Free The Man Who Folded Himself by David Gerrold Page A

exactly the same as the past, only it hasn’t happened yet. You haven’t perceived it. The real difference between the two—the only difference—is your point of view. If the future can be altered, so can the past.
    Every change you make is cumulative; it goes on top of every other change you’ve already made, and every change you add later will go on top of that. You can go back in time and talk yourself
out of winning a million and a half dollars, but the resultant world is not one where you didn’t win a million and a half dollars; it’s a world where you talked yourself out of it. See the difference?
    It’s subtle—but it’s important.
    Think of an artist drawing a picture. But he’s using indelible ink and he doesn’t have an eraser. If he wants to make a change, he has to paint over a line with white. The line hasn’t ceased to exist; it has just been painted over and a new line drawn on top.
    On the surface, it doesn’t appear to make much difference. The finished picture will look the same whether the artist uses an eraser or a gallon of white paint, but it’s important to the artist. He’s aware of the process he used to obtain the final result and it affects his consciousness. He’s aware of all the lines and drawings beneath the final one, the layer upon layer of images, each one not quite the one—all those discarded pieces; they haven’t ceased to exist, they’ve just been painted out of view.
    Subjectively, time travel is like that.
    I can lay down one timeline and then go back and do things differently the second time around. I can go back a third time and talk myself out of something, and I can go back a fourth time and change it still again. And in the end, the timestream is exactly what I’ve made it—it is the cumulative product of my changes. The closest I can get to the original is to go back and talk myself out of something. It won’t be the same world, but the difference will be undetectable. The difference will be in me. I—like the artist with his painting—will be conscious of all the other alternatives that did exist, do exist, and can exist again.
    The world I came from is like my innocence. I can never recapture it. At best, I can only simulate it.
    You can’t be a virgin twice.
    (Not that I would, of course. Virginity seems like a nice state of existence only to a virgin, only to someone who doesn’t know any better. From this side of the fence, it seems like such a waste. I remember my first time, and how I had reacted: Why, this was nothing to be scared of at all—in fact, it’s wonderful! Why had I taken so long to discover it? Afterward, all the time beforehand looked so . . . empty.)

    According to the timebelt instructions, what I had done by altering the situation the second time around was called tangling. Mine had been a simple tangle, easily unraveled, but there was no limit to how complex a tangle could be. You can tie as many knots in a ball of yarn as you like.
    There really isn’t any reason to unravel tangles (according to the instructions) because they usually take care of themselves; but the special cautions advise against letting a tangle get too complex because of the cumulative effects that might occur. You might suddenly find that you’ve changed your world beyond all recognition—and possibly beyond your ability to live in, let alone excise.
    Excising is what you do when you bounce back and talk yourself out of something—when you go back and undo a mistake. Like winning too much at the races. (How about that? I’d been tangling and excising and I hadn’t even known it.)
    The belt explained the impossibility of paradoxes this way: if there was only one timestream, then paradoxes would be possible and time travel would have to be impossible. But every time you make a change in the timestream, no matter how slight, you are actually shifting