It stands for "my domain is shorter than your domain"

9 November, 2007
by mpj

Wht is the SI unit for car fuel consuption?

The SI system of units is a wonderfully logical and functional system of units of measurement. In the SI system all units can be expressed in terms of a few fundamental, independently defined base units such as the second, the metre and the kilogram. (I freely admit that the fact the kilogram as a base unit is one of the less logical parts of the system.) When working in the base-10 SI system, no conversion factors are required and everything fits together beautifully.

The other day I realised we are routinely using at least one unit which is more complex than it need be. It is that of vehicle fuel consumption, typically expressed in SI countries in litres per 100 kilometres. (It’s interesting to note that in countries that use Imperial units, the custom is to use the reciprocal unit, that is, miles per gallon.)

So, what would be a better unit? Let’s simplify! Volume (in litres) divided by distance (in kilometres) is area.

1l/100km = 1dm3/100km = 1*10-3m3/105m = 1*10-8m2 = 10000μm2.

The beauty of this unit is that it does not feature the distance driven anywhere. It is superfluous because the distance driven is directly proportional to the fuel consumption. A neat way to visualise this is to imagine that when you drive, your car leaves behind it cylinder (or cuboid) of fuel with its cross-sectional area as above and its length the distance you’ve travelled.

So when you’re buying your next car, make sure it consumes less than 50 thousand square micrometers of fuel.

14 October, 2007
by mpj

Appendices. Can live with them, can live without them.

Appendix has a job, and Uncommon Descent reminds us that is the last nail in evolution’s coffin. But this is just too funny. In the comments, Mats says:

oh, by the way, needless to say that, if this paper is confirmed, then Darwinists will spin this around and say that this new found function of the apendix is exacly what “evolution would predict”.

Why, funny you should mention

The vermiform appendage—in which some recent medical writers have vainly endeavoured to find a utility—is the shrunken remainder of a large and normal intestine of a remote ancestor. This interpretation of it would stand even if it were found to have a certain use in the human body. Vestigial organs are sometimes pressed into a secondary use when their original function has been lost.
– Joseph McCabe: The Story of Evolution (1912), p. 264

(Emphasis mine)

That’s right, that was written 95 years ago.

12 October, 2007
by mpj
1 Comment

My pocket survival kit

Lifehacker continues its “show us what’s in your…” meme. So, welcome to a guided tour of my pockets.

The contents of my pockets

The Jimi wallet (back pocket). It currently has one debit card, one credit card, a ten-pound note, two business cards, my driving licence and an Oyster card, the RFID-based electronic ticket for the London public transport network. I am a member of a car hire scheme which allows me to book a car online then walk to the car and open it with my Oyster card, so the Oyster is also my set of car keys. The Oyster works fine through the Jimi, so I never have to take it out. Unfortunately, the TfL RFID readers don’t like my work RFID card, so I can carry the work card separately.

Keys (left pocket). The heart of my keychain is a Kikkerland carabiner/bottle opener. I’ve got separate keyrings for different functions: one keyring for my house keys, another one for work keys, one for my parents’ house and so on. When I leave the house, I only take the keyrings I need. The left-hand side keyring has the two things I tend to take anyway, a keyring-size version of my supermarket loyalty card and the combined SD/USB card, SanDisk Ultra II SD Plus, in its holder. (The card houses a bootable Linux distro, a few portable apps, and a truecrypt loopback partition for sensitive data.)

Nokia N95 smartphone (right pocket). This is my main communicator. It’s a phone, alarm clock, calendar, to-do list, email client, web browser (when I don’t have my 770), music player (when I don’t have my iPod), (video) camera (when I don’t have my Finepix F30) and GPS navigator. I normally carry a spare battery, too. A good data plan is vital with modern handsets, where many applications require constant transfer of data. Mine includes 3GB/month HSDPA transfer at 1.8Mbps.

Nokia 770 Internet Tablet (left pocket). I carry this most of the time. It’s pretty big but not too big to carry comfortably in my pocket. The 770 comes out when I need a bigger screen for surfing the web or looking at my calendar, and perhaps most importantly for offline RSS reading during my commute. It connects to the internet over bluetooth via my N95. Whenever I rent a car, the 770 and its Navicore software becomes my in-car navigator, with a suction-cup holder, car charger and a Nokia bluetooth GPS receiver.

I know I carry quite a lot of stuff. I’ve tried to go light where I can but I still want to be connected when I’m out and about. Still, all of this fits comfortably in my pockets, and is a big improvement over carrying a laptop.

10 October, 2007
by mpj

Wanna buy a smile?

A recent email I received had a link to Microsoft’s FREE emoticon download site (and yes, they’ve dedicated an entire domain for it, as have millions of others.) A few questions, if I may:

  1. Is this Microsoft’s business plan for Hotmail? If so, should they perhaps consider reading your email, like the smarter companies do?
  2. Who first came up with the (orthographic?) rule that the word FREE must always be capitalised?
  3. Has anyone ever paid money for emoticons? Who thinks a fiver is a fair price for (a) the immense joy they bring and (b) their incredible expressive power as literary devices?

I so hope the bubble bursts quickly.

8 October, 2007
by mpj


Did you know Finland has one of the last state churches in the civilised world? In a country which allegedly promotes freedom of religion, the Evangelical Lutheral Church is the only church mentioned in the Constitution. It has a right to tax people (and even companies!) through the state and it receives tax breaks no other religious or ideological organisations are eligible for.

In 2003, the Freethinkers of Tampere created eroakirkosta.fi, a website which allows church members to resign online. The service was made possible by a change in law which allowed members to resign by letter — before this time, one would have to go to the magistrate, on in some cases the church, in order to resign. The historical difficulty in resigning, combined with the extremely high baptism rate, means the church is still full of people in whose lives it plays no part but who continue to fund it.

The good folk behind eroakirkosta.fi have now published an article (in English!) which highlights some of the problems and inequalities behind the state church system, and reports promising developments in the resignation rates. The website seems to have been a great help in resigning; in 2006, as many as 80% of all resignations were submitted through the website, with many quoting the ease of resignation as an important motivator.

The article doesn’t go as far as to suggest ways to revoke the privileged status of the Evangelical Lutheran Church; I would’ve liked to see a short summary of this too, as it is the goal of the Finnish Union of Freethinkers. Anyway, it’s excellent work!

29 September, 2007
by mpj

Tubular H₂O and homeopathy

A floating water bridge between beakers. Credit: Elmar Fuchs, et al.

So, Austrian physicists have found an interesting property of water. Anyone care to guess how long until homeopaths try to use this research to justify the ‘memory of water’ effect?

For a good overview of all the latest woo in the subject of the memory of water, this article at Homunculus is an excellent place to start. The blog article gives an overview of all the articles in a special issues of the journal Homeopathy. It’s a heroic effort; I tried to read the articles myself but just couldn’t take it after a couple of pages.