at the junction of Henan and Anhui and more than 30 kilometers away from the county seat, science teacher Zhang Jiantao uses the bottles and jars he collected to make scientific experimental equipment, and the experimental results caused the children to exclaim.
"The children's eyes were shining. I knew that was their thirst for science," Zhang Jiantao told reporters. Zhangguang No. 1 Primary School has more than 1,400 teachers and students, 80% of whom are left-behind children. Zhang Jiantao himself probably didn't expect that six years ago, when he was still working in sales in another place, he would accidentally embark on the path of studying small scientific experiments and light up the light of science in the hearts of children with more than 100 small scientific experiments.
“Interest is the best teacher”
When Zhang Jiantao quit his sales job and applied for the teacher qualification exam, he never thought that he would become a science teacher in a rural primary school.
Six years ago, Zhang Jiantao studied hard for a year to obtain a math teacher's certificate, but was disqualified from taking the exam due to the age restriction policy. Later, he unexpectedly became a physics teacher in a private middle school. This inadvertently opened the door for him to explore scientific experiments: the salary of teachers in private schools is linked to students' test scores. Compared with the classes taught by experienced old teachers with a lot of test questions, Zhang Jiantao's class scores have always been at the bottom. "I was thinking about it when I went to bed at night, wondering if I could do experiments instead of lecturing on them. Because no other old teacher could explain them well, I wanted to use another teaching method to help my students improve their grades."
Therefore, Zhang Jiantao paid out of his own pocket to buy experimental equipment such as tuning forks, U-shaped tubes, and small sound cards online, and began to try to use hands-on demonstrations to teach students to understand physical principles. The children who had never done scientific experiments before were very excited. Half a year later, Teacher Zhang's class achieved the first place in the grade as expected. "I don't like the tactic of doing a sea of questions. I open students' minds through experiments and let them find problems by themselves, rather than mechanically doing the questions over and over again."
Two years later, Mr. Zhang became a math teacher in the second grade of Zhang Guangyi Primary School. He was troubled by the problem of children being distracted in class, so he thought of bringing the past experimental materials to school to attract the children's interest. "At that time, I just wanted to use scientific experiments as a means of reward. I told them that as long as they listened to the class carefully and completed their homework on time, I would take them to the science laboratory on Friday afternoon."
The first experiment was about "the formation of wind". A candle was placed under the wind tube. After the candle was lit, the hot air rose and pushed the wind wheel to rotate. Teacher Zhang distributed experimental materials to each group of children. The children were so excited that their eyes lit up when they first came into contact with a small scientific experiment. When they saw the windmill start to rotate, the whole class of children burst into warm applause and cheers. "It seemed that I could see a beam of light from their eyes in that class. This kind of light is not visible when you are teaching in the classroom."
The success of the first experiment gave Zhang Jiantao a great shock. "This is a very small experiment, but the children were so surprised and astonished!" Thinking that the science class, which should have allowed children to experience the charm of science, was not taken seriously, complex thoughts lingered in Teacher Zhang's mind: "I feel very uncomfortable. Every school is equipped with some experimental equipment, but how many schools have serious science classes?" So he promised the children that as long as they listened to the lectures and did their homework carefully, he would take them to do experiments every week.
Experimenting "secretly"
In order to fulfill his promise to the students, Zhang Jiantao began to insist on one experimental class per week. In order to ensure the success of the Friday experiment, Zhang Jiantao needs to conduct experiments himself every week to determine the feasibility and then prepare the materials for the children to operate by themselves. After get off work every day, he needs to spend an extra hour or two.
As a math teacher, it is inevitable that he will be regarded as "not doing his job properly" when taking students to do scientific experiments. In order to avoid being criticized, Zhang Jiantao needs to ensure that students' grades do not decline, and he goes to the laboratory "secretly" so that others will not find out. The school laboratory resources are limited, glassware is somewhat dangerous, and the previous junior high school experimental equipment is not suitable for elementary school children. It is even more impossible to apply for funds from the school. What to do? Teacher Zhang began to think of using waste materials in life as experimental materials and DIY some small experiments. "During the day, I teach math, prepare lessons, and correct homework. After dinner at night, I start to select small scientific experiments suitable for using waste materials from videos."
The idea of making a "pressure water rocket" with household waste came from that time. Zhang Jiantao browsed through scattered teaching videos on the Internet and pieced together a relatively complete assembly plan, but the experiment still required a lot of materials. The water rocket body alone required three plastic bottles. Zhang Jiantao then proposed the idea of making a water rocket to his classmates and collected plastic bottles. To his surprise, the children collected 235 plastic bottles from home the next day. "The children are very supportive, so I made up my mind to make this thing. The water rocket is one of the children's favorite experiments, and it is also the one that takes the longest time."
Although the first generation of water rockets was successfully launched very quickly, Zhang Jiantao did not stop exploring. The first generation of water rockets launched into the sky fell very quickly, and there was a risk of falling objects from high altitude injuring people, so a parachute was needed. At the same time, its production process was too complicated and not suitable for third graders. More importantly, the materials for the new generation of water rockets must be cheap and available in life. "It is impossible for every family to spend 60 or 70 yuan to buy materials for their children."
So Zhang Jiantao began to use his own ideas to modify and upgrade the first generation of water rockets. When a reducer was needed, he filled a ping-pong ball with water and sealed it with hot melt glue to the mouth of a plastic bottle to make a conical and heavy "hat"; when a parachute was needed, he cut a garbage bag into a circle as an umbrella and used cotton thread as the parachute rope; when a spring handle was needed, he cut a small section of the gel pen refill to serve as the handle; he cut the yellowed badge into the tail of the water rocket; the most difficult problem was the sealing problem. In order to maintain the air pressure in the bottle, an airtight sealing ring was needed. Zhang Jiantao tried sealant and shoe repair glue, but had to give up because of aging and price issues. In the end, he chose the bicycle liner that others threw in the garbage recycling station, which could be used as a sealing ring after cutting it into small pieces.
Every day, Zhang Jiantao would test-fly the water rocket on the playground. After three or four months of trial and adjustment, and more than 150 failed improvements, the plan of the "recyclable water rocket" finally took shape.
“We can now conduct experiments openly.”
"Three, two, one, take off!" On National Day, the improved water rocket was successfully launched on the playground of Zhangguang No. 1 Primary School, watched by teachers and students. The water rocket dragged a water mist of more than 30 meters long, rising into the sky like a white line. "You feel like launching a real rocket. The water mist is very beautiful, the effect is very good, and it is very spectacular."
After rising to the highest altitude, the bottle slowly descends on a parachute. The children on the playground stretch out their arms to catch the returning bottle. The breeze blows the parachute in different directions, and the children chase in the direction the parachute turns.
"The children have learned the scientific spirit and never give up easily when faced with setbacks. This change is my biggest gain." Talking about what he gained from this experience, Zhang Jiantao admitted that compared to his personal success, he felt that the trust of parents and the growth of children meant more to him.
Zhang Jiantao's science videos and experiences have attracted media attention and reports, and he has also changed from a math teacher to a real science teacher. "I can finally do experiments openly in the office." Teacher Zhang smiled. During the research on water rockets, he also studied and made a series of "flying" experiments such as "wandering balloons", rotating paper airplanes, and flying trash cans at the request of his classmates, and shared the tutorials for free on the Internet platform.
At the same time, Zhangguang No. 1 Primary School also built the "Young Eagle Science Museum" to provide children with more hands-on equipment resources. Teacher Zhang's actions to spread scientific experiments have also influenced surrounding schools. He was even invited to demonstrate in primary and secondary schools in Gansu and Jiangsu. The first "Zhangguangmiao Town Science Games" initiated by him was successfully held. Students used waste materials such as milk boxes, cans, and medicine bottles to make air cannons, floating and sinking markers, etc. In the future, Teacher Zhang will work with other science teachers in Zhangguangmiao Town to compile the teaching plan of "100 Small Science Experiments" to spread the seeds of science.
