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“Blow up” in Parc Montsouris, Paris.

“Blow up” in Parc Montsouris, Paris.

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I have been thinking again about images and photography at lot over the last few weeks, not in the least driven by my decision to purchase a new camera. After carefully reading “Digital photography review” once again, just to see how things have evolved since my last camera purchase around 4 years ago, I decided on the Olympus OMD-EM10. This is the first camera I have bought which has an interchangeable lens. For years I had wanted to buy an SLR-type camera but was always put off by the size and the weight: I wanted something I could take with me on my many trips and which wouldn’t add much to the overall weight of my bags. So a big heavy SLR with lenses was out of the question, even if they supposedly produced better images (which was not always the case, if you chose carefully). But this new camera is wonderful: it is very small, only slightly heavier than my old canon compact  (G11), but it produces fantastic images. There is also a very large large selection of lenses. Yesterday afternoon I went down to Parc Montsouris with my old and new cameras  and took photographs of bushes across the lake, as one does. Comparing the two photographs I realised in the olympus image I could see a man lying down next to the statue, unresolved in the canon image (okay, so the focal lengths are not exactly the same). Wasn’t that just like a film from a certain Italian director? And you know the best hing? When you press the shutter button, *it takes a photograph instantly*, not like digital cameras of even a few years ago.

This is not the first time I have used a camera with interchangeable lenses however. In one of the numerous cardboard boxes here I found an old Pentax K1000 camera that my parents gave to me for my first trip to Europe. They had bought this camera for taking pictures of headstones (yes,really), and they had allowed me to take it with me, that summer where I worked at the ETH in Zurich. I took maybe six rolls of film on that trip. Looking at the lens again yesterday I see that it was a fixed 50mm lens, radically different from the lenses on the cameras I had used since then all of which had zoom lenses with focal lengths of around 35mm at the wide end: most of the photographs I ended up taking, through laziness more than anything else, was with this wide end of the zoom, a view of the world completely different from the 50mm lens on the Pentax.  I used this camera from 1988-2002, right up to the digital epoch in 2002 when I bought my canon power-shot S40 in Bologna for the horrendously expensive price of ~1000 euro.  Now, once again, I am in the habit of using wide-angle lenses, so the first fixed-focus lens I bought for the olympus was the f1.8 17mm M.Zuiko lens — a 35mm equivalent lens. It’s an interesting experience trying to decide what fixed focal length to choose — like a lot of things today, zoom lenses I think have made people lazy.

Growing up, I remember that at first photography was expensive. We had a Polaroid camera and my mother and I would go to the graveyard to take pictures of headstones with it (this was not meant to be the third instalment of “a life in stone” but it is turning into it). There was no “catalogue”, of course, in my fathers’ business, so the best way for people decide what kind of monument they would like to have was to show them photographs. It was hard to get the polaroid prints to develop in the northern Irish cemeteries, I remember holding them inside my jersey to accelerate the process. Later, I remember pleading with my mother to let me please just take one photograph with the camera please in our garden in Burn road, and she agreed, and I took *my first photograph*, only to discover that half the image was obscured by a blurry blob. First lesson of photography, make sure that your finger is not in front of the camera. Sometime after we got the Pentax, I was eventually assigned gravestone-photographing duties and allowed to take photographs on holiday. The Pentax was a completely manual camera and the possibility of error was significant. I remember one trip we made to the ring of Kerry. Afterwards, when I opened the camera to take out the film, I discovered (with horror) that I had threaded the film incorrectly and not one single image had been exposed (I was terrified to open the box to check, certain that all the film would be lost if I did that, but of course this was not the case).

This camera accompanied me on my voyages to Zurich, New Mexico, Canada, Durham and Marseille but by the time I arrived in Bologna in 2002 I wasn’t taking that many photographs. But by 2002 it became possible to switch to digital. Now, I have around 23,000 photographs on disk. Have to organise them somehow…

The IAP at 75: The early history of our Institute

The IAP at 75: The early history of our Institute

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A grainy black-and-white photograph. A line of men stare into the camera. In the background, bare trees are outlined against the cold winter sky. The ground is thick with dead winter leaves. Four of the men are in suits and hats; three are labourers. One heavy-set man with a pencil moustache leans nonchalantly against a tree, another is there with his hands in his pockets. Behind them, a small truck is parked at an awkward angle. On the far left, one of the well-dressed men holds a pick in his hand. This man is Henri Mineur, who would in the following year become the first director of the IAP. The date is the 6 of January 1938: the date on which construction of the IAP started. Last Friday, we celebrated the institute’s 75th anniversary with a series of talks and presentations, and in addition a short film made by my friend Mr. Jean Mouette.

PremierCoupDePiocheIAP 1938
Henri Mineur starts construction work  for the IAP

The IAP was created out of an urgent need for new structures to carry out scientific research. In the early part of the 20th century, astronomy was undergoing a radical transformation. With the arrival of new instrumentation and new telescopes it became possible for the first time to apply our knowledge of physics to understand astrophysical processes and observation: the science of “astrophysics” came into being. For centuries, astronomy had been concerned with the positions and movements of stars and other objects, but with the arrival of richly quantitative measurements such as spectroscopy, which can provide detailed information concerning the chemical make-up of very distant objects, it became clear that a new approach was possible. However, it was not clear where this kind of new astronomy could be done in France – certainly not at the Universities which were orientated uniquely towards teaching, and saw no place for research. The observatories, steeped in centuries of positional astronomy (and still labouring to accomplish immense tasks like the “Carte Du Ciel”) were not quite ready for the transition.

One man, Jean Perrin, saw the need for a new national institution to carry out astrophysical research – an institution which would not be part of any existing structures but would be independent. A left-leaning government had just arrived in Paris, le “Front populaire”, and they fully supported Perrin’s idea. Jean Zay, a minister at the time, signed a decree on the 30th of October 1936 which led to the creation of the Observatoire de Haute Provence (the OHP, in some ways the “observing station” of the IAP), and the IAP itself, initally designated as a centre of research which would analyse data arriving from OHP and devise new instruments for the telescopes. The IAP would be constructed on a patch of ground in the Jardin de L’Observatoire, which the government had requisitioned for this purpose (leading to tensions between the Observatoire and the IAP which persisted for decades). The front populaire was uniquely disposed to these ideas. In fact, Perrin’s visits to the minister Jean Zay’s office invariably resulted in him receiving all the funds he requested.

Construction of the IAP started soon afterwards, and the building’s skeleton was in place by 1940: the interior, however was unfinished, and with the arrival of the Vichy regime and the German occupation, the construction was halted. Nevertheless, as Daniel Chalonge tells us after the war, building work was carried on in secret. Certainly other concerns occupied the scientists. Some left, others remained. Neither Perrin or Zey would survive the war: Perrin left for New York, where he died in 1942. Jean Zey was arrested by the Vichy government and later assassinated. In Paris, two astronomers, Holweck and Solomon, were arrested and executed by the Nazis. Henri Mineur himself was briefly imprisoned, before being released: he spent the remainder of the war in the resistance. Even astronomers long-dead suffered: the statue of Arago on the place Ile-de-Seine, in front of the site of the observatory, was melted down for bullets and shells. But finally, in 1944, some staff moved to the IAP. The building would not be completed until 1952 (and in the 1980s a third floor would be added to create the building as we know it today).

From almost the beginning, both theoretical and observational subjects were investigated at the IAP: spectrophotometric observations of the sun, stellar atmospheres, and every aspect of physical processes in an astrophysical context. We heard how Evry Schatzmann, aided by a large number of students, investigated almost every kind of astrophysical phenomena, and contributed greatly to the international reputation of our institute (but it made life difficult for the students: as they were all working on different topics, none could help each other). At the same time, machine shops and mirror polishing facilities, together with facilities for numerical calculations has ensured that new observations from OHP and elsewhere could be fully exploited. Today at IAP there are no longer any machine shops, but the importance of computing in astrophysics at the IAP has only grown in the intervening years.

How survey astronomy really got started, part 2: Astronomers realise how much work it takes

How survey astronomy really got started, part 2: Astronomers realise how much work it takes

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(This is the second part of a two-part article. Read the first part here).

Now skip ahead once again another ten or fifteen years. I found this fascinating book “The great star chart” written by a British astronomer, H.H. Turner, about the progress of the “Carte de Ciel” survey. Turner was an astronomer at the University of Oxford, and this short book is his account of the survey and the work that had been accomplished in Oxford by 1911.

It’s interesting to consider his book from a modern perspective: in those distant days our notions of the Universe were very different; cosmology did not exist as a science, Einstein had yet to formulate his theory of General Relativity, and we didn’t know what the true nature of the nebulae — those dim smudges which were picked up on the photographic plates from time to time — really were. That meant interpreting observations on the first deep plates quite challenging. In Turner’s book there is a lot of talk about the “fog” that might exist between the stars — that this fog might be part of an explanation why the numbers of stars varies so much from plate to plate. Were clusters of stars and were there really “stellar streams”? Similar confusion would exist in the coming years when we tried to understand the distribution of the counts of “nebulae” on the plates — was this variation again because of some kind of “fog” or was the distribution of the galaxies really non-uniform?

It turns out, that like a lot of things, the answer was a bit of both: there really is dust, but the distribution of stars and galaxies on the sky really is clustered, for the former because of the shape of our own milky way galaxy, and the latter because … well, that’s a much longer story. But it’s interesting to think of the parallels between counting stars to find out about the Milky Way and counting galaxies to find out about the Universe.

But getting back to the “carte du ciel”… There is the interesting table I have reproduced below, which shows the state of survey after ten years of operations, divided by into catalogue plates (the shallower survey) and “charts published” which are reproductions of the deeper survey plates.
Here it is:

Greatstarmapbein00turn pdf
Who actually got some work done

While some progress has been made in measurement, it is already clear at this stage that printing the plates will be very expensive: based on the techniques used in Paris to reproduce their part of the survey, Turner calculates that a complete set would weight over four tonnes, if it were ever to be completed. Printing the entire set would be staggeringly expensive.

The work was very time-consuming: it had taken four or five astronomers working full time almost ten years in Oxford to complete their part of the survey. The work was mind-numbingly repetitive, involving countless calculations to produce a catalogue for a single plate. Every position of every one of the stars on the plate was measured manually. To guard against errors, the plates were rotated 180 degrees and the measurement made a second time, and the positions compared. In those days “computers” were in fact room-full of workers with slide-rules. In fact, this chronic mismatch between the data-gathering capabilities of telescopes equipped with photographic plates and our ability to process it would last until the 1960s when digital computers finally became fast enough to handle the volumes of data involved. (In fact, the first extragalactic surveys also suffered from a lack of computing power, but that is a story for another day.) Given all this, it’s hardly surprising that very few observatories, more than ten years after the survey started, had completed their quota of plates. It’s interesting to note in passing that it is also said in some quarters the reason why Europe lagged America in the new science of observational cosmology was because all the astronomers on this side of the pond were tied up measuring positions of stars on thousands of photographic plates.

Turner also talks about cost.

Greatstarmapbein00turn pdf page 86 of 178
And how much it cost…

Well, not much has changed in survey operations in the last century or so: today staff costs and maintenance remains the most expensive items in running a survey. What is interesting from a contemporary point of view is that Turner talks about the trade-off between accuracy and speed: it’s obvious that in an undertaking this size, attempting to make the measurements to infinite precision would simply take infinitely long. Better do the job well enough to get the necessary precision — but not too well, otherwise it will never get finished. Tell that to a student finishing their first paper.
How could other observatories with smaller amounts of staff hope to complete such a massive enterprise? In fact, they couldn’t. The deeper survey plates were never printed out — it was simply too expensive. The rest of the survey, the astrographic catalogue, did actually get finished sometime in the 1950s, almost half a century after it started. In the 1980s and 90s, with the arrival of cheap and fast computing power, interest in the survey returned. One group of astronomers recalculated all the positions of the stars in the astrographic catalogue and compared them to those taken a century later with the Hipparcos satellite.

Another group turned to the photographic plates. Although plate-scanning equipment had been around for a while, it was much too slow to scan the plates of the survey, machines like the PdS microdensitometer would take one day to scan a single plate. Instead, another group of astronomers used off-the-shelf photographic film scanners to digitize some of the plates (this was in the last ten years) and compare them to more recent catalogues. In both cases, the age of the old plates becomes their greatest asset, providing an enormous baseline to measure the motions of stars in our galaxy…

Today, the carte du ciel is one of the major attractions at the “journee du Patrimoine” at the observatory. In fact, here you can see interested members of the public waiting to visit the old rusting domes of the carte du ciel this year just to hear this story that I’ve been telling you…

IMG 3138
The public visits the “carte du ciel”! 

We are just getting started. The Gaia satellite will be launched in the next month or so and will provide the most precise measurements of untold numbers of stars in the Milky Way.  Euclid,  further down the line, will do the same thing for galaxies. But we had better make sure the astronomers are properly motivated and that there are enough resources in place to complete the project, and actually do science with the data !

On Perec's "La vie mode d'emploi"

On Perec's "La vie mode d'emploi"

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Last week I just finished, after a quite a few months (yes, it’s hard to concentrate on books these days with all these electronic distractions), George Perec’s massive book “La vie mode d’emploi”. Perec’s book is an encyclopaedic tome that probably is the closest thing in the French language I think to a Gaddis or a Pynchon that I’ve come across, at least in terms of scope. And certainly in terms of length (more than 600 pages long). And written in a French is which is pretty damn obscure — I did have frequent recourses to asking ML “what does that word mean”?

The book describes all the inhabitants of a Parisian apartment building situated on the fictional Rue Simon-Crubeiller. And I when I say all the inhabitants, I mean all those who lived there from the building’s construction to around the mid 1970s — everyone who has lived in each apartment of each floor of the building. The book features not only an index, but also a chronological list of all the major events of the book, as well as a list of all the many stories that Perec tells us — by story, I mean here a short history or “fait divers” in most cases lasting no more than a few pages. And usually, but always, often ending badly or surprisingly.

All classes of characters swarm through the pages of Perec’s book — artists, confidence tricksters, millionaires, accountants, doctors, scholars, scientists. Perec fills his book with spurious scholarship, made-up citations from imaginary specialists of every field of human knowledge. Many characters spend their entire lives of fruitless quests that often end in failure, pursuing impossible endeavours. He includes everything. There are endless enumerations of every object found in the cellars of certain apartments. Paintings and interior decorations are described in excruciating detail. Not only the paintings themselves, but also the stories which take place inside the paintings. At one point, all the objects found in the stairway of the building over the last few decades is listed. Many of the characters know other characters in the building, but many others live separate lives. The events described in the book cover the four corners of the Earth, although we never leave rue Simon-Crubellier.

The main story running through the book is that of English billionaire Percival Bartelbooth, whose life’s work consists of a decades-long project to travel the four corners of the world (staying away from Paris for almost twenty years I think) and paint a series of watercolours in different seaside spots; back in Paris at rue Simon-Crubeiller, artisan Gaspard Winckler, on the orders of Bartelbooth, transforms each of these painting into a complicated jigsaw puzzle. For the next twenty years, Bartelbooth devotes all his energies to solving these puzzles; as each one is solved, he returns to the place where he first painted the picture and dissolves it, leaving a blank sheet of paper. Yup: I’m reminded of Beckett: everything we do in life is a means to avoid boredom.

Reading the book I couldn’t help thinking of the building I was reading it in: our building here at Avenue Rene-Coty was built at around the same time as Perec’s fictional building at 11, Rue Simon-Crubeller. Both of them are Haussmannien structures, built during the great housing boom in Paris at the end of the 19th century. Although, unlike Perec’s building, the most of the apartments in the building here have remained in the same family since its construction — talk about a particularly astute purchase, given that most of the apartments today in this seven-floor building are now worth more than 400,000 euros. I wonder what are all the stories of all the people who have lived here over the last 150 or so years?

Linking all these chaotic stories together is impossible — there is no thread running through them all. Well, that is real life, after all, where the people in the 7th floor may not necessarily know what happens on the ground floor. Links go unmade, after all. Perec does not make any attempt to step out from behind the curtain and tell us what it means. It doesn’t mean anything — we not in a novel, after all…