Information must have a physical substrate

I was reading a Jack Reacher novel where a character discusses the theory that adding pictures to your cellphone memory makes the phone weigh more. This got me realizing that "information" must have a physical substrate. Leading to the thought that any given mass has a maximum amount of information which it can store. That leads to equations with things like "e", "m", and "c^2". 

Not a physicist... but just sayin.

First Osprey 2025

 Saw one yesterday

feb 27 - first crocuses

2 weeks later than last year