Thursday, June 30, 2005

Day 57

[reading: Saunders Mac Lane, "Categories for the Working Mathematician"]

Still waiting for any signs of payoff in my explorations of category theory. On the surface, it sounded like a very interesting area to explore—a generalization of all of the concepts of morphism involved in mathematical structures. I like that kind of approach to mathematics: start with some interesting phenomenon (say, permutations of sets), but consider it in a more general setting so that the original problem is merely a special case (say: group theory). Then vary things further, sometimes by generalizing (say: semigroups), sometimes by specializing (say: rings, fields, topological groups), sometimes by changing the focus slightly (say: group actions, representations, morphisms).

I'm also old-fashioned enough to like a reasonably axiomatic approach to these things, so you know that if you're having a blonde moment you can always fall back to the basics to understand what's going on, step by step. Regardless of what Gödel might say, this is still a powerful and reliable way of going about things.

Combining the two, I found model theory to be one of my favourite bits of maths—exploring the whole class of axiomatized algebraic structures in one swell foop, to see what can be discovered in general about the things that satisfy those sets of axioms. Unlike category theory (at least so far), there are some genuinely surprising things that turn up quite early on in model theory—the Löwenheim-Skolem theorems, which show that you can't distinguish between different sizes of infinity in first-order logic (the downward version says any infinite model has a countably infinite submodel; the upward version says that any infinite model can be extended to a model of arbitrary size). This is unexpected (to me at least, although expectations involving transfinite numbers are often a little slippery), and leads to an almost-paradox. It also provides a rationale for why nonstandard analysis is valid.

Anyway, I'm still waiting to see anything equivalently startling show up in category theory, and to be honest my patience is running out.

Tuesday, June 28, 2005

Day 55

[reading: Saunders Mac Lane, "Categories for the Working Mathematician"]

Starting to get slightly worn down by the vast morass of terminology in the early pages of my book on Category Theory. I did start to wonder if maybe the "abstract nonsense" complaint has some truth to it, but then I compared this book against my favourite book on Model Theory—at about the same page number, that book had also only included definitions and examples, with no theorems. So I guess I'll keep wading through, hoping that my intuition starts to get tuned along the way.

Monday, June 27, 2005

Day 54

[reading: Michael Peskin & Daniel Schroeder, "An Introduction to Quantum Field Theory"]

I noticed a "123 meme" on a couple of blogs recently. Is it just me, or do these meme things really highlight the whole echo-chamber, nothing-of-interest-to-write-about nature of many blogs? (Pot, kettle, black). Or maybe that's just rampant cynicism (who, me?).

(Oh, and in my case the 123 thing is annoyingly difficult to do, given the status of Mac OS X MathML. An ugly version is: 'To do this, we replace the scalar particle φ with a vector particle Aμ and replace the Yukawa interation Hamiltonian with
Hint = ∫ d3x e ψ γ μ ψ A μ ').

Friday, June 24, 2005

Day 51

"Beer is proof that God loves us and wants us to be happy"—Ben Franklin

Slacker's lunch time again, only this time with a slightly different cast of characters.

Possibly not as drunken as previous expeditions, given that I recovered enough to go to a salsa class in the evening. The class was a distinct disappointment though—they taught something that was entirely different from every other salsa class I've been to, plus it was entirely footwork, and the teacher didn't always seem to dance in time with the music. Still, at least I know not to try it again.

Thursday, June 23, 2005

Day 50

[reading: Mary Gentle, "Cartomancy"]

Pleasant evening of West Wing watching and conversation, veering occasionally towards the surreal: "Is that real or mechanically recovered Belinda Carlisle?" is the comment that I particularly remember.

Tuesday, June 21, 2005

Day 48

[reading: Saunders Mac Lane, "Categories for the Working Mathematician"]

Curmudgeonliness is next to godliness

Kind of annoyed today on account of having to go to the gym twice. I turned up a little after 8 am to find the doors locked and a few people waiting outside. I felt most sorry for the cleaner, who'd apparently got there at 6.30 (ready for the 7am opening time) and been waiting since. So anyway I ended up going back to the gym at around 4pm, when it was much hotter and much busier.

I can't say that I'm hugely impressed with this gym. This is actually the second time they're screwed up my timetable for the day—and I've only been going for a month. The previous time, I tried to go to one of their classes only to discover they'd cancelled it without giving any notice. It's still cancelled, even though they continue to advertize it.

Given that I've already paid for a year and that it's the only semi-decent gym within walking distance, I'm kind of stuck with it, though.

Monday, June 20, 2005

Day 47

Finally finished reading my book on string theory, although I have to admit I did rather romp through the last third (unlike the first half, where I was dilligently checking all of the equations). I did end up with some sympathy with Penrose's position (chapter 31 of "The Road to Reality") that it's a cute theory but rather lacking in an obvious connection with reality (except in that it can reproduce the Standard Model—but then, so can the Standard Model).

The aspect I found particularly dubious is that the string theorists seem fond of proclaiming that string theory "predicts gravity". From what's covered in the book (which is admittedly only a beginners' guide), it's more the case that string theory has a traceless, symmetric, 2-index tensor field that can be put in correspondence with the linearized, source-free field equations.

Anyway, on to some abstract nonsense next.

Friday, June 17, 2005

Day 44

Some messing with CLX today, plus another attempt to get my digital camera fully talking to my Linux box.

Off for a spot of culture at the Globe this evening, which should be good.

Thursday, June 16, 2005

Day 43

[reading: Larry DiTillio, "The Masks of Nyarlathotep"]

Spent today writing three and half thousand words about code reviews.

Or rather re-writing: soon after I started my last job, the team I was in introduced a new code review policy. I've done lots and lots of code reviewing over the years in my previous job, so I ended up writing seven pages on how and why to do code reviews. Of course, since I wrote all this text at work, I don't get to keep the copyright. I thought it was good text, and since I've never actually seen anything similar written down anywhere, I wrote something similar again. The original text itself might be owned by my last employer, but they can hardly claim the ideas were theirs, as I'd only been there a month at the time (not that they'd really care, I suspect).

I occasionally toy with writing up more of my musings about software engineering, but I usually find that someone out there has already written roughly what I want to say. Usually it's Joel, and it usually pithier and funnier than anything I'm likely to write. Sigh.

Anyway, I'll leave what I've written for a few days to get some perspective on it, and then I may whack it onto a web page somewhere. Once I've finished fighting texinfo.

Wednesday, June 15, 2005

Day 42

[reading: Neil Gaiman & Dave McKean, "Mirrormask: The Illustrated Film Script"]

The last little bit of trimming and tidying up in the garden is done.

Before:

During:

After:

Tuesday, June 14, 2005

Day 41

[reading: Lois McMaster Bujold, "The Hallowed Hunt"]

Off to see Sin City again this afternoon, combined with some aspects of Slacker's Lunch. It'll be interesting to see how it stands up to a second viewing.

Sunday, June 12, 2005

Day 39

Urk. Twenty four continuous hours of guests. Not that I'm complaining . . . actually, hang on a minute. I really am complaining, aren't I?

Saturday, June 11, 2005

Day 38

Garden phase three: hefting lots of stones to fill up the area where the grass used to be. Not yet quite complete, but the main constraints in getting the stones were a) whether I could actually move the trolley (no sign of the gym sessions having any effect yet then) and b) whether the axle of the car was going to snap.

Friday, June 10, 2005

Day 37

[reading: Barton Zwiebach, "A First Course in String Theory"]

So bookmark B has now caught up with bookmark A, and they have joined forces to forge on in search of some connection with the rest of the universe.

Wednesday, June 08, 2005

Day 35

[reading:Dan Simmons, "Fires of Eden"]

A quiet day today. A gym visit; some shopping in town (on a weekday, so it's comparatively quiet); a couple of hours in A&E.

Tuesday, June 07, 2005

Day 34

Garden phase two: stone edging around the patio and path, in which I learn how to mix and apply cement.

Monday, June 06, 2005

Day 33

Garden phase one: wood edging around the flower beds.

Oh, and the right tax return form has finally arrived. Except it's missing some bits. And I still haven't had a P11D.

Sunday, June 05, 2005

Day 32

Went to see Sin City tonight, which is visually stunning and very violent. I'm guessing that the film is a lot more faithful to the original comic books than most of the other comic book adaptations, but I can't say for sure because I've not actually read the original Frank Miller comics.

Saturday, June 04, 2005

Day 31

[reading: Arthur Miller, "The Crucible"]

Away for the final weekend of half-term in Southwold. Sadly, the weather isn't really playing ball but we've managed to get out for a bit of a wander and take some pictures:

(Still only got the most rudimentary ideas of how to fiddle with things in Photoshop; I presume that there will be an easy way to get the same effect as a red filter when I convert images to black and white, but I haven't figured it out yet. Maybe I should read that book about the spanish chap.)

Friday, June 03, 2005

Day 30

Found an interesting blog that goes a little bit behind the scenes at the BBC's "Strictly Dance Fever" show. I normally find reality shows a bit turn-off, but they're definitely more interesting when the participants are actually showing some talent/skill other than for self-promotion. However, in this case I did watch the show occasionally and did actually break the habit of a lifetime and rang up to vote.

I do have an excuse, however—I know one of the couples on the show. This way, the next time I dance with Natasha I can truthfully say that I voted for her.

In fact, I also know a number of the dance teachers that were working with the contestants behind the scenes. It's reassuring that they at least are folk who know the dance styles in question, since the judges that appear on the show itself seem to be very poor at spotting when the dancers are doing anything like an authentic style or not (at least for the dance forms that I've got some knowledge or experience of—tango & milonga, lindy hop/jitterbug, charleston, shag and boogie-woogie).

Thursday, June 02, 2005

Day 29

Off to see Death of a Salesman this evening. I've wanted to see it for a long while now, since my brother was very keen on it back when he was in college, but I'd never quite got around to it. This year seems like an appropriate time to remedy the situation.

Wednesday, June 01, 2005

Day 28

Payday! In fact, probably my last payday for quite some time.

I resigned my previous job on the 4th May, so my official one months notice doesn't actually run out for another couple of days, but they've just sloshed the extra cash into this payslip. As a pleasant surprise, I also get paid for the week of holiday I'd accrued but not used—which seems bizarre to me, given that they gave me gardening leave and so they could just take the week's holiday as part of the notice period (but I'm hardly going to ring them up and complain about it).

And (sigh) I had to ring the tax office again to get the right tax form, since I fall into one of the categories where I can't use the short tax return they'd sent me. This is now the fourth time I've rung them to ask for a tax return form.

On a different note, I had my first fencing lesson in over 10 years tonight. I wanted to get a quick intro to the basics of sabre, but I have to say it didn't go particularly well—I distinctly got the feeling that the fencing coach considered me a waste of his precious time. There was muttering about how he prefers to concentrate on the people who are doing competitions; there was muttering about how there are beginners classes being run on other nights of the week.

Still, I had a quick waggle of the sabre against an opponent, which was quite fun. I guess I'll just figure out what I need to by experiment—I don't feel the urge to repeat the lesson. Ever.