A mathematical model captures the political impact of fake news

The fundamental problem of communication is to reproduce at one point in the universe a message created at another point. The problem is made more difficult by the fact that there is always noise that distorts this message--0s get flipped into 1s, b's sound like d's, and smoke signals get, well, blown away. So the receiver of any message has to have a strategy to deal with this noise. That turns out to be entirely possible in many situations. The mathematician and engineer Claude Shannon proved that a message can always be reproduced more or less exactly, provided noise is below some threshold level.