Elephants are not information media, even if they never forget…
In short, for a physical system to be an information medium two tasks must be possible. It must be capable of being set to a number of distinct attributes (at least two). And for those distinct attributes to be distinguishable too, it must be possible to set up a mechanism that would copy any of them (without knowing in advance which one) from that system to another system, and vice-versa. The copy must go both ways, so as to allow both storing of information and its retrieval.
These constraints are quite tight. They are satisfied by media such as flags of different colours; or a transistor in a computer, with its on and off attributes.
But not any old system would qualify as information medium.
An elephant, for instance, would not, even if it was immortal and never forgot. Because its information retrieval system is ‘buggy’.
Chiara Marletto and David Deutsch, 5th Feb 2014
Cartoon copyright 2014 by Zach Wienersmith. Reproduced by permission.