The Ripples from Heisenberg

Reading this article from The New York Times reminded me of other thought experiments:

• If time travel to the past is possible, then we should have visitors from the future among us--or, if we do not, then time travel to the past is not possible
• Frank Drake's calculations about the existence of life on other worlds: given a large enough universe, and the fact that the factors in is calculation do not result in zero probability, therefore life must exist somewhere else
• If life exists elsewhere, then it must be either be visiting us or in communication with us; else, if we can't find them here or see their communications, then they do not exist

Maybe I'm reaching a bit, but all of these rely upon assumptions not dissimilar to that of quantum mechanics, except that whereas quantum mechanics concerns itself with the very small, these experiments concern themselves with the very large. Yet, whether these examples or others drawn from quantum mechanics, the same rule is at work: "if it isn't strictly forbidden, then it's possible."

It is as if given space enough and time, anything may be possible. The universe, like a great serpent, somehow swallows itself, the very large falling back to the same rules as the very small. And our philosophy gently continues to bounce in the ripples from the twists and turns of that great snake...