> On 3 Aug 2019, at 03:02, 'Brent Meeker' via Everything List > <[email protected]> wrote: > > > > On 8/2/2019 5:52 PM, Jason Resch wrote: >> >> >> On Fri, Aug 2, 2019 at 7:33 PM 'Brent Meeker' via Everything List >> <[email protected] <mailto:[email protected]>> >> wrote: >> >> >> On 8/2/2019 5:12 PM, Jason Resch wrote: >>> >>> >>> On Fri, Aug 2, 2019 at 6:51 PM 'Brent Meeker' via Everything List >>> <[email protected] >>> <mailto:[email protected]>> wrote: >>> >>> >>> On 8/2/2019 4:36 PM, Jason Resch wrote: >>>> >>>> >>>> On Fri, Aug 2, 2019 at 5:18 PM 'Brent Meeker' via Everything List >>>> <[email protected] >>>> <mailto:[email protected]>> wrote: >>>> >>>> >>>> On 8/2/2019 1:41 PM, Jason Resch wrote: >>>>> >>>>> >>>>> On Fri, Aug 2, 2019 at 3:31 PM 'Brent Meeker' via Everything List >>>>> <[email protected] >>>>> <mailto:[email protected]>> wrote: >>>>> >>>>> >>>>> On 8/2/2019 1:19 PM, Jason Resch wrote: >>>>>> >>>>>> >>>>>> On Fri, Aug 2, 2019 at 3:17 PM 'Brent Meeker' via Everything List >>>>>> <[email protected] >>>>>> <mailto:[email protected]>> wrote: >>>>>> >>>>>> >>>>>> On 8/2/2019 12:53 PM, Jason Resch wrote: >>>>>>> >>>>>>> >>>>>>> On Fri, Aug 2, 2019 at 1:25 PM 'Brent Meeker' via Everything List >>>>>>> <[email protected] >>>>>>> <mailto:[email protected]>> wrote: >>>>>>> >>>>>>> >>>>>>> On 8/2/2019 10:42 AM, Jason Resch wrote: >>>>>>>> Quantum computers work by interference of quits, and such interference >>>>>>>> can only take place in one world -- different worlds are orthogonal. >>>>>>>> The fact that one can analyse a quantum computer in a particular basis >>>>>>>> which can be represented as a series of parallel >>>>>>>> computations does not mean that >>>>>>>> this is actually what happens. Heuristic constructs seldom correspond >>>>>>>> to reality. >>>>>>>> >>>>>>>> None of this comes anywhere close to addressing my question. >>>>>>>> >>>>>>>> Well, you have either not understood the question, or my answer to it. >>>>>>>> >>>>>>>> I asked where those 10^1000 intermediate computation states are >>>>>>>> realized, and your reply was >>>>>>>> a basic description of how quantum computers use >>>>>>>> qubits and interference. You said this all takes place in one world, >>>>>>>> but the total information content and computational capacity of the >>>>>>>> observable universe about 800 orders of magnitude less than 10^1000. >>>>>>>> >>>>>>>> You then added a sentence that suggested the intermediate >>>>>>>> computational states perhaps don't exist, but then how does the >>>>>>>> correct answer get into the output bits when we read it? >>>>>>>> >>>>>>>> David Deutsch said he has never seen a sensible answer to the question >>>>>>>> of how quantum computers work from the context of any single-universe >>>>>>>> interpretation. Do you think your answer would satisfy him? >>>>>>> >>>>>>> All those "intermediate computation states" are so "numerous" because >>>>>>> the state is being expressed as a superposition of qubit basis states. >>>>>>> >From another viewpoint the state is just a single ray in Hilbert space >>>>>>> that happens to not be orthogonal to any of those bases >>>>>>> >>>>>>> So in your view, are they real? >>>>>> >>>>>> What "they"? There's only a single state. It's like saying there are >>>>>> infinitely many tones in a square wave...just because you represented it >>>>>> as a Fourier series. The are 2^1e4 potential measurement results, >>>>>> depending on what you choose to measure...but that's true in the >>>>>> classical case too. >>>>>> >>>>>> Do you agree the final states you measured were caused by the >>>>>> intermediate states of the computation? >>>>>> >>>>>> How many intermediate states of the computation are there? >>>>> >>>>> One. It's a unitary evolution of the input state. >>>>> >>>>> We were speaking of computational states. Are you saying there is only >>>>> one computation state involved in Shor's algorithm? What causes the >>>>> interference necessary to yield the correct answer, if not these numerous >>>>> computational states? >>>> >>>> The interference is in the measurement which Deutsch would say projects >>>> out onto one of the multiple worlds...the non-unitary step. >>>> >>>> >>>> Does anyone claim interference happens during the measurement? In the >>>> double slit experiment the interference happens when the two photons >>>> overlap in their position, not when they strike the photographic plate. >>> >>> You write as though they were classical particles. The wave function >>> reaches the photographic plate and then there is an interaction which is >>> greater or lesser depending on the interference pattern over the plate. >>> >>> >>> To say interference happens at the time of measurement may be satisfactory >>> for making predictions, but it is completely unsatisfactory for >>> explanations. It is a way of stuffing the intermediate computations under >>> the rug and pretending they were never there. What of the conscious states >>> implied by the computations of an AI on a quantum computer? "Forget about >>> them, they never really existed." >>> >>>> Deutsch says as much in his introduction to Fabric of Reality when >>>> speaking of shadow selves and shadow photons. >>> >>> You can stop quoting Deutsch. I think he's just a MWI envangelist. >>> >>> Okay. It was only in response your mention of Deutsch. >> >> You cited him first: "David Deutsch said he has never seen a sensible answer >> to the question of how quantum computers work from the context of any >> single-universe interpretation." >> >>> I thought you were suggesting Deutsch believed interference happens during >>> measurement. >> >> Wherever it happens, it's one world. Worlds are things things that are >> orthogonal on to one another so that's why they're separate. I don't know >> what Deutsch believes. >> >>> >>> >>>> >>>> In any case, you have still managed to avoid the question of the reality >>>> of the 10^1000 intermediate computational states. I won't press for an >>>> answer if you don't have one. >>> >>> I already gave the answer. There is only one intermediate state. It just >>> happens to have lots of components in the basis you used to express it. >>> >>> And each of those components represents a trace of a computation performed >>> on one of the many possible values of the input qubits, do they not? >> >> That's one way of representing them. Just as citing the Fourier components >> of a firecracker going off shows the many components of the sound. >> >> That would be a convincing counterpoint, except here this "way of looking at >> the many components" performs a computation that would not otherwise be >> possible if all the atoms of the universe were mustered to perform the >> computation. > > You mean if they were mustered to perform a digital simulation of the wave > function. Remember all that information you imagine existing in the > intermediate stages of computation is inaccessible, even in principle (c.f. > Holevo's theorem).
But that is exactly what we expect from the computationalist hypothesis. Holevo’s theorem confirms Mechanism. Bruno > > Brent > > Brent > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected] > <mailto:[email protected]>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/everything-list/e1827948-6284-06e9-fc0d-7e53ba1dec79%40verizon.net > > <https://groups.google.com/d/msgid/everything-list/e1827948-6284-06e9-fc0d-7e53ba1dec79%40verizon.net?utm_medium=email&utm_source=footer>. -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/everything-list/2C84F53F-AFE2-4F77-92D2-E212087A3AD3%40ulb.ac.be.
