On Tuesday, August 21, 2018 at 8:02:52 PM UTC, Jason wrote: > > > > On Tue, Aug 21, 2018 at 2:20 PM <[email protected] <javascript:>> wrote: > >> >> >> On Tuesday, August 21, 2018 at 3:04:45 PM UTC, Jason wrote: >>> >>> >>> >>> On Wed, Aug 15, 2018 at 1:44 PM <[email protected]> wrote: >>> >>>> >>>> >>>> On Wednesday, August 15, 2018 at 2:41:12 PM UTC, Jason wrote: >>>>> >>>>> >>>>> >>>>> On Wednesday, August 15, 2018, <[email protected]> wrote: >>>>> >>>>>> >>>>>> >>>>>> On Wednesday, August 15, 2018 at 11:49:04 AM UTC, Bruno Marchal wrote: >>>>>>> >>>>>>> >>>>>>> On 15 Aug 2018, at 12:36, [email protected] wrote: >>>>>>> >>>>>>> >>>>>>> >>>>>>> On Wednesday, August 15, 2018 at 10:22:40 AM UTC, agrays...@ >>>>>>> gmail.com wrote: >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> On Wednesday, August 15, 2018 at 9:58:57 AM UTC, Bruno Marchal >>>>>>>> wrote: >>>>>>>>> >>>>>>>>> >>>>>>>>> > On 14 Aug 2018, at 22:12, Brent Meeker <[email protected]> >>>>>>>>> wrote: >>>>>>>>> > >>>>>>>>> > >>>>>>>>> > >>>>>>>>> > On 8/14/2018 3:54 AM, Bruno Marchal wrote: >>>>>>>>> >> How do you explain interference fringes in the two slits? How >>>>>>>>> do you explain the different behaviour of u+d and a mixture of u and >>>>>>>>> d. >>>>>>>>> >> >>>>>>>>> >> If the wave is not real, how doe it interfere even when we are >>>>>>>>> not there? >>>>>>>>> > >>>>>>>>> > How does it interfere with itself unless it goes through both >>>>>>>>> slits in the same world...thus being non-local. >>>>>>>>> >>>>>>>>> The wave is a trans-world notion. You should better see it as a >>>>>>>>> wave of histories/worlds, than a wave in one world. I don’t think >>>>>>>>> “one >>>>>>>>> world” is well defined enough to make sense in both Everett and >>>>>>>>> Mechanism. >>>>>>>>> >>>>>>>> >>>>>>>> *If you start with the error tGhat all possible results of a >>>>>>>> measurement must be realized, you can't avoid many worlds. Then, if >>>>>>>> you >>>>>>>> fall in love with the implications of this error, you are firmly in >>>>>>>> woo-woo >>>>>>>> land with the prime directive of bringing as many as possible into >>>>>>>> this >>>>>>>> illusion / delusion. This is where we're at IMO. AG * >>>>>>>> >>>>>>> >>>>>>> *Truthfully, I don't know why, when you do a slit experiment one >>>>>>> particle at a time, the result is quantum interference. It might be >>>>>>> because >>>>>>> particles move as waves and each particle goes through both slits. In >>>>>>> any >>>>>>> event, I don't see the MWI is a solution to this problem. It just takes >>>>>>> us >>>>>>> down a deeper rabbit hole. AG* >>>>>>> >>>>>>> >>>>>>> Everything is in the formalism, as well exemplified by the two >>>>>>> slits. If you miss this, then consider the quantum algorithm by Shor. >>>>>>> There, a “particle” is not just going through two slits, but >>>>>>> participate in >>>>>>> parallel, yet different computations, and we get an indirect evidence >>>>>>> by >>>>>>> the information we can extract from a quantum Fourier transform on all >>>>>>> results obtained in the parallel branches. >>>>>>> >>>>>> >>>>>> *No. It's all nonsense. AG * >>>>>> >>>>>>> >>>>>>> >>>>> No it's something you can already buy and use today: >>>>> >>>>> >>>>> >>>>> https://techcrunch.com/2017/11/10/ibm-passes-major-milestone-with-20-and-50-qubit-quantum-computers-as-a-service/ >>>>> >>>>> Jason >>>>> >>>> >>>> *If you're referring to my critique of the standard quantum >>>> interpretation of the superposition of states -- that a system in a >>>> superposition is in ALL component states SIMULTANEOUSLY -- show me where >>>> that INTERPRETATION is used in quantum computers.* >>>> >>> >>> It's in the definition of a qubit: https://en.wikipedia.org/wiki/Qubit >>> >> >> *But that's not nearly enough. You have to show where the assumption is >> applied. In the case of standard QM, the superposition is written as a sum >> of eigenstates, which are mutually orthogonal. So, as I pointed out >> exhaustively with no takers, the assumption isn't used in calculating >> probabilities. When you take the inner product of an eigenstate with the >> wf, all terms drop out except the eigenvalue whose probability you are >> calculating. Is the situation different with qubits*? AG >> > > > These superposed states either exist or they don't. Which is it in your > view? In my view they exist, because that is the only way to explain the > computational power of a quantum computer. >
*I am not doubting the existence of the superposed states; just their *interpretation* which is key to achieving the postulated speeds of quantum computers. See comment below. AG * > > >> >>> >>> >>>> >>>> * I know it isn't used to calculate probabilities in quantum theory. >>>> It's a postulate which is NOT used, so by Occam Razor it should be >>>> eliminated. AG* >>>> >>> >>> >>> You can't calculate the final probabilities without assuming the qubits >>> enter the superposition of all possible states, >>> >> >> *See above. I am not questioning the existence and utility of the >> superposition itself, but the assumption that a system in a superposition >> is simultaneously in all component states of the superposition. AG* >> >> > > If I start a 200 qubit quantum computer at time = 0, and 100 microseconds > later it has produced a result that required going through 2^200 = 1.6 x > 10^60 = states (more states than is possible for 200 things to go through > in 100 microseconds even if they changed their state every Plank time > (5.39121 x 10^-44 seconds), then physically speaking it **must** have > been simultaneous. I don't see any other way to explain this result. How > can 200 things explore 10^60 states in 10^-4 seconds, when a Plank time is > 5.39 x 10^-44 seconds? > *Impressive calculation to be sure, but is this a theoretical value based on the assumption I deny; or is it achieved by a working quantum computer? AG * > > > >> which is why it becomes exponentially hard to predict what happens with a >>> larger number of qubits in a quantum computer. This is why large scale >>> quantum computers must be built, we can't just simulate them with regular >>> computers because the number of states it is simultaneously in quickly >>> becomes enourmous: >>> >>> 1 qubit: 2 states >>> 5 qubits: 32 states (you can use this quantum computer for free on the >>> link I provided) >>> 10 qubits: 1024 states >>> 20 qubits: 1,048,576 states (you can pay to use this quantum computer >>> today >>> >> >> >>> ) >>> 30 qubits: 1,073,741,824 states >>> 50 qubits: 1,125,899,906,842,624 states (IBM recently built a quantum >>> computer with 50 qubits >>> <https://www.technologyreview.com/s/609451/ibm-raises-the-bar-with-a-50-qubit-quantum-computer/> >>> ) >>> 100 qubits: 1,267,650,600,228,229,401,496,703,205,376 states >>> 200 qubits: >>> 1,606,938,044,258,990,275,541,962,092,341,162,602,522,202,993,782,792,835,301,376 >>> >>> states >>> 1000 >>> qubits: >>> 10,715,086,071,862,673,209,484,250,490,600,018,105,614,048,117,055,336,074,437,503,883,703,510,511,249,361,224,931,983,788,156,958,581,275,946,729,175,531,468,251,871,452,856,923,140,435,984,577,574,698,574,803,934,567,774,824,230,985,421,074,605,062,371,141,877,954,182,153,046,474,983,581,941,267,398,767,559,165,543,946,077,062,914,571,196,477,686,542,167,660,429,831,652,624,386,837,205,668,069,376 >>> >>> states >>> >>> We know of nothing in principal that can accurately simulate the >>> behavior of a system of 1000 entangled atoms in a reasonable period of time >>> besides a quantum computer. The reason is the number above (2^1000) is so >>> large that ant attempt to simulate it will fail due to physical limits of >>> time, energy, and space within this universe. So if the computational >>> capacity of this universe is insufficient to compute what this system of >>> 1000 qubits will do, what in physics is known which has the sufficiently >>> large state and computational capacity to perform such a calculation? >>> >>> Answer: the wave function >>> >>> At the current time, there is no other known answer nor any hint of >>> another theory that can explain the power of quantum computers. The only >>> answer we have is that the wave function is something that is physically >>> real. >>> >>> >>> >>>> >>>> *WRT the MWI, it's too tortured and extravagant to be in the ballpark >>>> of reality. AG* >>>> >>> >>> Do you have an alternate theory for how quantum computers can be in so >>> many states simultaneously? >>> >> >> *I am not convinced of the simultaneous claim. Where is it actually >> applied? It isn't in standard QM. AG* >> >>> >>> > I don't know that there is any definition of "standard QM". > *I just meant the Copenhagen postulates of QM. Earlier I reproduced Dirac's comment (from Wiki, "Superposition of States") concerning the usual interpretation of a superposed state, which I don't think is formally a postulate. Also, Schroedinger's thought experiment was specifically designed to deny it. A*G > If would say to explain quantum computers you need to assume: > > 1. Reality of the wave function > 2. Reality of the superposition (and all of its states) > > Once you believe those, then there is an interesting question that gets > you to many worlds directly: "what happens if you run a conscious AI on a > quantum computer?" > > If you believe the AI program can be conscious (e.g. a belief in the > computational theory of mind), then you get many worlds, for the AI with a > 200 bit memory can be conscious of each of those 2^200 states that are > simultaneously explored by the quantum computer. > > 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 post to this group, send email to [email protected]. Visit this group at https://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/d/optout.
