In contrast, when arguing that the timeline 'splits' due to measurements, the resulting universes do not interact at all and remain completely unaware of each other—they can never even know if the others exist.
If quantum computers truly 'forked' the world, they would be equivalent to non-deterministic Turing machines (capable of solving NP-complete problems in polynomial time), but quantum computing experts agree that they can still be modeled as deterministic Turing machines.
It's better to think of quantum computers as a type of analog computer, capable of solving certain problems that fit their model well, but not generally more powerful. It’s like an Intel CPU having SIMD or AVX instructions that allow it to perform certain operations faster, but these don't fundamentally change its capabilities. The no-free-lunch theorem applies.
A typical quantum algorithm like Shor's works by sending every possible input through a gate, and so you get every possible output out in a superposition. If you were to just measure that, you'd get a random result - so instead, you need to somehow interfere the output to get the actual result. You do this by taking advantage of the fact that the superposition is a periodic function and the amplitude repeats. This is literally the core assumption of the algorithm.(a common way of doing this using the QFT).
Every quantum algorithm requires some kind of structure in the output like this. Deustch's algo, dumb ones like Simon's algo, etc. NP-Complete problems have no structure to them, so even if you build a gate that creates the superposition you want, it's not possible to destructively interfere it to get an answer (I don't know how to prove that there's no structure to NP-Complete outputs - it just feels trivial, since they're only solvable in exponential time, so there must be an exponential amount of "structure" there).
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[1] The only way to communicate with the other universe would be to try to use quantum mechanics with something like an entangled pair. But no information can be communicated through an entangled pair if all you just have 1 of the 2 particles! Measurement collapses a state nonlocally, and if you could somehow measure one particle and change the probability distribution of the other, you'd be communicating faster than light. The measurement genuinely changes the state and the amplitudes, but not in a way that the other person can detect. It's really interesting and leads to stuff like teleportation.
i.e. BPP is contained in BQP but the converse is thought to be false.
Why is there a speedup in quantum, though? Why can't you just brute force classically? The answer is that whether quantum or classical, you can always build a hard-coded circuit that essentially swaps the time and space complexity - just make it so that for every operation you were doing in time, instead, every operation happens at its own place in space.
Quantum is special because it also takes the "log" of the space complexity b/c n qubits represent 2^n bits. So quantum lets you swap space with time and then take the log of time, lol. Superposition, interference, etc aren't really even needed in the explanation.
Okay team, we’ve effectively entangled the success of our endeavor with the quantum dead man’s switch by all swearing to comply with the protocol. It’s time to start letting the universe tell us what works. QUESTION 1 for the Profit Manifold: promote yours truly to director or stay the course? Click bang hiss: 01.
Note to self: cut “universe B” (or just B? It’d hurt less) into my thigh with a razor blade 6 months before demonstrating The Device, as a plot device to be exploited for purposes TBD.
what difference is there to any 50/50 choice mechanism you chose, other than being horrendously expensive to implement?
Statement: I will make a minimal BTC transfer today, May 11. 2024, as near noon UTC+2 if the outcome is 1/true.
Result: [ { "0": 0.5140027374683648, "1": 0.4859972625316353 } ] So now we have(will) also split the bitcoin hash forever in more than 2 different branches (I guess way more than 2).
@andrewp123 Check my blog post. https://initsix.dev/in-finite-central-curve/ ,feedback appreciated :D
Morty: Aw, geez, Rick, I don't think we ought to--
Rick: Nothing ventured, nothing gained, Morty. Let's goooooooooooo!
[He clicks the mouse, and Solitaire comes up]
Rick: Haha, nice. [He starts playing.]
[We are shown a 16x16 grid of the same moment happening in 256 alternate universes.]
Ricks: Nothing ventured, nothing gained, Morty. Let's goooooooooooo!
[They click the mouse.]
Rick 183: Oh, sh--
Rick 39: Jesus Chr--
Rick 201: NO! We've gone too fa--
[237 of the alternate universes disappear in a white-hot light, their squares replaced by static.]
This is not true. It only provably does not exist in local hidden variables.
In actual practice there might as well be hidden local variables here. You wouldn't be able to tell the difference, even though you could in theory.
My preferred interpretation:
There is a density function across all possible realities (Hilbert space).
Schrodinger's cat has equal density of being alive and dead.
The person who opens the box can be happy or sad.
The density of cat being alive is entangled with the observer being happy. And the opposite for the death.
The original cat distribution did not "collapse" or "resolve" per se. The cat is still equal parts alive and dead. But it did become non-uniformly entangled with the distributions of rest of the universe.
Perhaps this is the many worlds interpretation.
probably a sign there is no real discussion here :/
It's theoretically useful, but quantum random number generation has been around for a long time. All you need is a way to detect nuclear decay.
