Time capsule

A time capsule is a historic cache of goods or information, usually intended as a method of communication with future people and to help future archaeologists, anthropologists, or historians. Time capsules are sometimes created and buried during celebrations such as a World's fair, a cornerstone laying for a building or at other events.

Time capsules are placed with the intention that they will be opened or accessed at a future date.

An early example of the use of a time capsule was the Detroit Century Box. The brainchild of Detroit mayor William C. Maybury, it was created on December 31, 1900, and scheduled to be opened 100 years later. It was filled with photographs and letters from 56 prominent residents describing life in 1900 and making predictions for the future, and included a letter by Maybury addressed to the mayor of Detroit in 2000. The capsule was opened by city officials on December 31, 2000, in a ceremony presided over by mayor Dennis Archer.

The 1939 New York World's Fair time capsule was created by Westinghouse as part of their exhibit. It was 90 inches (2.3 metres) long, with an interior diameter of 6.5 inches (16 cm), and weighed 800 pounds (360 kg). Westinghouse named the copper, chromium and silver alloy "Cupaloy", claiming it had the same strength as mild steel. It contained everyday items such as a spool of thread and doll, a Book of Record (description of the capsule and its creators), a vial of staple food crop seeds, a microscope and a 15-minute RKO Pathé Pictures newsreel. Microfilm spools condensed the contents of a Sears Roebuck catalog, dictionary, almanac, and other texts.

...
Wikipedia