The insoluble pancake

How survey astronomy began, part I: An international conference is held

September 26, 2013 H. J. McCracken Comments 0 Comment

It’s time to get this blog back on track and talk about SCIENCE (….”Mr. White”, if you understand the reference). It’s been too long.

Last weekend (14th-15th of September) was “Journée du patrimoine”, that wonderful day in which buildings normally closed are open to the public. I’ve seen any number of interesting things in Paris over the years. However, this year, I decided it was about time I was on the other side, so to speak, and I volunteered to assist at that august institution the IAP shares its grounds with, the “Observatoire de Paris”. The IAP is the oldest CNRS lab in France, and this year we are celebrating our 75th anniversary, but the Observatoire is much older — it was founded in 1667. It is probably one of the oldest Observatories in the world and probably one of the only ones in which there are still real astronomers doing real research. All the other institutions from that distant epoch have been either demolished or converted to museums and their staff shuttled off to unhappy ugly concrete buildings in the suburbs. So you may imagine what a rich heritage of science and learning there is to talk about when considering Paris Observatory (and how much Paris has transformed itself around the site of the observatory in the last three and half centuries, but that is another story).

There are so many interesting stories concerning the Observatory, but perhaps the most fascinating for me is the “Carte du Ciel” project — because it is no underestimate to say that with this undertaking modern international survey astronomy really began. There is a direct link between the Carte du Ciel and the Euclid project I’m involved in.

Modern survey astronomy started here !

But let’s take a step back. You have just left the IAP and are crossing the observatory gardens. On your left you see two small, rusted domes. The paint is peeling off. These are the domes of the “carte du ceil” observatory. Open the door, and inside the left dome, you can see a small refracting telescope. There is a large square metal box just below the eyepiece. Now take a step even further back. It’s end of the 19th century. Paris under the second Empire. Only a few years previously, in 1882, astronomers in the Cape of good hope, took some of the first images of the heavens with photographic plates — Halley’s comet — and they were astonished to see many, many stars on each plate. The image below shows of one of these first “deep sky” images made with photographic plates (by a Dr. David Gill). I found a scan of this plate (from H. H. Turner’s “Astronomical discovery” and have included it below):

The first deep sky image of all time !

It became clear very quickly that the information gathering capacity of photographic plates surpassed anything which was available before then. Moreover, photographic measurements had the great promise of being objective, unlike hand-drawn sketches and notes (think of those “canals” on Mars). Now the only thing missing was a telescope optimised for photographic measurements.
In Paris two opticians, the Henry brothers, working out of their garden shed (as far as I could tell) had a design for a refracting telescope which could provide a wide field of view, 2 degrees on a side. A second-Empire start-up! Admiral Mouchez, the director of the Paris observatory, impressed by their successes, ordered the construction of a much larger telescope with an objective of 34 centimetres. This would later become the first telescope of the “carte du ciel project”. Photographic plates attached this instrument could easily reach stars of V~12 or 13 magnitudes, unheard of at the time, and on each plate hundreds of stars were visible.

Such an instrument would be perfectly optimised to realise a modern survey of sky using photographic detectors. These was one problem — from Paris, only a small fraction of the heavens are visible. To survey the entire sky, observatories would be needed in the four corners of the world. Everyone would have to agree on what parts of the sky they would survey and what instruments they would use. To make progress… there would be to have a meeting. So an international conference in was held in April 1887 in Paris Observatory, under the instigations of the paris Academy of Science (suggested by Mouchez) — “The international astrophotographic congress”. It started on Saturday, 16th of April 1887, at 14:00, (so I should really not complain about meetings starting on Sunday). Was this the first international astronomy meeting? It was certainly the first international meeting to whose principal objective was a sky survey.

Now, today, in the 21st Century, everything has been virtualised … and I found, digging around just a little bit, the conference proceedings for this meeting. Well, not exactly: it is an account of the meeting written by a one A. G Winterhalter, who represented the American Academy of Sciences (and is published here as an annex to the 1887 proceedings of the United States Naval Observatory’s). Steam-ships and trains, natural products of the industrial revolution, meant that such an international conference could take place for the first time (Winterhalter writes in his introduction that his steam-ship voyage from New York to Cherbourg takes 11 days, and during the trip he met another astronomer who was attending the same conference – so nothing changes there!). There is a table listing attendance at the conference, broken down by country:

Who attended the first international astronomy conference

Winterhalter notes that “the proceeds were conducted entirely in the French language”. Hey, those were the days (sorry, French colleagues)! It’s interesting to read Winterhalter’s account of the meeting: a large part of the proceedings is concerned with finding the best possible technical solutions and fixing the parameters of they survey (to which everyone had to agree to). At the meeting, everyone agreed to use the Henry brothers’ telescope, paired with a standard photographic emulsion.
One important question which had to be addressed was: what would be the limiting magnitude of the survey? It was already clear at the outset that this would be a massive undertaking, because at the faintest limits accessible by the Henrys’ telescope there would be an overwhelming number of stars. Millions and millions. How could catalogues be made on paper containing all those stars? The could never be printed, they would simply be too large.

A compromise solution was adopted: the survey would be in two parts: a catalogue release containing all stars to V < 11 and an “imaging data release” which would consist of reproductions of the plates themselves and reach fainter magnitudes – down to V< 14.

Well, that was the plan… More coming up in the second post..

Hail and Farewell, Mr. Heaney

September 17, 2013 H. J. McCracken Comments 1 Comment

Seamus Heaney, the Irish poet, died a few weeks ago. Obituaries have been published, and Mr. Heaney has been laid to rest in his native County Derry. Heaney was probably our greatest poet and scholar of the last fifty years. Like everyone in Ireland of my generation or later, we encountered Heaney’s poems in school — in particular Heaney’s manifesto for the life of the writer, his famous poem “Digging” where he states “between my finger and thumb / the squat pen rests / I’ll dig with it”. But at the time, I was unmoved. I was still too close to Ireland, too close to land I was brought up in. I was maybe fourteen or fifteen. I was reading poems at this time, but it was Byron and Shelley and this kind of stuff, distant lands and strange places. Ozymandias. Who would want to read poems about Ireland?

Time passed, and I started my own travels, leaving Ireland when I was 18 to cross the sea to England, which was already seemed exotic enough, then further afield, America (where I discovered Milosz’s poems on top of that mountain in New Mexico — not on a stone, but written in a copy of the “New Yorker” I had taken with me, but that is a story for another day) and then Canada, England again, Marseille and Bologna. The dense ancient streets of Bologna. One day I was wandering around the University and saw a small poster proclaiming that there would be a reading from SEAMUS HEANEY. I was surprised. I noted the date.

Ireland is small country, and the north of Ireland even smaller. It’s a truism to say that everyone knows everyone. Heaney and his wife had in fact gone on holidays with my favourite aunt and her husband in the 1960s. I wonder what that holiday was like … My aunt and Heaney’s wife were splashing in the frosty waters of Ireland’s west cost, came running up the strand. “Write us a poem Seamus!”, at least that’s what my aunt said they exclaimed. This was the result, Girls bathing, Galway 1965. Yes, one of those girls is my aunt, frozen forever.

All this I knew on that evening in Bologna. The reading was in a small upstairs room in Bologna University, ancient beams crossing the ceiling. A good few centuries old, as befits the town with the world’s oldest University. Heaney of course was very famous by this time, not like that distant summer of 1965. He read his poems in his soft northern Irish accent, but after every poem he paused, and said graciously “well I would like to hear that in Italian”; and a translation followed. It was strange and beautiful to hear his poems in Italian, which is certainly one of the more beautiful languages there is. By the end of the evening, I was quite moved — I had already read some of these poems before, but now it was 12 years since I had left Ireland behind. Distance had intervened. Time and space. What a wonderful thing it was, I realised, to find a great poet who had written about your country, and where you came from and where you were brought up. I could see how true his poems were for the first time, once I had subtracted myself from environment I had grown up in. A revelation.

After the reading there was a gaggle of Italian girls pressing forward to have their books signed by the great Irish writer. I decided nevertheless to wait patiently to speak to the man — “Greetings from Tyrone Mr. Heaney”, I said. I spoke to him for a few minutes, mentioned “Girls bathing, Galway”. I didn’t want to take too much of his time, although I probably should have. I just said that I saw my own country for what it was, maybe for the first time, and thanked him for that. “Sure you are a good man yourself”, was his open-hearted response.

So, Mr. Heaney, thank you once again.

"Ceci tuera cela" — on books

March 24, 2013 H. J. McCracken Comments 1 Comment

Somewhere around one third of the way through Victor Hugo’s “Notre dame de paris” the story’s villan is in his attic erie and points at a thick, printed book on his table. Behind it, one can see through the grimy windows of his cell the faint shadows of the towers of Notre Dame outlined against the darkening evening sky. He says “Ceci tuera cela” — this will kill that. And then Hugo launches into a very long (and for my money, unconvincing) digression about how the printed books have ended the realisation of great works of architecture. What he was thinking about was how construction of the cathedrals in Europe (and mostly in France) stopped at around the time of the invention of printing press. But that, I think had a lot more to do with other factors. No cathedrals were ever built in the high middle ages in Italy, for example, because the monks were simply not as well organised as in France. But that’s a digression.

I see a picture now of a electronic book (we have such miracles now, in the early 21st century) next to and old, bound paper book. Ceci tuera cela. Like the picture above, where you can see an image of my copy of the first volume of Chateaubriand’s Memoires d’outre tombe in the La Pléiade edition. “La Pléiade” is the Apple, Inc., of book edition — each volume is hand-bound in leather and made to exacting standards. Each book contains around 1000 pages of text printed on what we call here “bible paper” — which is very thin indeed. Chateaubriand’s monumental work, which must be at least ten volumes in books of any normal paper and size, is reduced down to only two volumes. On the website you can even find a video explaining how each book is made to their exacting quality standards (missing only a shaven-headed soft-spoken English guy telling us how many different cows they tried to find the right leather). Each text which appears in “La Pléiade” strives to be the definitive edition; it one of the highest accolades a writer can hope for is to be published in “La Pléiade”. Almost all of the writers in La Pléiade are dead; their reputations confirmed. And next to that, my kindle Paperwhite, which can store probably more than one thousand books although who would want to as it is wirelessly connected to what we used to call “the internet” but we now call “the cloud” where, the last time I looked, there was about one and half million books ready for instantaneous download from anywhere in the world. Some for a fee, some not. Amongst them, the complete works of Francois Rene de Chateaubriand, which can be had for a euro or two. The Kindle Paperwhite itself, in its most inexpensive incarnation, costs about as much as two volumes of “La Pléiade”. Amazon, I understand, is regarded by some investors as a charity as it makes almost no profit from its hardware: it hopes that people buy books from their stores. But there are countless books out there with lapsed copyrights that can be downloaded instantly. Ceci tuera cela?

I admit I’m not sure. In terms of convenience, the Kindle is unbeatable. I like to read big thick books, and even the biggest, thickest book I have can be taken anywhere without incurring a heavy weight penalty. The text is legible: the screen is illuminated and can be read under any lighting conditions. But it doesn’t have the nervous lighting of an iPhone or iPad — it is simply white light LEDs that shine down on the e-ink display through a diffuser. In fact the thing that I appreciate most about it is that it makes it as easy to read a book, a real book as to ready all of the other electronic babble that we are surrounded by today. But… there is nothing there. There is no physical object. There is no proof that one has actually read the book, there is no crinkled spines or pages slightly worn where hands have passed. There is just a file somewhere in flash memory representing the physical object. The French call this process Dématérialisation which sounds wonderful to Irish ears — one imagines the physical object disappearing. And once that the physical object disappears, all sorts of bad things can happen. There was the celebrated example a year or two ago where Amazon remotely deleted users’ books, after discovering that they had no right to sell them in the first place (and, completely unintentionally I’m sure, that book they remotely deleted was Orwell’s 1984). Ray Bradbury never liked electronic books, complaining that they smelt like burning fuel.

Today, we are often offered something of great convenience and value — in this case an instant access to an almost limitless collection of books — and we have to hope that the corporation behind it all has our best interests at heart. Of course they do, right? They know what you read, how fast you read, where you read it. Where could be the harm in that?

Most modern printed books are not made to the exacting standards of La Pléiade. Cheap paper glued into a paperback cover: in a decade or so those pages will have yellowed and fallen out. What’s the point of accumulating books like that? But no power source is needed, and neither is anyone’s permission required read your own books. Ceci tuera cela? Maybe.

Reading Chateaubriand, visiting St. Malo…

January 1, 2013 H. J. McCracken Comments 1 Comment

A few weeks ago I found myself listening to a radio programme where they mentioned a new autobiography of the French 19th Century writer, Francois-Rene de Chateaubriand. Now, I had heard of this man before: he had lived in an apartment near the paris Observatory, which is marked by a plaque on the wall (It’s on the avenue Denfert-Rochereau). I had already heard of his last, long book, around ten years ago, the enormous “Memoires d’Outre-Tombe” (Memoires from beyond the grave) thanks to a certain American Writer. But hey – we are living in the 21st century, where every intellectual curiosity can be instantly satisfied. Within a few seconds I had downloaded the first volume (of ten I think) of “Memoires d’Outre-Tombe” on one of these shiny electronic devices we have these days and started to read it. Being wholly electronic, one has no real impression of the heft and size of the book: it’s not like for instance trying to read Pynchon’s “Against the Day” or David Foster Wallace’s “Infinite Jest”, both of which are more than 1000 pages in length. “Memoires d’Outre-Tombe” is even longer than that. One is not intimidated. So I started reading. And after a week or so I knew what I would be reading for the next few months — the book is much more interesting that I expected it to be.

Chateaubriand lived in an extremely tumultuous time in French history. Born in 1768, he died eighty years later in 1848 after having witnessing the French revolution and all that came after it (Napoleon the Emperor, the restoration). He travelled travelled widely. I’ve now read the first ten books out of forty-two (!) and there are many wonderful descriptions and scenes. Chateaubriand is considered as one of the first romantic writers and it’s easy to understand why. He describes his childhood in Combourg, a mediaeval chateau in Brittany: this chateau once held 100 people, but when his family moved there they were in total maybe 20 people in the Chateaubriand household. His father sent each member of the family to a separate tower and Chateaubriand (who was less than ten years of age) spends his evenings listening to the wind whistling around the rafters. He is in Paris during the storming of the Bastille, and his descriptions remind me more than a little of the scenes after the fall of the Berlin wall — people singing and reciting poetry on the rubble… In the purges and terror, he survives but most of his family do not. He travels to America, stopping off at Baltimore and embarking on a crazy quest to try to find the north-west passage (which for unknown reasons seems to involve going to Florida). He has an audience with George Washington. He heads out into the American countryside, he see the forests being cut down to make space for the European settlements, encounters indian tribes which will shortly be massacred. He comes back to France after six months abroad (after seeing a newspaper in an American farmhouse announcing the flight of the King)… he returns to Paris and then enlists in a emigrant army to fight the French Republicans alongside the Prussian army. This army is composed of a diverse collection of displaced badly-equipped aristocrats and they spend a few months wandering around in the mud to not much effect, laying siege to the French city of Thionville, which resists. Cheateaubriand is wounded and manages to make his way to England…

What’s actually surprising about the book is that it is very cutting, sarcastic and funny. His descriptions of Danton, Marat and friends are excellent and terrifying. And I found a lot of echoes with other books I had read which were written much later: they have all been influenced by Chateaubriand without perhaps even realising it. Thomas Wolfe, for sure, for my money.

Chateaubriand was a Breton, from St. Malo: and Marie-Laure and I have just come back from three days’ vacation over there, just after Christmas. A welcome trip: St. Malo is deserted at this time of year, there are long beaches to walk along, excellent oysters and clams to eat. I made good progress reading “Memoires”: strange and wonderful to hear his words in his town. And the day after we I arrived I discovered that Chateaubriand’s tomb is on one of the islands facing St. Malo. This island is isolated from the mainland at high tide. Mr. Chateaubriand is facing the ocean; it seems that the wind he felt in his childhood tower was something that he wished to stay near to for a long, long, time.