Yeah, I thought there was something like that about Jupiter. Under his definitions I think Jupiter is too big to be a planet. There will be ceaseless arguments about what size, what mass, what makeup constitutes a planet.
But it's the small end that really gets me. How do you know when a planet's gravity is stronger than it's material.
His definitions are about the worse I can imagine, and yet he thinks they are concise.
What if we call it a tiny brown dwarf star?