- Contemporary messages sorted: [ by date ] [ by thread ] [ by subject ] [ by author ] [ by messages with attachments ]

From: Jacques Mallah <jackmallah.domain.name.hidden>

Date: Thu, 30 Aug 2001 19:14:33 -0400

*>From: "Charles Goodwin" <cgoodwin.domain.name.hidden>
*

*>Hi, I have just joined this list after seeing it mentioned on the Fabric of
*

*>Reality list....
*

Hi. BTW, what's up on the FOR list? Ever see anything interesting

there? I thought the book sucked except for chapter 2 (I think; the one

explaining the MWI), but at least there are some MWIers on that list I would

think.

*>Would someone mind briefly explaining what FIN is (or at least what the
*

*>letters stand for)? Is it some version of QTI (Quantum
*

*>theory of immortality) ?
*

Yes, any version of "QTI" is FIN.

*>Why should a typical observer find himself to be older than the apparent
*

*>lifetime of his species?
*

I guess you mean "assuming FIN, why ..."

*>so *very* few observeres are going to notice the TU versions of anyone
*

*>else. So the only way to actually experience this phenomenon is to live to
*

*>be that old yourself.
*

Right ...

*>I must ask, though, what makes you think that a typical observer ISN'T much
*

*>older than the lifetime of his species would allow?
*

I'm not so old, but if FIN were true, the effective chance of me being

old would be 100%. So by Bayesian reasoning, it must be false.

*>Given that you can't observe anyone but yourself in this state (or it's
*

*>"TU" that you ever will) (and I'm assuming you haven't reached 120 yet),
*

*>you can't really use a self-sampling argument on this, surely?
*

On the contrary, you do use a SSA. After all, you will never (for any

question) have more than the one data point for use in the SSA. But with a

probability of 0% or 100%, that's plenty!

*> > It means - and I admit it does take a little thought here - _I want
*

*>to follow a guessing procedure that, in general, maximizes the fraction of
*

*>those people (who use that procedure) who get the right guess_. (Why would
*

*>I want a more error-prone method?) So I use Bayesian reasoning with the
*

*>best prior available, the uniform one on observer-moments, which maximizes
*

*>the fraction of observer-moments who guess right. No soul-hopping in that
*

*>reasoning, I assure you.
*

*>
*

*>I'm sorry, I still don't see how that applies to me. If I know which
*

*>observer moments I'm in (e.g. I know how old I am) why should I
*

*>reason as though I don't?
*

Because you want to know things, don't you? It's no different from any

Bayesian reasoning, in that regard.

Suppose you know that you just flipped a coin 10 times in a row, and it

landed on heads all ten times. Now you can apply Bayesian reasoning to

guess whether it is a 2-headed coin, or a regular coin. How to do it?

p(2-headed|got 10 heads) = [p(got 10 heads|2-headed) p_0(2-headed)] / N

p(1-headed|got 10 heads) = [p(got 10 heads|1-headed) p_0(1-headed)] / N

where N = p(got 10 heads) is the normalization factor so that these two

conditional probabilities sum to 1 (they are the only possibilities).

That's a standard use of Bayes' theorem. But - whoa there - what's the

p(got 10 heads) and the like? You already _know_ you got 10 heads, so why

not just set p(got 10 heads) to 1?

Obviously, you consider the counterfactual case of (didn't get 10 heads)

for a reason - that is, to help you guess something about the coin. In the

same way, the SSA helps you guess things. It's just a procedure to follow

which usually helps the people that use it to make correct guesses.

- - - - - - -

Jacques Mallah (jackmallah.domain.name.hidden)

Physicist / Many Worlder / Devil's Advocate

"I know what no one else knows" - 'Runaway Train', Soul Asylum

My URL: http://hammer.prohosting.com/~mathmind/

_________________________________________________________________

Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp

Received on Thu Aug 30 2001 - 16:15:52 PDT

Date: Thu, 30 Aug 2001 19:14:33 -0400

Hi. BTW, what's up on the FOR list? Ever see anything interesting

there? I thought the book sucked except for chapter 2 (I think; the one

explaining the MWI), but at least there are some MWIers on that list I would

think.

Yes, any version of "QTI" is FIN.

I guess you mean "assuming FIN, why ..."

Right ...

I'm not so old, but if FIN were true, the effective chance of me being

old would be 100%. So by Bayesian reasoning, it must be false.

On the contrary, you do use a SSA. After all, you will never (for any

question) have more than the one data point for use in the SSA. But with a

probability of 0% or 100%, that's plenty!

Because you want to know things, don't you? It's no different from any

Bayesian reasoning, in that regard.

Suppose you know that you just flipped a coin 10 times in a row, and it

landed on heads all ten times. Now you can apply Bayesian reasoning to

guess whether it is a 2-headed coin, or a regular coin. How to do it?

p(2-headed|got 10 heads) = [p(got 10 heads|2-headed) p_0(2-headed)] / N

p(1-headed|got 10 heads) = [p(got 10 heads|1-headed) p_0(1-headed)] / N

where N = p(got 10 heads) is the normalization factor so that these two

conditional probabilities sum to 1 (they are the only possibilities).

That's a standard use of Bayes' theorem. But - whoa there - what's the

p(got 10 heads) and the like? You already _know_ you got 10 heads, so why

not just set p(got 10 heads) to 1?

Obviously, you consider the counterfactual case of (didn't get 10 heads)

for a reason - that is, to help you guess something about the coin. In the

same way, the SSA helps you guess things. It's just a procedure to follow

which usually helps the people that use it to make correct guesses.

- - - - - - -

Jacques Mallah (jackmallah.domain.name.hidden)

Physicist / Many Worlder / Devil's Advocate

"I know what no one else knows" - 'Runaway Train', Soul Asylum

My URL: http://hammer.prohosting.com/~mathmind/

_________________________________________________________________

Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp

Received on Thu Aug 30 2001 - 16:15:52 PDT

*
This archive was generated by hypermail 2.3.0
: Fri Feb 16 2018 - 13:20:07 PST
*