Ah yes, pluto, the ninth planet

It took them a long time to finalize the definition of a planet. After they did, it wasn't. Sorry, not sorry.

yes, and one of the criteria to define a planet was that it MUST have an atmosphere, believing Pluto too small that it's gravity too weak to hold onto, but sorry, atmosphere discovered on flyby, not sorry

That's not the criteria I was talking about. Pluto hasn't cleared it's orbit. It's not even close. In time it might become a planet, but the time and space involved? Idk....

so in a few thousand years when it "clears" it's orbit, it'll be good enough to be called a planet? can barely see pluto from earth, how can you see small asteroids that are not cleared?

Actually he'd agree. There is only 1 provable universe. He did postulate that a multiverse could exist but also that at present there is no way to test for more. At best it's an abstract idea with no basis in reality. It makes for a good thought exercise but little else. A bit like an ant dreaming about alien fashions 64 trillion light years away. It's so far out our grasp at the moment that we don't even know where to begin to find out if it exists.