Went to the Los Gatos Xmas Parade this weekend. Sometimes it feels like a little mountain town here.

A bunch of guys had a giant zucchini squash marching drill team. The women standing in front of me where enthralled. “I want to be with those guys.” Phallic displays work!

Every year there’s a new twist on the Santa hat. Leopard fur is the new flash for 2007. This couple were cute and happy, you could tell they’d planned their outifits.

The best parade float is always from Jiffy Mart, which is basically a liquor store on Los Gatos Boulevard. I’m alway surprised—and glad—that the Authorities let this raffish crew bring their movable jump.

Yesterday we were at the SF MOMA to see the Olafur Eliasson show, definitely worth seeing. This one exhibit, called “Ventilator” is just a large fan hanging from a cable and moving chaotically, slowing down, speeding up, wandering about.

There are two dynamics at work: (a) as a suspended pendulum, the dangling fan tends to want to swing back and hang straight down (b) the fan’s blast pushes the fan according to which way the fan is pointing, and the fan itself is twisting back and forth simply because it’s a suspended object subject to torsional rotation.

If I was still teaching CS, I’d have my students write a program to emulate this. I think you could write the program as a 2D Java applet. Just think of the shadow of the fan on the floor. We’d have a moving object with (a) a centrally directed spring force proportional to some constant A times the distance from the center and (b) a force with a fixed magnitude B and a direction given by the formula C*sin(D*t), where t is the elapsed time in the simulation world.

Think of tracking a moving position. Update in time increments dt, tracking scalar t, and vector position, oldposition, newlocity , oldvelocity, acceleration. At time t, the accleration on the point can be expressed as follows if I temporarily convert the position to polar coordinates (r, theta). In polar coordinates, the central force is the vector (-A*r, theta) and the fan force is (B, C*sin(D*t). Convert these back to cartesian coordinates and add them to get the acceleration. Play with the algebra a little to get the back and forth conversion simple — really the conversion is just a coneptual thing to help you figure out the right cartesian formulae.

To simulate the motion, pick any old starting position=oldposition and velocity=oldvelocity, and then update as follows (i) Compute the acceleration for position and velocity. (ii) set velocity to oldvelocity + dt*accleration. Set position to oldposition + dt*velocity. (iii) Draw a line segment from oldposition to position. (iv) Then copy position to oldposition, velocity to oldvelocity, add dt to t, and return to (i).

Problem: Get the simulation working as a Java applet (keeping in mind that some of my suggestions may be wrong as I haven’t actually written this program (although I have written programs like it)), tweak A, B, C and D to produce attractively chaotic motion and send me the link! First person to get it right gets a free signed hardback of Postsingular in the mail.

Lovely winter mist this morning. The etching of the oak branches.

As well as that reindeer song, I keep hearing about “Rudy” and then they’re talking about an ugh Republican ugh Presidential ugh Candidate. Bring back the Clash song: “Rudie Can’t Fail”!

Let it go, merge into the mist.

Mentally I’m at the Szkocka Cafe (Scottish Cafe), fave hangout for Stan Ulam and other topologist/analyst/set theorist types in Lwow in th pre-war 1930s, and home of the famous Scottish Book of problems! Working on my story about infinity…

Today I was back at Castle Rock Park in my Monet/bum outfit; canvas strapped to the leather knapsack of paints on my back.

I also brought along some papers about infinity by Hugh Woodin, I’m trying to write this story, “Jack in Alefville”, for a special volume about infinity.

Scrambling up and down ravines, almost like where I lost my glasses last year. Nice trunk and boulder. Yin and yang.

Halfway up this rock called California Ridge I found a ledge leading out to some exposure.

A branching tree. It has c leaves. We don’t limit Alefville to being just countable sets. The higher world isn’t stratified this time. Everything’s mixed together, all the cardinalities. The branching streets lead to c houses.

Around the corner was a giant stone Homer Simpson! D’oh!

It occurs to Jack to check consistency of some theories. Could we have an issue with non-standard integers? The only theory that’s clearly inconsistent is physics.

In order to paint this I had to perch on a tiny spot with fifty foot drops on two sides. I figured if I moved slowly and stayed highly aware it wasn’t actually risky. Just don’t step back from the canvas…

The antagonist crab hides. They look in an infinite restaurant, it’s more than an Escher omega disk, it’s omega to the omega power, with infinite eddies and back rooms like a dream. The crab gets away, flees to his house

I got the underpainting done and took a bunch of pictures to work on at home. Rested lying on the ledge, trying to visualize levels of infinity, getting back into the old White Light head space—but 21st Century style with Woodin in mind.

Out across the San Lorenzo River basin I could see the sun shining on the Pacific Ocean.

They look for a city directory to locate the crab’s house. They find a book of size alef-one but it’s not big enough. They find an alef-two-sized book. It’s not big enough either. Etc.

Yesterday I finished my painting, “Mossy Trees,” that I started last week in Castle Rock park.

I spiced it up with an eyeball in one of the trees. I was thinking a little of Magritte, the way he’d slip fantastic details into so many of his more-or-less realistic paintings. Also it’s a way of making manifest the hylozoic notion that the trees are conscious.

And I put another eyeball in a part of a trunk that’s painted on the canvas edge. I’m into painting all around the edges, I like the effect, and it means you don’t have to worry about framing. The canvas becomes a sculptural object in itself.

Today’s egoboo: Matt Groening reads my books! I saw this in a Wired article about the return of Futurama. (Thanks to Paul DiFilippo for the heads-up.)

This explains why I felt such a shock of recognition when I saw one of the early Futurama episodes, and the robots were getting stoned and selling replacement human organs out of back alleys. That’s totally the world of my Ware series: Software, Wetware, Freeware, Realware. By the way, I’m making slow progress on getting the Wares back into print—more on this in a couple of months.

“The Perfect Wave” by Marc Laidlaw and me is the cover story of the January, 2008, issue of Asimov’s SF magazine.

I’m stoked; this is my second Asimov’s cover in six months, as Bruce Sterling and I scored for “Hormiga Canyon” in August, 2007.

Marc knows the “Perfect Wave” cover artist, Jeremy Bennett, and has a bit about him on the Laidlaw blog site, also a link to a big picture of the cover painting uncropped and unobscured by textual information.

The weird waves in our story were inspired by some nonlinear waves that I discovered in my CAPOW software.