I ❤ London

T-shirts on sale at Piccadilly Circus.

In case you’re wondering, I don’t own one of these. I look for exactitude in my T-shirt messages, and no one sells T-shirts saying I kind of like London.

The Breakfast Club

In keeping with the format of a previous restaurant review:

I like breakfast, and I like yellow. No reason, then, not to like The Breakfast Club – this cafe in Islington.

They have quirky interior decor, and a chalkboard where they scrawl thoughts for the day. Such as:

Look at this cafe / Look how it shines for you / And everything you do / And it’s all yellow

or the more succinct:

Sex, drugs and bacon rolls.

Colour Pencils

London, 7:46 am

Our house is on the north bank of the Thames; Greenwich is just across the river.

The twin domes are of the Old Royal Naval College. Behind the college (though you can’t see it from the photo) is the Royal Observatory, designed – as architect Christopher Wren said with engaging honesty – “for the observator’s habitation and a little for pompe.”

The Royal Observatory is of course most famous for being the ‘home’ of the prime meridian. Our house is very close to the meridian – at 0°0'47"W, to be precise. I would have liked to say: I cross the prime meridian when I step out to buy milk, but that is not exactly true. The nearest convenience store is also in the Western Hemisphere. But only just.

Minimalism

I have finally fixed the dice. (This is a random post generator link on the sidebar; it had vanished after I switched to the new template.) My achievement of the weekend.

It is one month since v3.0 was unveiled. I am happy with the new look, though I can’t say the initial goal of minimalism has been realised. But for lovers of minimalism, here are three of my favourite anecdotes on the subject.

1. Spartans

The Spartans were renowned for being men of few words. Indeed, Spartan is almost a synonym for minimalist, and the word laconic derives from Laconia, the principal region of the Spartan state.

Herodotus (The Histories, Book 3.46) tells us that when the banished Samians reached Sparta, they came before the magistrates and, as was customary, made a long speech to show the greatness of their need. But the Spartans answered that they had forgotten the beginning of the speech and could make nothing of the remainder. After this the Samians came a second time with a sack, and said nothing but this: “The sack wants flour.” The Spartans replied that they need not have said “the sack”; however, they resolved to give them aid.

2. Physicists

Wikipedia informs us that British physicist Paul Dirac was notoriously taciturn. After a lecture he gave at the University of Toronto, a member of the audience remarked that he hadn’t understood part of a derivation. There followed a long and increasingly awkward silence. When the host finally prodded him to respond, Dirac said, “That was a statement, not a question.”

3. Mathematicians

My high-school book on number theory had the story of how Mersenne’s conjecture was demonstrated to be false. In 1644 the French monk Marin Mersenne stated that the numbers 2ⁿ – 1 were prime for n = 2, 3, 5, 7, 13, 17, 19, 31, 67, 127 and 257, and were composite for all other positive integers n < 257. Mersenne admitted that he had not tested all the numbers, but owing to the notorious difficulty of integer factorisation, his conjecture went unverified for two and a half centuries.

In 1903 F. N. Cole made a presentation to the American Mathematical Society with the rather bland title, On the Factorisation of Large Numbers. Cole’s ‘lecture’ went thus. He approached the chalkboard and in complete silence proceeded to raise 2 to the power of 67. He then carefully subtracted 1, arriving at 147,573,952,589,676,412,927. Cole then moved to the other side of the board, wrote 193,707,721 × 761,838,257,287, and worked through the multiplication in longhand. The two results were equal. Cole returned to his seat, not having uttered a word during his hour-long presentation.

It is said that this is the only lecture in the history of the AMS where the audience applauded.

If I were Cole, I would have arranged for T-shirts to be sold outside the lecture venue:
M₆₇ is composite.