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MMost people know how much pound pound – 16 ounces. The socialites among us may know that a kilogram is 2.2 pounds – or 1,000 grams. But are we really do these numbers mean? To agree on units of measurement is much more complicated than it seems, and the way humans hear about weights around the world is about to change completely.
For more than a century, the world standard for the kilogram has been the international prototype of the kilogram, a platinum and iridium cylinder stored at the International Bureau of Weights and Measures in France. The BIPM is an international organization that contributes to the standardization of international science and trade by establishing measurement standards on which we can all agree. This is why the BIPM has the IPK: Without this small heavy cylinder, the world would not have a standard kilogram to determine the weight of a kilogram. Copies of the IPK (sometimes affectionately nicknamed "The Big K") have been distributed around the world so that member countries can maintain the standard. Every 40 years, the IPK is measured to ensure that one kilogram remains. Recent measurements, however, have shown that the masses of these Great K diverged, which could spell chaos for trade, science and potentially as sensitive areas as rockets, in which the calculations must be precise.
This system may seem odd and archaic, but it's a good reason why the world has been using this reference weight for so many years: it's very hard to know what a kilogram is. Here's why.
While we can think that different units of measurement are their own natural laws, defined in reference to each other – for example, one day is 24 hours, one hour is 60 minutes, and one minute is 60 seconds – the truth is that Measurement units have always been defined in terms of concrete phenomena in the world. In metrology, the study of measurement, these concrete phenomena are known as artifacts.
As an aerospace engineer Max Fagin described in a tweet thread On Thursday, scientists have come a long way over the years to find a way to go beyond artifacts in order to measure elements without having to place them next to other elements. For example, a second was measured in 1 / 31556925.9747 of the time it takes the Earth to circle the sun. This is now the time required for an electron in a cesium 133 atom to oscillate 9 192 631 770 times. This may seem unnecessarily specific and frankly bizarre, but by defining a unit of measure in terms of the behavior of an atom, scientists can say with a reasonable degree of certainty, that a second is a second, no matter your position in the world. universe – and no. It does not matter if you have a stopwatch.
In short, scientists have moved the standard reference point for measurements of man-made objects to universal constants. All except the kilogram.
The second, like the kilogram, the meter and four other units, constitutes the international system. These are the most basic units of measurement on which all others are based. Nowadays, most SI units can be determined without any artefact, but measuring a kilogram is much more difficult, as it requires complex calculations, complicated by gravity. After all, if we often consider mass and weight as identical, they are not. Mass, measured in kilograms, is the amount of matter contained in an object. But that's how scientists plan to make the IPK obsolete.
This is where Kibble balance comes in to save us. This device, being developed by several laboratories. The National Institute of Standards and Technology of the United States and the National Physical Laboratory of England are both working on this device, which is expected to redefine the kilogram in terms of Planck's constant, an essential figure for our understanding of quantum mechanics. In short, this device does not determine the mass by measuring the weight, but by measuring the electromagnetic force between two plates. Oh, and everything is done in a vacuum.
The Kibble Balance, to put it simply, should be able to measure the mass of an object – the IPK, for example – in terms of electrical power. To get all the necessary calculations, watch the video below. For those who are not in the thick of the subject of physics, suffice it to say that the croquette scale should help scientists to redefine the kilogram.
"One of the main reasons to do this work is to ensure international security," said Ian Robinson, head of the engineering measures division of the National Laboratory of Physics, Luxembourg. Delano. "If the Pavillon de Breteuil" – where the IPK is stored, "burned tomorrow and the kilogram stored in its vaults melted, we would have no further reference to the world system of metric weights. There would be chaos. The current definition of the kilogram is the weight of this cylinder in Paris, after all. "
And that is not enough for international science.
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