# Re: copy method important?

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Le 24-juin-05, à 01:03, Brent Meeker a écrit :```
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```And then I recall I gave an exercise: show that with comp the
no-cloning theorem can easily be justified a priori from comp. As I
said this follows easily from the Universal dovetailer Argument.
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But the UDA and the comp-hypothesis are not the same thing.
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No but the UDA presuppose the comp hyp, and, unless I am wrong,
the comp hyp entails the conclusion of the UDA.

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```The
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argument shows that physical observable reality (relatively to what you
```decide to measure here and now) emerges as an average on all
computations (generated by the UD) going through your actual state.
Suppose now that you decide to observe yourself with at a finer and
finer level of description. At some moment you will begin to observe
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yourself at a level below you substitution level (which I recall is the
```level where you survive through copy).
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How do you know you can observe that level?
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What would it mean not being able to observe that level?
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Mmh ... I can observe anything, I mean I can look at anything, I will "observe" the result of my experience, being perhaps fuzzy, indeterminate, multiple, etc.
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```Below that level comp predict
you will be confronted with the 1-comp indeterminacy, that is you will
"see" the many computation/histories.
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If comp predicts that then it seems to involve a self-contradiction. It
```implies that there was no substitution level after all.
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But it does look like in QM, no? If we try to observe, very indirectly perhaps, some isolate piece of reality, doesn'it looking like observing the "parallel" realities. I think that is what David Deutsch has try to do by explaining that the Young two holes can be interpreted as a mean to accept the many worlds. Do you think the many worlds idea is contradictory?
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Bruno

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

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