Gutenberg Galaxy

The Gutenberg Galaxy, named for Johannes Gutenberg, the inventor of printing, is the universe of all printed books ever published. The term was first used by Marshall McLuhan in his book The Gutenberg Galaxy: The Making of Typographic Man first published in 1962.

As an estimate of the size of the Gutenberg Galaxy, as of 2002/2003, the British Library claimed that it held over 150 million items, and the Library of Congress claimed that it held approximately 119 million items.

Given an estimated average book size of 6 Mbytes for a purely textual book containing 1 million words, this represents roughly 1,000,000,000,000,000 bytes (10¹⁵ bytes = 1,000,000 GB = 1,000 TB = 1 PB, see SI prefix) of text.