Originally Posted by Nereid

What I meant was that "Argumentum ad ignorantiam (argument to ignorance)", and/or its applicability in science, is different than in the courtroom/legal example you gave.

For example, we could discuss the criteria that one should (ideally) use to assess the extent to which a particular set of observations actually tests a particular hypothesis.

Or we could build on Ken G's post and take a deeper look at the purpose (or objectives) of astrophysics.

And so on.

Whatever we choose to discuss, I'm pretty sure we'll conclude that this kind of logic fallacy ("Argumentum ad ignorantiam (argument to ignorance)") is quite circumscribed in terms of its applicability and usefulness.