On an unrelated search, I discovered that Arthur Leonard’s treatise The Yolo Reflector had been scanned and made available, including translating all the mathematical formulas into MathML. A very nice job! I have copy of the dead tree version that was mailed to me by Leonard, and it’s good to see this nifty work get wider distribution.

For those of you who may not have heard of them before, a Yolo telescope has two concave mirrors which are tilted, and thereby yield a telescope which is unobstructed. Normally, this would not work very well, as the astigmatism of tilting each mirror would add, but Leonard experimented with warping mirrors into astigmatic figures by use of a warping harness: a mechanical aparatus that bends the secondary mirror into a potato chip like shape (not visibly, but detectably at the eyepiece).

I hadn’t looked at atmsite.org in quite some time. There is an impressive array of articles contributed. I’ll be back again.

Dan Bricklin, one of the co-inventors of Visicalc, has posted a nice article entitled Software That Lasts 200 Years. He points out that software which helps form societal infrastructure is necessarily concerned more with the long term and total cost of maintenance, and is poorly served by the normal business models which are common in the software industry.

I had a fairly similar notion a while ago. As a recreational programmer, I’ve written dozens if not hundreds of programs for my own enjoyment and experimentation. Every once in a while, I go through and make sure that they all compile and work, and maybe dust one off and extend it in a new direction. Most of the time, this is simple, but occasionally it requires more work. Since I had been working on a simulator for the PDP-1, I hypothesized creating a full machine simulator for an entirely hypothetical machine (probably resembling a MIPS processor of some sort). My software would target this machine, and my work would then merely need to target this emulator.

There are many practical problems with this approach (such as the need to maintain a compiler for the target). It’s hard to maintain the entire stack in some bootstrappable form. Perhaps if I reread Bricklin’s essay with an eye toward increasing maintainability, I’ll make more progress in my thoughts.

Oh well, time for breakfast.

Ever on the lookout for odd science/craft experiments, I was pleased to find instructions on how to make soap out of bacon, and poking around we see that this is part of a much larger list of idiotic things that you can do. I find the most tantalizing to be instructions on how to make Pruno, or prison wine made from fruit, sugar and ketchup. The author presents the resulting summary:

The only drawback pruno has, aside from its unappealing tannish-orange color, the white flecks of mold floating on the top and the smell you can’t wash off, is its taste. For lack of a better metaphor, pruno tastes like a bile flavored wine cooler. It tastes so bad, in fact, that it could very well be poisonous or psychedelic, which might explain the violence it induces in prisoners.

While doing an unrelated search, I browsed into Publications by Wolfgang Heidrich and started reading his paper entitled The Design of an Inexpensive Very High Resolution Scan Camera System. It’s a very interesting idea: they modify an inexpensive Canon scanner to use as the back for a large format camera. Ultimately they are able to construct images with over 122 million pixels. Pretty damned nifty. I’ve even got one of these scanners on my shelf… Hmmm.

Addendum: The paper above cites research by Yang of MIT on a similar project which used a flat bed scanner as the imaging component in a camera to acquire light field images.

World of Stuart has a nifty download: Big Songs For Little Attention Spans. It’s a 95 megabyte download of 99 (he says 100, but I think he can’t count) short songs which fit on a single 80 minute CD. It’s an eclectic mix, but somehow hangs together. Consider it music for the attention deficit crowd.

The NIST has a very nice history of radio controlled clocks which was written by Michael A. Lombardi. The National Institute of Standards and Technology runs the WWVB time service in Boulder, Colorado which broadcasts at 60khz, and allows my Skyscan Atomic clock to maintain accurate time (or would, if my office wasn’t essentially a Faraday cage). Some nifty bits of history.

Scaled Composites released some nice video on their website, including video M&Ms scattered in zero g’s. Nicely done (even if it is in Microsoft Media 9).

Neat paper: Holography without Photography, by Thad Walker. The author uses a simple C program to generate holograms which are then printed on overhead transparencies with a laser printer.

I’ll have to try this.

For some reason, I find knots fascinating. What’s even more fascinating is how often books about knots show up on the bargain shelves at Borders, and yet every year or so a new, nicely photographed, full color book on knots makes appears to replace them. Bizarre.

But if you want to learn about knots and their interesting mathematics, you can try The KnotPlot Site. Lots of good information.

As part of my brother’s ongoing experiments with streaming video, I’ve become somewhat more interested in the world of streaming video. Interestingly enough, the BBC has released an open source video codec called Dirac which is available under the Mozilla Public License and also the GPL. It is supposed to be competative to modern codecs, but is unencumbered by the patents and licenses which plague MPEG-4 and many other video codec technologies.

I’m already a big fan of the Ogg Vorbis format for audio, and am enthused that free license video codecs could be on their way. They are needed.

Pencilmation.com has some fun (if silly) flash animations, including the story of “The Monkey and the Coconut”, which perhaps people who appreciate monkeys might, in fact, appreciate.

Or not.