On Fri, Aug 2, 2019 at 7:33 PM 'Brent Meeker' via Everything List < [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]> 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]> 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]> 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]> 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]> 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. Jason -- 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/CA%2BBCJUhMpam_CPxkh%3DGMYHNYnQhytPDgpOJsb0hDFc-37o4Pmg%40mail.gmail.com.
