 Zimmermann is mentioned (as "Mr. Zimmerman") in Book 3 of Isaac Newton's "Philosophiæ Naturalis Principia Mathematica" in 1687 (on p. 505) as having observed the Great Comet of 1680.Johann Jacob Zimmermann believed a person's close relationship with God was more important than having a close relationship with the church, believing most, if not all, of the churches in Europe were corrupt.He believed the wonders in the sky were signs of the end times, and felt a change would occur in 1693.