Tipler wrote the general physics text book I used in college. I believe it is a widely used book. It cost a lot of money. I believe Tipler probably makes much more money from book sales than salary from his day job.
By the way it was a very good, well laid out text. It’s the only text that I can remember the author’s name. Plus it was very heavy.
Looked it up and found they are two different Tiplers. The textbook author is Paul Tipler.