We at CatSynth wish all our friends a happy summer solstice.
It’s a day to enjoy light, such as the late evening sun against the city skyline:
or a warm spot by a window:


We will be hosting the Bad Kitty Cats Festival of Chaos this weekend. The optional theme will be summer as the season is officially upon us. We also want to celebrate diversity with cats of different colors, geography, ages, histories and lifestyles.
To participate, please use the handy submission form, or leave a comment.
]]
From Meng Qi on flickr, via matrixsynth:

“Me, Voyager, MuRF, Xiaodaner”
Check out more Cats on Tuesday.
]]
When nothing else is happening on a quiet weekend afternoon, I will often go for a walk through our neighborhood, South of Market (SOMA) and South Beach. Our neighborhood is in many ways more like New York than the rest of San Francisco, with its old industrial buildings, dilapidated piers on the waterfront, and new condo developments. But perhaps that adds to the sense of familiarity, and of “home”, amidst the concrete.
Our walk usually begins on Townsend Street, heading east towards the waterfront. This area is dominated by AT&T Park, home of the San Francisco Giants. But while crowds head towards the stadium in the summer, we often head in the opposite direction. There is a little park at the end of Townsend along the Embarcadero, where I often see older Eastern European folks. Across the park is the cul-de-sac that marks the end of Delancy Street, a name reminiscent of the Lower East Side of Manhattan. Here I often stop at a small cafe – it has a large garden that can be enjoyed on its own or for the glimpses of the bay it affords.
![]() |
There are some books I only seem to read when I’m out at places like this, rather than at home. One such book is The Cat: A Tale of Feminine Redemption |
Beyond the cafe is the southern portion of the Embarcadero, which contains glimpses of a seedy and crumbling past while being revitalized with the stadium and frenzied development.
Heading south along the Embarcadero, one approaches the Bay Bridge. Commercial buildings, as well as residential complexes, have sprung up in its shadow. I enjoy seeing these buildings fit comfortably beneath the bridge:
Some of them have appear older, more reminiscent of the 1970s or even earlier, while huge new high rises are going up all around them.
I then often turn back inward from the waterfront on Bryant Street. This is generally a wide street that crosses SOMA and the Mission District, but here it is a narrow alley between the steep approaches to the Bay Bridge and a residential block.
Again, the feeling is more of a residential section of New York, perhaps Riverdale in the Bronx, or the Upper West Side. Of course, the fact that this block interests Delancy Street adds to this impression.
Longtime residents and admirers of San Francisco often look down upon this area, but I find it a comforting place to walk and explore. Certainly, there is familiarity coming from New York, which has always defined “city” for me. And perhaps the sense that I am finally living the city life that I should have done long ago – I am finally home.
The narrow streets and tall buildings abut the hill and the approach to the bridge, with a complex array of staircases and ramps. I often find an excuse to climb at least one, such as this that connects the lower alley section of Bryant Street to the main section that begins on top of the hill.
At the top, one is amazingly close to the freeway and byzantine ramps that feed onto the bridge:
Heading back down the hill towards the west, one can take a detour through South Park, which has nothing to do with the popular cartoon. Instead, it is a small park surrounded by two-story residences that feels more like a neighborhood in Brooklyn. Although it is not far from the this section of freeway we featured a few weeks ago, such things seem invisible and far away. But step outside this oasis, and one is back in the “concrete jungle” and the streets that lead home.
]]
From KittyL at flickr, via matrixsynth


Click here for more scribbles by KittyL. Some of the others also include cats.
]]
Luna’s Gotcha Day usually comes within a week of Father’s Day, so that, too, becomes a day to mark and celebrate here at CatSynth.
Fatherhood involves so many responsibilities.
Adoption:
Providing a wonderful loving home:
Providing food and drink:


And lots of toys to play with:
Exposure to culture and growth:

And lots of pets:

Happy Father’s Day:

Just in time for the occasion, we received our copy of Tom Cox’s Under the Paw: Confessions of a Cat Man. You can read more about “Cat Man” Tom at The Little Cat Diaries.
We look forward to reading it.

The M-Cats Club is hosting a special Father’s Day Edition of the Bad Kitty Cats Festival of Chaos. We will be heading over there shortly.
Weekend Cat Blogging #158 is being hosted by our friends Kashim and Othello and Astrid. They are remembering friends who have passed away this weekend.
The Carnival of Cats will be going up today at Mind of Mog.
And of course the Friday Ark is at the modulator, with special thoughts to those whose lives have been affected by the ongoing floods in Iowa. We send our thoughts as well.
]]

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.
]]
Tomorrow, Friday the 13th, we at CatSynth will be hosting the Carnival of Mathematics. To participate, you can contact us, or use the carnival submission form.
Given the date, it would be cool to have some entries that focus on the number 13…