Any aliens that would drop by Earth are presumably far more advanced than us. Their technology is far more sophisticated and miniaturized than ours. And if we

Any aliens that would drop by Earth are presumably far more advanced than us. Their technology is far more sophisticated and miniaturized than ours. And if we accept that the Singularity idea has any validity at all, they've long since become their technology, thereby reaping vast benefits of intelligence and longevity. In this form, they could move from star to star relatively easily. So the best way to imagine aliens is as swarms of ingenious nanomachines, spreading across the galaxy like a silent yet thoughtful breeze. There's liable to be several in the room with you right now.