It has been many days since the 4 geological survey team members were killed in Ailao Mountain, but what is still fresh in people's memory is that in addition to hundreds of search and rescue personnel, a number of search and rescue drones were also dispatched, and the thermal imaging equipment on the UAV once again played a major role, and the remains of 4 victims were found with thermal imaging technology on November 22.
The UAV has made a new contribution, but also sent the "thermal imaging technology" to the hot search, but also let many netizens wonder: the victims carry food is still left, in order to speculate, they may have been killed as early as November 14, 8 days have passed, the body has long been cold, why can it be found through thermal imaging technology?
In today's science and technology fast running, the application of thermal imaging technology is more and more extensive, especially when the epidemic is raging, many large supermarkets have thermal imaging instruments at the door, just look at the forehead can detect the body temperature, if it is a fever patient entering the supermarket will automatically trigger the alarm, so thermal imaging technology is used to detect the temperature of the object.
Thermal imaging technology is also known as infrared technology, here need to know a knowledge point is infrared, in physics, a simple triangular prism can divide the sunlight into 7 colors, red, orange, yellow, green, blue, indigo, purple, the reason is that the wavelength of light of 7 colors is not the same, the wavelength of red light is the longest, the wavelength of purple light is the shortest.
In fact, there are not only 7 colors of light waves in the sunlight, there are infrared rays with wavelengths longer than red light, and ultraviolet rays with shorter wavelengths than violet light, infrared rays and ultraviolet rays are invisible light waves, we are invisible to the naked eye, infrared is not visible, but it can heat objects, this conclusion has been drawn as early as 1800.
Infrared frequency is 0.3THz ~ 400THz, according to different wavelengths can be divided into three kinds, wavelength in 3 ~ 0.75μm, belongs to the near infrared, wavelength in 40 ~ 3μm, belongs to the intermediate frequency infrared, wavelength in 1500 ~ 40μm, belongs to the far infrared. Why segment? Because infrared rays of different wavelengths can be selected according to different needs.
Don't think that only the sun has infrared, in fact, everything will produce infrared, but the infrared produced by objects with extremely low temperatures is extremely weak and cannot be felt at all, physics defines infrared as such, as long as it is above absolute zero, it will produce infrared, and absolute 0 degrees is -273.15 ° C.
Since this is the case, then we only need an extremely sensitive infrared detector to detect the temperature of everything, mobile phones, computers, stones, people, tables, etc. The temperature can be quickly known, much faster than the traditional thermometer, which is the great convenience brought by modern science and technology to human beings.
After many updates, today's infrared detectors are very sensitive, even if the object appears 0.00001 °C slight change, precision infrared detectors can also be felt, but the infrared detector we usually use does not need to be so sensitive, only 0.01 °C sensitivity is already satisfied with commercial applications.
May be influenced by science fiction dramas, some people mistakenly think that infrared equipment is to see people hiding behind the wall, American blockbusters have appeared in such a scene, with infrared equipment to find enemies behind the wall, there are people mistakenly think that infrared equipment can penetrate clothes, but in fact it is not so magical, infrared can neither penetrate the wall, nor can it penetrate clothes.
After understanding the thermal imaging technology, let's answer the question of why the thermal imaging technology can find the remains of the victims. In general, people's normal body temperature is about 36.9 degrees Celsius, if the person dies, the internal heat production function of the body stops, and with the dissipation of heat, the body gradually becomes cold, and the 12 hours are basically close to the ambient temperature.
As we all know, the human body contains a variety of microorganisms, especially the intestine, after death, there is no control of the immune system, these microorganisms breed unscrupulously, and use the human body as food, microorganisms will produce heat in the process of decomposing the human body, in general, after 24 hours, the human body begins to decay.
Even a little bit of heat generated by the decomposition of microorganisms in the body can make the body temperature higher than the ambient temperature, even if it is 0.01 ° C, it can also make sensitive thermal imaging technology discover, which is why thermal imaging equipment can look for people who have just died recently, but also find people who have died for a long time, of course, comatose living people are better to find.
This is why the four geological team members of Ailao Mountain have been dead for many days, and the UAV thermal imaging can still find the victims, in the search and rescue operation of Ailao Mountain, if there is no UAV, I am afraid that the search and rescue personnel need to spend more time and energy to find, and they will only put themselves in danger. Interesting and informative scientific content, please pay attention to the only WeChat public account: Interesting Exploration # Four missing people in Ailao Mountain, Yunnan Have Found the ##哀牢山 #