h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Entry: Maria Gaetana Agnesi - Mathematician - A87936123
Author: SashaQ - happysad - U9936370

This Entry is dedicated to Elektra, who gave me the first link in a chain that led me to learning about this notable female mathematician.

Ms Agnesi sounds like a very lovely person.

Here's what I mean by insider knowledge being off-putting, though. You wrote:

'The book includes mention of a curve that now bears her name. The Agnesi Curve is described by the equation y = c3/(x2 + c2), where x is a variable and c is a constant. Its shape is reminiscent of a rope being used to hoist a sail, called la versiera in Italian.' Now, I'm the dummy who gets the pun, but is flummoxed by the mathematics.

What you wrote is really clear to someone with mathematical knowledge. They understand how a 'curve is described by the equation.' Could you imagine not knowing that? Then you'd be faced, as I was until I dredged my memory of algebra-induced migraines, with trying to figure out how a string of letters and numbers describes a curve.

This is why people make up thrillers about spies running around with 'the secret formula'. If you don't know how these things work, you're stuck with accepting that it's magic. Readers are okay with that, most of the time. They just need somewhere to put the information.

That's easy to fix: just put a small illustration in there. Comme ca:

http://commons.wikimedia.org/wiki/File:Witch_of_Agnesi,_a_1,_2,_4,_8.svg

We dummies still won't have a clue how Maria found that curve, or why it exists, or what it's good for, but we'll feel clever because we can see it looks just like a sail going up! And not a witch at all.

Wow, she was amazing ----a polyglot and a head for higher maths! And at the end of her life dedicating herself to help people. She really was unique. Thanks for letting us know about her.

Thanks Elektra

Thanks DG

And this is why I love Peer Review - I could see the equation, but not the sail! I see it now, and another diagram link has been added I moved the equation into a footnote, too, so it doesn't disrupt the narrative as much

Hi Sasha.

A good entry as always.

18th Century Italy --> 18th-Century Italy

Propositions philosophicae --> Propositiones philosophicae
(an 'e' before the final 's')

Your link on "Instituzioni" - I think it would be better on the whole of the book title.

Is it normal practice to refer to people by their first name? I thought we normally used their surnames in entries.

The rest of the entry is good, but I think Dmitri may have a point. The connection between something you are studying, a mathematical formula describing it and a curve in a coordinate geometry plane is not immediately obvious to the average reader. You might need to put an entire paragraph to explain that. I'll think about and may make more suggestions later.

Thanks Gnomon - I made those tweaks

I shall ponder the name situation - I don't like to use just surnames in this series, because of the risk of 'masculine by default' assumptions when it comes to surnames on their own, but Maria is not her first name, because her sister was also Maria...

I've made a tweak to the footnote, but I will also think about it some more.

More changes have been made

I think it might be worth putting the equation of the curve in the footnote. It won't interrupt the flow of the entry, and people who don't understand it can just skip the footnote.

I thought it was worth one more stab to make it comprehensible. If this doesn't work, or if you can't fix it to your standards of precision, just say so and I'll go away.

Suggestion:

The book includes mention of a curve that now bears her name. The Agnesi Curve is a way of deriving the function of a circle called an arctangent. As the numerical values in the equation change, the curve described by the equation [place equation here] changes when plotted on a graph:

[Place image here, or .gif, or Youtube.]

The process reminded the mathematician of a rope being used to hoist a sail. The rope is called la versiera in Italian.

[Continue as normal.]

[At end of paragraph, add:] Mathematicians, physicists and statisticians still use this equation as a modelling tool today.

"Pietro, with three wives" – not at the same time I take it? Was Anna Wife 1 or Wife 2? Was Maria the oldest surviving child?

I was left unsure whether Maria's achievement in her book 'Instituzioni' was that it combined the works of Newton, Leibniz and Leonhard Euler in a handy, user-friendly guide with room for annotations and diagrams, or whether it included her own, unique work too? It 'mention of a curve that now bears her name' but says it had been already studied by Pierre de Fermat. Why is it named after her, then? Was she the first person to derive an equation for this curve?

To avoid confusion you may wish to rephrase 'the Habsburg Empire' as it implies that there was only one Habsburg Empire (a different branch of the Habsburgs had ruled Spain and Spanish possessions including the Low Countries, Portugal, parts of the Americas, bits of Africa, various islands etc for almost two centuries until shortly before her birth).

When was she offered the various posts at Bologna? Just trying to work it out into the stage of her life if she published Volume I in 1748, Volume II: Return of the Revenge of Instituzioni analitiche ad uso della gioventù italiana in 1749 and her father snuffed it in 1752 – but Maria was (still) looking after 20+ siblings of various ages and states of life and/or death at the time? No wonder she longed to live the life of a nun! Peace and quiet enough at last to enjoy concentrating on corresponding with mathematical monks.

<BB<

Bluebottle, I think you've just stumbled across the main reason convents were invented.

Thanks for reading everyone

I took the equation out, because Instituzioni derived an equation that looks quite different, and as Dmitri found, there are special cases of the equation that are also of interest... (I see the *derivative* of the arctangent is an equation which has the shape of the Agnesi Curve when plotted on a graph ). I'll try to avoid confusion here, but have included links to more detail

Thanks <BB< - excellent points. I have made tweaks that hopefully clarify, and I appreciate your expertise in relation to history/geography.

"Peace and quiet enough at last to enjoy concentrating on corresponding with mathematical monks."

It seems it was peace and quiet to enjoy *not* having to correspond with mathematical monks...

I liked this, it was quite short and to the point, and it was something I knew nothing about before.

The thing with using her first name. I like it because of the reasons you stated before. On the other hand, it treats her differently to how men are treated. But she is different so … arghh. You decide. I like it either way.

Hi Sho!

Thanks for reading - glad you enjoyed it

I do favour making my Entries about people's lives more informal than an academic paper - I see I used first names here, too A87928807

Hmmm – that's made me wonder when writing about people, do I use surnames or first names more? My entry on 'Robin Hood films' contains 'Robin' almost twice as much as 'Hood' while my current entry on Moses uses name 'Moses' 80 times, but I'm not sure whether that counts as a surname or first name…? On my entry reviewing films about Winston Churchill I've called him 'Winston' when reviewing 'Young Winston' and 'Churchill' when reviewing film 'Churchill'.

The moral of the story is to always wash your hands.

<BB<

About the first names business - you do realise there's going to be a difference in the way one of these entries is read depending on where the reader comes from, right?

As an old ESL teacher, I'd expect non-native English speakers to read whatever significance into the use of first names that they apply in their own languages. You can't help that, but more formal options would be a safe bet.

US readers will definitely assume you are trying to insinuate a possibly unwarranted intimacy with your subject by using their first name, unless the subject is a minor child at the time you're describing, or there's more than one person in your account with the same last name. So I'd use those first names very sparingly.

Especially if you're talking about a modern 'celebrity', it's best to try to avoid sounding like you know them personally. There's a kind of public speaker in the US who's always talking about famous people in an overfamiliar way, and it makes listeners laugh. Not in a good way, though.

Interesting thoughts to ponder - thanks DG

I checked my US-based source materials for this series and found several that used first names, so my Entries are not totally incongruous in this field

Sounds all right to me in this case, especially since you're distinguishing between more than one person.