Van calamity (by alaric)

Last Sunday, we attempted to go to Cheltenham in the van, as Sarah had a WoPoWriMo launch meetup to attend.

We're used to having to deal with ice on the hills leading out of our valley, as water from the farm fields tends to run off into the road; so if it gets cold, it turns into sheets of ice. There were a few patches of ice on the way up, but nothing like what I've managed in the past, so imagine my surprise when I turned a sharp bend onto a sheet of ice that spanned the entire road. The van promptly lost traction, so I stopped and attempted to gently reverse back around the corner to try a different route.

Sadly, the steering had no effect, quickly followed by the brakes; the van began a slow, graceful, unstoppable pirouette until it ended up like this, with the nose wedged into the bank:

That's looking down the hill from above. As you can see, I'd already done a bit of salt-spreading by the time that photo was taken; before I spread the salt, the ice was so slick that I couldn't actually stay standing if I got out the driver's side, I had to climb across Jean and get out the other side.

Sarah had a deadline, so headed off on foot to try and catch a bus, leaving me with Jean to try and free the van. I could reverse it as the rear wheels just span, despite me shoving some road salt underneath. I tried letting the rear tyres down, in the hope that a larger surface area in contact with the ground would help me get traction, but no luck.

So I proceeded to salt the ice sheet; if I could find somebody with a tractor of a 4x4, perhaps they could pull the van from above and get it free of the bank, then I could complete the turn and head off down hill. The salt began to melt the ice, and then salty water started to flow underneath the ice sheet, creating pretty patterns; and allowing me to wack it with my folding shovel to break it, at which point I found out it was a good half inch thick, even after being partly dissolved from beneath:

But the one tractor-owner I knew the number of wasn't answering, and another that a passer-by knew couldn't help, so I continued to try and get it free myself. I gave up on being able to drive backwards, so I took the folding shovel (it's actually a military surplus trenching tool. Good job I carry a military surplus trenching tool in the van, isn't it?) and dug the bank away to release it.

After making sure the ice was well gritted. I didn't want to be downhill of a tonne of van, working away at the one thing holding it in place, while it was on a slick icy surface.

After much digging (indeed, it was now two hours after getting stuck in the first place), with the steering wheel on full lock to the left and the rear wheels spinning, I managed to get the van out forwards, and set off down the hill. Surprisingly, the front of the van wasn't ruined, as I'd thought it might be:

Jean was surprisingly patient for a four year old strapped into a stranded vehicle while I worked away; I figured she'd be safer strapped in than running around on the ice with me, even if another car came and hit the van.

Many Pockets (by alaric)

As I have mentioned before, I have many pockets.

A few people have asked about this now, so here's a run-down on what's in them.

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Haikus in git (by alaric)

I decided I'd write a haiku a day through February, for WoPoWriMo.

But I had to make it interesting, so I'm doing then in git, and letting GitHub publish them for me at http://alaricsp.github.com/wopowrimo/ using their pages system.

git is a system for looking after a bunch of files, keeping track of the 'history' - previous revisions. Since it knows the history, it can show you the changes made in each version; it can also do advanced stuff like letting you make several copies of your work, making changes to each copy, then comparing the results, merging the changes into one version, etc.

This has a number of uses. Perhaps you can have copies of your work on your laptop and your desktop, so you can work on either computer, and merge your changes when you get a chance. Perhaps you can try several different changes to your work, and decide which ones you want to keep. Perhaps a team can each take a copy of something, work on different parts of it, and merge them together again. Perhaps you can just put a copy on another computer, and merge your changes onto it from time to time, just in case you lose your laptop, so you have a backup.

Keeping the history means you can try making experimental changes, safe in the knowledge that you can undo them by going back to an earlier version.

It's normally used for things like computer software, but it's increasingly being used for things like writing projects as well. There's a git tutorial for designers, and writers such as Cory Doctorow and Tycho Garen are starting to adopt it.

GitHub is a site that hosts copies of your git repositories for you. You can push changes from your local copy to the github copy whenever you want to publish them to the world, and it has a nice Web interface to let people take copies of them, view the history, and so on; its pages system also exposes simple Web sites stored in git repositories onto the Web.

So you can view my efforts at http://alaricsp.github.com/wopowrimo/; or from that page you can find instructions on how to take your own local copy with git (that you can pull my changes into from time to time, and then look at the history), or you can follow the links through to http://github.com/alaricsp/wopowrimo/commits/gh-pages and view the history.

Intelligence, Knowledge, Wisdom (by alaric)

I see a lot of confusion between intelligence and knowledge. There's this cultural perception that a well-educated person is intelligent - and wise to boot. However, I've met plenty of people who are incredibly intelligent, yet know very little; or people who have memorised lots of information, but don't really understand it because they're not very intelligent.

So there's definitely a distinction between intelligence and knowledge, and I think there's also a third intellectual strength: wisdom. Note that I'm only analysing core intellectual strengths, too - skills like empathy are also important, but beyond the scope of this article; and thinks like mathematics are a matter of training the mind to do certain things quickly that can only be done if you're intelligent enough to master it in the first place, and have the knowledge - many skills, such as mathematics, being able to paint or to accurately outguess defenders and get a football into a goal, are also mental skills, but ones that are learnt by building upon the basic attributes of knowledge, intelligence, and wisdom.

(Players of role playing games will now recognise what got me thinking about all this in the first place)

Knowledge is stuff you can memorise directly from some external source. It might just be facts - the name of the first president of the United States, the melting point of lithium, who won the last World Cup.

Intelligence is a bit harder to define. It's about being able to perceive patterns, I think. An IQ test only really tests certain aspects of intelligence, but I think it's mainly pattern recognition and being able to hold complex structures in your short-term memory that you can then recognise the patterns in.

This can be likened to being able to gain a high-altitude view of things in your mind. The gifted artist looks at people's perceptions of the world, and sees them as all parts of a bigger picture; by spotting the bits of the picture that few people are seeing, and then managing to portray that to people (which is a skill), they manage to surprise and excite us, and to broaden our horizons by drawing our attention to things we had overlooked. The gifted mathematician looks at the properties of the Lambda calculus and of Hilbert systems and notices a shared pattern, and thus comes up with the Curry–Howard correspondence, and thereby realises profound facts about the processes of computation and reasoning that are driving the development of programming languages into the future.

And, yet, I have met people with great knowledge, and great intelligence who, nonetheless, are definitely fools.

There is a certain stereotype of the short-sighted baffled boffin; the kind who invents the nuclear weapon, then after it is used in anger, splutters "But... but... I thought it would be an end to warfare! I didn't think anybody would be so stupid as to use it!". The kind who sits there cranking out great work in their narrow field, yet without even being able to comprehend a reason why, yet alone wanting to.

And, also, I've met plenty of people who aren't intelligent, know very little, yet somehow manage to find their way peacefully and happily through life, bringing something undeniably good to everything they are involved with. They clearly have some positive core attribute, but what is it?

This is why I introduce the concept of wisdom. My hypothesis is that wise people have a grasp of certain fundamental patterns that underlie everything. Not the specific patterns that intelligence focuses on; more things like 'when two powerful forces are in opposition, things can slip and suddenly come out sideways'. This basic principle applies to physical forces, as well as to things like ideologies in opposition. They're patterns, and it's easy to mistake them for the rules that intelligence seeks to understand within complex systems; but there's some important differences. The patterns wisdom finds are broad. To find them, you need to look at a lot of things, rather than to look deeply at one. You can look at these things shallowly, and indeed, doing so can help you to spot the patterns without access to intelligence, by letting you "see the wood for the trees" rather than being tangled in details.

Also, they are weak correlations. They point to vague tendencies of systems, rather than to definite rules. They do not apply in all cases, even. They are more gut feelings, or intuitive hunches.

A truly great scientist combines all three attributes. They have knowledge of their field, the intelligence to understand it well enough to spot the rules, and wisdom that provides them with hunches; certain properties of a physical system may, based on past experience of such properties, lead the scientist to wonder if those properties will be conserved under rotation? Then they can use their knowledge and intelligence to do the maths and work it out, which may lead them to an interesting conclusion.

Similarly, the great artist has knowledge of the world, intelligence to spot interesting concepts - and wisdom that lets them guess how the viewers will react to their work. Nobody can know how the world will respond to something new, as we cannot know what's going on in other people's heads. No matter how intelligent you are, you'll never be able to reason the behaviour of millions of people. The best we can do is to draw on wisdom, to form hunches.

There is a stereotype of wisdom, but it's often confused with intelligence or knowledge. Sherlock Holmes is, perhaps, the stereotypical intellectual genius; his knowledge and intelligence are focussed on, but there's clearly wisdom as well. The purest expression of wisdom we find in popular media is the "wise old sage" stereotype. They're typically portrayed as old-fashioned and technophobic; they rarely exhibit vast stores of knowledge, or even great intelligence. They're usually an old-looking wispy-haired white male in a robe, spouting seemingly meaningless phrases that nonetheless turn out to be strangely insightful and useful.

This is a bit of a caricature, but with some vague connection to the reality, I think. A purely wise person would need to have been somewhat isolated from modern life in order to avoid ending up gaining knowledge, and the absence of knowledge would give them precious little complex mental structures to practise intelligence upon. But a long life would give an active mind time to figure out the deeper patterns, and build up wisdom. However, unless that wisdom didn't involve people much, I think a truly wise person would tend to have better communication skills than the traditional portrayal!

High power LEDs (by alaric)

I've got a few 3W RGB LEDs that I've been meaning to play with, so over the Christmas break, I decided to hook 'em up to the bench PSU and have a play.

As I have but one variable bench PSU with current limiting, I could only easily light one LED at a time. I didn't have big enough resistors to build individual LED current regulation circuits - I just set the current limit on my PSU to 0.35A and cranked the voltage up until it maxed out, hooked up to one LED in turn.

They are certainly dazzlingly bright:

Since the green and blue LEDs both have the same forward voltage, I figured I might be able to drive them together by using a pair of resistors as a current splitter, and setting the PSU for 700mA, thus ensuring that 350mA went to each LED.

However, my 0.25W resistors started to smoke when I got to about 400mA, so I shut it off - if one of the resistors burnt out then the entire 400mA would go into the surviving LED, overloading it (until its resistor also burnt out), and possibly making the thing explode. I ended up with a nice pair of burnt-out resistors:

Which is a shame, because I'd love to see how bright the thing is at maximum, with all three LEDs going!

My lab partner was most impressed, and asked me lots of questions about current and voltage; I had to resist her demands to keep making things, so I could go inside and write this blog post: