What's the matter, can you still stop me? Gu Liuxiao suddenly rebelled.

"....." Feng Yu was stunned by Gu Liuxiao's words, and soon, he said, "Yes." ”

Gu Liuxiao picked up the clothes that Feng Yu had poured on the table, found the belt from it, and then continued to fix it around his waist, so that it was even tighter: "Hey! I'm coming. ”

"You're not wearing it." Although Feng Yutian didn't see it, listening to the voice, he knew that she was just "pretending" to wear it.

"Come and see, I'll put on your coat and I won't see anything at all." Gu Liuxiao is really too lazy to wear it, and he has put on his clothes, which is really troublesome.

So, Gu Liuxiao sat down at the table, feeling like he wouldn't leave.

...........

"Nope." Feng Yutian was very persistent, Gu Liuxiao's appearance just now seemed to be vivid, she was simply.... Too defenseless against yourself.

Although she has lived as a boy for a long time, she is not a boy after all.

"Let you come in and have a look." Gu Liuxiao was helpless, it was so troublesome to redress like this, and he finally got hot.

"Put it on." Feng Yutian still insisted.

"Nope." Gu Liuxiao said, she had just finished soaking in the hot springs, and she didn't have much strength in her body, so she sat all the time, and there was nothing wrong anyway.

........

After sitting for a while, Gu Liuxiao got up and prepared to leave.

When she got to the door, she found that the door couldn't be opened.

"Hey, are you leaning against the door? There's no need. Gu Liuxiao kicked the door and said.

"Get dressed." Feng Yu said, with only a little internal force, he can make this door not open, he doesn't need to block the door at all.

"No." Gu Liuxiao insisted.

......

In the end, Feng Yutian still compromised, after all, Gu Liuxiao was the first scoundrel.

Gu Liuxiao opened the door, and saw Feng Yu standing in the air with a drum and grunting Gu Liuxiao Gu Liuxiao, she was suddenly a little curious: "Hey! ”

As the saying goes, there are no rules, and this shows the importance of standards. However, if we understand the arbitrariness of some standards at the beginning of formulation, the authority of the standards will inevitably be greatly reduced - among the standards for volume, weight, length, etc., the determination of length standards is the earliest and the most arbitrary.

Horse butt also constrains today's rocket boosters

The track spacing of modern railways is 4 feet 8.5 inches, and the track spacing is based on the standard of tram wheel base, which is the same as that of horse-drawn carriages.

In ancient times, certain parts of the human body were important in setting the standard of length by footage at the beginning of an adult's foot. But the Germans were not satisfied with this arbitrariness, believing that the length of the foot varied from person to person, and that it was too wrong for people to calculate the length based on their own foot length. So, in the 16th century, they took 16 men, added the length of their left foot and divided it by 16 to find the average foot length, which is now "feet."

Qin Shi Huang: The "Terminator" of Princely Body Parts

The arbitrary definition of length standards is not limited to foreigners, and the situation in China is basically similar. History records that in ancient times, the Chinese "knew the ruler of the hand", "the height is the zhang", and "the step is fixed". The length of the middle knuckle of the middle finger of the ancients was defined as "one inch", and until now, acupuncture in Chinese medicine has followed this standard.

Occupy.

The earliest recorded anthropogenic standard comes from ancient Egypt. The Egyptians used to make a length scale out of hard granite, which was the distance from the pharaoh's forearm (elbow to middle finger), hence the name "cubit". Although this criterion was determined rather arbitrarily, it solved important problems, such as ensuring the accurate construction of the pyramids. In the Spring and Autumn Period and the Warring States Period, the princes of each country set their own length standards within their territory. The palms of this king, the calves of that king, all came in handy, making the length standard extremely confusing and causing great inconvenience to the communication between countries. It was not until Qin Shi Huang unified weights and measures that the body parts of the princes withdrew from the stage of history.

"m"

Without the French, it would be difficult for people today to get rid of the embarrassment caused by "horse butts" and "calves". The unit of length widely used in today's world is the "meter", and the metric system was finally determined, no

After the victory of the French Revolution, Lagrange, a scientist with revolutionary ideas, was elected chairman of the French Commission on Weights and Measures in 1791. Under his push, the French authorities stipulated and "shank" much smarter. But the question is, how do you know the length of the Earth's meridians? Astronomers Joseph de Rumbull and André Mechamp took on this difficult task. In the midst of the frenzied revolution and the flames of war in Europe at that time, the two scientists risked their lives to work.

Seven years later, Dromble and Mechamps returned to Paris with survey data. The French Commission of Weights and Measures made a standard meter ruler out of platinum-iridium alloy based on the measurements of two scientists, which is what we often call the "rice prototype". In 1812, the meter system was introduced in France. In 1875, the International Committee on Weights and Measures held a meeting in Paris, and representatives of the governments of 17 countries, including France, Germany, the United States and Russia, jointly signed the "Metric Convention", and the metric system became the internationally accepted length standard.

With the increasing requirements of science and technology for the accuracy of length standards, the rice prototype is increasingly unable to meet the needs. As a result, a more precise natural datum was born. In 1960, at the 11th International Conference on Weights and Measures, the scientific community redefined the standard of meters: in a vacuum, Krypton-86 (an isotope of krypton) emits an isotropic orange light wavelength of 1,650,763 times 1 meter.

However, the light wave length of Krypton-86 is difficult to obtain, and countries find it inconvenient during use. Thus, one thought of the constant speed of light in a vacuum. In 1983, the International Bureau of Weights and Measures redefined the "meter": light in a vacuum, with a travel length of 299792.458 meters in 1/1 second. This criterion has been used to this day.

The ancient Greeks admired the beauty of the human body, and they found the beautiful man Curicius, and used the distance between the fingertips of his two hands when he stretched out his hands as the length standard, called "Yixun". In ancient Rome, Julius Caesar walked 2,000 steps as a "Roman mile" when his army marched. Later, it was used by the British, and this is the "mile".

In the 9th century, during the reign of King Henry I, he organized ministers to discuss "how long a yard should be", and the ministers argued endlessly, each with their own reasoning. Henry I was in a hurry, slapped his thigh and said: Don't make any trouble, one yard is the distance from the tip of my nose to the tip of my index finger. Thus, the "yard" was born with the wrath of Henry I. The standard for inches is the length of the thumb joint of Emperor Edgar in the 10th century. In the 14th century, Emperor Edward II promulgated the "Standard Legal Inches", which took the three largest grains of wheat from the ears of barley and arranged them in a row, which was one inch in length.

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