Τ (tau) equals Π times two. The circumference of a circle is 2Πr where r is radius of that circle, so it also equals Τr. Another way to express this is Πd where d is the diameter, or alternatively Τd/2 . These formulae are ratios.

Here’s what they’re arguing about. A circle is a real thing. The ratios mentioned above express, perhaps, something about the fundamental nature of reality. Putting the number ’2′ in any of them is a bodge to get the result right. It would be better to have a formula that didn’t have a number in it. Two versions of such a formula are available: Πd and Τr.

This raises the question, which is the more fundamental measurement of a circle, the radius or the diameter? If a circle is defined as the set of points a common distance from a given point, the centre, then the fundamental properties of a circle are the position of the centre and the radius. If you take an abstract circle with no set position but just its size, the only property is the radius.

That’s what the Taoists are arguing: the radius is the measurement that should be used and so children should be taught to multiply it by Τ, instead of using Π.

From Lt. Col. A.D. Wintle.
The Royal Dragoons
Cavalry Club
127 Piccadilly W.1.

To the Editor of The Times.

Sir,

I have just written you a long letter.

On reading it over, I have thrown it into the waste paper basket.

Hoping this will meet with your approval,

I am
Sir
Your obedient Servant

Via.

Dear Fellow Member of The Explorers Club:

Thank you for the opportunity to write to you about the admission of women to The Explorers Club. The human zest for exploration and discovery is the hallmark of our species and one of the secrets of our success. It is a tradition that goes back much further than the 76 proud years in which The Explorers Club has been in existence. When our organization was formed in 1905, men were preventing women from voting and from pursuing many occupations for which they are clearly suited. In the popular mind, exploration was not what women did. Even so, women had played a significant but unheralded role in the history of exploration — in Africa in the Nineteenth Century, for example. Similarly, Lewis and Clark were covered with glory, but Sacajewea, who guided them every inch of the way, was strangely forgotten. All institutions reflect the prejudices and conventions of their times, and when it was founded The Explorers Club necessarily reflected the attitudes of 1905.

Traditions are important. They provide continuity with our past. But it is up to us to decide which traditions are essential to The Explorers Club and which are accidents of the epoch in which it was institutionalized. Times have changed since 1905. It is very clear that a foolish rigidity can destroy otherwise worthwhile institutions; they are then replaced by other organizations more in tune with the times. IBM’s recent withdrawal of corporate support for The Explorers Club because of our “exclusionary policy toward women” should be pondered carefully by every member. Many other former supporters may follow suit.

Today women are making extraordinary contributions in areas of fundamental interest to our organization. There are several women astronauts. The earliest footprints — 3.6 million years old — made by a member of the human family have been found in a volcanic ash flow in Tanzania by Mary Leakey. Trailblazing studies of the behavior of primates in the wild have been performed by dozens of young women, each spending years with a different primate species. Jane Goodall’s studies of the chimpanzee are the best known of the investigations which illuminate human origins. The undersea depth record is held by Sylvia Earle. The solar wind was first measured in situ by Marcia Neugebauer, using the Mariner 2 spacecraft. The first active volcanos beyond the Earth were discovered on the Jovian moon Io by Linda Morabito, using the Voyager 1 spacecraft. These examples of modern exploration and discovery could be multiplied a hundredfold. They are of true historical significance. If membership in The Explorers Club is restricted to men, the loss will be ours; we will only be depriving ourselves.

The supposed parallelism between our situation and those of other organizations seems to me strained. The Bohemian Club is a resort; The Explorers Club is not. The Boy Scouts and Girl Scouts are for children. Their membership derives almost exclusively from adolescent and pre-adolescent youngsters, who have not yet fully accomodated to the opposite sex. But we presumably are adults, with a special responsibility for interacting with all humans on this planet.

I do not believe that the primary function of our organization is to promote male bonding or to serve as a social club — although there is certain room for both. I believe that the fundamental dedication of the club is that stated on the masthead of every issue of The Explorers Club Newsletter: “To the conquest of the unknown and the advancement of knowledge.” If this is our purpose, then admission should be open to all qualified members of the human species.

Cordially,

(Signed)

Carl Sagan

And here’s one from Franklin to a younger man – in praise of older mistresses.

My recent allowance is 40¢. This I used for areoplanes and other playthings of childhood but now I am a scout and I put away my childish things.

Via.

Simon Heffer enjoys writing in the manner he imagines was current around 1900.  Heaven forfend that I should deny a man his private pleasures. But setting out a cavalcade of rules that standard English does not comply with and never did, and representing them as instruction in how to write today, is dishonest.  Some linguistic masochists may delight in letting Heffer bully them into compliance with his whims and peeves; but I see this obtusely atavistic book as a perversion of grammatical education.

It gets better.
Via

Via Astropixie.

The find – which has become known as the Faddan More Psalter – was a fragmented illuminated vellum manuscript encased in an unusual leather binding, a book of psalms dating back to the late Eighth century. This unprecedented find, the first manuscript to be found in a water-logged state in a bog, posed unique and profound difficulties for the Conservation Department at the National Museum.

[...]

As the process reached its conclusion, fragments of papyrus were dramatically discovered in the lining of the Egyptian-style leather binding. This potentially represents the first tangible connection between early Irish Christianity and the Middle Eastern Coptic Church. It is a finding that asks many questions and has confounded some of the accepted theories about the history of early Christianity in Ireland.