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> It's not obvious to me that fern branches are 'anatomically variable and non-iterating bifurcations', rather than a recursive process that bottoms out at a si
by JadeNB 3y ago
> It's not obvious to me that fern branches are 'anatomically variable and non-iterating bifurcations', rather than a recursive process that bottoms out at a size boundary.
But hardly any (no?) real-life phenomena are the latter! As a mathematician, I'm as bothered by imprecise use of mathematical terminology as anyone, but, if we're going to call anything in real life a fractal, then it surely means something more like "appears to contain structure at multiple scales" than "the same structure at all scales". As @throwbadubadu points out (https://news.ycombinator.com/item?id=35903049 https://news.ycombinator.com/item?id=35903049), the classical example of a coast-line will also have different structure at small scales and at large ones, so either we throw out calling that a fractal (OK with me!), or we accept that we're using precise language imprecisely.
- robotresearcher 3y agoCrystals perhaps? Bottom up rather than top down, but locally recursive.
- JadeNB 3y ago> Crystals perhaps? Bottom up rather than top down, but locally recursive. Great example!
- CoolGuySteve 3y agoThere were fractal body plans in the precambrian era but they went extinct pretty quickly. https://en.wikipedia.org/wiki/Rangeomorph https://en.wikipedia.org/wiki/Rangeomorph
- JadeNB 3y ago> There were fractal body plans in the precambrian era but they went extinct pretty quickly. Cool! I didn't know about that.