I left the Maelstrom game part way through the latest event (Appropriation, Easter weekend 2012), and I don't particularly expect to be coming back. I have absolutely no hard feelings for the team at Profound Decisions (who are the company running Maelstrom), and I expect to continue playing Odyssey and am looking at Empire with interest.

The Maelstrom game I played for three years was a game of exploration and intrigue, and I played a character with some pretty serious emotional baggage and a past he wanted to escape. He came to the New World, found people of like mind and founded a church. It was a good life for a bit. Then, the rumblings of apocalypse sounded under the surface. For the next couple of games things got bleaker and darker, and my character and a load of others fought against it, and it was good fun. The Undead rose, my God told me to fight them, and I did so to the best of my ability. Then, on friday, three quarters of the characters I play with were either killed or driven off the field for the weekend.

All of the above is fine. Interfactional tension is a fine thing, and it's been simmering along, grounding in little scuffles and scraps for years. We've all been expecting a fight like that, half the field against the other half, and now it's happened. And it's just driven home that the game as it is now isn't really the game I want to play.

Two data points:

• Just before the fight kicked off, I went to GOD to do some admin. Had my character been on the field, he would have been very, very busy keeping the fight off the surgeon he bodyguards while she saves lives, dragging people out of the fight so they don't get trampled and so on. But he wasn't there. While I was sat OC in the caterers, a group of other players came in having been on the attacking side (as undead, of whom there seem to be more every time I turn around). Opinions in the group seemed very much to be "Yeah, join the undead, it doesn't matter if you die, come back and slap the guy that killed you about. It's a great laugh!". I'm sure it is, but again, I've spent the last few years building up a deep character with motivations, and family history, and faith and relationships - I'm not looking for a great laugh, I can get that in other systems.
• In the run-up to this event, I've spent every night last week up until 1AM: packing, writing material for the game, and dreading another night in lockdown. We watch the sun cross the horizon, and we post guards and set watches and agree passphrases, and the camp hunkers down and prepares to repel the inevitable undead attacks. The atmosphere is wonderful, right up until you realise you're wound so tight you can't get to sleep for two hours after the game stops for the night, and that the thought of another evening of roleplay essentially being forced to stand guard the whole night (because you're one of comparatively few characters with the necessary skillset) is poisoning your entire day.

Maelstrom continues to be a great game. It's a different game from the one I started playing in 2009, and the game as it stands is not one I wish to play. So I'm leaving, and reallocating my time to games I enjoy more. See y'all on the field in the future.

Three whole months since a useful entry, in fact. So it goes. As you may have guessed, Advent Science totally imploded fairly early on when I realised I really needed to write the sessions in advance, not on the night. I have no doubt it's possible to put out that volume of information each night for 24 days and have it be correct, complete and coherent, but I wasn't able to do it. Maybe next year I'll actually do the prep :)

Work is work, and continues apace. My department has me doing a lot of XSLT and Python at the moment, and I'm finding that the latter isn't the terrible language I was sure it was a while ago. Syntactic whitespace still bugs me somewhat, but at least it isn't Perl... It's maintaining my interest without any trouble, and while it's a really big job, it breaks down into small achievable sections such that I get a sense of progress, which is nice.

At home, the house is pretty much sorted out now, though it could use a spring-clean. Everything works, there isn't too much mess around and I'm slowly getting used to the idea of having a living room for, you know, living in. I still spend most of my time in my bedroom, which seems like a waste of a space. Have to address that.

LARP is mostly going well (although see the following post). CUTT will start back up soon, I'm looking forward to the next Odyssey game, and I await more details on Empire with interest.

Anything else? Not much of significance. I have a new bicycle, which is nice for the commute (the gears and brakes work properly!). It's a Raleigh Oakland in British Racing Green, with aftermarket Schwalbe Marathon Plus tyres. The latter have taken my puncture rate down from two or three a month to zero in three months, and I highly recommend them for use on harsh commutes. My commute isn't too bad: cross the river by footbridge, cycle along beside the Cam for a bit, cross Newmarket Road and then follow Coldhams Lane to Cherry Hinton, then down the High Street and left at the crossroads. Thirty minutes / four miles each way, which has to be good for me, and it's all the nicer now it's still light when I get out of work in the evening.

An atom, as I said in the last advent science session, can be considered as a nucleus (containing protons and neutrons) and a series of orbiting electrons. But those electrons don't all orbit at the same "altitude". It turns out that there are set "altitudes" (energy levels) at which electrons can orbit around the nucleus, and a certain number of electrons can fit in each. The energy levels aren't called energy levels for nothing, as an electron can move between them by gaining or losing energy - the more energy an electron has, the higher altitude it orbits around the nucleus, the higher its energy level. The terminology all kind of makes sense (although this is a massive simplification on the actual physics).

Different elements have different energy levels, and the spacing between the levels varies. The energy levels tend to be occupied from the nucleus out, as with time electrons will lose energy and fall inward to the lowest unoccupied level. An electron that has enough energy to transition to a higher level is said to be "excited". The highest energy level in which unexcited electrons are normally found for a particular element is called the Valence Band. The energy level immediately above it (which is "normally" empty of electrons) is called the Conduction Band. Electrons in this level can be exchanged between atoms moderately freely, as they are highly energised and loosely bound to their nucleus, but because electrons are drawn to positive ions (such as those created when an electron leaves an atom), it tends to be more a case of atoms swapping electrons with their neighbours than of electrons migrating freely around the material. As a rule, electrons in the Valence Band are too strongly fixed in place to move around like this.

As I said a while back, an electron must take in energy (and become excited) in order to step up to a higher energy level. This is ... mostly true. The trouble is, an energy level isn't just a single, clearly defined circle around a nucleus, it's a fuzzy band within which electrons can have one of several excitation levels, all very close together. So the bands can be different widths, and different elements have different distances between their bands... can you see where this is going?

CONDUCTORS are materials, such as metals, in which the valence band and the conduction band actually partially overlap. Electrons can swap in and out between the two bands freely. As a result, the conductor can be considered as a virtual sea of electrons, coexisting with a virtual sea of positive ions, despite the fact that the material as a whole is approximately neutral. Electrons within the conductor have a drift velocity (on the order of millimetres per second), which is the speed at which they move about, trading between atoms. Note, however, that electricity moves much more quickly than this (about 0.75 light-speed in vacuum). This is because electrons are traded, not moved - the whole thing behaves a bit like a Newton's Cradle. Push an electron in one end, and all the electrons jump forward one place in line, and an electron comes out the other end almost immediately. It's not the same electron, but it may as well be.

INSULATORS are materials, such as glass or rubber, in which the valence band and the conduction band are widely separated. Electrons need to gain a great deal of energy to move between bands, and they rarely manage it. As a result, attempting to push electrons in one end of a insulative material (or pull them out) has minimal effects, BUT it can cause charge buildup at the end. This is why insulative materials can hold a static charge - electrons are added to or removed from the material, but because it isn't conductive they can't go anywhere. The "not-electrons" that are left behind when electrons are removed are called Holes. They'll be useful later.

Finally, SEMICONDUCTORS are materials (like silicon) in which the valence band and the conduction band are close together. Electrons don't need a lot of energy to hop the gap, but they can't do it spontaneously. Semiconductors, it turns out, are really useful if you're smart in how you prepare them and lay them out - all integrated circuits are made from semiconductors. If a semiconductor is "doped" with other materials, it can be made to have a slight excess of electrons or holes, and when the two types of semiconductor are laid out in certain patterns, you can use a flow of electrons in one area to control the flow of electrons in a nearby area very precisely. But that's transistors, which is another session, yet to come.

I can't promise to post every day, as you've noticed, but I'm trying. The next session is on other fun particle physics trickery that's used in the field of electronics, then we'll move on to the actual machinery involved, starting with the transistor and moving on from there.

• Britney Spears' Guide to Semiconductor Physics
• Static electricity
• Electrical conductivity

Pufferfish is talking about genetics, and duckbunny about the history of the atmosphere. In the next 24 days, I hope to lead you on a journey from science to engineering, and beyond, in one very narrow field.

Computers are everywhere these days, on our desks, in our pockets, in the back rooms behind companies like Google, and Facebook, and Oracle. They cook our food, wash our clothes, and guide our aircraft. But to many people, the computer is a magic box, a Thing within which humankind is not meant to peer.

That's nonsense. They're machines, just like everything else, the parts are just smaller and less obvious in function. I happen to know my way around them quite well, so I'm going to impart some of that knowledge to you, if you keep reading. I'll necessarily have to gloss over details from time to time, but I mean to touch everything important, and leave a trail of links for you to follow if you want to learn more.

Join me, then, as we wander from Electrons, to Email.

If we're going to go from Electrons to Email, I guess we'd better start at the beginning. Time for some particle physics.

The electron is a particle with a unit negative charge. That is, it is a particle with the smallest negative electrical charge known to exist - there's no such thing as "half an electron's worth of charge". An atom consists of protons and neutrons in the nucleus, and orbiting electrons: a proton has a unit positive charge, an uncharged atom has an equal number of protons in the nucleus as it has electrons orbiting it.

Opposites attract, as well we all know, and electrons are no different. Electrons, being negative, are drawn towards positively charged objects. But what's charge? It's the presence or absence of "the right number" of electrons. When I said that an uncharged atom has an equal number of electrons and protons a paragraph ago, I didn't mention what happened if the numbers weren't equal. If an atom has less electrons than protons, it is positively charged. If it has more, it is negatively charged. A charged atom is called an ion. Positive ions "want to" gain electrons, and achieve neutrality. Negative ions "want to" lose electrons. I put "want to" in quotes because there is, of course, no desire involved. Equally, it's not something I can easily explain without going deeper into partical physics than I really want to, so you kind of have to accept it.

Electrons are drawn to positively charged objects, and repelled by negatively charged objects. This is as true at the macroscopic level as it is at the atomic: a positive electrode will attract electrons, and negatively charged objects, to itself.

It follows that given a difference in charge, electrons will tend to flow from a negatively-charged object to a positively charged object, until the charges are equalised. This flow is called electricity. The chemical reactions within an AA battery cause one end to become more positive and the other more negative as they proceed, and it is possible to extract energy to light lamps, sound buzzers and so on by placing the item to be powered between the positive and negative ends: the electrons flow and, on their way, they power the item. Given enough time, the chemical reactions within the battery will cease as their fuel is consumed and the electrons will slowly drift back to equal out across the battery - this is what happens when a battery is discharged, or "flat".

The difference in charge between two objects is called the Voltage, or potential difference, that exists between them. The number of electrons per unit of time that flow between them is called the Current. Current is measured in Amperes, or "amps", and a single ampere is 6.241x10^18 electrons per second.

Given that that's an awful lot of electrons (roughly six quintillion), it should come as no surprise that in electronics, it is normal to deal with thousandths or millionths of an amp, or even smaller amounts.

So, that's the electron, more or less. I've glossed over some bits, because down at the tiny tiny scale of particle physics, it can be a bit too easy to get sucked down the rabbithole of detail, but that's enough that I can explain the next bit with. See you tomorrow.

For more in-depth information...

• Wikipedia: The Electron
• Wikipedia: Voltage
• Wikipedia: Electric current
• Wikipedia: Electricity

Well well well.

I live in Cambridge. And I work at (but not yet for) ARM. Life is more or less good. And I'm back on the net, as this entry shows. Hello again.

I have a (rented) house, which is still a mess, because I haven't finished unpacking (it's traditional, you know).

I have a job, and I'm responsible for a manual the company will be releasing soon. This is ... well, not going perfectly smoothly, but so it goes. I'm doing the best I can under tricky conditions, and I don't think it'll be too late (but when one's co-author, manager and mentor all independently go on holiday at the same time, there's only so much a new hire can manage).

Life is, for the most part, good.

Watch this space, I guess :)

The Glass: half-empty

I'm due to start work on Monday, and all the details for that are sorted out now. I still need to finish servicing my bicycle for the commute, but that's a couple of hours' work, and will probably be done on Saturday morning. Then I just have to find the route...

Not a lot to say here, really, but thought I should just put up a "things still happening" post. Money is tight, as expected after just moving house, but all the major bills are taken care of and I'm (barely) solvent this month. Once I'm actually being paid again, and Brighton Uni get that last pay-cheque to me, everything should be just fine.

For now, well, I guess it's cheese sandwiches for me :)

Having the river and Stourbridge Common thirty seconds' walk from my door is a lovely thing, though. I'll try and get some pictures at some point, and post them here. Realisation of the day, though: rowing skiffs have head- and tail-lights, and they appear to be exactly the same models as used on bicycles - horizontal lines of LEDs, powered by two AAA batteries per unit. It's odd, and interesting, to see the same design reused in a way I'd never have expected.

The glass: half-full

There are a few issues I need to raise with the letting agency, mostly relating to the security of one of the external doors and the fact that the doorbell does not work, but for the most part I'm pretty happy with it. Once I've raised my list of issues, I wonder who the letting agency will think is more anal, me or the landlady... Given the place has fire safety posters, smoke alarms and fire extinguishers everywhere, she probably still wins.

Ah well. That's sorted, and I have a work contract in my bag to read and sign tomorrow. Things are coming together. Tomorrow I go back to Brighton, and finish putting things in boxes, then start moving in earnest. For now I have a new bed, and some Egyptian Cotton sheets. Tomorrow can wait :)

The Glass: half empty

So, I'm pretty busy at the moment. I'm packing the world into boxes in the evening, when I'm not packing for Maelstrom. I'm writing yet more extensions and plugins and patches and add-ons for the Winter in the Willows website. I'm wrangling a frankly unhelpful letting agency in Cambridge, forcing them to follow their own process and hoping they'll get everything sorted out before I need to move in. I'm ... still waiting for a contract for my new job, despite everything now having been agreed, and my being more than halfway through my notice period. And that notice period? I'm still lead programmer on a critical project at work, and likely still will be until the day I leave, because without meaning to sound insulting, I am actually better at what we're doing than the other guys on this project. Exactly how they're going to cope when I'm gone is not my problem.

I'm ... almost coping. It's like holding slightly more than a handful of marbles - things keep falling out when I'm not paying attention, and then it's two weeks later and I realise they need doing right the hell now, and I didn't have the time before and I don't now. On some of the bigger projects above, I'm supposed to be part of a team, and the rest of the team seem to be hiding a lot of the time. But. I keep at it, and look forward to the long weekend I have at the end of September, before I actually start working for ARM properly, and after I've moved to Cambridge. I'm going to need the rest.

The Glass: drained

Easy, right?

So far I've managed about a box every three days, so I'm going to have to speed up some. I have a lot of boxes, but I also have a lot of stuff... If I had more time I'd have a clear-out before the move, but as it is I rather suspect I'll have to do it when I hit Cambridge, instead. On the up side, in exchange for some creative timetable-meddling, my old department at university is willing to lend me a van, which will remove the rental expense and make the journey substantially cheaper.

As things start to pack down, it's odd to see the empty space they vacate. I know I'm leaving, but it doesn't feel like it till there are rectangles on the walls where pictures were, and empty shelves, and coat-hangers swinging in the breeze...

The Glass: half-empty

You get on a train, and it takes you where you want to go, more or less. Assuming it's a long distance train, like those I mostly ride, it'll get up a fair bit of speed and give you something like a back massage as it rattles, sways and judders over tired old track. And then there's the view from the window.

When it was built, a hundred and fifty odd years ago, the railway sliced through empty space, leaping across country to join cities and towns and villages together. But as soon as the railway was built, people and their dwellings began to accrete against it, as if they were some kind of immune reaction and the railway was something...intrusive. Foreign. Alien.

Nowadays, you could believe that the railway cut through fully formed towns and villages and suburbs, the houses and roads and shops crowd up so close to the line. And it's that that I like the most, I think. Riding through the world in a fast metal tube, skimming the very ground, you pass over and through and past tens if not hundreds of neighbourhoods, getting a moment's insight into the lives of your fellow humans. The hutches of a guinea-pig breeder, the rusting hulk of a car they always meant to restore, the caravan with bumper stickers from every country in the EU. And moments later an industrial estate, or a park, or a cemetary, and then more people. Maybe some farmland or a river.

You are in a maze of twisty little vignettes, most almost alike. It's never dull.

State of the Dan: ARM are sending me a contract to sign (I have the job, now it's all admin). Now, I'm trying to sort out somewhere to live, and to that end I'm travelling to Cambridge again, hoping to get an application in on a particular place before someone else. The admin fees and deposit are going to push my bank account quite hard, but I think it will be worth it.

The Glass: full