Le 05-déc.-05, à 02:46, Saibal Mitra a écrit :

## Advertising

I still think that if you double everything and then annihilate onlythedoubled person, the probability will be 1.

Actually I agree with this.

This is simply a consequence of using the absolute measure.

`Ah ? I am not sure this makes sense. If this makes sense, then the`

`Absolute Measurer and the Relative one are closer than I was used to`

`think.`

The idea is that the future is ''already out there''.

`Again I agree, but I would say the 2^aleph_0 futures are "already out`

`there". That's why we need a measure. I could say that the`

`mathematical shape of that measure should be absolute (the same in all`

`the worlds of the multiverse). The value of the measure with respect to`

`the choice of some experiment is relative. Would you agree?`

So, the correct picture is not that suddenly the plenitude is madelarger because a copy of the person plus (part of) his universe isappendedto the plenitude. The plenitude itself is a timeless entity,containing allpossible states. If someone wants to carry out a duplicationexperiment thenthe results of that are ''already'' present in the plenitude.

`I agree if you are talking about the 3-plenitude. For the 1-plenitude,`

`the question is more delicate.`

`(G* can show that the 1 and 3 notions of plenitude are the same, but`

`from the machine point of view (either 1 or 3 view) this in not the`

`case at all: the 1-plenitude will look much vaster than the`

`3-plenitude. This is akin to the Skolem paradox in axiomatic set`

`theory, but also to some carrolian or monthy-python like fantasies`

`where some place look tiny as seen from outside and very big from`

`inside :)`

When death can be ignored then the apparent time evolution can bedescribedby a relative measure which is given as the ratio of absolute measurestakenbefore and after an experiment (as pointed out by George Levy in apreviousreply).

`Yes but as far as I remember older posts by George Levy, we need also`

`to take into account some fusion of histories, by amnesy or "quantum"`

`erasure, and this prohibits trust in the use of intuitive`

`probabilities. Then the interview of the Universal machine explains`

`somehow why things are counter-intuitive there (self-reference`

`limitations).`

Note that the locality of the laws of physics imply that you can never directly experience the past.

`Yes but then you should make clear if you assume the laws of physics`

`just for illustration or as a fundamental hypothesis. From you other`

`recent post I guess you don't assume the physical laws, just the`

`algorithm (and I add the "mathematical execution of those algorithm in`

`platonia. OK?`

So, if you measure the z-component of aspin polarized in the x-direction, you will find yourself in a statewhereyou have measured, say, spin up, while you have a memory of how you prepaired the spin of the particle, some time before you made the measurement. One thus has to distinguish between the three states: S1: the experimenter prepaires the spin of the particleS2: the experimenter finds spin up while having the memory of being inS1S3: the experimenter finds spin down while having the memory of beingin S1These three states are ''timeless'' elements of the plenitude. Theyhavetheir own intrinsic measures. I challenge people on this list toexplain whythis is not the case. If you have a plenitude you have everything. So,S1,S2 and S3 are just ''out there''.

OK.

The measure of S2 and S3 are half that ofS1. The probability of being in either S2 or S3 is thus the same asbeing inS1.

OK (relatively). 3-point-of- view talk.

But if measuring spin down leads to instant death, then the probabilityof being alive after the experiment is half that of being alive beforetheexperiment.

`Except that "death" has no 1-meaning, and should not be taken into`

`account for evaluating a probability question. Here too George Levy`

`argued some time ago that, strictly speaking the probability to find`

`oneself 1-alive is always 1. But here too it is a little delicate`

`because it is a typical "pure theological truth", it belongs to G* \ G.`

`I recall G formalizes correctly and completely what sound machines can`

`prove about themselves, and that G* formalizes correctly and completely`

`what is true about the sound machine, but not necessarily provable`

`(that's mainly Solovay theorem). G* \ G literally axiomatizes what`

`sound machines can "correctly hope" about themselves.`

`Your post makes me doubt the difference between Absolutist and`

`Relativist, about measure, is less big than I was used to think.`

Bruno http://iridia.ulb.ac.be/~marchal/