>You're saying you can't conclude anything useful about American culture and civilisation from a discarded Coke can? (As well as the act of casually discarding it.)

Could an ant? This is the scale we may be operating on. One of the biggest fallacies with the alien question is that they'd operate on our scale. Let alone "think" as we've observed thinking on earth, but that is another story. Some science fiction has explored this concept based on gravity or metabolism leading to dramatically different scale in either space or time for a species and the implications that brings when meeting a species on a different scale.