What are the advantages of defining standard units in terms of intrinsic physical phenomena rather than artifacts? Give examples
Standard Unit
Standard units are defined as those units that do not depend on other units are qualities to describe them. These units are invariable, predetermined and reproducible after every experimental measurement. These units are easy to convert.
Intrinsic Physical Properties
The intrinsic physical property of matter is defined as the inherent quality that is present in the object fundamentally due to its chemical composition and structure of the material. An intrinsic property is independent of other things.
Artifact
The artifact is not inherently present in the matter but can produce due to artificial and preparatory procedures. Artifacts are duplicate or inaccurate results and observations. Artifacts are defined as experimental error.
So, it is better to explain standard units in terms of intrinsic physical phenomenon that artifacts, here are some examples.
Temperature
According to Charles’ equation, when the temperature is increased, its volume increased, keeping the pressure the same. So, when the temperature is decreased, its volume decreased too. In the case of water, it has abnormal behaviour. When water is cooled down, it contracts till 3.98o C or 32o F. Then it starts expanding till 0o C or 32o F. Thus, water density is maximum at 3.98o C. It is the intrinsic physical property of water that shows this anomalous behaviour. So, using the Kelvin scale is better to use instead of Celsius or Fahrenheit because Kelvin starts from absolute zero. Celsius and Fahrenheit do not start from absolute zero and are not directly related to change in kinetic energy and volume changes.
Mass Unit
Physicists believe that it is time to replace 115 years old Kilogram artifact with the new definition based on nature. It will have many benefits, including the precision and invariable measurements. For example, it would increase the precision of electrical measurements by 50 times, and this would help the physicists to get more precise values in studying quantum properties of matter. The current definition doesn’t reach the level of precision needed because it is not based on intrinsic properties of matter.