This one is a bit odd. I will randomly come across different theories, principles, ideas, etc. They'll also have some naming convention like the <person>'s Effect or <name>'s Law.
I don't necessarily believe or not believe any of these, but I'd like to start keep a collection for kicks as I come across them. These are likely oversimplified and the definitions are definitely copy and pasted from Wikipedia or wherever I stumbled upon them.
I claim no ownership of these definitions.