https://en.wikipedia.org/wiki/Agnosticism
"Agnosticism is the view that the existence of God, of the divine or the supernatural is unknown or unknowable. An agnostic can also be one who holds neither of two opposing positions on a topic."
https://en.wikipedia.org/wiki/Agnosticism
"Agnosticism is the view that the existence of God, of the divine or the supernatural is unknown or unknowable. An agnostic can also be one who holds neither of two opposing positions on a topic."
https://en.wikipedia.org/wiki/Atheism
"Atheism is, in the broadest sense, the absence of belief in the existence of deities. Less broadly, atheism is the rejection of belief that any deities exist. In an even narrower sense, atheism is specifically the position that there are no deities. Atheism is contrasted with theism, which, in its most general form, is the belief that at least one deity exists."
Of course not. Absence of belief is not belief in absence. If "not believing in something" were an active task, I'd be busy all day not-believing in trillions of bizarre things.
Using his argument, the two very different words "amoral" and "immoral" would mean the same thing.
The particular example of intelligent life in another galaxy is rather odd, since we actually do have reasons to believe such life exists inasmuch as we have pretty good ideas about how life came about on earth and a lot of evidence that similar conditions should exist elsewhere.
There is no name for lack of belief in invisible aliens in my garage.