Mutability

{{for|the concept of mutability in programming|immutable object}}

The principle of mutability is the notion that any physical property which appears to follow a conservation law may undergo some physical process that violates its conservation.{{citation| url=https://www.youtube.com/watch?v=0y4AMA8mhYA |archive-url=https://ghostarchive.org/varchive/youtube/20211212/0y4AMA8mhYA| archive-date=2021-12-12 |url-status=live| title=John Wheeler - Principle of mutability (Part 2) (89/130)| date=October 6, 2017}}{{cbignore}}{{citation| title=From Relativity to Mutability| work=The Physicist’s Conception of Nature| doi=10.1007/978-94-010-2602-4_9| pages=202–247| author=John Archibald Wheeler| year=1973| isbn=978-94-010-2604-8}}{{citation|title=General Relativity and John Archibald Wheeler|author=Richard A. Matzner|publisher=Springer Science & Business Media|year=2010|isbn=9789048137350|pages=34}} John Archibald Wheeler offered this speculative principle after Stephen Hawking predicted the evaporation of black holes which violates baryon number conservation.{{citation| title=John Archibald Wheeler: A Few Highlights of His Contributions to Physics| editor=Kip S. Thorne| date=October 28, 1985| work=Between Quantum and Cosmos|pages=9}}