What is The Information: A History, a Theory, a Flood about?

The Information traces the history of information — as a concept, a technology, and a way of understanding the universe — from the talking drums of West Africa through the telegraph, the printing press, the telephone, and into the digital age. James Gleick's argument is that information is not just a byproduct of human communication but one of the most fundamental concepts in science, and that the twentieth century's greatest intellectual achievement was learning to think precisely about it.

The book's central figure is Claude Shannon, the Bell Labs mathematician who in 1948 published "A Mathematical Theory of Communication," one of the most consequential papers of the twentieth century. Shannon defined information in terms of surprise and uncertainty: a message carries information in proportion to how much it reduces uncertainty. He introduced the bit as the unit of information, defined the channel capacity of communication systems, and proved the existence of error-correcting codes that allow reliable communication across noisy channels. These ideas underpinned the entire digital age — from hard drives to the internet — but Shannon remained obscure outside engineering until writers like Gleick began explaining his work to general audiences.

Gleick pursues information through unexpected historical channels: the development of the Oxford English Dictionary as a technology for capturing the instability of language; Charles Babbage's mechanical calculating engines; Ada Lovelace's early conceptualization of programming; the genetics code as a form of information storage; and the thermodynamic interpretation of entropy as a measure of disorder that Shannon and the physicist Leo Szilard recognized was equivalent to information. The connections between thermodynamic entropy and Shannon entropy — the same mathematics describing two apparently unrelated things — are among the book's most striking passages.

The final chapters address the information overload of the contemporary world: the way an abundance of information creates new forms of scarcity (of attention, of curation, of judgment), and the question of whether the universe itself is, at some fundamental level, informational. These speculative sections are less resolved than the historical narrative, but they give the book an ambition proportionate to its subject.