How to kill a gram

Main Topic: The redefinition of the kilogram, a fundamental unit of mass, and its implications on science, measurement, and society.

Key Points:

1. The kilogram, a standard unit of mass, was redefined on May 20th, 2019, to be based on the Planck constant, a fundamental constant of nature.
2. The redefinition was made possible by a machine called the kibble balance, which allows scientists to measure the Planck constant with high precision.
3. The new definition of the kilogram is more precise and stable than the old definition, which was based on a physical object called the International Prototype Kilogram (IPK).
4. The redefinition of the kilogram has significant implications for science, measurement, and society, including the ability to make precise measurements of mass and the potential for new discoveries.
5. The use of the metric system, which is based on the kilogram, is widespread in science and medicine, but the United States is one of the few countries that has not adopted it as its official system of measurement.

Participants:

1. Brian Resnick, science journalist and host of the podcast
2. Doreen El-Haddad, scientist at the National Institute of Standards and Technology (NIST)