I was recently in danger of my life (really). Out of nowhere last fall I found myself thrust into a serious medical situation requiring immediate surgery, followed by an arduous period of recovery. My chances were good, but by no means certain.
Now I'm fine. In that disorienting manner of 21st century life, a disaster that would have quickly snuffed any of my progenitors over the past 200,000 years was corrected by modern medical intervention, and - albeit with no small effort - I found myself plunked back into my previous existence, once again fit and healthy. Things broke for me in just the right way. The required technology was available; I was in the right place geographically, and financially, to take advantage of it; I had been exercising and eating well for many years, allowing my body to handle the stress; nothing untoward took place.
And yet any number of slips could so easily have spelled my end. People don't come back from anesthesia. They develop clots that shoot into their brains. They don't get to emergency rooms in time and bleed out on the gurney; and so on, and on. It seems a little odd--can one experience survivor guilt regarding oneself?--that everything went so smoothly.
But then, I realized, of course it did; Hugh Everett already figured that out.
How? By postulating the existence of multiple parallel universes, each taking off in a new direction every time a wavefunction is collapsed. This is the (in)famous Many-Worlds Interpretation of QM, in which an incredibly huge number of realities contains an equally huge number of Me's, each of which is experiencing a slight variation on my story. Thus I will necessarily live an astonishingly long life; in fact, one of record-breaking length; indeed, I am going to live as long as it is physically possible for me to live (this may mean centuries). And so will you.
But surely people perish! the voices cry -- every day, by all the terrible ways of which we know. That is unquestionably so. But the point is, none of those people are you . . . and they can't be.
To see how we get there, consider for a moment the admittedly metaphysical suggestion that at each turn, every possibility allowed by physics is realized in some kind of higher space, making "Me" a more spread-out concept than we generally think it to be. From your perspective I may be run over by a cab tomorrow and cease to exist; very good. From my perspective lightning might blast you to cinders in the next thunderstorm. But from your perspective, *you* cannot be killed that easily, because in a Many-Worlds universe there is another you who stepped back just in time. And that you is still you; except that when *this* you died, *that* you survived. It turns out you didn't disappear when the lightning flashed; not in the larger sense of You. (Notice that had you both survived but in different ways, that person would no longer be You, but an alternate version whose world-line diverged from yours at that point.)
Now, that surviving You may immediately fall on a pair of scissors cutting out Valentines. But somewhere in the Many Worlds they were those child-safe scissors with the rounded ends.
*That* surviving you gets drunk and stumbles into the path of a wrecking ball; but another You, round scissors still safely in pocket, sneezes at just the right moment to duck.
A trillion trillion deaths may come to different version of you - indeed, they all *do* - and yet none of them stops You, because some version necessarily escapes them all. Whichever becomes the most absurdly lucky, getting every break, making it to a record-setting old age, is the final You. Identical to the others except in its bizarre tendency to avoid mortal shock, that You will live as long as it is physically possible to do so. And that's the You who is reading this blog post right now.
Having stumbled myself across this happy (?) observation, I was crestfallen to discover that it is already well-known: this is the notion of "Quantum Immortality." Pity - although I suppose in some branch of the multiverse I got there first.
There's a caveat to all this speculation, of course. This scenario says nothing at all about *happy* life, except insofar as happiness increases one's tendency to survive. The severed woman's head in The Brain That Wouldn't Die was still alive, so if it's possible that that kind of technology could intersect with you at any point, and if that you outlives all the others, then that's what You'll do. The physicist who attempts the Quantum Suicide Experiment, by the way, should remember that many versions of him will only be maimed by the gunshot, and live long lives of bitter regret, wishing they had gone into a less speculative field.
And then, isolated as we are by our own perspectives, our loved ones will still perish around us at the usual heartbreaking rate (forgive me; even brief time in a hospital bed sends one toward morose meditation). But we all have the cold comfort of knowing that tragically shortened lives come only to others.
If Everett - who must have been surprised to find himself live longer than anyone else in history -- was right.
image: ell brown