杏吧原创

Toy story

Question: While toying with a Meccano model, I wondered if any significant
inventions or principles owe their discovery to the use of Meccano, Lego or
similar construction toys.

Answer: My grandfather Douglas Hartree used Meccano to build several large
calculus machines for numerical analysis in the 1940s and 1950s. There is an
exhibit in the permanent collection at the Science Museum, London, which
features part of one of the inventions. He wrote several books on the subject,
some of which contain photographs of the machines.

Justin Hartree

Bristol

Answer: Vannevar Bush鈥檚 differential analyser, which he built at MIT in 1930,
was a versatile analogue device for producing graphical solutions to
differential equations.

In 1934, Douglas Hartree, then at the University of Manchester, needed such a
device for his research on molecular structure but at the time it was not easy
to raise the money to build such expensive apparatus.

However, Hartree was inspired by a photograph of Bush leaning over his
differential analyser. To Hartree, the picture resembled an image of a boy
gloating over a particularly magnificent Meccano set.

Consequently, Hartree and his graduate student Andrew Porter set about making
a small demonstration model of a differential analyser from Meccano on the
expectation (which later proved to be justified) that the sight of a working
model would persuade some funding body somewhere to provide money for the
construction of a full-scale machine.

Hartree and Porter were greatly surprised to find that their Meccano
differential analyser could itself be used for some scientific computations
(Meccano Magazine, June 1934, vol 19, no 6, p 441).

Hartree used his Meccano device to model the Hartree-Fock equation and
generate diagrams of the quantum electron structure of molecules. At least 15
differential analysers were made from Meccano during the following 15 years, and
these were used for a diverse range of computations.

Garry Tee

Department of Mathematics

University of Auckland

Answer: It is claimed that the gearbox of the Mini motorcar was developed by
Alec Issigonis using Meccano. A close link with Meccano is suggested by the fact
that he was presented with the best Meccano set on his retirement.

Alan Partridge

Olney, Buckinghamshire

Answer: When compiling classification schemes, librarians use the principles
of faceted classification pioneered by Shiyali Ramamrita Ranganathan. In A
Descriptive Account of the Colon Classification, Ranganathan describes how
he saw a Meccano set for the first time in Selfridge鈥檚 store in London. His
鈥淢eccano idea鈥� of building classification numbers encouraged him to use faceted
classification.

Alan Cooper

London

Answer: An English plant virologist colleague of mine was attempting to
purify a virus and decided that it would benefit from protracted agitation. This
was more than 30 years ago and such things as orbital shakers were not exactly
commonplace. However, he remembered he had a Meccano set from his childhood.

He used it to build a system that he could connect to a motor and examine the
effect of agitation on the technique of purification. It worked, and he was the
first person to successfully purify cucumber mosaic cucumovirus, now regarded as
the most economically important virus occurring in plants.

Ray Pares

Rainbow Flat, New South Wales

This week鈥檚 questions

A heavy night: What is the origin of the unpleasant odour which emanates from
the mouth, especially after sleeping?

I. Likhtina

Yekaterinburg, Russia

Fatal attraction: A recent coroner鈥檚 report implicated underwired bras in the
tragic death by lightning of two women in Hyde Park, London, last summer.

Does the mere presence of metallic objects on the body, however well
concealed, really increase the chances of being struck?

William Hudson

Oxford

Knowing your dews: There have been many times that I have unzipped the flap
door on my tent while still in my sleeping bag to see that a heavy dew had
fallen during the night. Being so close to the dew-laden grass, I always notice
that the individual drops occupy an apparently precarious position at the very
tips of grass blades. How do they get there and, more importantly, how do they
stay there?

John Lamont-Black

Newcastle-upon-Tyne

Frazzled: Why do people get grumpy when they are tired? Does it require more
energy to be cheerful or something?

Jun Kino

Cambridge

Seeing double: My sister, who is quite short-sighted, pointed out that when
she looks in a mirror, the image of a distant object looks just as out of focus
as the actual object when viewed directly. Why is this?

Charlotte Webbon

Bristol