How we define the weight will change forever.
Image: Photo source: in sycamore, a Duke was found in the vault under his former happy Palace
In the forest west of Paris, there is an apple-sized object that determines the weight of the world.
Under the background of scientific and political turmoil after the French Revolution, a single small platinum cylinder --
In the 130 s, the iridium alloy was largely undisturbed, making it a benchmark of 1 kg in the world.
The international prototype of kilograms, known as Le Grand K, is one of the most sacred relics in science, an analogy that compares all other weights, it is also the totem of the measurement system that accompanies the era of freedom, equality and fraternity.
In fact, it is very respected and has only weighed four times since 1889, and the room stored in the Breteuil pavilion may only be opened when the holders of the three living keys are opened --
People for security reasons must be people of different nationalities.
Turn the lock at the same time.
However, it will soon lose its job.
This week, hundreds of scientists from around the world will gather at the Palace of Versailles to attend the 26 weight and measurement conferences.
There, in a belated act, the founding commitment of the metric system "for all ages, for all" is realized, and they will replace Grand K with a universal formula, the formula defines kilograms using natural quantum laws.
"The kilogram is the last unit of measurement based on physical objects," said Thomas Glenn, director of the national laboratory for measurement and testing in France.
"The problem is that it has its own life;
It may fluctuate.
Given the precision we need today, it's not good enough.
"The prototype of the kilogram was made with an alloy of 1880 platinum and platinum.
Four of the six official copies came from the same period.
Source: afpwhat in a second?
With the adoption of the measurement system, scientists in the late 18 th century need to compile a single structure to express distance, time, electrical processes and quality in similar, transferable units of measurement.
They define Rice as one in a million in the Earth quadrant.
It's natural to cross Paris.
"We look back now and say that the process they went through is very good and we won't do very different things today," said Dr. Martin Milton, director of BIPM, the international custodian of our measurement system.
Rice is used to define quality-
How much per cubic meter (
10 cm x 10 cm)
After that, it's called 1 kg of water.
But science has been developing since then.
Now, the definition of the meter is the propagation distance of light in a vacuum.
The second itself was represented by the rotation of the Earth.
But it has officially become a caesium time since 1960 --
133 atomic swings 9,192,631,770 times-
Not a revolution missing.
The KG is not related to the mass of a single physical object, but will be defined in the future with the Mapo constant-
The ratio of the quantum energy that the frequency of light can carry to the same frequency, or 6. 626 x 10-
34 joules seconds
As Einstein proved with his equation E = mc2, energy has an intrinsic connection to mass.
The Planck constant, combined with two quantum phenomena that allow power generation, can be used to calculate mass based on the equivalent mechanical power required to replace it.
"If you push a quality, the strength you need depends on that quality.
"You can provide power entirely based on our quantum constants," Dr. Milton said . ".
Proponents of this approach say it is at least 1 million times more stable than physical artifacts and will have a range of practical applications in the future.
"1 kg is a very large quality for many applications," Dr. Milton said . ".
Advances in pharmaceutical and chemical production mean that the ingredients in the drug are increasingly measured to micrograms and are becoming more accurate.
"One catty is good for potatoes because they don't need to be very precise, but it's not the right weight for many applications in demanding science and industry.
The new system is infinitely scalable.
"The Kibble balance is an electro-mechanical weight measuring instrument that measures the weight of the test object very precisely through the strength of current and voltage.
Image Source: American scientists will also use the Versailles summit to change amps (
Current), kelvin (temperature)and mole (atoms)
It is expressed through the universal laws of nature.
Dr Milton said the decision was a way to ensure that the world always agreed on what 1 kg is --
Whether it's a bag of sugar, a liter of water or a precise quantum ratio.
"We are in a world where there is concern that efforts to be multilateral have stopped and may be reversed.
But in the field of metrology, states do come together to reach an agreement . "
As for Le Grand K, it may already be more useful as a perfect kilogram, but its contribution to science is far from over.
"It will remain in the coffers in a state since 1889," Dr. Milton said . ".
"It's actually a long term.
The semester experiment, because we will measure it in the next few decades, to see how it responds to conditions.
It is still an object of interest to science.