Now that mobile phones are more and more intelligent, we are more and more dependent on them. However, the doubt that mobile phone radiation harms our health has never dissipated.

Tang Can, a third-year doctoral student in theoretical physics (nuclear physics) in Peking University, once thought that mobile phone radiation would be harmful to people's health. He would put his mobile phone far away from himself when he slept at night, and it was not until he learned some knowledge about radiation in college that he dispelled this doubt.

You can safely use your mobile phone and microwave oven.

Mobile phone radiation, like visible light in the sun, belongs to electromagnetic radiation (also known as "electromagnetic wave"). Tang Can explained: "Generally speaking, the smaller the wavelength of electromagnetic radiation, the greater the energy, and the greater the harm to people." The wavelength radiated by mobile phones is more than 800,000 times that of visible light. Among them, the wavelength of mobile phone radiation is between 17 cm and 37.5 cm (the wavelength of China mobile signal is 17 cm or 33 cm, the wavelength of China telecom signal is about 37.5cm, and China Unicom has it-reporter's note), while the wavelength of visible light in sunlight is 400-760nm (1nm = 0.000).

Nora, a neuroscientist at the National Institutes of Health? Dr Volkow has also done research in this field, in which he used a Samsung mobile phone (Samsung? Trick? Phone), its peak electromagnetic wave absorption rate (SAR) in human head is lower than 1 watt/kg, iPhone? This data of mobile phone is 2 watts/kg. When people sunbathe, the average SAR of the sun will reach 5 watts/kg. So we live between sunrise and sunset every day, and there is absolutely no need to worry about the harm of mobile phone radiation to our health.

However, the wavelength of microwave oven, which is often worried about radiation, is between 1 mm and 1 m, which is much larger than the wavelength of visible light, so the radiation of microwave oven is not harmful to people's health.

Tang Can said that the space we live in is full of electromagnetic radiation, including broadcast signals, which is also a kind of electromagnetic radiation. Computer screens and TV screens also emit electromagnetic radiation, but the wavelength of these electromagnetic radiation is longer than visible light, which is not harmful to people's health.

When asked if he would buy radiation protection clothes for his pregnant wife in the future, Tang Can said, "It is totally unnecessary. It is difficult for us to come into contact with electromagnetic radiation that is harmful to our health in our daily life. "