24 February 2012

Review Beginning Of Infinity 3

Review Beginning Of Infinity 3

Been busy

I've been busy adding a major feature to Rosegarden, so I've let this go for a while. But I fixed the last known bug today, so I may already be done (or not).


So now that I have a little time again, this has been jangling around in my mind. Patchwork Zombie compared hard-to-vary to peaks on a fitness landscape, in order to make the concept more obvious.

How much is hard-to-vary like a fitness landscape?

A pointy landscape is definitely part of the picture. The layout of the landscape corresponds in the familiar way to the dimensions of variation.

But it's not a fitness landscape, because hard-to-vary is itself the fitness condition. Or to be tiresomely pedantic, Deutsch appeals to it as being the relevant fitness condition on various topics. So height can't also be the fitness condition.

That much I'm sure of. Now comes the part where I have to relate what he "surely must have meant". ISTM that height on the landscape corresponds to some perceptual dimension. Sharp peaks which fall off very steeply are hard to vary and rounded peaks aren't.

And I bet you noticed, where I said "some perceptual dimension", that there wasn't just one perceptual dimension in the previous posts. Right. A landscape could have many height dimensions / perceptual dimensions. Steepness on all of them would count; presumably it's something like the norm of the gradient.

Deutsch's motivating example

I'll relate how Deutsch introduced hard-to-vary, which may make it clearer.

He initially talks about hard-to-vary by comparing two ways of copying things. Both are like "telephone", the children's game where one person tells a secret to the next, who tells it to the next, to the next, and the last person tells it aloud, and you see how much it has changed.

Each person sees a picture of a Chinese junk, and draws it, and then shows that drawing to the next person. Every generation of copy is a little less faithful to the original. Probably no copy is very much worse than the previous, but the result at the end scarcely resembles the picture at the start of the chain.
Origami (paper-folding). Each person is shown how to fold a Chinese junk. If an intermediate guy makes a sloppy copy, the next guy may still understand what he was trying to do; his copy won't inherit the sloppiness. Or the next guy may fail to understand the intent, and then his copy will not be much like the original at all, and everyone further down the line will inherit his mistake. Every generation of copy is either basically the same as the original or very wrong.

The "digital" copying, Deutsch says, is the one that's hard to vary. Variations either disappear or they change the design into some grossly different design.


  1. I checked out a copy of "the fabric of reality"*, because it's lazy of me to ask you to keep explaining what he's saying without me reading. A new summary of what he's saying is "if you can break it it must've been working". But we can only tell if is still working if you know what it's supposed to do. This circularity confounds me, we don't learn anything we don't already know.

    Let's take art: good are is not usually improved by putting a random splotch of paint on. But how do we tell if it improved? By appealing to our art evaluator that tells good art from bad.

    The origami example doesn't re-enforce my understanding because it sounds like a simple error correcting code (probably my understanding is wrong). Certainly some kinds of errors with be corrected but it doesn't seem to have much to do with an explanation of beauty.

    * Beginning of infinity was checked out and you said they were pretty similar.

    if you want, there is more discussion of david deutsch's flowers here http://shkrobius.livejournal.com/329132.html

  2. Thanks for the link.

    I said those books by Deutsch were similar? Perhaps in the emphasis they put on explanation as a fundamental thing. I don't want to leave the impression that they are that much like each other.

    Circularity - it struck me as flirting with circularity too, but I don't it actually fails there.

    True that the origami example is like a simple error correcting code. The implication seems to be that "hard to vary" is analogous to how an error correcting code drags small variations back to the original form.