GOOD QUESTIONS / Dragging out the lobster theory

SEVERAL topics recently raised in this column have provoked correspondence of great interest, so this week's contribution to solutions of the world's problems features a large feedback section. We start, however, with some new themes:

'My daughter was inundated with blue cards on the birth of her son. She wasn't amused. Can you please explain to us why, where and when this convention of 'blue for a boy' and 'pink for a girl' arose. Do we need it?' (Davina Huxley, Oxford.)

Several unconvincing theories have been advanced to answer the question of colour-coding the gender of babies, most of which are connected with religious or superstitious beliefs ascribing a protective quality to blue. Sorting fact from speculation, the main points seem to be as follows:

Several European countries, including Belgium, advocate pink for boys and blue for girls. Indeed, in Catholic countries there is a strong tendency to associate blue with girls, since that was the colour of the Virgin Mary's robe.

In England, blue-boys and pink- girls (BBPG) are a comparatively recent innovation. The book Yesterday's Children: Antiques and History of Childcare by Sally Kevill-Davies, includes a typical portrait of a Scottish family of 1782 featuring a boy and girl, both in white frocks, with the girl having a blue sash and the boy a pink one.

There are also indications that the Women's Institute were advising blue for girls and pink for boys as late as 1920.

However, whereas all babies in Britain are, according to folklore, found under unisex gooseberry bushes, in Germany boys are born under cabbages and girls under roses, which more or less tallies with the BBPG theory.

The whole thing can be dated back to the Bible. 'Speak unto the children of Israel, and bid them that they make fringes in the borders of their garments throughout their generations, and that they put upon the fringe of the borders a riband of blue.' The fringe of protective blue then adorned many religions and folk beliefs.

In England, there is an 1816 report of blue threads being worn as protection against fever, and a 1909 report of blue beads being worn to ward off colds or quinsy among London schoolchildren. Pink seems only to come in as a contrast to blue when a gender-marker is needed.

Even then it seems almost arbitrary whether boys or girls are chosen to be privileged with blue, though there is a dubious theory that male babies have been wrapped in blue since ancient times because their protection is more important than that of girls.

In our case, BBPG seems to have happened in the late Victorian and Edwardian eras, with the greetings card industry probably to blame for the present uniformity. A modern fashion book, incidentally, advises women against wearing pink if they are hoping to seduce someone.

Principal Sources: Noreen Marshall (Bethnal Green Museum of Childhood) and Dictionary of Superstitions by I Opie and M Tatem.

'Why is New York called 'the Big Apple'?' (Karen Makin, Newton Solney, Derbyshire).

For something that has happened recently, the origins of this expression are surprisingly vague, though seem to have come from the American jazz world of the late 1920s or early 1930s. In November 1937, Dancing Times reported a new dance craze: 'Such steps as the Shag, the Flea Hop, the Strut, and the Walk are combined with the new Big Apple.' The dance, however, came after, and was perhaps named for a Harlem night-club called 'The Big Apple'.

In jazz slang, any large place - from the universe and the earth down to a big city - could be referred to as an 'apple' of which everyone wanted to take a bite. And New York was the Big Apple.

In Dictionary of Phrase and Allusion, Nigel Rees mentions that manzana, the Spanish for apple, is also the word for a block of houses. He also points out that London was called 'The Strawberry' by Horace Walpole.

FEEDBACK: Ron Wells, of Waterlooville, Hampshire, provides a fascinating answer to which we had provided no question, relating to an item in last week's Happy Anniversary column:

'Guy Fawkes was not hanged, drawn and quartered. He was drawn, hanged and quartered. Traitors were dragged to the gallows at the tail of a horse. They were then partially hanged, taken down alive, disembowelled, beheaded and quartered. 'Drawn' means dragged to the gallows, not disembowelled.'

Brewer's Dictionary of Phrase and Fable confirms this explananation, citing the sentence for high treason on Sir William Wallace in 1305 that he should be drawn from the Palace of Westminster to the Tower, then hanged, then disembowelled or drawn and then beheaded and quartered. 'His quarters were gibbeted at Newcastle, Berwick, Stirling and Perth.'

The controversy over optimal speeds for cars and lobsters continues. John Fischer from Saxmundham, Suffolk and Christopher Padley (Market Rasen, Lincs) have both written with mathematical solutions to the problem of maximum car-flow under safe driving conditions.

Whereas our explanation last week applied the Highway Code safe braking-distance figures to idealised cars of zero length, both our correspondents have incorporated the vehicle length into a quadratic formula relating braking-distance to speed.

Simple calculus then tells us that car-flow is at a maximum when car length = braking distance. For an average 14ft-long saloon car, according to John Fischer, this results in an optimal speed of 16.73mph, allowing a flow of 32.92 cars a minute. A J Padley (who did the sums for his brother Christopher) takes an average vehicle length of 16ft and allows a 20 per cent reduction in theoretical braking distance for steadily flowing traffic to reach an optimal speed of 20mph.

Which is still considerably quicker than migrating lobsters, whose queueing habits still seem to be confusing readers. Malcolm Coles questions whether crustacean queues can really go faster than lone lobsters: 'The one at the front does not benefit from a lessening of water resistance and so ought not to be able to exceed 28cm per sec. If the one at the front is only going at this speed then the lobsters behind can go no faster (unless they are pushing it along).'

Evidently we did not explain this very well, so let's go back to the original research. In 1976, R G Bill and W F Herrnkind of Florida State University observed lobsters in their natural habitat and found that well-formed queues did indeed move faster than individuals. Their subsequent research was performed by dragging dead lobsters through a laboratory tank.

Queues were held together with stainless steel wire, and a capstan, pulley and weighted pendulum device enabled precise measurement of the drag. The findings confirmed that the longer the queue of lobsters, the less the drag. For example, 19 lobsters wired together and towed at 35cm per sec produced 65 per cent less drag than 19 individuals. They also discovered an optimal distance between lobsters for drag reduction, which is close to the actual distance maintained when live lobsters remain in antenna contact with each other.

The experiments confirmed that in real life, lobster migratory behaviour takes full advantage of drag reduction. Queues of up to 65 lobsters have been observed travelling together for several days, although they tend to split and rejoin, so ensuring different lobsters take on the pole position where drag is greatest.

(Photograph omitted)