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Comment by wrnr | Hacker News Reader

Nature uses symmetrie when it is useful, but if it isn't it doesn't. Many such examples, L-sucrose vs R-sucrose, male-female differences. The same in physics and mathematics, Higgs mechanism is dependent on symmetry breaking of the weak force, and in mathematics the very nature of symmetry (group theory) has all sort of random exceptions of the pariah group of the sporadic simple groups.

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Personally I consider any "random" abberations to be symptoms of the hairy dog theorom: you cant comb all the hair to lie flat, somewhere on the spherical dog, you're going to get a cowlick, it is unavoidable

in the meantime, chirality is simply mirror symmetry : curious part to me, is how mirror symmetry works out as one half being the "inside out" version of the other, turn a left handed glove inside out and it will fit the right hand. Maybe points to 4th dimensional stuffs, I never could grok how to turn a sphere inside out without pinching

Here are two classic youtube videos on the topic of sphere eversion; they mostly overlap, but I am posting both for double the hilarity in the comment sections :)

(the full 21 minute one) https://www.youtube.com/watch?v=wO61D9x6lNY

(the first 10 minutes) https://www.youtube.com/watch?v=sKqt6e7EcCs

If I remember correctly, I think the 10 minute one has the more hilarious comment section.

the technical name is 'the hairy ball theorem'

This is tautological; it's a slight rewording of "Nature favors symmetry when nature favors symmetry." This can be seen to be true without knowing anything about nature or symmetry, so it's a singularly unilluminating proposition about either. From my point of view, the interesting question is this: when are those times, and what are the particular properties of nature, or of symmetry, that causes nature to favor symmetry at those times but not others?

The article kinda says the opposite: that even when symmetry gives the organism no particular advantage, it still tends to get used because it's easier to code in the DNA.

That doesn't mean there will be no counterexamples ever. Sometimes asymmetry gives an advantage so it's worth the extra coding.

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