Aliens are the kind of thing that: 1. Wouldn't suddenly appear recently. On the human timeline, I'd say if they were around, we'd be neighbors. 2. If they did

Aliens are the kind of thing that: 1. Wouldn't suddenly appear recently. On the human timeline, I'd say if they were around, we'd be neighbors. 2. If they did suddenly appear, it would be as obvious as the earth is round.