He's written two books about Star Trek, a critical filmography of 1960s horror cinema, and, most recently, a FAQ about Star Wars.
He recently visited Mentor Public Library and was kind enough to talk about his writing.
Clark explained how he gathers new information on topics as well researched as Star Trek and Star Wars. He also discussed how he picks the subjects for his books.
He even weighed in on two of the most important pop-culture debates of our era: Kirk v. Picard; and Star Trek v. Star Wars.
That's right. The man behind not one but two Star Trek FAQs divulged if he's an original-series or Next-Gen guy, a Trekkie or a Jedi!
He also told us the biggest myth surrounding the making of Star Wars. It's a tale that even George Lucas perpetuates.
For more author talks at Mentor Public Library, visit our YouTube page.