# Peter Lynch's That's Maths

**Oct 2016:**

That's Maths book was just published, based on his long-running blog and Irish Times column |

Peter Lynch hails from Glenageary, near Dun Laoghaire, in south County Dublin. He earned his BSc and MSc in mathematical science from UCD in 1968 and 1969 respectively. He has fond memories of Prof. David Judge ("He taught us the great beauty of classical mechanics") and Prof J.R. Timoney ("At the time I thought the material in his lectures old-fashioned--I was so smart then--only later did I come to realise that it was timeless").

Peter spent the Summer of ’69 in New York, and recalls, “I may have been at Woodstock although I have no memory of that (they say if you can remember, you weren’t there).” Three of his Belfield classmates headed to the USA that year for doctoral studies: Steve Comerford (who tragically died soon thereafter), Joe McKenna (who has had a long career at the University of Connecticut) and Liam O'Callaghan (who ended up in the US aerospace software industry).

After a little teaching and work for an industrial chemical wholesalers, Peter joined the Irish meteorological service in 1971, starting his training in Rosslare. By the time he resigned from Met Éireann, in 2004, he was Deputy Director, and had also served as Head of the Research and Training Division. Along the way, he earned a PhD in dynamic meteorology under Ray Bates at TCD in 1982, and was an active researcher.

Peter’s second career has been as Met Éireann Professor of Meteorology at the School of Mathematical Sciences at University College Dublin, as well as Director of the Meteorology & Climate Centre. His first book The Emergence of Numerical Weather Prediction: Richardson's Dream (Cambridge University Press) appeared in 2006. He has had numerous postgraduate students, and among the doctoral students he's supervised are Michael Clarke, Paul Nolan, Colm Clancy and Jennifer Courtney. A book of a totally different nature appeared in 2010, Rambling Round Ireland: A Commodius Vicus of Recirculation (The Liffey Press). It tells the story of Peter’s (intermittent) walk around the island of Ireland over a 13-year period.

In 2011, he formally retired from UCD, though he remains active in research, writing, and research supervision. In 2014, he was the recipient of the European Meteorological Society’s (EMS) Silver Medal, which led to his giving a special lecture at UCD on “Balanced Flow on the Spinning Globe.”

In 2012, Peter inaugurated ** That’s Maths**, a blog of expository and far-ranging articles on pure and applied mathematics. While some of these are a little technical, many are not, being aimed at the general public. Almost half of the 225 articles on his blog have appeared in print (as well as online) in the

**as a column using the same moniker. Peter has just published**

*Irish Times***(subtitled**

*That’s Maths*

*“*

*The Mathematical Magic in Everyday**(Gill), a compendium to celebrate his 100*

**Life**”)^{th}

**piece. It was launched at Hodges Figgis in Dublin on Tuesday, 25 Oct 2016, by UCD maths colleague and broadcaster Aoibhinn Ní Shúilleabháin.**

*Irish Times*

(Photo credit: Brian McEvoy)

We took the occasion to pose some questions to him. Unlike in another online interview, in which he had two contrasting answers to every question, his responses here are direct and unambiguous.

1. When was the first column? Has it been regular every fortnight?

The first article was on 19 July 2012, so they are going over four years. With a few gaps (editorial reasons at IT) they have appeared regularly on the first and third Thursday of each month. About 102 have appeared as of October 2016.

2. How far ahead do you plan/write them?I have a big block of ideas, but very little developed to a final stage. Normally, I am up against a deadline. I have to file articles ten days ahead of publication date and usually do not know what I will write about until a few days before that. Of course, some articles are done farther in advance, e.g. the one for Bloomsday this year (Leopold tried to square the circle), and the poem for the 100th article. They were written weeks or months ahead. There is a full list of blog posts under “Contents” on the blog, giving the date of posting.

3. Do you have to pitch ideas to get approval or do you just write them and submit and see if they want to run them?No prior approval required. I am completely free to write about whatever I like. The Science Editor Dick Ahlstrom is happy. I just jump from one fascinating topic to another, over pure and applied areas, as the Spirit moves me. TheIrish Timeshas never rejected a piece.

4. What is the relationship between the ones that appear in IT and the ones that appear on your own blog?Irish Timeson first and third Thursdays each month. I also post these more or less verbatim on the blog. Additional posts on all the other Thursdays, about 225 in total.

Articles for theIrish Timesnever contain equations or symbols. Even getting them to print pi can be problematical, so I avoid the problem. Articles on the blog may be, and frequently are, more advanced and more detailed.

5. What percentage of yourblog posts also appeared in theThat’s MathsIrish Times?(24 / 52 ) * 100 = 45% inIrish Times(to a Babylonian level of approximation). There are precisely 100 articles in the book, split about evenly between Irish Times columns and blog posts, along with numerous new articles.6. The topics you write about are broad in scope. Have your interests always been that wide, or have you expanded your horizons since you started writing these?

I see mathematics as one great glorious universe. It is all amazing and all fascinating. I always had broad interests but more on the applied side than the pure. In particular, I find classical mechanics inexpressibly elegant and delightful. Any topic that catches my interest is grist to the mill. I love learning something about new areas and have enjoyed finding out more about areas like differential geometry.

So, I would say that my horizons have broadened considerably. Of course, there are ethereal regions, like the school of Grothendieck, that are far beyond my comprehension (and ability). But if I can understand a topic sufficiently well to be comfortable in explaining it for general numerate readers, I will give it a go.

7. What writers about maths/science do you admire, and which ones do you think have influenced your own style?Difficult to say. Of course, I read E T Bell like everyone else. And of course the Maestro, Martin Gardner. Not sure about influences. I think I learn from everyone. Two recent beautiful books are Richeson’s“Euler’s Gem”and Glen van Brummelen’s“Heavenly Mathematics”.There are so many wonderful books now that it is hard to choose. But the ones by William Dunham, e.g.“Journey through Genius”,are masterful.

On 20th Dec 2016, at a meeting at UCD to mark the 40th anniversary of the founding of the Irish Mathematical Society, Peter will deliver a lecture on "A Painless Overview of the Riemann Hypothesis (proof omitted)."