Click above to listen to part 2 of For Good Measure, featuring Jon Pratt, Mechanical engineer and engineer and Chief of the Quantum Measurement Division of the Physical Measurement Laboratory (PML) at the National Institute of Standards and Technology (NIST), on the demise of “Le Grand K”, a platinum/iridium cylinder kept in a vault in France (under not one, but two glass cloches), which used to be THE definition of a kilogram. Jon and Molly discuss the drawbacks of having the standard for metric mass represented by a man-made object.
For Good Measure:
Part 1: The Banana Challenge
Part 2: Jon Pratt / The Old Kilogram
Part 3: Wolfgang Ketterle / The New Kilogram
Part 4: Simon Winchester / The Price of Precision
