The fact that we have never observed other intelligent life does not it doesn’t exist. The unimaginable size of the universe leads me to believe that our special set of conditions are possible elsewhere, though it might be exceedingly rare. And because of this, we will never know about it anyway. You might say that’s the same as it not existing at all, but that’s a question for philosophers braver than I.

One of the scariest thoughts I have ever had is that we truly are alone, but the sheer size of the universe makes me feel slightly better about that prospect.