Re: What is complexity?

In article <0L2dnVpDOovLaeDeRVn-sw@xxxxxxxxxxx>,
dkomo <dkomo871@xxxxxxxxxxx> wrote:
>Kim G. S. Øyhus wrote:
>>
>> That is obviously Dawkings scientific popularizing of Kolmogorov
>> complexity.
>>
>
>No it is not. Dawkins is writing about a description of complexity that
>has semantic content and is meant to be *understood*.

That is still inside of Kolmogorov complexity.
And before you argue that it is humans who shall understand, not
Turing machines, I hereby preempt this by telling you that humans
could also be implemented as programs on a Turing machine, as may
the entire universe, with humans.

>Frankly, I wish people would stop even mentioning Kolmogorov complexity
>as some kind of a metric to consider. Whatever utility this idea has
>for AIT, the sad fact is that there is no known method for even
>computing the length of the minimal program that will output a given
>string, nor to tell if a particular such program is of minimal length.
>As a general metric for complexity, Kolmogorov complexity is useless.

No, it is not, because it IS possible to give upper bounds on the
Kolmogorov complexity. Just take the best description we have so
far, and use that as the upper bound.


>Dawkins' proposal, on the other hand, is practical and could be put to
>immediate use. It doesn't differ that much from the kind of verbal,
>mathematical and pictorial descriptions biologists and naturalists have
>been writing for hundreds of years now.

Neither does Kolmogorov complexity. It incorporates all that stuff as well.



>> It is like cryptography, where it is very much easier to describe the
>> messages if one have the key than without.
>>
>> And this is why Kolmogorov complexity assumes infinitely powerful machines,
>> to avoid the comlexity of missing difficult solutions which are
>difficult to find.
>>
>> Kim0
>>
>
>Maybe so. But my claim is that Kolmogorov complexity is pretty
>irrelevant to characterizing real world complexity. Unless you think
>the universe is a gigantic computer, the physical laws are algorithms,
>and the objects are strings. There are some people who believe that.

I am a physicist, and I know the laws we have found do indeed look
like algorithms, and the universe does indeed look like it is made of
strings.

And even if it didn't look like that, AIT would still be valid,
because there is no alternative at all.

Kim0

.

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