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Showing posts with label animals. Show all posts
Showing posts with label animals. Show all posts

Saturday, December 15, 2018

Spirals: Golden or Not: Fib O’ Gnocchi?

      I attended a presentation recently that included a discussion of the Fibonacci number sequence and golden spirals. We have discussed Fibonacci numbers and golden spirals here at Partial Ellipsis of the Sun before.




        The Fibonacci number series begins as 0, 1, 1, 2, 5, 8, 13, 21, 34, 55, 89,144; each term is the sum of the previous two terms. The Golden Spiral is created using phi, the ratio of 1.6180.  In mathematics, two quantities are in the golden ratio if their ratio is the same as the ratio of their sum to the larger of the two quantities thus: 



       The illustrations in the presentation included spirals that looked like this:







      Of course, Golden Spirals look like this:




       No one else in the audience seemed bothered by equal spacing on the spiral; it drove me bonkers.  Folks commented on how beautiful the illustration was; but it was wrong!



      The Golden Spiral can be seen in the Milky Way:



And in storm patterns:




      It can also be used in image composition:



     I brought the spiral conundrum to the kindergartners who all saw immediately that the spiral had to grow so the chambered nautilus could grow, too.




      From the mouths of babes. . .




      Speaking of babes, a shout-out to my co-teacher who turned 60 on the 6th. The Babylonians considered 60 the most sacred number and a resetting of the odometer to zero in their base-60 number system. Happy sexagesimal reset, Mary!

     Does it drive you bonkers when illustrations are wrong? 



    ^^^Thanksgiving Square Chapel, Dallas, TX

Steph

Christmas Eve at Great Sand Dunes National Park and Preserve. It was an extraordinary day shared with a herd of 30 elk. See if you can find them.










Happy Sandy Holidays!

Tuesday, August 8, 2017

Crinoids for Cri-nerds

     We discussed crinoids,
also known as sea "lilies," here at Partial Ellipsis of the Sun in April. This extraordinarily well-preserved Paleozoic crinoid fossil sample (below) inspired another look at this animal that looks like a plant.



      Compare the sample above to the "Smarties" stem pieces we found in northern Arkansas in April. The disarticulated crinoid stems or stalks are relatively common, but the delicate, lacy crown pieces are much rarer.



      Modern day crinoids and the fossil animals are quite similar, hence they are often referred to by the non-scientific term "living fossils."



       The parts of crinoid animals are labelled below, though the terms are quite plant-based:



I guess you could say I'm a bit of a cri-nerd ;-).


     How about you?
     Steph