> Under the theory of science as the study of what is falsifiable, there's nothing here to falsify because there is no way to disprove that a conjectured but unobserved collision of two massive bodies was something else or didn't occur.
Yes, there is: if the predicted kind of observations did not occur, it would imply one of two things:
(1) the model of gravity waves and their generation and propagation on which the prediction was based was incorrect, or
(2) the expectation of large-object collisions on which the prediction was also based is incorrect.
Now, were that the case, distinguishing which of those assumptions was false would require coming up with a new set of experiments that would have different results if the first was correct and the second false than if those were flipped, and yet a different set of results if both were false.
> That there is not a geophysical theory, doesn't have a bearing on the correctness of the gravitational wave theory one way or the other
Science isn't about correctness, its about continuous refinement of models which better predict observations. The absence of a better alternative model doesn't "prove" that a given model is "correct", but science deals with neither proof (except in the negative sense) nor correctness. (Further, the model of gravity waves being tested here is an implication of broader models whose other implications have also withstood attempts to falsify them.)
Yes, there is: if the predicted kind of observations did not occur, it would imply one of two things:
(1) the model of gravity waves and their generation and propagation on which the prediction was based was incorrect, or
(2) the expectation of large-object collisions on which the prediction was also based is incorrect.
Now, were that the case, distinguishing which of those assumptions was false would require coming up with a new set of experiments that would have different results if the first was correct and the second false than if those were flipped, and yet a different set of results if both were false.
> That there is not a geophysical theory, doesn't have a bearing on the correctness of the gravitational wave theory one way or the other
Science isn't about correctness, its about continuous refinement of models which better predict observations. The absence of a better alternative model doesn't "prove" that a given model is "correct", but science deals with neither proof (except in the negative sense) nor correctness. (Further, the model of gravity waves being tested here is an implication of broader models whose other implications have also withstood attempts to falsify them.)