That’s well done although two of the central premises are likely incorrect. First, the notion that a quantum computer would have infinite processing capability is incorrect. Quantum computation allows speed-ups of certain computational processes. Thus for example, Shor’s algorithm allows us to factor integers quickly. But if our understanding of the laws of quantum mechanics is at all correct, this can’t lead to anything like that in the story. In particular, under the standard descriptor for quantum computing, the class of problems reliably solvable on a quantum computer in polynomial time (that is the time required to solve is bounded above by a polynomial function of the length of the input sequence), BQP is is a subset of of PSPACE, the set of problems which can be solved on a classical computer using memory bounded by a polynomial of the space of the input. Our understanding of quantum mechanics would have to be very far off for this to be wrong.
Second, if our understanding of quantum mechanics is correct, there’s a fundamentally random aspect to the laws of physics. Thus, we can’t simply make a simulation and advance it ahead the way they do in this story and expect to get the same result.
Even if everything in the story was correct, I’m not at all convinced that things would settle down on a stable sequence as they do here. If your universe is infinite then your possible number of worlds are infinite so there’s no reason you couldn’t have a wandering sequence of worlds. Edit: Or for that matter, couldn’t have branches if people simulate additional worlds with other laws of physics or the same laws but different starting conditions.
First, the notion that a quantum computer would have infinite processing capability is incorrect… Second, if our understanding of quantum mechanics is correct
It isn’t. They can simulate a world where quantum computers have infinite power because because they live in a world where quantum computers have infinite power because...
Ok, but in that case, that world in question almost certainly can’t be our world. We’d have to have deep misunderstandings about the rules for this universe. Such a universe might be self-consistent but it isn’t our universe.
What I mean is that this isn’t a type of fiction that could plausibly occur in our universe. In contrast for example, there’s nothing in the central premises of say Blindsight that as we know it would prevent the story from taking place. The central premise here is one that doesn’t work in our universe.
The likely impossibility of getting infinite comutational power is a problem, but quantum nondeterminism or quantum branching don’t prevent using the trick described in the story, they just make it more difficult. You don’t have to identify one unique universe that you’re in, just a set of universes that includes it. Given an infinitely fast, infinite storage computer, and source code to the universe which follows quantum branching rules, you can get root powers by the following procedure:
Write a function to detect a particular arrangement of atoms with very high information content—enough that it probably doesn’t appear by accident anywhere in the universe. A few terabytes encoded as iron atoms present or absent at spots on a substrate, for example. Construct that same arrangement of atoms in the physical world. Then run a program that implements the regular laws of physics, except that wherever it detects that exact arrangement of atoms, it deletes them and puts a magical item, written into the modified laws of physics, in their place.
The only caveat to this method (other than requiring an impossible computer) is that it also modifies other worlds, and other places within the same world, in the same way. If the magical item created is programmable (as it should be), then every possible program will be run on it somewhere, including programs that destroy everything in range, so there will need to be some range limit.
That’s well done although two of the central premises are likely incorrect. First, the notion that a quantum computer would have infinite processing capability is incorrect. Quantum computation allows speed-ups of certain computational processes. Thus for example, Shor’s algorithm allows us to factor integers quickly. But if our understanding of the laws of quantum mechanics is at all correct, this can’t lead to anything like that in the story. In particular, under the standard descriptor for quantum computing, the class of problems reliably solvable on a quantum computer in polynomial time (that is the time required to solve is bounded above by a polynomial function of the length of the input sequence), BQP is is a subset of of PSPACE, the set of problems which can be solved on a classical computer using memory bounded by a polynomial of the space of the input. Our understanding of quantum mechanics would have to be very far off for this to be wrong.
Second, if our understanding of quantum mechanics is correct, there’s a fundamentally random aspect to the laws of physics. Thus, we can’t simply make a simulation and advance it ahead the way they do in this story and expect to get the same result.
Even if everything in the story was correct, I’m not at all convinced that things would settle down on a stable sequence as they do here. If your universe is infinite then your possible number of worlds are infinite so there’s no reason you couldn’t have a wandering sequence of worlds. Edit: Or for that matter, couldn’t have branches if people simulate additional worlds with other laws of physics or the same laws but different starting conditions.
It isn’t. They can simulate a world where quantum computers have infinite power because because they live in a world where quantum computers have infinite power because...
Ok, but in that case, that world in question almost certainly can’t be our world. We’d have to have deep misunderstandings about the rules for this universe. Such a universe might be self-consistent but it isn’t our universe.
Of course. It’s fiction.
What I mean is that this isn’t a type of fiction that could plausibly occur in our universe. In contrast for example, there’s nothing in the central premises of say Blindsight that as we know it would prevent the story from taking place. The central premise here is one that doesn’t work in our universe.
Well, it does suggest they’ve made recent discoveries that changed the way they understood the laws of physics, which could happen in our world.
The likely impossibility of getting infinite comutational power is a problem, but quantum nondeterminism or quantum branching don’t prevent using the trick described in the story, they just make it more difficult. You don’t have to identify one unique universe that you’re in, just a set of universes that includes it. Given an infinitely fast, infinite storage computer, and source code to the universe which follows quantum branching rules, you can get root powers by the following procedure:
Write a function to detect a particular arrangement of atoms with very high information content—enough that it probably doesn’t appear by accident anywhere in the universe. A few terabytes encoded as iron atoms present or absent at spots on a substrate, for example. Construct that same arrangement of atoms in the physical world. Then run a program that implements the regular laws of physics, except that wherever it detects that exact arrangement of atoms, it deletes them and puts a magical item, written into the modified laws of physics, in their place.
The only caveat to this method (other than requiring an impossible computer) is that it also modifies other worlds, and other places within the same world, in the same way. If the magical item created is programmable (as it should be), then every possible program will be run on it somewhere, including programs that destroy everything in range, so there will need to be some range limit.