> Can you tell me the thickness of a U.S. Postage stamp with the glue on it?
A: Get a pile of stamp sheets, measure the height, and do a calculation. (You did go to school, didn't you.)
A history lesson for you young-uns.
Back before the internet, guys like this were generally only found in the back room of libraries, sorting incoming books and handling interlibrary loans - safely sequestered from the rest of society.
(My college job was at our university library, way back in the 1980s... no, at the front desk!)