The fallacy of appeal to ignorance applies to the argument that
a proposition is true because it hasn't been proven false. To put
it differently, it is the argument that a proposition is true
because the opposing proposition hasn't been proven true.
The fallacy has the structure:
Not-p has not been proven true. Therefore, p is true.
This is a fallacy because a lack of evidence for not-p does not imply
that there is evidence for p. All it means is that we do not
know that not-p is true.
I can't prove that a storm is not brewing in the atmosphere of
Jupiter, but that would hardly count as evidence that a storm is