J and I had a nice conversation over tea the night before last, which was the first like it since we moved. He thought that when he dropped a brick into a plastic paddling pool full of water, the water would slow the brick down so it would just touch the bottom gently. Unfortunately it didn’t slow it down enough and it made a large hole in the bottom. This was more irritating than normal because the paddling pool was collecting water from a downpipe with nowhere else to go (other than the ground). There are four downpipes that empty straight onto the ground – I find it hard to believe that a house that was generally well maintained had such a bad drainage problem.
We’re trying to get a builder to put in some soakaways to sort it out, but the downpipes at the front go near the gas supply, so this could be tricky i.e. expensive. Also possibly expensive is the damp patch on the wall near the hot water tank – again I’m surprised this wasn’t sorted or even picked up on the survey as it’s fairly obvious.
Anyway, I told J that the water could have slowed down the brick, but not enough. To be sure he’d need a control, where he dropped a brick into an empty paddling pool. This went on to testing medicines, double blind tests, and placebos. Yes, a brick meets paddling pool incident can be used as an opportunity for learning about experimental technique.
We’ve found the local swings and K took lots of photos including some of some nesting swans, and L’s silk rainbow wings from my parents finally arrived and made her happy. The children were bouncing off the walls a bit so Katy’s been going through some maths, English and science work books with them that weren’t part of the normal pattern of things but help to keep sanity. Also colouring-in books have proved surprisingly popular – K’s done some excellent stuff and L’s are colourful!
Katy found a complete bargain – a set of children’s books about the body for 20p each, and as there are 31(!) of them they go into quite a lot of detail (I must confess I was very vague about what the lymphatic system was) but they’re almost like comic books so aren’t too heavy. The children seem to like them and J has probably finished them all by now.
Before they were scattered all round the house they were in a pile in the children’s bedroom. They are all numbered on the spine and I asked J how he would put them in order. He described selection sort, which is what most people would do – search through to find the smallest, pull it out of the pile and put it at the bottom, then go through to find the next smallest and so on. I described bubble sort to him (go through the pile and swap adjacent pairs that are the wrong way round; keep repeating till you’ve not swapped anything) and then we had a go at quick sort together and I said that’s the way that computers usually put things into order.
We picked a book at random from the middle (which was book 12), and put it to the end temporarily. J then started from the left end looking for books greater than 12 and I started from the right looking for books less than 12. When we’d each found something we swapped them. When we met in the middle we slipped book 12 back into the place where we’d met. Then all the books to the left of 12 were less than it, all the books to the right of 12 were greater than it, and hence 12 was in the correct place. He guessed that we’d repeat the whole process on the less-than-12 bit and on the greater-than-12 bit, but we didn’t bother actually doing it.
(So next time you put your iPod on shuffle, or sort a list of things in Excel or Word, this is probably what’s happening behind the scenes. In case you’re wondering, I expect that the iPod labels each track with a random number, and then sorts the tracks by that number, so even shuffling is actually putting into an order.)
In digging around Wikipedia to get my facts straight about sorting, which is meant to be bread-and-butter to geeks like me and something I thought that clever maths types had analysed to bits to work out efficiencies and worst cases etc, I learned that some people had invented a new kind of sorting in the last five years! It’s called the library sort, and it’s a variant on insertion sort.
We continue to try to tame the sea of boxes and disorder around the house. I was chuffed when I found (in an unmarked box in a random room) the clock radio so we don’t have to rely on my mobile phone’s alarm to wake us up. So far I’ve managed to keep to at least one box unpacked per night (on top of things like unloading stuff from the car that I’ve taken back from the lock-up) and Katy’s doing loads.
The car doesn’t seem to like us almost running out of petrol. I broke down on the way to work – an intermittent fuel pump problem which the roadside rescue bloke managed to sort out. Unfortunately it played up again for Katy en route to opening up Parents and Tots, and defeated the roadside bloke was taken to a garage. The children thought a ride in the breakdown truck was a bit of an adventure (J took a bit of getting used to the idea).
The helpful BT engineer has been to get the phone working again – only 10 days till broadband now (sigh). Unfortunately the phone socket is in the most remote part of the house (the extension) as the previous people were on NTL (boo hiss) so the handy sockets are useless. So I’ll have to turn into a phone engineer and then network engineer to sort this all out – a bit of drilling, cable pulling and stapling, and then socket bashing. At least I get to buy and use a new tool (a krone tool, for attaching the phone wires to the phone socket).