Who is Archie in Stargirl? Why do the kids enjoy spending time with him

Archie,
or Archibald Hapwood Brubaker, to give him his full name, is an old man who lives in the
neighborhood near to Mica Area High School. He's a retired paleontologist, someone who uses
fossils to study the history of life on earth. A widower, he moved to Arizona after his wife
passed away and brought his extensive collection of fossils and bones with him....