Wednesday, 28 February 2007

What colour's that? And when?

The Welsh traditionally had no words that directly correspond to the English words green, blue, grey or brown. The word "glas" matched part of what English would call green, but a totally different word covered what (to English) would be another shade of green. That term also covered blue and some of grey. I knew that certain cultures made different boundaries between colours, but Welsh was a surprise - the physical experiences and their significances must be very similar on either side of Offa's Dyke.

The word "grue" to a logician/philosopher refers to things that are green before the year 2000 and blue afterwards. Similarly, "bleen" things are blue before 2000 then green. It was introduced in 1955 by Nelson Goodman as a way to discuss potential paradoxes in predicate logic. The choice of the year "2000" in 1955 and subsequent writings was of course shorthand for "some point in the future" but now, in 2007, is better understood as "some point in the past." Thus one inherent paradox of predictate logic no longer applies, and we can safely use it.

Thursday, 22 February 2007

You can't see me!

Well, not if I'm painted just the right shade of green and you're reading this of a standard monitor. Monitors show colour by mixing red, green and blue light sources, so-called primary colours. Mixing them in different proportions produces a huge gamut of colours, but nonetheless, there is no mixture that produces wavelengths around 500nm - or "green" to you and me. To get that, as I understand it, you need to either have a negative amount of red (impossible if you're just adding light to other light) or else start with super-saturated light sources (also impossible). A normal RGB monitor will of course show green, just not certain wavelengths of it.

It also might be true that if you balance a scared chameleon on the back of a randy squid, it will die, for one of two reasons. Squids attract partners by changing their skin colours, often quite rapidly and extremely. Chameleons change their skin colour to blend in to the background, especially when frightened by a potential predator. This takes a lot of energy, so the chameleon will rapidly exhaust itself and die. Either that, or it will drown first.

Tuesday, 20 February 2007

Big bags

Paddy Doyle holds the world record for bag punching. In 1983, he punched his way out of 38 wet paper bags in under a minute, an achievement never officially bettered. (The Soviet athlete, Alexander Borchuk, claimed to have punched through 41 in the same time in 1986, but this was never officially accepted.)

Things on the floor around ten feet (or more) away from you appear closer that they really are. The higher something gets, the further away it looks. At eye level, things look further away than they really are.

Friday, 16 February 2007


The Spanish national anthem has no words. Every time they 'sing' it, they feel the need to explain this, just in case observers think that they have all forgotten them. Still, that's better than having to sing "...May she sedition hush and like a torrent rush, Rebellious Scots to crush, God Save the Queen!" as the British anthem concludes. Sadly, I haven't made that last bit up. It's just that the word were written at a time when the Scots were playing up a bit, and we never got round to changing them.

Smacking things

Some things I learned last week.

"Among heroin users, the major artery for injection is known as "your bitch", hence the Prodigy's most famous track Smack My Bitch Up," according to Kate Figes in her article "Who are you calling a bitch?",,1999060,00.html
I feel slightly happier about that song now.

In Avignon, the traditional way to cook snails is to fry them in garlic and white wine after shelling. The shelling takes place by dousing the live snail with eau de vie and then sharply smacking the back of the shell. The snail is too drunk to hold on to the inside of its own shell, and falls neatly into the waiting hot pan. A local children's playground game is known as "frapper l'escargot!"


I've been thinking about setting up a blog for ages. Years, probably. So finally I've done it, and will faithfully maintain it with regular updates until the inspiration runs dry.

Facts are sacred, but some more so than others. So half of this blog will consist of things that I have learned, usually on or shortly after I have learned them. The rest will consist of random stuff I make up. I only hope that it is obvious which is which, at least half the time... For example, every sentiment in this entry is true, up until this point. From now on, who knows? After all,
if I say I'm eating a banana while typing, who can contradict it?