I have tons of questions regarding your quant-ph/0209055 [Ref. 1] and the issue of probabilities [Ref. 2]. Surely your efforts are heroic [Ref. 3], but let me please ask just two question.

After we make a measurement, I have a copy with nonzero weight [Ref. 1].

1. How far away is my doppelgänger? Just 10 to the 10^28 meters from here or a bit more? Please see

http://members.aon.at/chakalov/Tegmark.html

2. How could you stack all my doppelgängers with nonzero weight? Would that be on a transcendental tachyon?

I will be happy to learn the opinion of your colleagues as well.

BTW you have written a very serious paper, "A Quantum Search Algorithm for a Specified Number of Targets", quant-ph/0104082. I have a proposal that is not necessarily alternative,

http://members.aon.at/chakalov/Feedback.html#NB

Should you have questions, please don't hesitate.

Regards,

Dimi Chakalov
http://members.aon.at/chakalov
--

References

[Ref. 1] Mark A. Rubin, Relative Frequency and Probability in the Everett Interpretation of Heisenberg-Picture Quantum Mechanics,
http://xxx.lanl.gov/abs/quant-ph/0209055

"This work was sponsored by the Air Force under Air Force Contract F19628-00-C-0002.
...

"In a long series of repetitions of  E , it is practically certain that the [relative] frequency of E will be approximately equal to P ... This statement will be referred to as the frequency interpretation of the probability P [3, pp. 148-9].” Or, more succinctly, probability is “the theoretical value of long range relative frequency [5, p. 58].”
...

"(b) Only those copies with nonzero weight (see Sec. 2.2) exist.
...

"One can never actually experiment with an infinitely-large ensemble, [footnote 5] so one will never encounter this "mass extinction" of Everett copies.

[Footnote 5]: "This fact does not pose any problems in using the frequency interpretation of probability as we have above. Although we cannot experiment with an N --> [infinity] ensemble, this limiting case is well-defined within the quantum formalism, which, as we have seen, gives an unambiguous answer as to what would happen if we *could* do such experiments."
...

"In the Everett interpretation in the Heisenberg picture, the number of these continuously-infinite copies or minds will be proportional to the weight. However, if one introduces the notion of the weight, one can then consider ensembles of many such measurements, thereby obtaining the conclusions obtained in this paper and rendering the ad hoc introduction of continuous infinities of copies, minds etc. superfluous."

[Ref. 2] Lev Vaidman, Many-Worlds Interpretation of Quantum Mechanics, Sec. 6.3, Derivation of the Probability Postulate from the Formalism of the MWI,
http://plato.stanford.edu/entries/qm-manyworlds/#6.3
 

[Ref. 3] Jeffrey Barrett, Everett's Relative-State Formulation of Quantum Mechanics,
http://plato.stanford.edu/entries/qm-everett/#9

"It will probably never be entirely clear precisely what Everett himself had in mind, but his goal of trying to make sense of quantum mechanics without the collapse postulate was heroic."