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I am reading Stephen Wolfram's "A New Kind of Science".

At present, I cannot understand how the cellular automata illustrations on p79 are created.

In the patterns, the active cell, representing the head, appears to change orientation between up and -45 degrees (towards bottom right). However, none of the rules seem to include an active cell with an orientation other than up or down. How does the active cell orientation of -45 degrees come about in the patterns?

Am I missing something obvious (I am a beginner in this area)?

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  • $\begingroup$ Could you provide a better scan or screenshot? The page you linked to doesn't have enough resolution to actually tell the head states apart, and while I do happen to own a copy of ANKoS, I don't have it handy right now. $\endgroup$ – Ilmari Karonen Dec 25 '13 at 0:31
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I think that it is an inconsistency between the printing of the rules and the diagrams.

If the downward (-90 degrees) arrows in the rules are replaced with arrows pointing to the bottom right (-45 degrees) then the rules seem to make sense.

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  • $\begingroup$ Are there errata to the book that might clarify this? If not, someone might want to point this out to the author. $\endgroup$ – Wolfgang Bangerth Nov 24 '13 at 17:16
  • $\begingroup$ I couldn't find a list of errata and have sent an email to Wolfram Science... $\endgroup$ – atomh33ls Nov 24 '13 at 19:58

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