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Weekend Cat Blogging and Photo Hunt: Spiral

The theme of this week’s Photo Hunt is spiral, a shape that appears frequently in art, mathematics, nature, and of course in Luna’s expressive tail.

This is an old photo with a much younger Luna in our former home in Santa Cruz.  It is one of the best examples of the tight curl she often forms in her tail.  Here is a more recent example:

The spirals in Luna’s tail are all about motion, and often difficult to capture in a still photograph. However, you can see them very clearly in the recent videos from our performance.

With respect to music, a spiral was also one of the symbols I used in my recent piece for conduct your own orchestra night:

This is the classic Archimedean spiral, defined by the formula r = aθ. Essentially the distance from the center increases proportionally to the angle as one “spirals out” from the center. There are other formal mathematical variations on the spiral, such as Fermat’s spiral, which I find visually interesting.

Is mathematics, music and cats not a fine way to start the weekend?

Weekend Cat Blogging #249 will be hosted by our friends LB and breadchick at The Sour Dough.

The Photo Hunt is hosted by tnchick. This week’s theme is spiral.

The Carnival of the Cats will be hosted this Sunday by Kashim, Othello and Salome.

And the friday ark is at the modulator.

Carnival of Mathematics #35

We at CatSynth are delighted to be hosting the 35th Carnival of Mathematics.

The date “Friday the 13th” of course evokes many superstitions. And perhaps that is why we have so few entries so far this weekend. That having been said, we at CatSynth take a dim view of superstitions. Many of the traditions that led to the irrational fear of the number 13 (including skipping over of 13 in building floor numbers, etc) are the same ones that promote the unfair treatment of black cats. Neither has a place in a modern, rational, society.

Consider that 13th of the month is no more likely to fall on a Friday than any other day of the week. Over a period of 28 years, that is 48 “Fridays the 13th,” as described here.

Let us turn away from superstition and myth, so some of the more mathematical properties of the number 13. It is a prime number (indeed, the sixth smallest prime). It is also a well-known twin prime, and it is one of only three known Wilson primes. For those less interested that I am in prime numbers, it is also a Fibnoacci number, and the number of Archimedean solids.

You can find more about the mathematics and mythology of 13 at “13 the Unlucky”.

Last week’s host, the blog 360, has a post about 13 and other “unlucky” numbers. But they also contribute a demonstration, using Godzilla, of how to calculate the speed of a
dinosaur by its footprints.

Recursivity introduces us to the Open Problem Garden, a site collecting open problems in mathematics and theoretical computer science. He presents an open problem about discrete iterations that is easy to state yet frustratingly hard to solve, as are many of the great problems of mathematics.

Looking for a more modest challenge? Math and Logic Play presents a bicycle-racing puzzle. Practice your math skills while staying healthy and reducing your carbon footprint…

Larry Ferlazzo describes a site for math games and education in Tutpup Math & Spelling Games.

Andrée from meeyauw treats us to Sierpinski cookies and earings this week. Those cookies look pretty good, but challenging to make. Fractals are by nature very detail oriented, and I am by nature very not detail oriented. But I’m sure they would taste great in either case.

The state of math education (in the United States) in a frequent topic on Carnival of Mathematics. This week, female math professor critiques an elementary school math program at Life on the Tenure-Track. It seems that at least in some classes, teachers aren’t able to make it through the full syllabus.

More topics in math education can be found at Teach College Math, where we are introduced to the Math Girl videos. “Who says there’s nothing good on YouTube?”

For the more discriminating reader, we have Discriminating Determinants, third in a series from Matt-a-matical Thinking.

We get back to our theme of the number 13. The fashionablemathematician presents the sum of prime factors. For a prime number like 13, the sum is of course the same: 13. But are there other numbers whose prime factors sum to 13? Well, the number 22 has prime factors 2 and 11, which add up to 13.

Sometimes a mathematician can end up being an astrophysicist, especially on Friday the 13th, as is the case with this article from Math Trek.

That is all the posts we currently have. We will continue to add sites throughout the weekend, so please leave a comment or contact us if you would like to participate.



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