Ada Lovelace day

Kind of sad that I didn't see Ada Lovelace day coming.   I don't know if it needs better publicity, but I hope it's no reflection on a perceived lack of importance of women in computing.  For sure we're not at a point where there's no need to enhance women's position in the discipline.

So a woman who influenced me in computing?

The more I thought about it the more obvious it became.

Margaret Gent, of course.  My mother.   So apart from obvious motherly things, then here are some things about her which influenced me in computing.

Curta Calculator, from Wikipedia

She gave my dad his Curta calculator, roughly 1950 or so.    He later gave it to me, and I still think it is the most beautiful object I own.  Bearing in mind of course I don't own my wife or children.


A long time ago, she made a 4 bit adder out of components, a large piece of board, switches and solder.    To illustrate how computers work for her students - she was a maths teacher.   I don't know when it was done but the 1960s is a safe bet - I remember it when I was very young.   It seemed almost magical to me.  Brilliant.

TI-57 Calculator, from Wikipedia

She bought me - to be honest I don't know how much the split of decision making was with my father - my first programmable calculator, the wondrous TI-57.    Not quite my first programming as that had been done on an HP 25 borrowed by my dad from work - or lent by Spencer Noble.

She got my name into print for computing for the first time by commissioning me to calculate a table for her book "Maths for Scientists".    So yes, my first ever computing publication in any form was published by Mills & Boon!

Fairey Swordfish, image from Wikipedia

Nothing to do with computing.    But during World War II, as a radar technician at TRE Malvern, she once swapped cockpits in a Swordfish in mid air.   A good idea to look at the picture, as you'll see this is not swapping seats in a jumbo, it's a lot more fun than that.   More notably perhaps, to this day she denies it as being anything of note to have done it.


Maybe not so surprising that the first thing I did when I was promoted to Professor was to make sure my mother could come to the ceremony.

How to steal a laptop

Years ago my colleague (who we'll call Woolf T Flywheel) had his laptop stolen.  How did it happen?

His laptop developed a fault, so he called up Compaq to get it repaired under warranty.  (I told you it was years ago, they were later bought by HP.)   They sent out DHL to take it back to their service centre. 

A day or two later a nice chap from Compaq rang up to ask what the problem was with the laptop.   Woolf told him, of course.

A few days later Woolf rang up Compaq to ask what had happened to his laptop.   The reply was "What laptop?  We never got it."  

It had been stolen, the police came to the office.  It more or less must have been an inside job at DHL. Somebody's insurers (probably DHL's) paid Woolf back, and laptop prices had fallen so much that the difference was enough for Woolf to buy a £600 fat boy lazy chair (or was it two?)   

But what has always stuck in my mind was the brilliance of ringing up to ask what was wrong with the laptop.    It did two things at once.  First, it delayed for a few days Woolf ringing up to ask what had happened.  And second, they could find out what was wrong with it so they could fix it  before selling it!  

Future Theatre Director

Just came back from the Shakespeare School's Festival. 4x 30 minute productions by various high schools. Outstanding production of The Tempest directed by one Alex Horan of Balwearie High School. Turns out she's 16! Director of the charity (who also commisioned the animated Shakespeare for S4C) says she wants to work as a director - she could make it.

55% doesn't seem right.

In the general hoopla about the LibDem-Con coalition, one thing has received little attention, though it has been picked up by a couple of people like Peter Hennessey.

This is that to make fixed term parliaments stickable, they want to change the law so that a government can't be brought down without a 55% majority against them.   But this is to confuse two things.   One is whether a government survives or not, and the other is whether to have a general election.   In principle they are separate.   The fact that David Cameron is PM now should not give him a lease until 2015, even if all the individual MPs do have that lease.    He needs to be able to be brought down in a confidence vote, possibly leading to another prime minister, either Tory or from another party.

For a confidence vote in the government, which means in practice in the Prime Minister, it should be 50% + 1 against to win.   Otherwise there is the ridiculous idea of a government which can't put any of its business through, but which can't be kicked out.

On the other hand, to stop the PM calling an election when he wants, you need a larger number than 55%.    Many PMs with a large majority could have got 55% of their MPs on their own.   Both of Tony Blair's first parliaments for example, and the second of Maggie's three victories.    So it doesn't really stop a dominant PM calling an election.   Even in this parliament, Tories plus Lib Dems have more than 55%, so could if they agreed force an election.

And this seems a nicely tuned number ... Con + LD is > 55% so can call an election anytime.  But Con >  45% so can't be defeated on a vote of confidence anytime.  So, theoretically, Cons could discard the coalition and form an invincible minority government.    Have the Lib Dems been sold a pup on this one?

In practice confidence votes to bring down a government are very rare - the last one in 1979 only months before the end of the parliament.    So it's unlikely this matters very much.  But my main point remains.  There needs to be the standard threshold for bringing down a government, but a much higher threshold than 55% to call an election.

Deborah Underwood sales widgets

A business model to die for?

Here's a business model to die for.   A newish mail client for macs that you have to pay money for, called Postbox.

It's based on Thunderbird, which is free.   It competes with Apple Mail, which is free and built in to the OS.  And it doesn't have support for Exchange servers, which is what I need to read my email.

And it costs $39.95.

I'm not buying shares.

Get 55, or any other number, with three 4s.

SPOILER ALERT.   This post contains the solution to this week's  Car Talk puzzler.

The puzzle is construct the number 55 using three 4s and any mathematical symbols you like.  I remembered that somewhere I had come across a general solution to this, maybe from Halmos's book "Problems for Mathematicians Young and Old".

I half remembered it involved logs and square roots, and I managed to reconstruct it.    First of all I did it with 2's.   The first image shows you how to do it (constructed using a lovely tool called LaTeXiT.)   The number of square root symbols in a row is n, if you want to get the number n.   So for car talk it would be 55 square roots.

I was puzzling over how to do it with 4's, and my wife couldn't understand my problem.    Because she didn't realise I didn't realise that every 2 could be replaced with the square root of 4.   So the second image shows that, and so this time there are n+1 square roots, in the car talk puzzle there would be 56.

So my wife is just slightly more intelligent than me, which as we all know is the best kind of wife.     I love her.