readx;?“ That...... What do you all study? Niu Tiangou seems to have taken some interest in Weng Yuerou's scientific research institutions. Pen, fun, and www.biquge.info

"Mainly research stealth materials." Weng Yuerou replied casually.

Stealth materials? Niu Tiangou was taken aback.

Could she ...... It's impossible, her own cowhide clothes don't say that she just met, and even Dr. Xue Lian, who shared the bed with him, couldn't know.

Like bobbin nail shells, the cowhide gown is an eternal secret in his heart, and he will never tell anyone.

"What are the stealth materials?" Niu Tiangou smiled and pretended to be stunned.

Hearing that Niu Tiangou seemed to be interested in what he was studying, Weng Yuerou was willing to talk to him more, stopped her chopsticks and thought about it: "Stealth materials are roughly divided into two categories-

"One is a material with a special lattice structure, which can change the refractive index of the object itself, so that the electromagnetic waves such as visible light, microwave and infrared rays 'turn', called 'light stealth material';

"The other type is the absorbing material with the function of absorbing electromagnetic waves, which is mainly aimed at microwaves with a short wavelength and does not involve the field of visible light, which is called 'absorbing stealth material'.

"Wave-absorbing stealth materials are mainly aimed at radar's 'electronic eye', fighters, warships, missiles, etc., in order not to be discovered by the enemy's radar, this material must be used, therefore, this wave-absorbing stealth material has been vigorously studied by various advanced countries, and is widely used in military targets such as stealth fighters, stealth warships, and stealth missiles.

"The inflection stealth material is mainly aimed at the human body's 'naked eye', which is composed of tens of millions of 'metamaterials' similar to man-made glass fibers, which can catch visible light, microwave and infrared electromagnetic waves and change their direction, if the research is successful, it will be widely used in the stealth of the human body and the stealth of ground targets.

"Because the wave-absorbing stealth material is only for the microwave with a short wavelength and does not involve the field of visible light, the stealth fighters, stealth warships, stealth missiles, etc. painted with it cannot be detected by radar, but can be observed by the naked eye of the human body, while the bending stealth material is not only for microwaves, but also for infrared and visible light These electromagnetic waves, therefore, the human body or objects hidden by it cannot be seen by the naked eye, and the radar cannot find it.

"Therefore, the light stealth material is closer to the original meaning of stealth than the absorbing stealth material, and it is more difficult in the current research technology."

"The invisibility material you mentioned is used to make an invisibility cloak, right?"

Hearing this, Niu Tiangou finally understood two points, one is that the light stealth material is more 'high-tech' than the wave-absorbing stealth material, and the hidden human body or object can not only be found by radar, but also cannot be seen by the naked eye, and the second is that the current research technology of the light stealth material is immature.

That is to say, his cowhide robe is likely to be a "high-tech" invisibility material, which has not yet been fully developed by humans, and no one in this world has a real 'invisibility suit' except for him.

"You can say the same thing."

Unexpectedly, Niu Tiangou understood so quickly, Weng Yuerou continued: "Although there are many technical bottlenecks to be broken, the research of stealth clothing has still developed rapidly in various advanced countries, and has become one of the most cutting-edge and popular research fields in electromagnetism, physics, optics, materials science and its interdisciplinary disciplines in recent years. ”

"That'...... How exactly does the invisibility cloak work? Although Niu Tiangou didn't know anything about the stealth material, he was secretly very curious about his cowhide coat.

Weng Yuerou smiled and explained: "The reason why people can see all kinds of objects with the naked eye is because after the light hits the surface of the object, it is blocked by the object and reflected into the human eye, so that various 'images' of the object are formed in the human eye, and it is 'seen' by people." If there is a material attached to the surface of an object that can guide the light waves that hit the surface of the object to turn around and 'go around' the object without reflecting it into the human eye, then in the eyes of the person, the object seems to become 'non-existent', and the visual 'invisibility' is realized.

"It's like putting a stone in a stream, and the stream will go around the stone and continue forward, the principle of the cloak is basically the same, except that the cloak is equivalent to the surface of the stone.

"However, there are still many technical difficulties in the development of this kind of material that allows light waves to turn around and 'bypass' objects.

"There is a theoretical physicist in Yanguo who proposed the method of using coordinate transformation to design an invisibility cloak, so that electromagnetic waves (light waves belong to a type of electromagnetic waves) can bypass the object and propagate in the original direction, so that people can see the scenery behind the object after 'seeing' the object, so that the object can be completely invisible, and the theoretical system of invisibility cloak research has been laid.

"However, the stealth suit designed by this method can theoretically only achieve 'turning light' on a certain electromagnetic frequency, and it is difficult to achieve stealth in a wide frequency band.

"In addition, the parameters of the stealth suit are complex, and to achieve stealth in the visible frequency band, fine nanofabrication accuracy is required, which is very demanding on the process.

"Besides, a person puts on an invisibility cloak and wraps it tightly, like a guinea pig sewn into a cloth bag, others can't see him, and he can't see others, unless two small holes are dug in the invisibility cloak to expose his eyes, but the two big eyes hanging in the air and blinking not only 'expose' themselves, but also enough to scare others away.

"Therefore, it is also necessary to attach anti-stealth materials to the eye part of the invisibility suit, so that the person wrapped in the invisibility suit can see the outside without being seen by others.

"The invisibility materials and anti-stealth materials used to make stealth suits are 'metamaterials' composed of nano-scale tiny particles, which do not exist in nature, but are completely developed by scientists in the laboratory, and there are some technical bottlenecks for the time being. In addition, there are many problems such as ventilation and heat dissipation, deep technology, and high cost.

"In short, humanity still has a long way to go before it can create the perfect invisibility cloak and achieve complete invisibility in science fiction. However, many things in science fiction have become reality, and with the development of technology, it is very likely that the invisibility cloak will become a reality in the future. ”

"But...... How do I seem to have seen an invisibility cloak like this somewhere? Niu Tiangou didn't know if he was a little dizzy after drinking too much or listening too devotedly, and he was a little ignorant and involuntarily said, "It seems to be super thin." ”

These words made Old Professor Weng, who had been listening to him beside him, stunned and looked at him suspiciously.

"Absolutely impossible."

Weng Yuerou was stunned for a moment, then shook her head categorically, looking at Niu Tiangou with a very strange expression: "At present, the level of human science and technology has not yet reached that level, unless ......"

"Unless what?"

"Unless it's alien technology!" Weng Yuerou glanced at him a little playfully.

Alien technology?

Niu Tiangou's heart shrank suddenly, his brain immediately sobered up, and he smiled disguisedly: "Ahem...... I've probably watched too many science fiction movies. ”

Grandma's, almost said that she showed her mouth in front of the beauty, but fortunately, Weng Yuerou didn't believe it.

Nima, this cowhide robe from the aliens, its stealth performance is at least one to two centuries ahead of human technology, how can humans have it?

However, Weng Yuerou's words gave him a more scientific understanding of the cowhide Tianyi, and he no longer had that sense of mystery.

Damn, communicating with people who are engaged in scientific research, the harvest is different, and talking to you is better than reading a book for ten years.

He has to thank Dr. Xue Lian, this visit to Professor Weng Lao is really not in vain.