I know (have even used tlit as a metaphor for our lack of knowledge in my MA thesis), but the existence of planet 9 is a falsifiable theory. Maybe not today, and not with the technology/funds we have to look at it, but if we wanted to get on top of that, we could, unless it is a primordial black hole the size of a tennisball that is.
But my point was that in this case we can say: yeah, there is some unaccounted mass (observation) let's form explainations about what it could be (theory). There are only so many things with mass we know in our solar system, so it being a other planet is a reasonable assumption. It being a invisible giant unicorn-shaped teapot is not.
If you have a theory without an observation it is called a story. And now someone would bring up eyewitness accounts or declassified airforce videos and call them observations. The point here is that you need to go from observation to theory and not the other way around. If every unidentified flying object is extraterrestrial life you are gonna be wrong a lot of times, just because there is a big likelihood of unidentified flying objects being of terrestrial origin (or them not even be objects in the first place).
That means you got a needle/haystack problem there and front-loading the theory like that isn't gonna help.
Both can be, but the teapot is an arbitrary enough stand-in that the idea behind what I said should be clear.
Because we do not know what it is we could assume it is anything, it could also be Kurt Cobain, Elvis Presley and Jim Morrison in a pink whirlpool in space.
But just because we can't as of now disprove that theory, doesn't mean it is a good one, unless we judge entertainment value. White spots on the map of knowledge seem to have an attraction on people that feel the need to put the most colorful, most exciting things there.
