**Edible art by M&Ms**

What can I say .... it's Friday.

A U-turn on the road that is my life.

Just in from the Institute of Physics:

Scientists calculate how high heels can go

Sex and the City stars stay upright because h = Q.(12+3s/8) say scientists.

As Sex and the City's Carrie finally wanders off the UK's television screens, physicists at the Institute of Physics (London, UK) have devised a formula that high-heel fans can use to work out just how high they can go. Based on your shoe size, the formula tells you the maximum height of heel you can wear without toppling over or suffering agonies.

h = Q•(12+3s /8)

h is the maximum height of the heel (in cm)

Q is a sociological factor and has a value between 0 and 1 (see below to work this out)

S is the shoe size (UK ladies sizes). This factor makes sure that the base of support is just good enough for an experienced and sober, high-heel wearer not to fall over.

"Although at first glance our formula looks scary" said Dr Paul Stevenson of the University of Surrey who carried out the research for the Institute, "It's actually pretty simple as it's based on the science you learnt at school and which you never thought you would use in real life, in this case Pythagoras' theorem 1 Applying this to shoes can tell us just how high the heel of the foot can be lifted above the ground."

Dr Stevenson went on to describe how 'Q' – the essential sociological factor had been worked out.

"Essentially this part of the formula explains what women have always known – that you don't buy shoes just because they are comfortable, you can afford them and they look good – many other variables come into play"

'Q' is defined as follows:

p•(y+9)•L

Q = ----------------------------------

(t+1)•(A+1)•(y+10)•(L+£20)

The variables are:

p – the probability that wearing the shoes will help you 'pull' (in a range from 0 to 1, where 1 is pwhooar and 0 is stick to carpet slippers). If the shoes are a turn-off, there's no point wearing them.

y – the number of years experience you have in wearing high heels. As you become more adept, you can wear a higher heel. Beginners should take it easy.

L – the cost of the shoes, in pounds. Clearly, if the shoe is particularly expensive, you can put up with a higher heel.

t – the time since the shoe was the height of fashion, in months (0 = it's the 'in thing' right now!). One has to suffer for one's art, and if the shoes are terribly fashionable, you should be prepared to put up with a little pain.

A – units of alcohol consumed. If you're planning on drinking, be careful to give yourself a little leeway for reduced coordination.

So using this formula, if Carrie Bradshaw, who is an experienced high-heel wearer (let's guess at 5 years experience) wears her latest drop-dead gorgeous designer originals when sober, she can cope with a heel height of a staggering 12.5 centimetres (just over 5 inches) [See footnote 2]. However, if she over-indulges in cocktails, the 'safe' heel height (and perhaps also Carrie) plummets. Using the same example as above, if she consumes 6 units of alcohol she would be better advised to stick to shoes with only 2cm heels. [See footnote 3].

Laura Grant, a physicist from Liverpool University welcomes the Institute's new formula commenting, "many of my physicist colleagues have no trouble understanding quantum mechanics but can't figure out how women can wear high heels. Now I can explain to them how I minimise the probability of tripping up".

The Institute of Physics has more fascinating facts on the physics of shoes, including high heels. Just type 'high heeled shoes' into the enquiry box.

Footnotes:

1 Pythagoras' theorem: In a right-angled triangle the square of the hypotenuse (longest side) is equal to the sum of the squares of the other two sides.

2 In this example, shoe size (s) is 6

p = 1, y = 5, L = £300, t = 0, A = 0 giving a Q factor of 0.88

so heel height is 12.54 cm

3 As above but with A (alcohol) = 6, Q factor falls to 0.15, giving a heel height of 2.01cm

People have taken to the streets of DC. Every cab is packed with two or more passengers. Figures on the one day I'm running late for work, there's a fire on the red line. So I walked.

I used to walk to work all the time, but this last year I've taken the metro. I'm turning into a wuss.

How do you get to work?

Isaura writes me monthly. I immediately recognize her familiar scrawl on envelopes crushed between issues of the New Yorker and Vanity Fair. Sometimes a card flits out and a sober saint will stare up at me off the hardwood floor. Other times I'll find a $10 bill carefully folded in the note. Always her correspondence conveys news of my parents or brothers or distant cousins.

When we speak, the conversation never alters. She asks me how I'm doing. We quickly move on to work. Then she provides an update about her day and news of our relatives. She worries about how much my long distance charges cost. I inform her that the call is free, but she doesn't understand calling plans that provide unlimited minutes after 8:00 p.m. As we say goodnight, her voice thickens with emotion.

I don't phone her enough, although I think of her often. I'm Isaura's only granddaughter.

Today is her 80th birthday. My last surving grandparent is a fount of valuable information - stories of growing up in the Azores, recipes to exotic Portuguese meals, the answer to the confusing maze of our family tree.

When I call later today, I'll dig through the treasure of her memory and encourage a story about a place long gone and its people long past.