On Fri, Aug 2, 2019 at 6:44 PM Bruce Kellett <[email protected]> wrote:
> On Sat, Aug 3, 2019 at 9:36 AM Jason Resch <[email protected]> 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: >>> >>> [Brent]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. >> Deutsch says as much in his introduction to Fabric of Reality when speaking >> of shadow selves and shadow photons. >> >> 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. >> > > Brent is correct. There is only ever one state -- one vector in Hilbert > space. The computation involves nothing more than unitary rotations of this > vector in Hilbert space. The final result is obtained by projecting this > state on to some set of basis vectors. None of the intermediate projections > on to arbitrary basis vectors is "real" in any sense, since such basis > vectors are arbitrary. > A lot of computational work gets done for by something that isn't real in any sense. > > So, in that sense, the final measurement does do the interference because > it involves a choice of a particular basis. Just as the spots on the screen > behind a double-slit experiment decide the interference -- they amount to a > choice of basis in position space -- position along the axis of the screen. > > So the Morpho butterfly isn't sending out blue light until you look at it? 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%2BBCJUi5GYR4XJ47SwTPVbw4Vi4JQrVadWeAWQOZpa5H6YiF7A%40mail.gmail.com.
