Redefine the kilogram

Scientists have said they are nearing an immaterial definition for kilograms (kilograms) after detecting that the standard weight is mysteriously lightening.

Researchers believe that there are still some things to do before completing this difficult swallowing mission. However, if they succeed, it will completely stop relying on the standard kilogram block when measuring.

Standard weight at Sevres

Currently, the international standard for kilograms is a carefully preserved metal block in the bunker of the International Weighing Agency (BIPM) in Sevres, France since 1889. Most countries have copies. of the standard kilogram block and they are compared to the original every 10 years.

However, the worrying scientific community when it came to finding that the weight of platinum and iridium was suddenly lightened without knowing the reason . BIPM experts revealed in 2007 that the standard weight lost about 50 micrograms within 100 years compared to its versions.

Therefore, experts are looking for another way to define the kilogram by non-physical methods such as the other 6 units of international base units, meters (length), seconds (time), ampere (intensity electric current), kelvin (thermodynamic temperature), mol (amount of matter) and candela (light intensity). There are currently no units other than kilograms measured by objects.

In an effort to find a method to replace the standard weights, scientists have conducted experiments that focus on establishing the relationship between mass and Planck's constant, the basic unit of measurement in physics. atom.

The BIPM scientist, Michael Stock, said the standard weights were almost out of use. " Measurement is becoming more accurate, and accurate measurements need to have accurate definition units to get the most results ," AFP quoted Stock.

Stock said the experiments had very positive results, but it is still too early to apply the new definition to the kilogram.