Point is...we don't know. Don't even have a clue. So why indulge in adult activities with unknown adult risks when we're barely toddlers, if that?
Let's be mature enough to learn something about the galaxy before we rush forward bleating our presence in acts of utter hubris.
Someone else mentioned that SETI proponents always cite analogies like "Look at how easily simple life started here THEREFORE it's reasonable to assume that such life is common where the environment allows." Fair enough, but these same experts then take exception to citing analogies about what happened to less technical human cultures when a superior technical culture encountered them.
Exploration is a risky activity. Those who go best prepared into the unknown fare best. It's not a macho contest.
Space/Science » in reply to I sense much fear in y'all
Caution
