[HN Gopher] The Cicada's Love Affair with Prime Numbers (2013) ___________________________________________________________________ The Cicada's Love Affair with Prime Numbers (2013) Author : optimalsolver Score : 31 points Date : 2021-05-21 18:52 UTC (4 hours ago) (HTM) web link (www.newyorker.com) (TXT) w3m dump (www.newyorker.com) | deepdmistry wrote: | Anyone got the non paywall link? | greenyoda wrote: | https://archive.vn/oRlwW | the__prestige wrote: | The article does a great job explaining why lifecycle periodicity | is prime. But its very curious that 13 and 17 year cicadas are | common, but not 7 or 11. Do such cicadas exists as well? Why do | we not see cycles beyond 17 years? | filoeleven wrote: | The upper bound could be because it's a long time to live as a | glorified grub. | | It's also interesting that the different periodical broods have | pretty distinct boundaries: | https://en.m.wikipedia.org/wiki/Periodical_cicadas#Map_of_br... | | Perhaps the same selective pressures that separated the broods | geographically also filtered out shorter cycles due to | predation? | pwg wrote: | The article briefly touches on why not 7 or (almost) 11: | | "If we discount those cicadas with life cycles of ten years or | fewer (as being too close to predator life cycles), we find | that the most successful emergence rates for cyber cicadas are | thirteen and seventeen years--precisely what we find in the | wild." | | Why not beyond 17? The article does not say. The next prime | would be 19 (only two years longer). Perhaps 17 provides a | sufficiently large local optimum that there is little pressure | to lengthen the cycle to 19 or beyond. | cracker_jacks wrote: | Not just minimizing contact with predators, also minimizes | resource competition with other species of cicadas. | filoeleven wrote: | The title immediately made me think of this article on using | prime numbers in CSS to grow natural-looking variations. | | https://www.sitepoint.com/the-cicada-principle-and-why-it-ma... | | I'm excited to see the badass Deluxe Edition coloration of Brood | X when they emerge in my area. I dunno what I was doing in 2004, | but I clearly was not spending enough time outside. | cpeterso wrote: | I've read about a system that used prime numbers in scheduling | timers and timeouts to reduce the chances of event | synchronization. If you've got to pick a mostly-arbitrary | number, why not make it prime? :) ___________________________________________________________________ (page generated 2021-05-21 23:00 UTC)