Katherine Johnson on Double-Checking

A very short clip of an interview with Katherine Johnson -- subject of the book and movie Hidden Figures -- who had her 99th birthday last week. Here she talks about John Glenn demanding, before his first spaceflight, that she double-check by hand the trajectory calculations from the digital computer in use at the time.

I feel like this might be an excellent starting point for a classroom discussion on, "Why would anyone ever want to double-check a computer calculation? How could it be wrong? Was John Glenn totally insane?" Granted that I become more and more convinced that the topic of sanity/double-checking may be the most fundamental sense-making theme that runs through all the classes we teach at a community college.