This is a layman's book about the possibility of information being quantifiable and scientifically useful in a Quantum Bayesianist world. It was written before the term 'QBism' was even coined, so if you're interested in this topic (basically the leading non-realist foundation of quantum mechanics) and want a more up-to-date introduction, von Baeyer has a newer book which looks pretty swell.

My dad is a disciple of Everett, so this was a fun lil foray from the multiverse interpretation. QBism still feels pretty hokey to me but apparently people who work on quantum computing are really into it so idk maybe in the future I, too, will fuck with participatory realism.