“Whether in real life or in the world of nature and animals there is a lot of 'invisibility', and this is not magic, is a scientific means,” Chu Junhao, infrared physicist and the academician of the Chinese Academy of Sciences, said at a scientific event on Saturday evening. Photo: Sina Weibo

"Whether in real life or in the world of nature and animals there is a lot of 'invisibility', and this is not magic, is a scientific means,"Chu Junhao, infrared physicist and the academician of the Chinese Academy of Sciences, said at a scientific event on Saturday evening.

In fact, today's technological developments have opened the door to the possibility that Harry Potter's invisible cloak could go from magic to reality. Chu demonstrated the "invisibility" at the event, and he made his legs disappear directly with the help of a magical material called "lenticular grating" that allows light to be refracted regularly. The magical scene elicited gasps from the audience at the scene.

This is a special kind of material, made up of rows of tiny cylindrical convex lenses arranged into a cylindrical convex lens, each cylindrical convex lens will compress the object behind the object into a thin strip, and enough lenses break the object into an infinite number of identical thin strips, giving people a kind of illusion of invisibility.

"In addition, refractive index can also be used to 'invisibility', for example, objects with high borosilicate glass materials can also be 'invisible' when moving in glycerol with a refractive index close to its own," Chu noted.

This is actually one of the principles of realizing the "invisible cloak", when the fabric of a garment and the air refractive index are the same, people can be freely "invisible" after wearing it, said the expert.

Chu further said that the current exploration of the forefront of "invisibility" cannot only avoid the naked eye, but also avoid infrared monitoring.

With the increasing diversification of modern detection means, for a single spectrum, such as visible light, infrared light, or for a single type of detector, such as radar, laser detection has long been unable to meet people's needs for "invisibility".

"The real 'perfect invisibility' requires that the above detection means can be avoided, and its essence is the low detectability of any electromagnetic wave,"Chu added.

The advent of "metamaterials" provides a new solution for the perfect invisibility of any electromagnetic wave. It is a man-made composite material that changes the conventional properties of light and electromagnetic waves by designing and reorganizing the fine structure of the material.

"In the future, with the gradual maturity of technology and 'metamaterials', the 'invisibility 'fantasy in science fiction works will gradually come to reality." Chu said that it is believed that there will be more "invisibility" equipment to change our lives in the future, such as invisible rooms with better privacy and invisible hearing aids.

"When I read Harry Potter as a child, I never thought that one day someone would be able to appear in front of me wearing such a cloak of invisibility, and now I look at the day may not be too far away,"one netizen said on Chinese social media platform Sina Weibo. If this technology does become widespread, won't it mean the cost of crime will fall? The law should also be improved to prevent similar situations from happening, said another.

Global Times