Jesse Mazer writes: > Would you say that because you think running multiple identical copies of a > given mind in parallel doesn't necessarily increase the absolute measure of > those observer-moments (that would be my opinion)...
Here is an argument I wrote a couple of years ago on another list that first made me think that copies count, that is, that having more identical copies should be considered to increase measure. Previously I was skeptical about it, I thought what mattered was whether something or someone got instantiated at all, not how many there were. And of course since then I not only believe that copies count, I have followed my logic to the absurd sounding conclusion that size and slowness increase measure as well. Consider an experiment where we are simulating someone and can give them either a good or bad experience. These are not replays, they are new experiences which we can accurately anticipate will be pleasant or unpleasant. Suppose we are going to flip a biased quantum coin, one which has a 90% chance of coming up heads. We will generate the good or bad experience depending on the outcome of the coin flip. I claim that it is obvious that it is better to give the good experience when we get the 90% outcome and the bad experience when we get the 10% outcome. That's the assumption I will start with. Now consider Tegmark's level 1 of parallelism, the fact that in a sufficiently large volume of space I can find a large number of copies of me, in fact copies of the entire earth and our entire visible universe (the "Hubble bubble"?). When I do my quantum coin flip, 90% of the copies will see it come up heads and cause the good experience for the subject, and 10% will see tails and cause the bad experience. I will also assume that my knowledge of this fact about the physical universe will not change my mind about the ethical value of my decision to give the good experience for the 90% outcome. Now the problem is this. There are really only two different programs being run for our experimental subject, the guy in the simulation. One is a good experience and one is bad. All my decision does is to change how many copies of each of these two programs are run. In making my decision about which experiences to assign to the two coin flip outcomes, I have chosen that the copies of the good experience will outnumber copies of the bad experience by 9 to 1. But if I don't believe that the number of copies being run makes a difference, then I haven't accomplished what I desired. The fact that I am running more copies of the good program than the bad wouldn't make any difference. Therefore there is no actual ethical value in what I have done, I might have just as validly reversed the outcome of my coin flips and it wouldn't have made any difference. In this way I reach a contradiction between the belief that the number of copies doesn't matter, the belief that the existence of distant parallel copies of myself doesn't make much difference in what I should do, and the idea that there is value in making people happy. Of these, the most questionable seems to be the assumption that copies don't matter, so this line of reasoning turns me away from that belief. I can come up with similar contradictions from simpler cases like our own observations of subjective probability. The fact that I do experience a subjective 90% chance of seeing the quantum coin come up heads corresponds very well with the fact that 90% of the copies of me will see heads - but only if I assume that the multiplicity of the copies matters. After the coin flip, in a certain voume of space there are 90 copies of me that see heads and 10 copies that see tails. But within the two groups all copies are identical (neglecting other quantum events which would further split me). If the multiplicity doesn't count, then there are really just two outcomes and I might expect to subjectively experience equal probability for them. This is a variant on an old argument against the MWI, but in that case I always felt the answer was "measure", that some of the outcomes occured in a quantum branch which had this intangible quality which made it count more. In this case I can't invoke any such magic; all the copies of me are running in the same universe and with equal quantum amplitude. I have to resort to counting the instances separately and assuming that each one makes its own independent contribution to my subjective experiences, in order to gain correspondence with subjective probability. Therefore it is most consistent to say that separate runs of identical programs do "count", they do add to the measure of the subjective experience. Hal Finney