Re: The Anthropic Trilemma - Less Wrong

2012-02-14 Thread Bruno Marchal


On 14 Feb 2012, at 04:00, Stephen P. King wrote:


On 2/13/2012 5:54 PM, acw wrote:

On 2/12/2012 17:29, Stephen P. King wrote:

Hi Folks,

I would like to bring the following to your attention. I think  
that we

do need to revisit this problem.

http://lesswrong.com/lw/19d/the_anthropic_trilemma/


The Anthropic Trilemma
http://lesswrong.com/lw/19d/the_anthropic_trilemma/

snip


I gave a tentative (and likely wrong) possible solution to it in  
another thread. The trillema is much lessened if one considers a  
relative measure on histories (chains of OMs) and their length.  
That is, if a branch has more OMs, it should be more likely.


The first horn doesn't apply because you'd have to keep the copies  
running indefinitely (merging won't work).
The second horn, I'm not so sure if it's avoided: COMP-immortality  
implies potentially infinite histories (although mergers may make  
them finite), which makes formalizing my idea not trivial.

The third horn only applies to ASSA, not RSSA (implicit in COMP).
The fourth horn is acceptable to me, we can't really deny Boltzmann  
brains, but they shouldn't be that important as the experience  
isn't spatially located anyway(MGA). The white rabbit problem is  
more of a worry in COMP than this horn.
The fifth horn is interesting, but also the most difficult to  
solve: it would require deriving local physics from COMP.


My solution doesn't really solve the first horn though, it just  
makes it more difficult: if you do happen to make 3^^^3 copies of  
yourself in the future and they live very different and long lives,  
that might make it more likely that you end up with a continuation  
in such a future, however making copies and merging them shortly  
afterwards won't work.



Hi ACW,

   This solution only will work for finite and very special versions  
of infinite sets. For the infinities like that of the Integers, it  
will not work because any proper subset of the infinite set is  
identical to the complete set as we can demonstrated with a one-to- 
one map between the odd integers and the integers.


You should not confuse bijection (set isomorphism) and equality. Also,  
measure exists on infinite discrete sets, by weakening the sigma- 
additivity constraints. And then, finally, the measure problem bears  
on infinite extension of computations, and they are 2^aleph_0.


Remember the one line UD program:

For all i, j,k compute the kth first steps of phi_i(j).

We can describe a computation a sequence phi_i(j)^0,  
phi_i(j)^1,  , phi_i(j)^k.


That set is enumerable, but the set of all sequences going through  
equivalent 1p-steps is not enumerable, and you can define a measure by  
just using the normal distribution in a manner similar to the  
dovetailing on the reals. This has just to be corrected to take into  
account the constraints of self-reference, which seems to be the  
origin of an arithmetical quantization, negative amplitude of  
probability, etc.





   Given that the number of computations that a universal TM can run  
is at least the countable infinity of the integers, we cannot use a  
comparison procedure to define the measure.


You confuse the computations made by the UD, and observed by an  
outsider, and the infinite computations going through your actual 1p- 
state. Those includes all the dummies dovetailing on the reals, and  
cannot be enumerable.
Think about the iterated self-duplication. It leads to the usual  
Gaussian.




(Maybe this is one of the reasons many very smart people have tried,  
unsuccessfully,  to ban infinite sets...)


Not al all. The infinite set have been introduced to make the measure  
problem more easy, even for problem handling finite objects when they  
are very numerous.
Mathematical logic explains that finite and enumerable is more complex  
than the continuum, which existence is basically motivated by  
searching to simplify the problem. For example, Fermat on the reals is  
trivial. Not so on non negative integers.


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.



Re: The Anthropic Trilemma - Less Wrong

2012-02-13 Thread acw

On 2/12/2012 17:29, Stephen P. King wrote:

Hi Folks,

I would like to bring the following to your attention. I think that we
do need to revisit this problem.

http://lesswrong.com/lw/19d/the_anthropic_trilemma/


The Anthropic Trilemma
http://lesswrong.com/lw/19d/the_anthropic_trilemma/

21Eliezer_Yudkowsky http://lesswrong.com/user/Eliezer_Yudkowsky/27
September 2009 01:47AM

Speaking of problems I don't know how to solve, here's one that's been
gnawing at me for years.

The operation of splitting a subjective worldline seems obvious enough -
the skeptical initiate can consider the Ebborians
http://lesswrong.com/lw/ps/where_physics_meets_experience/, creatures
whose brains come in flat sheets and who can symmetrically divide down
their thickness. The more sophisticated need merely consider a sentient
computer program: stop, copy, paste, start, and what was one person has
now continued on in two places. If one of your future selves will see
red, and one of your future selves will see green, then (it seems) you
should /anticipate/ seeing red or green when you wake up with 50%
probability. That is, it's a known fact that different versions of you
will see red, or alternatively green, and you should weight the two
anticipated possibilities equally. (Consider what happens when you're
flipping a quantum coin: half your measure will continue into either
branch, and subjective probability will follow quantum measure for
unknown reasons http://lesswrong.com/lw/py/the_born_probabilities/.)

But if I make two copies of the same computer program, is there twice as
much experience, or only the same experience? Does someone who runs
redundantly on three processors, get three times as much weight as
someone who runs on one processor?

Let's suppose that three copies get three times as much experience. (If
not, then, in a Big universe, large enough that at least one copy of
anything exists /somewhere,/ you run into the Boltzmann Brain problem
http://lesswrong.com/lw/17d/forcing_anthropics_boltzmann_brains/.)

Just as computer programs or brains can split, they ought to be able to
merge. If we imagine a version of the Ebborian species that computes
digitally, so that the brains remain synchronized so long as they go on
getting the same sensory inputs, then we ought to be able to put two
brains back together along the thickness, after dividing them. In the
case of computer programs, we should be able to perform an operation
where we compare each two bits in the program, and if they are the same,
copy them, and if they are different, delete the whole program. (This
seems to establish an equal causal dependency of the final program on
the two original programs that went into it. E.g., if you test the
causal dependency via counterfactuals, then disturbing any bit of the
two originals, results in the final program being completely different
(namely deleted).)

So here's a simple algorithm for winning the lottery:

Buy a ticket. Suspend your computer program just before the lottery
drawing - which should of course be a quantum lottery, so that every
ticket wins somewhere. Program your computational environment to, if you
win, make a trillion copies of yourself, and wake them up for ten
seconds, long enough to experience winning the lottery. Then suspend the
programs, merge them again, and start the result. If you don't win the
lottery, then just wake up automatically.

The odds of winning the lottery are ordinarily a billion to one. But now
the branch in which you /win /has your measure, your amount of
experience, /temporarily/ multiplied by a trillion. So with the brief
expenditure of a little extra computing power, you can subjectively win
the lottery - be reasonably sure that when next you open your eyes, you
will see a computer screen flashing You won! As for what happens ten
seconds after that, you have no way of knowing how many processors you
run on, so you shouldn't feel a thing.

Now you could just bite this bullet. You could say, Sounds to me like
it should work fine. You could say, There's no reason why you
/shouldn't /be able to exert anthropic psychic powers. You could say,
I have no problem with the idea that no one else could see you exerting
your anthropic psychic powers, and I have no problem with the idea that
different people can send different portions of their subjective futures
into different realities.

I find myself somewhat reluctant to bite that bullet, personally.

Nick Bostrom, when I proposed this problem to him, offered that you
should anticipate winning the lottery after five seconds, but anticipate
losing the lottery after fifteen seconds.

To bite this bullet, you have to throw away the idea that your joint
subjective probabilities are the product of your conditional subjective
probabilities. If you win the lottery, the subjective probability of
having still won the lottery, ten seconds later, is ~1. And if you lose
the lottery, the subjective probability of having lost the lottery, ten

Re: The Anthropic Trilemma - Less Wrong

2012-02-13 Thread Stephen P. King

On 2/13/2012 5:54 PM, acw wrote:

On 2/12/2012 17:29, Stephen P. King wrote:

Hi Folks,

I would like to bring the following to your attention. I think that we
do need to revisit this problem.

http://lesswrong.com/lw/19d/the_anthropic_trilemma/


The Anthropic Trilemma
http://lesswrong.com/lw/19d/the_anthropic_trilemma/

snip


I gave a tentative (and likely wrong) possible solution to it in 
another thread. The trillema is much lessened if one considers a 
relative measure on histories (chains of OMs) and their length. That 
is, if a branch has more OMs, it should be more likely.


The first horn doesn't apply because you'd have to keep the copies 
running indefinitely (merging won't work).
The second horn, I'm not so sure if it's avoided: COMP-immortality 
implies potentially infinite histories (although mergers may make them 
finite), which makes formalizing my idea not trivial.

The third horn only applies to ASSA, not RSSA (implicit in COMP).
The fourth horn is acceptable to me, we can't really deny Boltzmann 
brains, but they shouldn't be that important as the experience isn't 
spatially located anyway(MGA). The white rabbit problem is more of a 
worry in COMP than this horn.
The fifth horn is interesting, but also the most difficult to solve: 
it would require deriving local physics from COMP.


My solution doesn't really solve the first horn though, it just makes 
it more difficult: if you do happen to make 3^^^3 copies of yourself 
in the future and they live very different and long lives, that might 
make it more likely that you end up with a continuation in such a 
future, however making copies and merging them shortly afterwards 
won't work.



Hi ACW,

This solution only will work for finite and very special versions 
of infinite sets. For the infinities like that of the Integers, it will 
not work because any proper subset of the infinite set is identical to 
the complete set as we can demonstrated with a one-to-one map between 
the odd integers and the integers.
Given that the number of computations that a universal TM can run 
is at least the countable infinity of the integers, we cannot use a 
comparison procedure to define the measure. (Maybe this is one of the 
reasons many very smart people have tried, unsuccessfully,  to ban 
infinite sets...)


Onward!

Stephen

--
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.



Re: The Anthropic Trilemma - Less Wrong

2012-02-13 Thread acw

On 2/14/2012 03:00, Stephen P. King wrote:

On 2/13/2012 5:54 PM, acw wrote:

On 2/12/2012 17:29, Stephen P. King wrote:

Hi Folks,

I would like to bring the following to your attention. I think that we
do need to revisit this problem.

http://lesswrong.com/lw/19d/the_anthropic_trilemma/


The Anthropic Trilemma
http://lesswrong.com/lw/19d/the_anthropic_trilemma/

snip


I gave a tentative (and likely wrong) possible solution to it in
another thread. The trillema is much lessened if one considers a
relative measure on histories (chains of OMs) and their length. That
is, if a branch has more OMs, it should be more likely.

The first horn doesn't apply because you'd have to keep the copies
running indefinitely (merging won't work).
The second horn, I'm not so sure if it's avoided: COMP-immortality
implies potentially infinite histories (although mergers may make them
finite), which makes formalizing my idea not trivial.
The third horn only applies to ASSA, not RSSA (implicit in COMP).
The fourth horn is acceptable to me, we can't really deny Boltzmann
brains, but they shouldn't be that important as the experience isn't
spatially located anyway(MGA). The white rabbit problem is more of a
worry in COMP than this horn.
The fifth horn is interesting, but also the most difficult to solve:
it would require deriving local physics from COMP.

My solution doesn't really solve the first horn though, it just makes
it more difficult: if you do happen to make 3^^^3 copies of yourself
in the future and they live very different and long lives, that might
make it more likely that you end up with a continuation in such a
future, however making copies and merging them shortly afterwards
won't work.


Hi ACW,

This solution only will work for finite and very special versions of
infinite sets. For the infinities like that of the Integers, it will not
work because any proper subset of the infinite set is identical to the
complete set as we can demonstrated with a one-to-one map between the
odd integers and the integers.
Hence why it's a measure, not a sets cardinality. Although, you're 
right, it's not obvious to me how this can be solved in a satisfactory 
manner with infinite non-merging histories. One could give up on finding 
a computable measure and just consider each history as it is, without 
trying to quantify directly over all histories. Such a measure would be 
most likely uncomputable, although it'd still be better than nothing. 
It's not obvious that some histories wouldn't be finite if one considers 
their mergers with other histories (consider the case of humans which 
have finite brains and memories, eventually a loop/merge would exist if 
they don't self-modify somehow, simply because of finite amount of 
memory, even in the case of a SIM which never dies or deteriorates due 
to biological issues).



Given that the number of computations that a universal TM can run is at
least the countable infinity of the integers, we cannot use a comparison
procedure to define the measure. (Maybe this is one of the reasons many
very smart people have tried, unsuccessfully, to ban infinite sets...)

Unfortunately (or maybe fortunately?), one cannot avoid the countable 
infinity of naturals.

Onward!

Stephen




--
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.