These coined terms belong to the field of quantitative analysis of science known as scientometrics.
These ideas of half-life applied to different fields differ from the concept of half-life in physics in that there is no guarantee that the knowledge or facts in areas of study are declining exponentially.
It is unclear whether there is any way to establish what constitutes "knowledge" in a particular area, as opposed to mere opinion or theory.
An engineering degree went from having a half life of 35 years in ca.
[3] The concept of "half-life of knowledge" is attributed to Fritz Machlup (1962).