On Wed, May 30, 2012 at 3:27 AM, Bruno Marchal <marc...@ulb.ac.be> wrote:

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> > On 29 May 2012, at 22:26, Jason Resch wrote: > > > > On Tue, May 29, 2012 at 12:55 PM, Bruno Marchal <marc...@ulb.ac.be> wrote: > >> >> To see this the following thought experience can help. Some guy won a >> price consisting in visiting Mars by teleportation. But his state law >> forbid annihilation of human. So he made a teleportation to Mars without >> annihilation. The version of Mars is very happy, and the version of earth >> complained, and so try again and again, and again ... You are the observer, >> and from your point of view, you can of course only see the guy who got the >> feeling to be infinitely unlucky, as if P = 1/2, staying on earth for n >> experience has probability 1/2^n (that the Harry Potter experience). >> Assuming the infinite iteration, the guy as a probability near one to go >> quickly on Mars. >> >> > Bruno, > > Thanks for your very detailed reply in the other thread, I intend to get > back to it later, but I had a strange thought while reading about the above > experiment that I wanted to clear up. > > You mentioned that the probability of remaining on Earth is (1/2)^n, where > n is the number of teleportations. > > > Not really. I pretend that this is the relative probability inferred by > the person in front of you. But he is wrong of course. Each time the > probability is 1/2, but his experience is "harry-Potter-like". > > > > > I can see clearly that the probability of remaining on earth after the > first teleportation is 50%, but as the teleportations continue, does it > remain 50%? > > > Yes. > > > > Let's say that N = 5, therefore there are 5 copies on Mars, and 1 copy on > earth. Wouldn't the probability of remaining on Earth be equal to 1/6th? > > > You cannot use absolute sampling. I don't think it makes any sense. > > > > > While I can see it this way, I can also shift my perspective so that I see > the probability as 1/32 (since each time the teleport button is pressed, I > split in two). It is easier for me to see how this works in quantum > mechanics under the following experiment: > > I choose 5 different electrons and measure the spin on the y-axis, the > probability that I measure all 5 to be in the up state is 1 in 32 (as I > have caused 5 splittings), > > > OK. > > > but what if the experiment is: measure the spin states of up to 5 > electrons, but stop once you find one in the up state. > > > That is a different protocol. The one above is the one corresponding to > the earth/mars experience. > > > > In this case it seems there are 6 copies of me, with the following records: > > 1. D > 2. DU > 3. DDU > 4. DDDU > 5. DDDDU > 6. DDDDD > > However, not all of these copies should have the same measure. The way I > see it is they have the following probabilities: > > 1. D (1/2) > 2. DU (1/4) > 3. DDU (1/8) > 4. DDDU (1/16) > 5. DDDDU (1/32) > 6. DDDDD (1/32) > > I suppose what is bothering me is that in the Mars transporter experiment, > it seems the end result (having 1 copy on earth, and 5 copies on mars) is > no different from the case where the transporter creates all 5 copies on > Mars at once. > > > This is ambiguous. > What I mean is me stepping into the teleporter 5 times, with the net result being 1 copy on Earth and 5 copies on Mars, seems just like stepping into the teleporter once, and the teleporter then creating 5 copies (with delay) on Mars. Like the diagram on step 4 of UDA: http://iridia.ulb.ac.be/~marchal/publications/SANE2004MARCHAL_fichiers/image012.gif Except there is no annihilation on Earth, and there are 4 copies created with delay on Mars (instead of one with delay). When stepping into the teleporter once, and having 5 copies created on Mars (with various delays between each one being produced) is the probability of remaining on Earth 1/6th? Is the difference with the iterated example receiving the knowledge that the other copy made it to Mars before stepping into the Teleporter again? Thanks, Jason > > > > In that case, it is clear that the chance of remaining on Earth should be > (1/6th) > > > Yes. In that case. > > > > but if the beginning and end states of the experiment are the same, why > should it matter if the replication is done iteratively or all at once? Do > RSSA and ASSA make different predictions in this case? > > > RSSA has to be applied. Your first protocol is faithful, isomorphic, to > the experience I was describing. Te second is not. > > OK? > > Bruno > > > http://iridia.ulb.ac.be/~marchal/ > > > > -- > You received this message because you are subscribed to the Google Groups > "Everything List" group. > To post to this group, send email to everything-list@googlegroups.com. > To unsubscribe from this group, send email to > everything-list+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/everything-list?hl=en. > -- You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-list@googlegroups.com. To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.