The insoluble pancake

Photographs for Tim

March 20, 2024 H. J. McCracken Comments 0 Comment

It’s now over a year since Tim’s passing. There is this story I need to tell:

On a cold, grey Saturday in December 2022, I took the metro to the other side of Paris to meet Tim’s friend, Jorge. Tim and Jorge met when Tim was studying in Paris. When Tim’s cancer returned, Jorge went to North Carolina to see Tim and his family. When he was there, Tim gave Jorge several rolls of bulk film to bring to back to Paris for me.

Jorge and I met up in a tiny café near where he worked. Soon after meeting, I realised that I had already seen his photographs: Tim had published them in Leicaphilia. You remember them, I am sure, in particular the guy with the mask on his head with two round eye-holes. Fantastic and mysterious and funny. On the cold winter morning, Jorge and I talked for maybe an hour or two about photography and many other things. I showed him a few of my own photographs on my telephone. “I don’t know,” he said, “but I think you need to get closer”. Looking at my photographs, I would have to agree. At the end, it was almost lunchtime, we parted company and Jorge handed me over three black bags on which were written ‘TMAX’ and ‘Kentmere’ on yellowing masking tape. Tim had said to me a few months previously: “This should keep you in film for a while” and indeed it seemed to be a lot. A quick calculation suggested that it was around 60 rolls of 36 exposures each. But it was bulk film, not already rolled into cartridges. I had never rolled bulk film into cassettes before.

Back on the other side of Paris, I went searching on the internet for a bulk roller and film cartridges, although I knew that at first I could just re-use a few of the old cassettes from film I was currently shooting. After developing and printing my own films for almost ten years now, bulk rolling was the ”final frontier”: something I had yet to try (there is still one thing left, I guess: mixing your own film developer from scratch. Not ready to go there yet). It was almost impossible to find good-quality metal cassettes: eventually, I tracked down an ebayer in … Kyiv, Ukraine. At one point many cameras were made there, and I supppose there must be mountains of film cassettes still lying around. The cartridges arrived early in the new year, and I couldn’t imagine the environment they must have come from. I did try loading one cassette without the bulk loader, in the darkroom at the Observatory. In the darkness, I spooled out what (I thought) was the right amount of film and prepared to put into the cassette. At that moment, the whole darkroom lit up. A notification on my telephone. Luckily, the light from the screen was partially blocked by my body and the film was undamaged.

By the end of December, I had rolled my first cassettes of Tim’s film. I did what I always do: I went for a walk around town and took photographs in the grey, shadowless winter light. This flat light is perfect for photography: no need to change any settings on the camera. But when I developed and scanned the first rolls them, I was disappointed to see the streets and buildings of Paris under a heavy curtain of grain. But I soon realised: this was obviously a message from Tim. On Leicaphilia he wrote (I am sure) thousands of words about the nature of film grain and how it was (mostly) different from electronic noise captured by digital detectors. Tim loved grain, and his images were bathed in it. Some of it real, some of it cooked up with software. I was not expecting TMAX (known to be a fine-grained film) to look like this, but perhaps the rolls had been too long in Tim’s freezer. I tried a few different developers (including one Tim sent me just before he died), but the grain remained. Obviously, this was Tim’s plan. It’s a message, it’s a message, I repeated to myself.

Soon, walking around with those rolls of film in my camera, I felt different. To start with, I knew that perhaps I shouldn’t care too much about getting the exposure or focus exactly right: with so much more grain, such considerations were secondary. I felt I had essentially a limitless amount of film, so perhaps I could take more photographs and be less careful? Because being careful doesn’t always lead to good photographs. Over the past few years, I’d see something, stop walking, take a photograph, then walk on. Time to try something different. I took off the 50mm lens and put on the small compact skopar 35mm lens, actually the first lens I bought with my M6 in 2015, and (I knew) a favourite of Tim’s. I decided to take this film with me on a few of my 2023 trips. The risk was that the images be lost to waves of grain didn’t bother me. When I came back from a trip to North America, on the scans I saw the Niagra Falls through a curtain of static and mist. It was fine.

I went to Ireland and the green hills dissolved under a grainy torrent. Looking at the scans, I realised it didn’t look so bad.

Euclid launched in July, and I was in Paris almost all of July and August. There are quite a few stories to tell about the first images from Euclid and how not everything worked out exactly as we expected immediately. Everyone working on the project in those days was under enormous pressure to understand the satellite and what was happening out in space. But on the weekends I was happy to take my camera filled with rolls of Tim’s film and walk for miles around town in the baking heat, taking many pictures. Shutter set to 1/250, don’t stop, click. I got close enough. I saw some weird stuff.

I had my zones of predilection. In the Marais you could see all sorts of things if you walked around enough. It is hard taking pictures in Paris: everything here has been worn down, photographed millions of times.

Soon enough, it was winter again, and the gray days were back. Before I knew it, I had my last roll of film in the camera. I was walking across the street. There was some kind of weird glitch. 70 years slipped away. And then it was the last exposure in the roll.

By the end of the year, I had around 30 or so interesting photographs that maybe I wouldn’t have taken if Tim hadn’t sent me that film. They are here. Thanks, Tim!

On seeing the Euclid launch

July 6, 2023 H. J. McCracken Comments 0 Comment

In July, I had the great luck to visit the Kennedy Space Flight Center to see the launch of the Euclid satellite. I wrote this a few days after the launch, but with the great amount of work that we have all been doing since then, I have not had time to publish this! I was thinking I had better get caught up…

My trip to Florida started inauspiciously enough, with a text message telling me that my flight to Newark, the first leg of my journey, had been delayed. This meant that I would miss my connection to Orlando. At CDG the united staff told me that, although they couldn’t rebook my flight from Paris, don’t worry, in Newark they will look after you. I imagined disembarking from the plane and walking right to the smiling United representative at the service desk who would immediately put me on the next available flight. The reality was a four-hour wait in the line-up at Newark until finally a very helpful lady booked me on a flight to Orlando the next morning. I arrived in the humid Florida heat on Friday with enough time to pick up my tickets and those of my colleagues. I will pass in silence over the night spent in a hotel in the grey post-industrial suburbs of New Jersey.

I admit that I had a certain ‘frisson’ seeing the signs for ‘Kennedy Space Flight Center’ (KSFC) as I drove away from Orlando airport. As a child in Ireland in the 1970s I wrote to KSFC and asked them to send me stuff about space and planets. Soon enough, a big wad of old press releases as well as some nice colour pictures of planets arrived from America in a big yellow envelope. It was wonderful. I couldn’t understand why more people were not interested in astronomy given the Universe was so large and the Earth was so small. And so now, 40 years later, I was on a highway heading right to KSC. Soon enough, I was flying over a large river inlet and in the distance I could see what I knew was the famous Vehicle Assembly Building, the largest building in the world. But right now, I was not going to KSC, I was only going to the hotel to get the tickets…

The next morning, I left the hotel at 07:20. The launch was scheduled for 11:12AM, but I knew that My bag was full of cameras and factor 50 sunscreen. I had a big hat I bought at the surf shop near my hotel, ready for the intense heat and light of a summer morning in Florida. I picked up a colleague at his nearby hotel.

Although we had left early, there were already many people at Kennedy for the launch. It was blisteringly hot, and the sun shone brightly in a blue sky without clouds. Although I have been working on the Euclid project for more than a decade and have been to every consortium meeting (except one), there were many people I had never seen before.

Soon enough, we left on the first bus carrying everyone to the bleachers at banana creek, a prime viewing location across the water from the launch towers. The bleachers, however, had not an inch of shade, and it was more than an hour until the launch; no question of staying outside. But next to the bleachers was the Saturn V Apollo building, and we spent a good hour there looking at this impressive space hardware from the past. Soon it was time to go outside again

At the bleachers, everyone was finding their places. There was blinding heat and light. To the right, there was a big screen relaying the SpaceX/ESA livestream, and a local commentator provided us some additional context. I stared out at the horizon at where the Euclid will soon leave the Earth. Confusingly, there were several different launch towers.

And suddenly, we were only a few minutes before launch. We were in the bleachers. I had promised to do a livestream with IAP auditorium where everyone was gathered to watch the launch. I put in my AirPods and my colleague Amadine tried to film me with my iPhone. There was so blinding light everywhere it was impossible to see the screen, but I could hear the questions from Paris and I tried to formulate some intelligent answers.

We were in the final minutes before the countdown. No sign of a hold or a delay. There were no clouds in the sky. We were told there was a delay between the livestream and the real world, a few seconds, not much but enough to make everyone chanting countdown pointless. We didn’t know the real-world number of minutes left. Suddenly, there was an enormous cloud on the horizon, low down, and rising from the clouds we could see the Falcon 9 rocket atop a bright orange-yellow flame. It was one of the brightest things I have ever seen. But at first it was completely silent as the rocket arched up into the sky. Then the sound came, a great rolling rumbling wave of sound energy. My cheap straw hat vibrated in time to the roar of the nine merlin rocket engines. Clearly, it takes a lot of energy to get a one-ton rocket to L2, I thought to myself.

I was transfixed. In the bag at my feet I had my two Leica cameras, I had my telephone and a Ricoh compact camera too, but I didn’t want to do anything but look at this bright orange candle as it disappeared into the cloudless sky. On the callout from the screen we heard ‘maxq’ indicating the rocket had passed through the zone of maximum aerodynamic pressure. And then, it was gone, and there was finally just a cloud in the sky, a cloud of water vapour made by the Falcon 9 rocket.

The livestream from ESA and SpaceX continued. We saw the booster coming back, landing on the drone ship. There in orbit was a short coast phase and the second stage ignited again. By this time, all the public had left and there were only a few of us in the bleachers or sheltering nearby. Then, on the “jumbotron” — the big screen they have there — we saw Euclid deploy, the silvery yellow foil catching the sunlight as at it separated from the SpaceX second stage. But still, the story was not over. Was the satellite alive and communicating with the Earth? Then finally on the screen we saw the first signal from the spacecraft. Euclid was alive and heading to L2. And the real work would start very soon.

Waiting for the signal from Euclid at KFC

The road to the space coast (looking back on the ideas that led to Euclid)

June 25, 2023 H. J. McCracken Comments 1 Comment

On Florida’s Space Coast, the Euclid satellite is undergoing the final preparations for launch on a Falcon 9 rocket next Saturday, July 1st at 11:12 EDT. Although the Euclid mission was approved by ESA in 2011, the origins of the project date back more than a decade before that, starting with the realisation that the expansion of the Universe is accelerating.

In cinema, great discoveries are usually accompanied by the leading lights throwing their hands in the air and exclaiming, “This changes everything!” But in real life, scientists are cautious, and the first reaction to any new discovery is usually: is there a mistake? Is the data right? Did we miss anything? You need to think carefully about finding the right balance between double-checking endlessly (and getting scooped by your competitors) or rushing into print with something that is wrong. At the end of the 1990s, measurements of distant supernovae suggesting the accelerated expansion of the Universe were initially greeted by scepticism.

Conceptually, what those measurements were saying was simple: the further away an object is, the faster it is receding from us. Edwin Hubble’s early observations of galaxies demonstrated that there was a straight-line relationship between the distance of an object and the speed of movement. The most simple explanation (although one that scientists took a while to accept) was that the Universe was expanding.

Over the next few decades, researchers embarked on a long quest to find different classes of objects for which they could estimate distances. Supernovae were one of the best: it turned out that if you could measure how the brightness of supernovae changed with time, you could estimate their distances. You could then compare how the distance depended on redshift, which you could measure with a spectrograph. Wide-field cameras on large telescopes allowed astronomers to find supernovae further and further away, and by the end of the 90s, samples were large enough to detect the first tiny deviations from Hubble’s simple straight-line law. The expansion was accelerating. The origin of the physical process of expansion was codified by “Lambda”. Or “dark energy”.

First measurements of distant supernovae from two teams. The most distant measurements are above the straight-line measurements by ~20%.

But those points on the right-hand side of the graphs which deviated from Hubble’s straight-line law had big error bars. Everyone knew that supernovae were fickle creatures in any case, subject to a variety of poorly understood physical mechanisms that could mimic the effect that the observers were reporting.

Initially, there was a lot of resistance to this idea of an accelerating Universe, and to dark energy. Nobody wanted Lambda. Not the theorists, because there were no good theoretical explanations for Lambda. And not the simulators, because Lambda unnecessarily complicated their simulations. And not even the observers, because it meant that every piece of code used to estimate physical properties of distant galaxies had to be re-written (a lot of boring work). Meanwhile, the supernovae measurements became more robust and the reality of the existence of Lambda become harder and harder to avoid. But what was it? It was hard to get large samples of supernovae, what other techniques could be used to discover what Lambda really is? Soon, measurements of the cosmic microwave background indicated that Lambda was indeed the preferred model, but because the acceleration only happens at relatively recent epochs in the Universe, microwave background observations only have limited utility here.

Meanwhile, several key instrumental developments were taking place. At the Canada France Hawaii Telescope and other observatories, wide-field cameras with electronic detectors — charge coupled devices, or CCDs — were being perfected. These instruments enabled astronomers for the first time to survey wide swathes of the sky and measure the positions, shapes and colours of tens of thousands of objects. At the same, at least two groups were testing the first wide-field spectrographs for the world’s largest telescopes. Fed by targets selected from the new wide-field survey cameras, these instruments allowed the determination of the precise distances and physical properties of tens of thousands of galaxies. This quickly led to many new discoveries of how galaxies form and evolve. But these new instruments would also allow us to return to the still-unsolved nature of the cosmic acceleration, using a variety of new techniques which were first tested with these deep, wide-field surveys.

In the 1980s, observations of galaxy clusters with CCD cameras led to the discovery of the first gravitational arcs. These are images of distant galaxies which are, incredibly, magnified by the passage of light near the cluster. The deflection of light by mass is one of the key predictions of Einstein’s theory of general relativity. The grossly distorted images can only be explained if a large part of the mass of the cluster is concealed in invisible or ‘dark’ matter. However, in current models of galaxy formation, the observed growth of structures in the Universe can only be explained if this dark matter is distributed throughout the Universe and not only in the centres of galaxy clusters. This means also that even the shapes of galaxies of the ‘cosmic wallpaper’ throughout the night sky should be very slightly correlated, as light rays from these distant objects pass close to dark matter everywhere in the Universe. The effect would be tiny, but it should be detectable.

Simulation of the passage of light rays through the Universe, passing close to dark matter (S. Colombi, IAP).

Around the world, several teams raced to measure this effect in new wide-field survey camera data. The challenges were significant: the tiny effect required a rigorous control of every source of instrumental error and detailed knowledge of telescope optics. But by the early 2000s, a few groups had measured the ”correlated shapes” of faint galaxies. They also showed that this measurement could be used to constrain how rapidly structures grow in the Universe. At the same time, other groups, using the first wide field spectroscopic surveys, found that measurements of galaxy clustering could be used to independently constrain the parameters of the cosmological model.

Halfway through the first decade of the 21st century, it was beginning to become clear that both clustering combined with gravitational lensing could be an excellent technique to probe the nature of the acceleration. Neither method was easy: one required very precise measurements of galaxy shapes, which was very hard to do with ground-based surveys which suffered from atmospheric blurring; the other required spectroscopic measurements of hundreds of thousands of galaxies. And both techniques seemed highly complementary to supernovae measurements.

In 2006, the report from a group of scientists from Europe’s large observatories and space agencies charted a way forward to understand the origin of the acceleration. Clearly, what was needed was a space mission to provide wide-field high-resolution imaging over the whole sky to measure the shapes, coupled with an extensive spectroscopic survey. Both these ideas were submitted as proposals for two satellites: one would provide the spectroscopic survey (SPACE) and the other would provide the high-resolution imaging (Dune). The committee, finding both concepts compelling, asked the two teams to work together to design a single mission, which would become Euclid. In 2012, the mission was formally approved.

Euclid aims to make the most precise measurement ever of the geometry of the Universe and to derive the most stringent possible constraints on the parameters of the cosmological model. Euclid uses two methods: galaxy clustering with the spectrograph and imager NISP (sensitive to dark energy) and gravitational lensing with the imager VIS (sensitive to dark matter). Euclid‘s origins in ground-based surveys makes it unique. Euclid aims to make a survey of the whole extragalactic sky over six years. But unlike in ground-based surveys, no changes can be made to the instrument after launch. After launch, Euclid will travel to the remote L2 orbit, one of the best places in the solar system for astronomy, to begin a detailed instrument checkout and prepare for the survey.

I have been involved in the team which will process VIS images for more than a decade. The next few weeks will be exciting and stressful in equal measures. VIS is the “Leica Monochrom” of satellite cameras: there is only one broad filter. The images will be in black-and-white. It will (mostly) not make images deeper than Hubble or James Webb: Euclid‘s telescope mirror is relatively modest (there are some Euclid deep fields, but that is another story). But to measure shapes to the required precision to detect dark matter, every aspect of the processing must be rigorously controlled.

VIS images will cover tens of thousands of square degrees. Over the next few years, our view of the Universe will dramatically snap into high resolution. That, I am certain, will reveal wonders. Those images will be one of the great legacies of Euclid, together with a much deeper understanding of the cosmological model underpinning the Universe that will come from them and the data from NISP.

This Thursday, I’ll be travelling to Florida to see Euclid start its journey to its L2 orbit for myself. I’ll be awaiting anxiously with many of my colleagues for our first glimpse of the wide-field, high-resolution Universe that will arrive a few weeks later.

A post for Tim

January 15, 2023 H. J. McCracken Comments 2 Comments

Tim Vanderweert, author of the Leicaphilia.com blog, left us last week. I couldn’t let Tim’s passing go without comment: like many people, I owe him a lot.

About a decade ago, just after the death of my father (I am sure these events were linked), I started taking photographs and photography more seriously. More intentionally, at least. Some mysterious path led me to film and Leica rangefinder cameras. The first time I held a Leica rangefinder was in a second-hand shop on the boulevard Beaumarchais, and that camera is still the camera I have with me almost every day. But what was going on? Like we do today I searched the internet to understand, and soon enough I came across Leicaphilia.

A revelation! Leicaphilia was easily the most lucid, funny and opinionated website about film, Leica cameras and photography on the internet. The mysterious site administrator was well aware of all the contradictions of using such cameras today. A relief: most photography web-sites take themselves much too seriously. Soon after (January 2016), I wrote an email to Leicaphilia and sent through an article that I though might fit into the Leicaphilia ethos. I was surprised and happy when I received an almost immediate response from the admin (whom I learned was called Tim V) telling me that he’d be happy to run my article in a few weeks.

When I learned later that year that Tim was coming to Paris, I invited him to visit our institute and to come for espresso in my office. In person, Tim turned out to be like you’d expect from reading Leicaphila: immensely knowledgable, opinionated and cultured. But also very generous and encouraging. I showed him around where I work, and we visited the old Observatory buildings. We even got into the normally-closed museum of astronomical instruments after I told the observatory staff that Tim was a visiting specialist of rare optical instruments (which is true!).

Tim met my colleagues and at the end we had espressos once again this time on the IAP terrace. It was a thoroughly enjoyable afternoon. When I told him about my film-developing technique, he arranged for a pack of Diafine developer to be hand-delivered to my office by relatives who were visiting Paris. They came for coffee too, and coincidentally it was a day that we had birthday cake in the office. A big party ! It was a revelation seeing what my rolls of Tri-X looked like in Diafine. In emails since then, Tim promised to keep my in Diafine indefinitely.

Over the next years, I followed Leicaphilia closely. There was no place on the internet you could find such abstruse, challenging and funny content. Tim was trying to work out what all this stuff meant, where photography was going, or not, and it was great to follow along on his journey. Then there were the excellent take-downs of crooks and charlatans like that time he found the mugshots and police records of a couple of scammers who were selling ”black paint” Leica cameras. I was amazed he was able to write so much given that many of the articles seemed to be so deeply researched and knowledgable. Somewhere in there, Tim activated commenting on the site, and those comments were a revelation: it turned out that there was a community of civilised, intelligent people following the site who could have a meaningful conversation without descending into polemic and outrage; very uncommon on today’s internet.

A few times, Leicaphilia went dark or offline: Once Tim was (perhaps) hacked by Scientologist friends of Thorsten O. (frequently a subject of ridicule on Leicaphilia). But often the silences were simply Tim’s centres of interests changing. They made us all realise how much we valued Leicaphilia and how eagerly we awaited Tim’s next idiosyncratic update.

But then, around two years ago after a longer pause, Tim announced he had cancer. I was shocked. It sounded hopeless but after surgery and treatment he recovered and in summer 2021 we met once again in Paris. First at a cafe in the Marais, and then for a meal at our small Parisian apartment. Tim and his wife came as well as two exchange students that they had been hosting at their house. It was a lovely evening. Tim was in great form. He had brought copies of his books for me and we would have talked late into the night if the evening hadn’t been cut short by the results of a faulty COVID test.

For most of the next 12 months, the only update on Leicaphilia was a brief message announcing that Tim was selling his digital Leica. I expected that Tim had been once again zooming around the back roads of North Carolina on his motorcycle. So I was unprepared for the message from Tim in August 2022 telling me that his cancer had returned and this time it didn’t look like there would be an easy escape. I remember around five years ago when I told him I was being treated for a ”minor” cancer (which is now thankfully under control). Tim mentioned that if something like that ever happened to him, he would be frightened. But talking to him after he sent me that message, he seemed more annoyed than frightened. Annoyed that this would happen to him now.

Readers of Leicaphilia know the rest of the story: Tim confounded the doctors by not dying then and there, but living for another four months. And during those four months Leicaphilia was a torrent of posts, often several every day. There was much new material, together with old posts that had been on the shelves. All of them in Tim’s trenchant funny style. He gave so much of the little energy he had left to us, the readers of Leicaphila. He was generous in other ways too: I travelled to the other side of Paris and picked up almost a hundred metres of film that Tim had sent to me via a friend who had been to Tim’s premature ”going-away-party’;.

Leicaphilia was inspirational. In person, Tim was an exceptional character. You don’t meet so many people like Tim in a lifetime. Returning to my apartment the evening after the day Tim died, I found a parcel waiting for me. It was a packet of Diafine that Tim had sent me only a few days before his death. Hail and farewell, Tim, and thanks!