1. What colorful part of the human eye expands and contracts the size of the pupil?

2. Watch out for the phrase "Caveat lector" in books, because it means "Let" who "beware"?

3. What September holiday was rushed into law following the violent Pullman Strike of 1894?

4. In math, what kind of series has partial sums that don't add up to a finite limit?

5. In 1985, Robert Ballard used a remote-controlled vehicle called 'Argo' to discover the wreck of what?

What’s the "Kennection" between all five answers?