The world's standard weight is mysteriously lightening

The 118-year-old cylinder, the international symbol for mass units, is strictly preserved by a key in the suburbs of Paris, which is lightly understood.

This 1 kilogram weight seems to have lost 50 micrograms compared to the average weight of its many versions, physicist Richard Davis from the International Commission for Volume and Metrology.

"The mystery is that all of them are made of the same material, and many weights are made at the same time and stored under the same conditions, but until now, their masses are gradually different," he said. "We have not really had a good explanation for this issue."

The change in the kilogram weight may even affect countries that do not use the metric system, according to the conversion rule. For scientists, the volatility of this variable unit of measurement threatens to compute large precision projects, such as power plants.

Of course, it is difficult to immediately see the effect of weight loss: 50 micrograms are only equivalent to the weight of a fingerprint.

"For a person lying, that doesn't mean anything. The kilogram remains the same, and your weight index remains exactly the same."

Richard Davis and international standard weights. (Photo: AP)

T. An