Friday, March 13, 2009

Pi(e) Day ?

From www.timesonline.co.uk

From
March 13, 2009

Try a slice of the irrational on Pi Day

It's time to get irrational. Tomorrow is Pi Day, when mathematicians will gather to celebrate the mystery of science's most famous strange number — Pi.

Pi, or the Greek letter π, starts with 3.1415926535 . . . ad infinitum without repeating. It is the figure obtained when the circumference of a circle is divided by its diameter, and it cannot be expressed as a fraction, making it an irrational number. Computers have calculated it to more than one trillion digits past the decimal point.

March 14 has been celebrated as Pi Day for more than 20 years after Larry Shaw, a physicist at the San Francisco Exploratorium science exhibition, decided to start it as a "geek holiday". The event has snowballed into an international phenomenon, with Pi parties and educational events in many different countries.

The symbol for Pi was first used in 1706 by William Jones, but became popular after it was adopted by the Swiss mathematician Leonhard Euler in 1737. Pi has intrigued and exasperated mathematicians and scientists for milleniums — how can such a simple concept as the circle be so difficult to pin down? Pi goes beyond geometry, it is a basic tool in architecture and is used to calculate economic statistics and a wide range of other complex computations.

At the Exploratorium tomorrow at 1.59pm a parade of people will process approximately 3.14 times around a shrine to Pi — and then eat pie. The day is also celebrated in schools and the US Congress has recognised it officially as a way to encourage maths and science education.

For devotees, there are Pi plates for your piece of pie, Pi T-shirts and even a limerick competition at www.piday.org .

At Pi parties, people will compete to recite as many decimal places for Pi as possible. They will need to show some endurance if they are to beat the world record held by Lu Chao, a 24-year-old graduate student from China, who took 24 hours and 4 minutes to recite to the 67,890th decimal place of Pi without an error.

Members of the World Federation of Pi will be logging on to the website mathematicianspictures.com to watch a giant Pi symbol drop down like the crystal ball in Times Square on New Year's Eve.

Visitors to www.piday.org bear witness to the fervour Pi can engender in those who like numbers Summer commented: "It makes me so happy, the possiblitly of an infinite number inspires me. It makes me feel like my dreams are infinite. I love math, and Pi is a real inspiration."

Erin wrote: "Pi is a magical loophole in our assumed and intuitive structures."

Joe said: "It's yum."

Sunday, March 8, 2009

Jam Today

From www.timesonline.co.uk.

http://www.timesonline.co.uk/tol/life_and_style/food_and_drink/real_food/article5810163.ece

From
February 27, 2009

How to beat the M&S 75p jam sandwich

Marks & Spencer's jam sandwich went on sale yesterday. But surely it's possible to make a better one yourself at home?

A jam sandwich

At 6.32pm last Thursday I held in my hand the finest jam sandwich ever made. A few people witnessed this event, and photographs were taken, but by 6.40pm the sandwich had disappeared. Sandwich aficionados may wonder why such an important sandwich was not preserved for posterity, or at least for long enough to verify its greatness. All I can say is that it was truly a sandwich of unsurpassed quality, and that nearly six hours had passed since lunch.

The quest to construct the perfect jam sandwich began when Marks & Spencer announced the introduction of 75p jam sandwiches, in a ploy to harness the common recession-induced nostalgia for cheaper pleasures. After years of profligate prawn sandwich eating, the nation would turn to a more innocent sandwich from a bygone age. As promised, these arrived on shop shelves yesterday, prompting questions such as: “Do you think we were born yesterday?”' and “Don't you think we can jolly well make our own jam sandwiches for that kind of money?”

Larger questions were emerging, too. What is a jam sandwich? Is it perfectible? Is there an ideal, a Platonic form, a jam sandwich in comparison to which all those triangles in M&S branded cardboard are but flickering shadows on the cave wall?

“This isn't entirely clear,” says Roger Crisp, a professor of philosophy at St Anne's College, Oxford. “At Parmenides 130, Socrates says that things such as hair, mud, and dirt ‘are as we see them to be' - so no need to postulate a form. I doubt there'd be such a specific form as the form of ‘jam sandwich', anyway. Surely we could make do with one for jam, and one for sandwich, since a jam sandwich isn't like an omelette; its ingredients are mixed, not compounded. But the person who is good at making jam sandwiches must have his or her eye on some forms or other.”

Could the perfect jam sandwich ever be achieved? Professor Crisp is blunt. “You'd never create the ‘perfect' jam sandwich,” he writes, “as physical objects always fall short of the form in various ways.”

Perhaps it was impossible, perhaps I was tilting at bread-and-jam windmills. Still, there are two types of people in this world: the people who think about making jam sandwiches, and the people who make jam sandwiches. I think; therefore I would jam.

I board a train to Axminster, on the eastern border of Devon. A taxi driver drops me off in a lay-by on top of a ridge 20 minutes out of town. Walking down the rutted lane you can just make out the sweep of the valley, the far ridge covered with bare trees that stick up into the sky like whisks, a white farmhouse far below.

River Cottage Farm belongs to Hugh Fearnley-Whittingstall: foodies from across the land make pilgrimages there to gut rabbits and forage three-course meals. The great man himself is out - perhaps roaming the countryside drinking birch sap and flambéing water voles.

Instead, Project Jam Sandwich brought together Pam “The Jam” Corbin, a giant of modern fruit preserving, and Daniel Stevens, a rising star of British baking. Stevens, 34, works as a chef at River Cottage Farm; Pam runs ‘Preserving Days' at the farm, works as a jam consultant and judges at competitions across the country.

We begin with an ideas meeting in the farm's converted barn house. “I definitely consider my bread to be a carrier for Pam's jam,” says Stevens.

Corbin had been up all night, her mind like a maslin pan on a stove top, boiling with ideas. M&S is using strawberry jam, a populist but limited strategy in her opinion, as she finds strawberry jam rather insipid. There were more possibilities with raspberries. She had a tub of them in her freezer, picked in a field outside Lyme Regis last summer.

“The jam can't be too soft,” she says. “Otherwise it's going to stain the bread.”

“I think maybe brown flour,” says Stevens. There is silence. “I think white,” says Corbin. “Soft white.”

I fear it could turn nasty: a clash of creative temperaments, baker on jam-maker, to match those fabled confrontations between Gordon Ramsay and Marco Pierre White. But Stevens simply says: “OK, white. I will do it with milk as well to make it extra soft and extra light.” Later he tells me that it is a mistake to cross a woman who works with boiling syrup.

He goes straight to work, making “sort of a safety loaf, in case we run out of time on the main one”. Then we repair to the cottage kitchen to make a more considered dough on Fearnley-Whittingstall's knife-scarred wooden table. Stevens's feeling for dough came to him in his early 20s. “I was a bit of a dropout, living at my mum's house, delivering pizzas,” he says. To make himself more employable, he taught himself to cook. After some catastrophic yeast-based experiments, he found his vocation.

We stretch our dough on the table, pushing it apart, sinuous cords emerging like guitar strings. “See the strings of gluten?” says Stevens. He pulls it back together again. Hands flat on the table, palms up, he scissors his hands together beneath it, setting it spinning. The top of the dough swells upwards, growing smooth and round like a balloon filling with breath.

Stevens is in a good mood. “I'm pleased with this,” he says, putting the dough in a proving basket and wrapping it with a ripped binbag to keep it airtight.

Then he stands aside for Corbin. Covered in jam sugar, her raspberries are left to stand for a few minutes. Their juice draws into the sugar, forming translucent red sugar crystals, a mountain of rubies that she pounds into a sludge and places in a maslin pan on the stove.

“In commercial jam you need a minimum of 60 per cent sugar, that's what preserves it,” she says. “I'm using 55 per cent, for more taste.”

Corbin, now 54, and needless to say, extremely well preserved, has always made jam, but 20 years ago she turned professional. She bought a redundant farm building, turned it into a jam factory and began producing three thousand jars a day. After winning almost every award in the business she sold up to work as an adviser.

As “The Jam” lines up six oven-warmed glass jars on the table like shot glasses and fills them to the brim, Stevens races back into the kitchen, pulls his dough out of the proving basket, pays it various compliments, scores the top with a razor blade and slides it into the oven. He grabs a spray bottle, the sort gardeners use, yanks open the oven door and begins squirting the loaf as it bakes. Clouds of steam hiss out from the base of the rising loaf; it looks like a spaceship trying to take off. “Keeps the outside soft, but crispy like a baguette,” he says.

Time is running out. It is nearly tea. When can we create the jam sandwich? “This jam won't be ready till tomorrow,” says Corbin. “It needs to set.”

This is unacceptable. I can't wait till then. I am one of a generation that wants jam today. Corbin had anticipated this problem. The night before, she had crept out of bed and made a jarful. Now she pulls it from her bag and places it on the table very carefully, as if it is the Holy Grail itself.

As for the bread, the loaf has risen beautifully, but it needs to cool. “Otherwise when we cut it, the slices will be doughy,” says Stevens. We have to use his safety loaf. I cannot help but look at the fat loaf cooling on the windowsill and think of what might have been. What was it that Professor Crisp said? Physical objects always fall short of the form in various ways.

Then I consider the example of a certain 18th-century earl. If John Montagu had been stopped by every setback, surely he would never have invented the sandwich.

Stevens's safety loaf is still a magnificent piece of baking. He saws it into neat slices, we spread the best two with butter. Corbin applies jam. “It needs to be within the border of the crust,” she says.

Nerves jangling, we lift the second slice and lower it on to the jammed bread. It must have felt like this when they positioned the primary mirror inside the Hubble Space Telescope. It sinks into place. Houston - we have a sandwich! We stare in wonder at our creation. Then I eat it.

The bread is fluffy, with a hint of fermentation, rich and soft like the smell of sherry. Then jam explodes, as if one is eating raspberries loosened from their tiny white cones in a field in July.

It was the perfect jam sandwich. But am I really any closer to understanding what that is? I consult Professor Crisp once more. What is a jam sandwich? I ask him.

“Two pieces of bread with jam in the middle,” he replies. “I don't think ‘open sandwiches' are really sandwiches.”