nameless places

I remember asking John Mackin once, what would he like me to get him from London? He replied, A book from an occult bookshop which is on a street which appears on no map. It is near the British Museum.
I went to London, and asked my father. Ah!, he said. I know where that is.

When I was much younger, my father drove me along a street of nameless Georgian terraces, and said, Look at that house. If you ever need an address for a house which does not exist, that is the house you should choose. Even though you can see a house, there is no house there. It was removed so that a train line could be built for the expanding London rail network.

I looked at the house, with front door, windows, roof and front garden.

Accordingly, I have a memory of an address but no memory of the address.

R and T are off to Glasgow today to play for those crazy Glaswegians. R is gonna do a surround sound set. I listened to it last night - mono, then stereo, then four channels of sound! Wow! It made me giggle heaps, as the sound changed in my ears. Those lucky Glaswegians - they are in for a real treat.

It's gone cold again, 7°.

The magpies seem to have taken charge of their nest now.

A navy blue hour

S. asked me to write about spring.

From the windows which look onto the back yard, one can see a very tall poplar tree. It's obviously grown like bingo for the last ten or fifteen years, and now that the crown has overtopped the roofline, the branches thicken and diversify at the top. A pair of european magpies (corvidae pica, or Elster) have a nest that they refurbish each year. Because we are very close to the park-which-used-to-be-a-railway-terminus, there is also a very large murder of crows around these here parts.
The last few mornings, it has been an intra-species drama. The magpies are attempting to rebuild the nest, and some of the crows, in a most desultory fashion, have been attempting to take it over. This means that a crow waits until one magpie has flown off to get a stick, and then goes and sits in the nest with its own stick, picking at the structure. Stick magpie returns, and with its partner they threaten the crow by flying up at it and crying out. The crow remains standing on the nest, or hops to one side a bit.
After a while, about ten minutes, all parties are tired. They sit within a metre of each other, making no sound, and then eventually the crow flies away.

When I unlocked my bike in the backyard this morning, I stood and looked up at the tree. From the ground, the nest is invisible. I breathed in deeply through my nose, and could smell a scent. Whilst the change is invisible, the vines, trees and bushes have begun to exude delicate aromas, and via this cool damp air my heart was refreshed.

My friend Stefanie loves the colour blue, and as we leave work we remark to each other upon the delicate annd immense indigo of the evening sky. It is a sky both radiant and absorbing.

This evening, watching the Spree from Schillingbrücke, I saw a whirlpool form in the water.

it happened

I saw my company's domain name many times today whilst hand pruning some long, long lists. Mixed in there was also the domain name internode.net, a domain name that got eyeballed probably hundreds of thousands of times when I worked there.

Some little thing in my brain changed, I felt it. The current domain became as familiar as internode. It looks different now. Hard to explain.

The Provocative Clue

Today I read "Puzzling Problems in Computer Engineering", published in the February 2009 issue of Computer, the magazine of the IEEE.

Anyway, made me think ... when I was an assistant teacher in Philosophy at Adelaide University, I liked to employ a method which I called "The Provocative Clue". It was based on the Socratic principle that
* there's nothing new under the sun, or
* if I can think of it, so can you

I used this mainly because it's a technique that if employed correctly, really can set off a chain of associations and new pathways in someone's thinking. Usually, it means giving only the very barest minimum of information, in a scenario where the outcome is not crucial, for a situation that has not previously been questioned or rationalised. For instance, which is more morally reprehensible - killing one chicken for dinner, or genetically altering the chicken genome to produce unnaturally large, meaty chicken legs?

In order to answer that question, I would encourage my students to think about who is making the statement, how are they making the statement, and why are they making the statement. This gives a good map of the issue, of course with big gaps.

So, as the teacher, the idea is to show students how to go further with what they have. That's the process of analytical thinking - you can analogise it to a toolbox- If I have a hammer, some nails, planks of wood, a tree, but no saw, how can I build a good treehouse? It's also the basis of lateral thinking as well. I often think that the only difference between lateral and analytical thinking is that lateral thinking uses framing concepts or elements which are not habitually, or customarily, related to the problem at hand.

Back to the provocative clue. Once students are thinking in terms of who, how and why, and have laid out their thinking in this regard, then you have to present the clue. The clue is going to be different for every individual and for every group. It's easy to give lots of physical analogies for the clue - a rope dangling just outside reach where you have to jump to get it, a signpost pointing into the fog, a barely audible tinkling sound which seems to come from that little park over there, a perfume that drifts in the air after a lovely person has a passed you in the street ...
All refer to the horizon of perception, and in cognitive terms, I think this cashes out as a sensation whose range of possible interpretations is maximised, whilst still restricting itself to particular moment or thought.

The best kinds of provocative clues are the ones where both the students and the teacher become intrigued and discover something new. That's dialogue, that's the real deal, that's when it transforms out of a pedagogical relationship into one of equality.

exim II

I guess I should explain that I'm writing these posts so that I can remember better what I'm doing. It's easy to feel stupid at work - my colleague is really gun, and often I don't want to ask him about some detail that he's told me before.

Jaye once told me that she needs to hear something 3 times before she really knows it, and the same is true for me. Colleague is a tell-once kinda fellow, not because he's mean, just that he's really busy with stuff most of the time.

The second thing that I want to work out with exim is how to stick in a filter that catches mails with multiple recipients, and alters one of the recipients.

Usually, if a mail comes in that matches one of the recipients, it will deliver according to your specification. That's cool. But say you have an email with mulitple recipients, one of which is a role-based email address, the others of which are particular people. Well, if the filter instructs to deliver seen alternative_role_based_address@domain.com, then the mail only goes there, and the personal addressees don't get the mail at all.

If you use deliver unseen alternative_role_based_address@domain.com, all the personal addressees will get the mail, but you'll get one email to role_based_address@, and a copy to alternative_role_based_address@.

Given that exim bases itself on delivery routing of /mails/, rather than delivery routing to /recipients/, this makes sense.

I hope to work out the solution soon.

exim I

exim is the mail filter at work. I had a good time this evening trying to get the system_filter to work properly for the customer care guys.

Question that's not fully answered in the documentation:
Is there a difference between $sender_address and $header_sender ?

I think there is, because the filter (using $sender_address) hasn't been catching the emails, which have a different Sender: and From: value. I#ve changed the test line to check for $header_sender - won't make any difference if it's wrong, because the mails haven't been going to right place at the moment anyway.

The documentation on exim's string expansion doesn't go into any detail about which $header_n strings are legal, and which ones aren't. My guess is that legal values are taken from some RFC, but it's not for sure.

Oh yeah, and unlike our shorewall, it doesn't look like there's a way to get exim to check the system_filter file for syntax errors. That's because the file is continually live, so watch out - if you mistype something, mail will stop being delivered. So the only way to see if there /is/ a problem is to tail -f exim_main.log; sudden silence means your system_filter is broken.