[snowwrestler]

Where does the idea come from that information cannot be destroyed? Is that supported by strong evidence, or is it just an assumption, axiom, or hypothesis?

My intuitive sense is that information can be created and destroyed. For example if I arrange wooden block letters to form a sentence, I have expended energy to encode information. If I scatter the blocks randomly, I have expended more energy to destroy information.

[jarin]

It's supported in both classical mechanics (Liouville's theorem, which is a vital component of the proof of Newton's second law) and in quantum mechanics (quantum unitarity).

http://van.physics.illinois.edu/qa/listing.php?id=24045

[snowwrestler]

Ah, looks like I am confused between quantum information and classical information (bits). We can create and destroy the latter.