Philosophy of information
Going forward, the world will be increasingly centered around information. And so it is necessary to understand a few things about information.
1) Information has no location. At a fundamental level, information just IS. It can be instantiated at a certain place and time (I write down the number 3 on a sheet of paper), but it is fundamentally placeless (the existence of 3 has nothing to do with whether I write it down or not).
2) It is more proper to talk about instances of information than it is to talk about copies. Since information is placeless, there is no "original" and no "copy". Rather, information may exist (may have instances) in various locations at the same time.
3) Since there are no originals and no copies, multiple instances of information are not really different things, they are one thing.
4) The more similar two pieces of information are to each other, the "closer" they are in the only way that matters.
5) As soon as two instances of a piece of information begin to diverge, they are no longer the same thing. Now they are getting farther away from each other in the only way that matters.
6) Conversely, if two different pieces of information become more and more similar until they are identical, they have moved closer and closer until becoming one thing.
7) The best way to describe these kinds of motions might be "possibility space". Possibility space is a way of talking about how different different pieces of information are. Similar pieces of information are close, dissimilar pieces are far away. Identical pieces of information occupy the same location in possibility space, which is why they are considered identical.