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6 Sep 2024 15:20:14 EDT (-0400)
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From: Warp
Subject: Re: Weekly calibration
Date: 21 Apr 2009 11:36:32
Message: <49ede800@news.povray.org>
Darren New <dne### [at] sanrrcom> wrote:
> Warp wrote:
> >   Do you disagree that a probability of zero does not mean that the event
> > will never happen?

> A probability of zero does not mean the event won't happen with an infinite 
> number of trials. Zero times infinity is not zero.

  True. The event happens with *one* trial. You don't even need an infinite
amount of them.

  Now explain that.

-- 
                                                          - Warp


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From: scott
Subject: Re: Weekly calibration
Date: 21 Apr 2009 11:37:32
Message: <49ede83c$1@news.povray.org>
> Sorry, but no - the explanation doesn't work. If you read my original
> long post, you'd see that the two cases are *identical*.

The mistake in your logic is assuming the probability of choosing 1 item 
from an infinite set is zero, it isn't, it is 1/infinity or "infinitely 
small".  In many cases this can be treated as zero, but when you start 
summing over an infinite number of items (ie what is the probability that I 
chose any of these items, or if I try an infinite times will I get this 
one?) there is an important difference.

The probability of you choosing 1.847 when asked to choose a number between 
0 and 1 is really zero.  Even if you try an infinite number of times, it's 
still zero probability.

> Getting a sequence of all heads forever is identical to picking a point
> from 0 to 1. Both have probability 0.

Mathematicians seem to disagree with you on that one.  1/infinity is not 
defined as zero (because it can often lead to problems like the above), 
however the infinite sum of 1/2+1/4+1/8+... (ie probability of getting no 
tails after infinite throws) is defined as 1.

Of course you can discuss how this relates to reality, but I'd rather not 
get involved in that one, it could an infinitely long time :-)


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From: Warp
Subject: Re: Weekly calibration
Date: 21 Apr 2009 11:37:48
Message: <49ede84c@news.povray.org>
Darren New <dne### [at] sanrrcom> wrote:
> Warp wrote:
> >   So exactly at which point are the works forced to appear, to fulfill
> > the probability of 1?

> Infinity.  That's the point.

  In other words: Never. At no point is it forced to happen.

  That's the point.

> The limit does not equal the value at infinity. Unbounded is not the same as 
> infinite. You're still confusing the two.

  The analogy is that the monkey will type Shakespeare's work for sure.
Exactly when is this 100% certainty reached? Never.

-- 
                                                          - Warp


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From: scott
Subject: Re: Weekly calibration
Date: 21 Apr 2009 11:41:33
Message: <49ede92d@news.povray.org>
>  In other words, you would have to pop up an infinite amount of numbers
> before you reach the situation where the works must appear. However, no
> matter how many values you pop up, they will never be infinite. By 
> definition
> you can *not* pop up an infinite amount. You will never reach infinity.
>
>  Thus the works are *never* forced to appear.

It seems to me you are concerned about an event taking place an infinite 
number of times, rather than anything to do with probability.

Yes I know the text says that "with infinite time", and in reality this can 
never happen, so I guess that's the explanation you are looking for?


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From: Darren New
Subject: Re: Weekly calibration
Date: 21 Apr 2009 12:15:29
Message: <49edf121$1@news.povray.org>
Warp wrote:
>   So at which point exactly will it happen with 100% certainty?

When an infinite number of flips are flipped, and not before.

> What are the exact mechanics which cause it to happen?

The mathematics of infinity.

>   "At infinity" is the same thing as "never" in this case.

It has nothing to do with "time", so you are technically correct in saying 
that it's physically impossible to do an infinite number of flips in a 
non-infinite length of time.

>> Resolve this discrepency, in your mind, and you'll understand why 
>> shakespeare must appear.
> 
>   Once you explain to me the discrepancy that an event having zero
> probability can happen.

When you do it an infinite number of times.

Do you understand what I'm saying when I say you're confusing unbounded with 
infinite?

Is it possible to have an infinitely long string of zeros? Yes. Is it 
possible to program a turing machine to write an infinitely long string of 
zeros on its tape?  No. A turing machine can only write an unbounded number 
of zeros on the tape.


-- 
   Darren New, San Diego CA, USA (PST)
   There's no CD like OCD, there's no CD I knoooow!


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From: Darren New
Subject: Re: Weekly calibration
Date: 21 Apr 2009 12:19:44
Message: <49edf220@news.povray.org>
Warp wrote:
>   In other words, you would have to pop up an infinite amount of numbers
> before you reach the situation where the works must appear. However, no
> matter how many values you pop up, they will never be infinite.

The problem statement presumes an infinite number of monkeys, or an infinite 
duration of typing. Hence, yes, the number of values will be infinite.

If you have an infinite number of monkeys, and each types one page, you will 
have an infinite number of pages.

You're arguing "but you can't *get* to infinity by counting one at a time." 
Of course. But the premise is that you're already at infinity.

>   The monkey analogy is thus flawed. No matter how long the monkey hammers
> the typewriter, at no point are the works of Shakespeare appearing with
> absolute certainty. They may appear, but there's no absolute guarantee.

Because you can't get to an infinite number of keypresses by looking at them 
one at a time.

Would you agree that an infinite number of monkeys each pressing one key is 
identical to one monkey pressing an infinite number of keys?

>   There may be mathematical background for the infinity and the certain
> probability, but the *monkey analogy* is inherently flawed.

Well, yes. Because there aren't an infinite number of monkeys, nor is there 
any way a single monkey will live an infinite number of seconds.

However, if you *presume* either of those has come to pass, you get the answer.

-- 
   Darren New, San Diego CA, USA (PST)
   There's no CD like OCD, there's no CD I knoooow!


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From: Darren New
Subject: Re: Weekly calibration
Date: 21 Apr 2009 12:21:05
Message: <49edf271$1@news.povray.org>
Warp wrote:
>   True. The event happens with *one* trial. You don't even need an infinite
> amount of them.

Selection bias. :-)

-- 
   Darren New, San Diego CA, USA (PST)
   There's no CD like OCD, there's no CD I knoooow!


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From: Darren New
Subject: Re: Weekly calibration
Date: 21 Apr 2009 12:22:30
Message: <49edf2c6$1@news.povray.org>
Warp wrote:
> Darren New <dne### [at] sanrrcom> wrote:
>> Warp wrote:
>>>   So exactly at which point are the works forced to appear, to fulfill
>>> the probability of 1?
> 
>> Infinity.  That's the point.
> 
>   In other words: Never. At no point is it forced to happen.

No. You're getting wrapped up in Zeno's paradox here.

>   The analogy is that the monkey will type Shakespeare's work for sure.
> Exactly when is this 100% certainty reached? Never.

Yes. After infinite time. But you're refusing to look at that case, trying 
to get to "after infinite time has passed" by looking one second at a time.

Assume you have an infinite number of monkeys, each typing one block of text 
the size of shakespeare, and they all finish within one day. Is Shakespeare 
in there?

-- 
   Darren New, San Diego CA, USA (PST)
   There's no CD like OCD, there's no CD I knoooow!


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From: Warp
Subject: Re: Weekly calibration
Date: 21 Apr 2009 12:39:11
Message: <49edf6af@news.povray.org>
Darren New <dne### [at] sanrrcom> wrote:
> Warp wrote:
> >   So at which point exactly will it happen with 100% certainty?

> When an infinite number of flips are flipped, and not before.

  In other words, never.

> >   "At infinity" is the same thing as "never" in this case.

> It has nothing to do with "time", so you are technically correct in saying 
> that it's physically impossible to do an infinite number of flips in a 
> non-infinite length of time.

  Thus the monkey analogy is technically flawed. Which is my original point.

> >> Resolve this discrepency, in your mind, and you'll understand why 
> >> shakespeare must appear.
> > 
> >   Once you explain to me the discrepancy that an event having zero
> > probability can happen.

> When you do it an infinite number of times.

  But it happens with only one attempt, not an infinite amount of them.

> Do you understand what I'm saying when I say you're confusing unbounded with 
> infinite?

  The monkey analogy is trying to make a connection between theoretical
math dealing with infinites and physical reality, which are at completely
different conceptual levels. I do not fully understand the math, but I'm
pretty sure I understand the physical process depicted by the analogy,
and I'm pretty sure the claim is flawed.

-- 
                                                          - Warp


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From: Warp
Subject: Re: Weekly calibration
Date: 21 Apr 2009 12:43:03
Message: <49edf797@news.povray.org>
Darren New <dne### [at] sanrrcom> wrote:
> Assume you have an infinite number of monkeys, each typing one block of text 
> the size of shakespeare, and they all finish within one day. Is Shakespeare 
> in there?

  If all the monkeys press the key 'a', then obviously not.

  What forces any of the monkeys to press some other key?

-- 
                                                          - Warp


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