English: Green: “materials science”, red: “condensed matter physics” and blue: “solid state physics” Smoothing level 3. Ngrams isolate the rate with which search terms occur in Google’s digitized catalogue as a percentage of all word strings of that length (y-axis). These data are limited to texts Google has digitized, leaving the possibility of sampling error and other inconsistencies. The chart is used here to illustrate general trends, which will be otherwise substantiated in the text.