“Discoloration card?”


  “Three-dimensional stereograph painting?”


  The accompanying students first thought about the kind of card toys that they saw at different angles and saw different pictures when they were young. But soon this conjecture was overturned. The font on the iron ruler was not flat at all. Instead, it was dug into the iron ruler, and they could clearly see the traces of the dent.

  "Forever Friendship," Professor Kobayashi’s eyes were like the helpless firewood in the fire.

  There was nothing unusual in the front view, he could only see the font from another angle: "What does this mean? It shows that the four characters on the iron ruler are unimaginably horizontal and vertical.

  Its principle is very simple to explain. If a piece of paper is as thin as a wing of the cicada and its sides horizontal and perpendicular to the gaze, then it can easily disappear. Similarly, the bottom of the font that is recessed on the iron ruler should be as rough as the surface. This effect can be achieved by processing straight lines with terrifying accuracy on the side. The explanation is simple, but it is very difficult to do.

  In the live broadcast room, after the popularization of science by knowledgeable mechanical talents, the students brushed sixty-six in the bullet screen……

  "Haha~ Just now, the Japan Institute of Technology was determined that there was nothing, so it was slapped at another angle."

  "It’s so cool, just look at this visual effect, and you can compare that nut. The thread isn’t invisible, but the thread is as thin as the silk. And our four words are as big as mahjong, and the difficulty is natural. It’s much higher."

  "Is this the only thing, student?" Kobayashi lose a word, let the bullet screen and the students below suddenly quiet: "Great ideas, admirable machining accuracy. But in our opinion, the industrial level represented by this gift is still a bit short of the top manufacturing technology."

  It was not arrogance. The technology demonstrated by this iron rule, Professor Kobayashi could also manufacture it using the famous national factory of high-precision instruments. Of course, there were difficulties, and it would take much time, but it was not difficult for him.

  "It’s over, looking at this guy’s confident look as if he can also make this kind of magical lettering."

  "After all, their precision machining technology is the best in the world, and they can’t help but be excused."

  "Ah~ Although it is not difficult, it is not a loss."

  Discussions resumed in the live broadcast room.

  "Professor Kobayashi, I think you misunderstood me." Ye Qing raised the iron ruler in his hand and turned the other side around.

  "In the beginning, you gave us a nut and let us process a screw. Then naturally, we should repay our efforts and present a complete commemorative gift that requires the cooperation of our two schools."

  After a pause, Ye Qing was satisfied with the deflated expression on the opposite side. After showing the iron ruler in different angles and confirming there were no Chinese characters on the opposite side of the iron ruler, Ye Qing’s eyes became calm: "The long friendship is a blessing we send to your school. I want to invite your school to write another sentence in your language on the opposite side of this iron ruler to prove our friendship."

  "Engrave a sentence?" Kobayashi did not respond a little: "What is this sentence?"

  "The answer to what has already been written on the iron ruler, just interpret it, then use your text to engrave it."

  After talking, Ye Qing handed this iron ruler to Professor Kobayashi.

  The camera clearly captured the suspicious ghost on Kobayashi’s face, and the moment he took the iron ruler, his right hand sank obviously, revealing why he was so heavy.

  The students of Japanese science and technology came around with a crash. The highlight is here, it turns out that this iron ruler not only has amazing precision machining technology but also hides a puzzle to solve it. Fortunately, the Japanese University of Science and Technology had already made preparations here.

  At noon, Professor Cai informed them that they would give away an iron ruler as a gift. They kept guessing this iron ruler would be troublesome. Therefore, many of the town’s instruments that needed to be packed into shockproof metal boxes and packed away were also taken to the multimedia center.

  The iron ruler was more than thirty centimeters long, and even the scale was not marked on it. Kobayashi believed that even if there was a mystery, he could easily crack it. This confidence came from the equipment they carried.

  A Nikon s 1500 industrial electronic digital microscope was moved to the desk by students from the Japanese University of Science and Technology.

  Nikon is one of the world’s top optical lens factories. The microscope they took out was the one with the highest effective magnification among the current optical microscopes, and none of them compete. Hum~ Anything, that is so greasy, is nowhere to be hidden under this top optical microscope.

  However, when the students of the Japan University of Technology set up the microscope and turned their gaze to the liquid crystal display on the microscope. Their reaction was more exaggerated than the detonation of a grenade. With a snap, they took a step back.

  "This is impossible!" Kobayashi yelled in his native language: "Why is its surface flat?"

  Other students said probably damn expressions. Because when they just adjusted the magnification to the best observation multiple of 1,200 times, they actually saw the surface of this iron ruler, and it was still smooth. Although it was not as flat as a mirror, it was close to ordinary steel with the naked eye, and its surface was almost the same.

  To study metal, the first step is to study its characterization. At a magnification of 1,200 times, you can directly see the microstructure of the metal surface, like the metal, like snow-like martensite and austenite.

  In the same way, they observed the iron ruler with their naked eyes and found no greasiness. They naturally thought they were hidden under a microscopic mechanism that was invisible to the naked eye.

  "What did they see?"

  If we say the previous lettering. For them, it could be called a difficult level of processing technology. The smooth characterization of this iron ruler was equivalent to the fear level processing technology.

  It took many old energies to suppress the fear in their hearts and continue to study this iron ruler.

  Time passed little by little, and here at the Japan University of Technology side, they had already flown to Siberia for a long time with their pride which had been changing to dignity and madness. Because they couldn’t find anything, no matter what way they would observe. The surface of this iron ruler was all flat, let alone a greasy puzzle, even a non-black stain is unfound.

  "Haha~ You see how they are tangled."

  "I’m embarrassed. Let them look down upon us and give a try again."

  "I think…… they need Detective Conan to save the scene!"

  After half an hour passed, Kobayashi raised his head with difficulty, and his face was covered with sweat beads: After…… After our unanimous study, there seems to be no mystery on this iron ruler. "

  "Yes." Ye Qing replied unhurriedly, making the students of the Japan Institute of Technology almost uncomfortable.

  "Have you measured the length of this iron ruler?"

  "Yes…… I have measured it." Kobayashi took out a handheld rangefinder: "This is a rangefinder produced by our Nikon company. We have measured not only the length but also the width and height."

  "Its length is 0.32569 meter."

  "The length of the ruler is long, and the answer lies in its length." Ye Qing stood up and shook his head: "The accuracy of the rangefinder is not enough. You need to change to a more advanced instrument to re-measure its length."

  "But we have reached the accuracy of Sim, its length is too long to measure with a micrometer. If you want more accuracy, you need to use a laser interferometer."

  "To what level can your laser interferometer be accurate?"

  "Nano level."

  Kobayashi’s voice gave a hint of a roar: "We can be accurate to 2 nanometers, but what’s the point of measuring this iron ruler?"

  "The accuracy of two billionths of a meter is unmachined at this stage. Even our industrial mother machine can only determine the accuracy of metal materials at 50 nanometers."

  "0.32569 meters?" Ye Qing said with a serious look.

  "What do you mean? We measured this length."

  "There are 734 behind." Ye Qing looked at him and reported a number.

  Kobayashi didn’t believe in the authenticity: "Have you made precision to 0.1 silk?"

  "Since your laser jammer does not meet the accuracy standard, then I will tell you the accurate answer."

  Ye Qing said quietly: "We have fixed the accuracy to one-half nanometer, which is the accuracy of 5 parts per billion."

  "The ruler energy is long."

  "If you are in a vacuum box, use a more advanced jammer to measure the length of this iron ruler."

  "You will get such a set of numbers 0.32569734830 a very simple set of decimal numbers, as long as you replace this set of numbers with your text in decimal, you can get the words you want to engrave on."

  There was a tomb silence. The old man of time dropped a time bomb in the multimedia center, allowing for their expression to freeze instantly.

  Convert the length of the ruler to their text? Is it concluded that?

  What words are they going to engrave?

  Ps: (By becoming a Patreon, you can read more chapters, for this; your support is my most principal motivation.)