Carl's room has several props connected to The 1939-40 New York World's Fair: an iconic poster featuring Trylon and Perisphere, an authentic postcard with the same motif, and a 3D-printed physical model of Trylon, Perisphere and Helicline.
The pharmacist (Mr. Schechter), as well as the boy antagonistic towards Carl (Snoony) are based upon real people Carl Sagan wrote of in his works. Samuel and Rachel Sagan are also based on real people, his parents.