Ahujia: The definition of kilograms will no longer be the international kgka, but the calculation of Planck's constant, which plays a very important role in quantum physics.
No drinker likes to have a short pound and less. Just as Magna Carta (Magna Carta) realized this more than 800 years ago: the country should have a unified measure.The amount of alcohol, mighty wheat wine and grain is based on London Quar as the standard; the width of dyed cloth, soil cloth, and locks should be based on the two codes below the weaving as the standard hellip;
Last Friday (November 16, 2018), measuring mdash; mdash; scientific mdash; mdash; ushered in another important moment.After an international vote, the definition of a kilogram was changed.Standard quality units are no longer the international kg original (IPK) mdash; mdash; a 19th -century platinum alloy cylinder is stored in a three -layer tank of an underground insurance library near Paris (see the first photo of the text).Instead, a kilogram will use Plancksquo; s constant calculation, which is an incredible number that plays a very important role in quantum physics.
This is a historic moment: kilograms are the last main unit defined by real substance.Voting held by the International Bureau of Weights and Measure in France means that this seemingly so solid measure is based on a basic but intangible natural constant.
At present, the problem of kilograms is hellip; hellip; it is a thing.About 40 copies of the national laboratory around the world, including the National Physical Laboratory of the United Kingdom.Due to surface pollution and oxidation, their quality is gradually different and different, and the difference is about the weight of a eyelashes.
These differences mdash; mdash; measured MDASH; mdash; triggers two problems.First of all, some industries, such as pharmaceuticals and precision processing, are now more accurate for quality requirements, and these old antiques are no longer satisfied.Secondly, the international kgloger is also used to calculate other units, such as Newton, Pascal, and Jiao Er (units of force, pressure, and energy). Quality fluctuations will cause a series of uncertainty in other links of the measurement chain.
The use of basic natural constants to redefine kilograms will make the international unit system stabilize (SI).The international unit system is the 7 basic units formulated in 1960, which constitutes the pillar of today's measurement.A new kg mdash; mdash; plus three other redefined units mdash; mdash; will re -update the Metre Convention, which is an intergovernmental treaty and signed by 17 countries in 1875.
The measurement update allowed two milestone equations in physics to become the protagonist. These two equations associate the basic quantities in the universe, such as quality, energy, radiation frequency and speed of light.
The first equation was e = mcsup2; and the Albert Bull; Albert Einstein proposed in 1905. In the formula, E represents energy, M represents quality, and C represents the speed of light.The second equation was a German scientist Max Bull; Max Planck contributed. He was a prodigy when he was a child, and finally chose physics instead of music.In 1900, Planck proposed a theory that light could only be used as a discontinued energy mdash; mdash; called quantum mdash; mdash; launch, transmission or absorption.
This principle constitutes the foundation of the quantum theoretical. It is expressed in the simple equations of E = HF. In the formula, E represents energy. F represents the radiation frequency. H is a constant.Planck won the Nobel Prize in Physics in 1918, and H became Planck's constant.
Combining Einstein and Planck's formula means that the quality can be defined by Planck's constant.Since 2011, scientists from all over the world have used an extremely precise weighing device called the Kibul scale to establish an accurate value for H, which is finally determined to be 6.626070150 x 10#8315; SUP3;#8308; jbull;s.
The cylindrical body in Paris will eventually fade out of history and become an elegant note, just like the royal law defined in the 12th century: from the tip of the king's nose to the tip he extended.Let us give up a lot of wine, or fierce wheat wine.
The author of this article is a scientific commentator
Translator/He Li
