It is a "natural enemy" and also a friend, a weapon of war and also a medical artifact. Visit these magical "lights" in "Zhejiang" that can kill bacteria, provide night vision, and even perform surgery

Spring brings blessings, and everything shines. "Light" has brought many changes to our world. We seem to be very familiar with it, but sometimes we feel a little strange. On the afternoon of May 31, the Zhejiang Association for Science and Technology's series of activities came to Jiaxing. With the support of the Jiaxing Association for Science and Technology, we visited two scientific research institutions that focus on optical research. There, we took the children to explore the science of "light".

Invisible Light:

What is light? Physics experts discuss

What is light? Is it a particle or a wave? Almost all the great physicists have joined this discussion. Newton proposed the "corpuscle theory", Huygens proposed the "wave theory", and Einstein proposed the "photon theory". Combining their statements, we can basically get a glimpse of the nature of light. Light can propagate forward like a wave, and sometimes it exhibits the characteristics of a particle, so we call light "wave-particle duality".

There are different types of light, such as infrared, ultraviolet, laser, etc. At the event, teachers from two scientific research institutions gave in-depth and easy-to-understand popular science lectures on these "lights".

With the arrival of summer, ultraviolet rays have become the "natural enemy" of many people. "Children, have you noticed the English labels on the sunscreen your mother uses?" A popular science teacher from Jiaxing Dingjia Semiconductor Co., Ltd. told the children that the UV on the sunscreen stands for Ultra Violet, which is divided into UVA, UVB and UVC (short-wave ultraviolet rays) according to different wavelengths. The UVA band is relatively long and will make us tan and get sun spots. Although the penetration of UVB is not as good as that of UVA, it can still make us sunburned and sunburned. In comparison, the penetration of UVC is the weakest among all lights, so UVC is safe within a certain dosage.

On the other hand, we don’t have to avoid all ultraviolet rays. If short-wave ultraviolet rays are used properly, they can become a good friend of human beings. At the event, the children also tried portable sterilization under the guidance of the teacher. The mobile phone was placed on the conveyor belt and sterilized quickly in 0.3 seconds. Many people also have sweeping robots at home, which are equipped with deep ultraviolet sterilization chips in front, which can quickly kill E. coli and other bacteria.

In addition to ultraviolet rays that can kill bacteria, infrared rays can also bring a lot of help to our lives. The popular science teacher from Zhejiang Weiyuan Electronics told everyone that medical infrared rays can be divided into two categories: near infrared rays and far infrared rays. Infrared rays have a thermal effect and can resonate with most molecules, converting light energy into molecular internal energy. For example, the heat from the sun that we feel is mainly transmitted to the earth through infrared rays. The students also learned that infrared imaging is an extremely important application field of infrared rays. Using infrared rays, humans can detect and capture information that is not suitable or cannot be obtained with visible light, and can be used in the fields of object recognition, intelligent driving, industrial automation, and chemical gas detection.

Visible Light:

Performing surgery to measure the distance between the Earth and the Moon

Infrared and ultraviolet rays are both invisible light. There is another common "light" in our lives - laser, which is visible light. "The English name of laser is lesser, which is an abbreviation of the first letters of the English words Light Amplification by Stimulated Emission of Radiation, which means 'light amplification by stimulated emission'," the science teacher told the children, "The full English name of laser has fully expressed the main process of making lasers." The name "laser" we use now is also the name of "laser" that the famous Chinese scientist Qian Xuesen suggested to change "light stimulated emission" to "laser".

Laser, as a major invention of the 20th century, has the characteristics of high brightness, monochromaticity, and directionality. It is also called "the most accurate ruler", "the brightest light", and "the fastest knife". Lasers have many applications due to these characteristics. For example, in the medical field, many surgeries are completed with the help of lasers; and the distance between the earth and the moon, which we know now, is also obtained by scientists through laser measurement. The students also experienced laser imaging in person and felt the many incomparable advantages of laser imaging over ordinary light imaging.

After listening to the popular science explanation, the children were led by the teacher to visit the scientific research laboratory. They witnessed with their own eyes how the deep ultraviolet air purifier instantly purified the oil smoke in the experimental cabin, observed the structure of the deep ultraviolet sterilization chip magnified 400 times under a microscope, and walked into the clean laboratory for the first time to learn the secrets of the chip testing process... Curious little heads gathered in front of the experimental equipment.

At the end of the science class, the science teacher raised the following question: the light and fire produced by lightning brought the origin of civilization to mankind; the electric energy technology discovered in lightning brought the explosive development of the information age to mankind; what kind of changes will the light quantum technology from lightning bring to mankind? The answer to this question may need to be discovered by these children who are curious about science.

"Walk In" series of popular science theme activities <br /> The "Walk In" series of activities launched by Zhejiang Association for Science and Technology lead the public to touch the magic of science, light up children's future with curiosity, strengthen the interaction and communication between young people and science, enlighten scientific thinking, and encourage more young people to embark on the road of science. Next, the activities will also enter more Zhejiang high-tech industries and popular science education bases, and will also enter scientists' laboratories to explore. Please continue to pay attention.

Metropolis Express·Chengshi Interactive reporters Weng Danni and Jin Jingxin