brainwagon

When it comes to television, I’m about as jaded as they come. Let’s face it, it’s mostly crap. That’s what makes it so difficult when genuinely great shows are cancelled. Such a show was Fox’s Firefly.

I must admit: I was skeptical of the premise. A mixture of space and Wild West? What’s up with that? But creator Joss Whedon really outdid himself, piecing together 14 excellent episodes (now available on DVD) that were well done, thought provoking, funny, warm, exciting and chilling, all at intervals frequent enough to suck in the viewer. It is quite simply one of the best shows I’ve seen in decades, and it was a great tragedy that Fox chose to cancel it while preserving so much utter crap.

Luckily, there is some life beyond the grave. Universal is producing a Firefly movie, and principle photography has just begun. There is even an official fan site with a weblog for the production. I can’t wait.

K3PGP has a nice website which I’ve seen before since he and I share some common interests: astronomy and lasers, notably. He’s got an interesting page on his K3PGP Experimenters Corner that detail his experiments with laser communications. Basically, he created a beacon transmitter which transmits 30 second long pulses of particular frequencies spaced 0.5hz apart. This modulates an IR diode, which flashes up to the night sky. Five miles away, he targets the region with a PIN diode laser reciever, which is fronted by a 12 inch Fresnel lens. Incredibly enough, he can easily receive characters sent this way. It’s very slow speed (two chars per second), but it’s a neat trick.

In keeping with the earlier paper model theme, I give you Jun Mitani, who has a paper in this year’s SIGGRAPH conference on turning polygonal meshes into paper models, with some examples shown here on the right. His other papers appear interesting too.

Picture this: you run across a reference to a patent that you want to read, but you are too cheap to spend the money that the U.S. Patent Office charges you to download images of the patent in question. What do you do? Apparently you use pat2pdf, a cool bash shell script that downloads TIFF images from the U.S. Patent Office and neatly assembles them into a PDF file. For instance, check out this patent which originally spawned the search for such a gadget. Much thanks to Oren Tirosh for writing this useful little script.

For reasons which escape me, Yamaha has a really nice webpage on paper crafts, which include patterns that you can download and build. These include not only cool motorcycles, but also animals like the Japanese macaque or the yellow-eyed penguin or the Cape penguin, pictured at right.

The patterns are all available as PDF files which you can download, print, cut and assemble. Neat! The motorcycles are especially well done, it’s really incredible what you can do with paper models.

New Scientist is currently running an interview with Burt Rutan where he admits there was some potentially catastrophic failings in SpaceShipOne’s inaguaral space flight: a coupling collapsed when the rocket motor kicked in (the bang reported by astronaut Mike Melvill) and a brief period where the craft lost attitude control. Had this loss of control occurred earlier, it could have been “bad”.

The fellows at Scaled Composites have not announced when there X-prize attempt will occur. It’s clear that they have a few problems to work through, less the celebration of yesterday be turned into a catastrophe, and an astronaut be turned into confetti.

Mark Pilgrim has released a new version of his Universal Feed Parser. I have mixed feelings about the long term viability of this code, since it parses feeds which do not meet the specifications, which ultimately means that people never fix their broken feeds, but the specification itself is wooly enough that this is perhaps unavoidable. In any case, I’ve used it before, it works, and he seems to have done a lot of work generating test cases for it. Give it a try.

The conventional wisdom of baseball is that five game series are easier for bad teams to win than seven game series. But how much easier? I made a graph:

The red line is seven games, the blue, a five game series. The difference is about 3% max.

I was pondering yesterday’s flight of SpaceShipOne, and decided to lookup the information surrounding the first American sub-orbital flights. Alan Shepard - Project Mercury Freedom 7 has most of the details. It’s interesting to compare the two flight profiles: Shepard pulls something over six g’s on ascent, and hits 11 on descent, whereas SpaceShipOne pulled about five on ascent, and just coasted down with very little excessive g-loading. The Mercury capsule required explosive bolts, parachutes, and a water landing. SpaceShipOne coasted to a stop on an ordinary runway, and allowed Melvill to wave to the crowd even before he stopped rolling. And of course, the Mercury Freedom 7 required a pressure suit, apparently without appropriate accomadation for urination…

Oh, and here are some plans for a paper model of the Mercury Redstone rocket.

While watching the Athletics lose another game (sigh), I dusted off this paper and coded up a quick implementation. It seems to work, although I’m having some problem with the tone mapping bits, and haven’t bothered getting any color into it yet. It’s not really very useful, except perhaps for making backgrounds for your desktop.

Realtime implementations of this are available, especially as screensavers. My favorite is the electric sheep, which provides a never-ending variety of cool looking flame fractals.

Another cool link from the Geometry Junkbox: George Hart’s instructions on building Soda Straw Tensegrity Structures. I can see myself wandering off to the store to buy soda straws, paper clips and rubberbands tonight.

I like arts and crafts, particularly those with a mathematical bent. Wholemovement - The Work of Bradford Hansen-Smith shows what cool stuff you can do with paper plates. Be sure to read the commentary about the “wholeness of circles” and the like. I’d like some of whatever he’s smoking. Found this while perusing the terrific Geometry Junkyard, which I noticed now has an RSS feed. I’ll be adding it to my list shortly.

The recent Wired article on the use of evolutionary computation to optimize Formula-1 cars has been getting a bit of press lately, and finally made it to Slashdot. Buried in the comments I found a link to some work of which I was previously unaware: Differential Evolution. You can also read a matching tech report. The nifty thing is that DE works on real valued functions rather than discrete ones, which may make it more easily adaptable to optimizing functions which are more naturally represented in floating point. I haven’t skimmed the paper, but I suspect this evening I’ll be coding up my own version in Python to try to sort out the details.

Addendum: I had the chance to read the paper at lunch. The idea is really very simple and straightforward to implement. You begin by generating a pool of individuals, each of which contains a vector of floating point values, You can use these values to generate a fitness value for the individual by passing it through a fitness function. Initially, the individuals are assigned random floating point values uniformly generated over sensible domains. In each time step, two individuals are chosen from the population, and a difference vector is generated as the difference between these two individuals. A third individual is chosen, and a subset of its parameters are modified by adding a scaled version of the delta vector to the original values. This new individual is then evaluated, and if its fitness is greater than the previous one, it replaces it in the gene pool.

It seems almost too simple to be useful, but it’s dead simple to code. I’ll have to write up some demo code to give it a try in the not too distant future.

Well, I bailed on the six hour drive down to Mojave to see the launch of SpaceShipOne, but somehow they’ve managed to muddle along without me, and I’m currently watching footage on the major networks. Best wishes to all involved in the project, and I’ll post updates here as the day goes on.

SpaceShipOne is shown here landing during a previous test flight. The craft is actually dropped from a mothership christened “White Knight” at an altitude of 50,000 feet, fires its rockets and climbs to maximum altitude, then glides back to a landing. Previous test flights have reached 40 miles in altidude, today’s attempt will be 68 miles if successful. The pilot, Mike Melvill, is 62 years old and is not carrying a parachute.

• Yahoo! News - First-Of-A-Kind Private Rocket Plane Heads to Space
• Scaled Composites website, creators of SpaceShipOne
• Yahoo! News - Private rocket-plane completes historic space mission

Addendum [Mon Jun 21 07:59:48 PDT 2004]: SpaceShipOne has apparently fired its rocket engine and is on its way to apogee. Wahoo!

Addendum [Mon Jun 21 08:14:42 PDT 2004]: Touchdown! Just viewed the landing on MSNBC, he is coasting to a stop after reaching an altitude of 62 miles. Congratulations to all those at Scaled Composites in becoming the first non-governmental power to put a man in space.

Tom Mangan proposed a blog-in at the Athletics-Giants game on June 27. I don’t have tickets yet, but I may have to give the idea a try (and catch a baseball game to boot!). Check out Blog Me Out to the Ballgame 2004

Addendum: Yep, just got some View level seats: I’ll be there, and will blog about it when I return.