When you observe the universe carefully, you will find that the shape of most celestial bodies is a sphere . Although some spheres do not look so round, such as the "walnut"-like Titan , but from Basically, everyone is still very similar. And when humans discovered the mystery of the sphere, they have been trying to make it more perfect.
Sphere in the universe
So, is there really no perfect sphere in this world? The most perfect sphere created by scientists still has deviations.
The "most perfect sphere" created by scientists
Spherical things are still very common in people's daily lives, and from our naked eyes, those ordinary spheres are already very round, but in the eyes of scientists "poor Under the strict requirements of , the ordinary spheres of are not suitable for the table.
Round billiard ball
Because of this, scientists want to create a most perfect sphere. It is reported that the process of creating took 5 years, and about 2 million euros were invested.
In this "Perfect Sphere Research Group" , there are top scientists from various countries and fields. They work together to discuss in order to make the project progress more smoothly.
Scientists are measuring the most perfect sphere
This project to create a perfect sphere is code-named "Avogadro" . Avogadro himself is an outstanding physicist and chemist, the famous " Avogadro's Law" comes from his research. In order to make this sphere more perfect, scientists have paid great attention from the planning and building process to the selection of materials .
Avogadro
Many people may not understand, isn’t it just to build a sphere? How can there be so many and difficult ?
In fact, the first step to create a perfect sphere is to measure the volume of the sphere. In this process, not only the high-precision interferometer but also the optical crystal detector is used.
The former aims to measure tens of thousands of points on the sphere, while the latter is to detect the distance and structure between the " atoms " that make up the sphere.
needs to measure the atomic distance
It can be seen that 's calculation of the volume of the sphere is not done by just plugging in the formula, but it has gone deep into the microscopic level. Rather than measuring it, it is better to say that it is performing an anatomy on the sphere. .
After determining the volume model, looked for a suitable material . After selecting and choosing, we finally decided to use silicon 28. This raw material was separated from using an centrifuge. This process was not smooth sailing. After several failures, we finally obtained a crystal made of silicon 28.
Silicon element
It's not over yet, because although the creation was planned according to the previous calculations, this sphere is still not perfect . Therefore, the last step is "polishing".
We Chinese people always say that "jade cannot be used unless it is polished." But in the eyes of these scientists, this ball cannot be perfect unless it is polished. The polishing of
and is very fine, and the polishing of is not done by machines, but manually. In this way, everyone worked around the ball for a long time, and finally controlled its diameter to 93.75 mm, making its roundness reach 0.3 nanometers.
Simply put, the error of any point on the surface of this "sphere" to its center can be controlled within 3 times the atomic diameter .
Hand-polished
It can be seen that although it took five years and the help of so many professionals, this most perfect sphere still has deviations. Even though this deviation is not visible to our naked eyes, it still cannot be judged as "perfect".
Seems perfect, but there are still errors
Speaking of which, you may think that this kind of experiment is a complete waste of time on . After all, as early as the beginning of the experiment, scientists thought that should be scaled from the microscopic level. This ball It's impossible to be perfect. If is like this, why do we still have to waste time and effort to build it?
How much does one kilogram weigh?
Most people have heard such a brain teaser when they were young, which is "one kilogram of cotton or one kilogram of iron" which is heavier . At that time, many people may blurt out that iron is heavier. Although we now know that this is a word game, we still don't know much about how much a kilogram of weighs and how it is defined .
Brain teasers about 1 kilogram
Therefore, the ball with a diameter of 93.75 mm created by scientists is actually to "define the kilogram" . The weight of this ball is 1 kilogram. After its birth, it was used to compare with the "kilogram prototypes" of several countries to verify whether these kilogram prototypes were accurate enough.
You must know that although the kilogram prototypes in various countries were standard at the beginning, they will gradually appear errors as the environment affects .
The data shows that the physical object that defines the "kilogram" is a standard weight made of 90% platinum and 10% iridium. However, this physical benchmark is easily affected by the environment. France's IPK has gained 50 micrograms in weight over the past 100 years, leading to deviations in quality-related measurements.
The original kilogram
can be seen. The previous kilogram of is no longer applicable to . In this case, , the International Committee for Weights and Measures decided to improve the accuracy of one kilogram again, using Planck's constant as the benchmark. , to redefine the mass unit.
Under this circumstance, kilogram prototypes around the world have undergone changes and calibrations. When people correct the kilogram, they no longer use the big K, but use the Kibble scale.
Stock, who is responsible for this change, said, "Nobel Prize winner Charles Édouard Guillaume believed that the current definition of the kilogram could be used for 10,000 years, which was obviously too optimistic. I'm not sure if this will be the last time the kilogram is redefined, but the new definition should be enough to last for a while."
The structure of the Kibble scale
In summary, whether it is the near-perfect ball or the work of scientists. Some other work is essentially for to make the basic unit realize quantum into .
This seems a bit unnecessary to ordinary people. After all, no matter how accurate the kilogram is, its impact on our daily lives seems to be very slight. But in the eyes of scientists, this is what must do in order for to assist the future scientific development of . Why does
need to quantize the measurement unit?
First of all, with the advancement of human science and technology, many high-end fields have increasingly strict requirements for accuracy . In these fields, the smaller the error, the better. This kind of error is not as simple as whether the naked eye can distinguish it, but it must be close to perfect. After all, the basic unit of must be physically reproduced in . It cannot just be perfect in theory. Once it comes to experiments, various errors will appear. deviation.
High-precision field requirements
Secondly, if we always use the big K in to define the unit , then we must accept its damage and changes in the daily environment. The changes in the kilogram prototype are often unknown to us. If it is measured with and calibrated with every year, it will be very time-consuming.
The last thing is that this move is actually a manifestation of human technological progress. In the past, although we also knew that quantized would be more standard , we did not have that condition. Although
is not perfect now, it is getting closer at least. Therefore, in order to make the basic units appear more "scientific", it is important to redefine .
Quantize the unit
In fact, in the process of pursuing the exploration of the world, human beings have done many things that seem unnecessary , because these things cannot achieve perfect results even after thousands or even tens of thousands of years. . But our must do , because sometimes the result of is not the most important, what is important is the process of exploration.
Perfection is far out of reach, but the pursuit is endless
From the perspective of ordinary people, it seems useless to create a perfect sphere. Similarly, there is no point in constantly calculating pi or experimenting to approach absolute zero .
But in fact, many of 's brilliant theoretical achievements were born in these experiments. Human beings are not actually pursuing perfect "effects", but want to find more "causes" in the process.
"The most perfect sphere"
Take pi as an example, we all know that it is a non- recurring decimal , so no matter how you calculate it, you will not find any rules from it. But even so, scientists will still use the supercomputer to calculate more digits after the decimal point.
This not only highlights the perseverance of human beings to explore, is also of great significance for verifying the performance of computers. And like the experiment of absolute zero, we can only infinitely close to minus 237.15℃, but we can never reach it.
Humanity's exploration of pi
But scientists will not give up the experiment just because they know that "the experiment has no ending", because many truths are obtained through seemingly meaningless exploration, it requires long-term accumulation. In fact, this applies not only to scientific research, but also to our lives. After all, although perfection is out of reach, the pursuit is never-ending.
Exploration never ends
