Isaac Newton's seventeenth-century book, the Principia, gave the famous English scientist a reputation: "Here goes the man who wrote a book that neither he nor any other body understands," a Cambridge student commented when Newton passed by a day.
Similarly, historians have assumed that only a few scientists and mathematicians have been able to understand the highly technical book, which introduced game-changing concepts of physics as the universal law of gravitation.
But a new census, described Sept. 2 in the Annals of Science, of the remaining copies of the first edition of the book suggests the student's mockery was misleading. “An anecdote only tells you part of the story,” says study co-author and science historian Mordechai Feingold of Caltech.
A search in the 1950s found only 189 copies of the first edition, published in 1687 with the full title Philosophiae Naturalis Principia Mathematica (SN: 4/7/87). But Feingold and his former student Andrej Svorenčík, now at the University of Mannheim in Germany, unearthed 386 copies, suggesting a more substantial readership.
By tracing the original owners and studying the annotations the readers made, the researchers concluded that in addition to scientists, well-educated lay people were also reading the book.