BPJ Code

Feral grapevine

I didn't deliberately plant this grapevine; it germinated while lying on top of some compacted soil with some other seeds (of various species). One day I noticed it had germinated, and that the leaves looked like those of a grapevine. Even a small plant like this one has beautiful autumn colours!

Map of the Atrum IRC chativerse

Map of the Free Chat Republic of #Chatania

Art

I have several notebooks which I've more or less filled with random algebraic calculations. Because these are often exploratory and because I often need to go back to revise some expressions (whether due to mistakes or because I'm changing the model), I tend to scribble all over the page. No child should ever see my notes, lest they be put off math for good.

Scary striped spider

Bioluminescent worm

I went camping with some friends in the mountains near McGregor, and after our drive up to the cottage, I walked back down the access road hoping to catch friends who were in a separate car. On the way up the road we had clearly squished a few worms, and as a result they were secreting some sort of bioluminescent slime. I took this photo with a 15 second exposure - the glow was quite dim.

View down the valley towards Greyton

Cross section of a pin oak branch

I think it's pin oak anyway. My neighbour's housesitter once said he recognized it. And the wood does have oak-like rays.

Charging my car battery with a solar panel

Eight days of no driving is too long - the engine cranked maybe once and then the electrical system collapsed. Because I don't have a real battery charger, I jury-rigged a solar panel Jochen donated to me a while ago to the car battery. Open-circuit voltage is about 20V, short-circuit current about 4.5A (both measured shortly before connecting it to the battery - not just optimistic label ratings).

Woodwork

Shortly after Christmas 2013 I found a silverside roast at Pick n Pay at quite a low price, and decided to try making biltong from it. That meant I had to make a biltong cabinet. Here it is, waiting for the glue to dry:

The biltong cabinet works quite nicely! Over four days in Worcester my chunks of silverside have turned into still somewhat moist biltong; no sign of decay or infestation. I've cut a hole in the top to accommodate a fan scavenged from an old ATX power supply, which forces air movement through the cabinet in addition to what natural air movement provides. Here's a picture of the cabinet with a small solar panel powering the fan:

Electronics

While visiting my dad, I took advantage of his decently equipped workshop to build a crystal-controlled oscillator. I had a vague concept of a circuit in mind that would take advantage of a better understanding of phase noise. But what a circuit it eventually became! After fixing a few mistakes, the HF receiver tuned to about 20.3MHz found a carrier, drifting slowly up and down. There was still something wrong with the circuit, since the bias voltages were wrong, but given what its realization looks like, I call it a success that it oscillated at all, and as stably as it did: