The New Kilogram
Posted by on Saturday, November 17, 2018
A slightly different form of science today, as the international scientific community has today officially changed the definition of the kilogram. And while it may not be the most exciting scientific discovery, it has many ramifications for a number of future research projects and experiments.
In a historic vote, scientists and engineers (and a few politicians) from more than sixty different nations unanimously approved a change to the international measurement system that is the basis for global trade and scientific research, with new definitions for metric units such as the kilogram that no longer rely on physical and inconsistent objects.
The most notable and important of these is the redefinition of the kilogram, the standard unit of mass. For over a century the kilogram has been defined as the mass of a cylinder of platinum-iridium alloy which is kept in a secure vault in France. That standard mass, which was nicknamed "Le Grand K," has been the world's reference for the kilogram since 1889.
However using a standard mass creates a number of problems for high precision research and engineering. Although it is kept in a carefully controlled environment, the standard mass can acquire dust and dirt which increases the mass of a kilogram slightly. As a result, high precision measurements in the past have had a significant uncertainty due to the lack of a clearly defined kilogram. The new system should resolve such issues as the kilogram (and other units) will no longer be dependent on a physical object.
Under the new system, the kilogram and all the other standard units will be defined using physical quantities that are not dependent on an arbitrary object. Scientists already base the measurement of seconds and meters on the properties of light and on atomic physics, and the new system will also define the kilogram based on various fundamental constants in gravity and quantum mechanics.
For most people this change will be meaningless. The new definition was carefully selected to match up as closely as possible with the previous standard, and the difference is truly minute. For scientists, it was a change that was long overdue...
In a historic vote, scientists and engineers (and a few politicians) from more than sixty different nations unanimously approved a change to the international measurement system that is the basis for global trade and scientific research, with new definitions for metric units such as the kilogram that no longer rely on physical and inconsistent objects.
The most notable and important of these is the redefinition of the kilogram, the standard unit of mass. For over a century the kilogram has been defined as the mass of a cylinder of platinum-iridium alloy which is kept in a secure vault in France. That standard mass, which was nicknamed "Le Grand K," has been the world's reference for the kilogram since 1889.
However using a standard mass creates a number of problems for high precision research and engineering. Although it is kept in a carefully controlled environment, the standard mass can acquire dust and dirt which increases the mass of a kilogram slightly. As a result, high precision measurements in the past have had a significant uncertainty due to the lack of a clearly defined kilogram. The new system should resolve such issues as the kilogram (and other units) will no longer be dependent on a physical object.
Under the new system, the kilogram and all the other standard units will be defined using physical quantities that are not dependent on an arbitrary object. Scientists already base the measurement of seconds and meters on the properties of light and on atomic physics, and the new system will also define the kilogram based on various fundamental constants in gravity and quantum mechanics.
For most people this change will be meaningless. The new definition was carefully selected to match up as closely as possible with the previous standard, and the difference is truly minute. For scientists, it was a change that was long overdue...
I am a theoretical physicist & mathematician, with training in electronics, programming, robotics, and a number of other related fields.
