Although infrared light cannot be seen by the naked eye, its applications range from large-scale weather satellites and Mars rovers to small-scale touchless faucets and airport security equipment. Behind these applications lies a formula named after a Chinese scientist, and that scientist is our guest in this episode of "Let's Talk": Academician Chu Junhao, a physicist specializing in infrared technology at the Chinese Academy of Sciences. What unexpected applications does infrared technology have? What efforts have Chinese scientists made in the research of infrared radiation? In this episode, Academician Chu will share with young audiences the story behind "invisible light."
【Do you remember this WeChat cover?】
Don't peek at your phone! Can you tell which one is the current WeChat splash screen? This question stumped many at the scene. It wasn't until Academician Chu stepped in with an explanation that the mystery was solved. Turns out, the one on the left is the actual WeChat splash screen. It's none other than the first complete Earth photo publicly released worldwide by NASA. However, the one on the right isn't a nobody either. It's a meteorological cloud image taken from space by China's independently developed "Earth Photographer," Fengyun-4A satellite. It also graced the WeChat splash screen from 5 p.m. on September 25 to 5 p.m. on September 28, 2017. But how was this image captured? Academician Chu revealed the story behind it at the event. Contrary to popular belief, it wasn't a straightforward snap from space. Instead, it was composed using lenses with 14 spectral bands, and the final image we see now is a result of combining them. The clarity and resolution of this picture have already reached top-notch international standards.
[Is Harry Potter's invisibility cloak becoming a reality?]
How amazing is optics really? At a recent scientific conference, Academician Chu Junhao showcased a "cloak of invisibility," sparking much debate online and inspiring many to try to replicate it. However, the reality is quite different. According to Chu Junhao, what we see is merely a visual illusion caused by the refraction of light, not true "invisibility magic." So, Harry Potter's "invisibility cloak" remains difficult to achieve. The "cloak of invisibility" we see is stiff and cannot be worn, let alone render anyone invisible. The initial purpose of such experiments was not to promote "invisibility cloaks" but rather to stimulate interest in science.
Expert Insight: Is Beauty Equipment a "Tax on Intelligence"?
Various "beauty devices" flood the market nowadays, with some finding them effective while others dismissing them as a "tax on intelligence." Addressing the curiosity of young people on this matter, Academician Chu explained on the program that "beauty devices" have some scientific basis. They work on the principle of the interaction between light and matter. However, excessive use is not advisable. For instance, while moderate exposure to ultraviolet light can increase vitamin D levels and aid in calcium absorption, excessive exposure is harmful to the skin. Lastly, Academician Chu humorously suggested that one doesn't really need "beauty devices" – a hot water bag works just fine since it emits various radiations like near-infrared and mid-infrared, which can also be beneficial for skincare.
Just How Impressive is This Formula Named after a Chinese Person?
From the very beginning of our schooling, we've learned countless mathematical and physical formulas, but there are few named by Chinese people. "CXT" is one such example. It serves as a crucial measure for determining the suitability of a material for infrared detectors and finds applications in cutting-edge fields like the Fengyun satellites, Mars rovers, missile early warning systems, and more. Even today, it continues to play a pivotal role worldwide. The "C" in "CXT" stands for the initial letter of Academician Chu Junhao's surname. The second letter, "X," represents Xu Shiqiu, while the third, "T," symbolizes Academician Tang Dingyuan, who was Chu's teacher.
This achievement is not solely the result of Chu Junhao's years of scientific endeavors. Looking back 70 years ago, it was also the dream and aspiration of a young Chinese. During the event, Academician Chu shared his high school notebook, in which he wrote: "With its ancient history, China surprisingly lacks any laws named after its people. This fact serves as a great stimulus and challenge to anyone with national pride. We must rise to this challenge and, within the shortest time, establish laws named after Chinese people, proportionate to our population. It is a discovery made by our great China, and we must strive to bring honor to our magnificent motherland." Today, as a world-renowned expert in infrared physics, Academician Chu Junhao continues to lead his team in exploring the mysteries of the infrared world, bringing more convenience and improvements to our lives.
