The Gala Dinner of the CIE conference is just over. And it is way too late to report anything sensible about the Circadian Cycle. See you tomorrow

Thomas Alva Edison opens CIE 2010

The CIE conference started this morning, with quite a nice opening ceremony. An actor, impersonating no less of a man than Thomas Alva Edison, and holding a shining bulb in his hand brings us to the early times of electric lighting. I am not sure I would call this a “brilliant” idea, but it was certainly original. The appearance of T.A. Edison was followed by a group of dancers, wearing “electric” costumes and lit by a bluish light.

Then it was the turn of the President of CIE, followed by a representative of the International Standard Organization (ISO) and one from the International Electrotecnic  Commission (IEC). Then the audience split into 3 parallel sessions. I attended talks in two of them, one on the environment and the other on the regional lighting laws. In particular, there was a very good talk by two Belgian participants, who had tested LEDs against conventional high pressure sodium lamps for street lighting. And the conclusion is that, as of today, LEDs are not yet in a mature state for that purpose, both as far as energy consumption and maintainability are concerned. This is good news for us, since blue light definitely destroys what is left of the dark sky. There are also concerns about the effects on circadian cycles. But I will talk a bit about this tomorrow.

The presentations at CIE are organized as follows. Each session includes 3 plenary speeches (30 minutes each, the so called keynote talks), which are then followed by the parallel sessions (with presentations of 15 minutes each). I was invited to give a keynote talk in the second session, just after lunch. And what is most interesting is that my talk was after the representatives of two big lighting companies. I’ll make no names, but believe me, they are big, especially one of the two. During the first of the two talks, the speaker kept saying that “the future is bright!“. And he was saying that like declaring a victory after centuries of obscuration. The end of a photonic middle-age.

Part of CIE audience at the start of my talk. I took the photo from the stage.

You can imagine me, sitting there in the first row, fuming… I had many thoughts on how I should start my presentation, and how I should retort that statement on the bright future. I finally decided  to first capture the audience attention using what the Latins called “captatio benevolentiae“. It is a rhetoric trick, that allows a trained speaker (or should I say preacher) to positively prepare the audience for what is to come. Very briefly, you try to make them like you before you start telling them what you want to say. “Before I start my presentation” - I said - “let me take a picture of you. In fact, I think you are never going to invite me again to a CIE conference after you hear what I have to tell you“. And this is exactly what I did. I pulled out my camera and took a picture of the audience (well, actually only part of it, since the room is huge). That hit the mark. Lots of people kind of woke up (after the soporific talks by the previous two speakers), turned their heads and smiled. Encouraged by this reaction (sometimes the “captatio” does not work and it may actually put you in an embarrassing situation). In this case it did work. Taking advantage of this, I started off. “I thank the organizers for inviting me. I appreciate this very much, because it is like inviting the enemy at your place“. Laughter. I feel the empathy of the audience growing.

“It is often said the astronomers hate light. Well, this is actually not true. We love light, because light is the only way we have to perceive and understand the universe“. And from that I started making the point about the value of astronomy in culture, starting from the stone age, through Galileo and Copernicus, to the quest for extra-solar planets and life in the universe. While doing this, I had launched an automatic series of astronomical pictures taken by the VLT. Beautiful, indeed. Then a picture of a light polluted site would appear, followed by a completely white slide. “This is all what we are going to see in the near future“. You have never to charge to much and, at some point, you need to relax the tension. So, the next slide was the European flag, with a short text: “This are the only stars we are going to see from Europe“. Laughter and signs of approval (quite unexpected, given the audience). This idea was suggested to me by Andrej Mohar, Dark Sky - Slovenia. “As we have heard many times, the future will be bright. I argue we do not need to illuminate more. We need to illuminate better“.

I spare you the rest of the presentation, which was on the effects of blue-white light produced by LEDs, the recommendations put forward by the International Dark Sky Association, and the concerns for the future. You can find something here. What I can tell you is that when the talk was over lots of people came to me asking questions, thanking me for bringing this up and raising their awareness. As it turns out, in fact, many people in the lighting field simply ignore the issue. They just never thought about it, neither were they told.

Tomorrow there are interesting presentations on the circadian cycle. I’ll give you more details in the next post. Oh, one more thing before I go to bed. The representative of the big company, the one of the “bright future”, left the audience immediately after his talk. The fact in itself, which might sound disturbing, worked actually in our favor. Several people noticed it and commented that “the guy should have staid, listening to what you had to say. That would have been a sign of intelligence“. Sociologically interesting aspects…

A short one. I arrived in Vienna some hours ago. Beautiful city! I am done with the presentation for tomorrow. The more I look at it the more I am convinced some people are not going to like it… I will be talking tomorrow at 14:30. I am in the keynote speakers list, and I have been given half an hour. That is more than enough to convey the two main messages I have in mind:

-Astronomy is a pervasive science, which has percolated through millennia of history, going down to the roots of culture itself (some of you might recognize Hamlet’s Mill here);
-The night sky and all what it entangles is at risk. The appearance of highly efficient (in terms of lumens/watt) devices (e.g. LEDs), producing bluish-white light, represent a serious threaten.

I hope I will manage to have the audience digest this without opening a can of warms. The audience is going to be full of people from the lighting field, and the meeting is sponsored by many lighting industries. Wish me good luck…

I took this photo an hour ago. You can recognize the beautiful St. Stefan's Cathedral. It is also a nice example of bad illumination. What is the purpose of these globes? Illuminate the skies? Make you blind? Prevent you from seeing the Cathedral?

Daniel Hope, yesterday evening in Munich.

You may wonder why from time to time there is a post, in my blog, that is apparently not so much related to astronomy. Well, the lack of connection is indeed only apparent. The way I think and perceive the world is the result of a complex process (as is for my kids, you, and all the rest of mankind for that matter). It is always difficult to say which events, people met, books read, music listened and so on led you where you are. In my personal experience, music and astronomy are strongly connected. To be more precise, the music of J.S. Bach and astronomy are tightly linked to each other. I think it was by chance (could it be otherwise?) that an old friend of mine one day (it must have been around 1980) made for me a copy on tape of the Brandeburg Concertos n. 4, 5 and 6, in the version by the Berliner led by von Karajan (nowadays one would certainly say that was not a philological interpretation of one of Bach’s masterpieces). That was exactly in the years in which my interest for astronomy started changing from curiosity into a real passion. And during those cold winters, when I started going out in the nights to observe the skies with an hand made 150mm Newtonian telescope, that music was a sort of soundtrack. And still now, after [gosh] thirty years, when I listen to that music I feel like being out in the Friulian hills, with the frost depositing on the tube of the telescope.

Why am I telling you this? Well, yesterday evening I had the privilege of listening Daniel Hope here at the Prinzregententheater in Munich, accompanied by the Zürcher Kammerorchester. If you have never heard about him, just a few words. He is one of the most acclaimed violinists worldwide. Yehudi Menuhin was his teacher. I think I do not need to say more.

The concert, a real dive into the baroque era, was wonderful. And, of course, lots of Bach’s music, including the notorious Concert for two violins BWV 1043, wonderfully played with Willi Zimmermann. At the end, after being called back on the stage many many times by a never ending applause, Hope said: “We have started this concert with Bach. And we will close it with Bach. Today is a special day for me. It is the 11th anniversary of Yehudi Menuhin’s death. We dedicate this piece to his memory“. You can imagine the commotion in the audience when they started the famous Air from the Orchestral Suite n.3…

Tomorrow I am leaving to Vienna for a quite unusual task: give a talk to the CIE Conference on Lighting Quality and Energy Efficiency. For the record, CIE is the International Commission on Illumination. You might wonder what on earth have I to do with this. As I said in one of my previous posts, in my spare time I have done some research on the night sky brightness and made some contribution to the understanding of some related phenomena. This then brought me in touch with the pressing issue of light pollution. The bottom line is that I will represent the International Astronomical Union, trying to make the point about the impact of an improper illumination on professional astronomy. More in general, I will also try to rise the awareness about this issue in a more global and cultural context.

This is going to be an interesting and unusual experience for an astronomer. I will report from Vienna in the next days.

Giovanni Carraro in the VLT control room.

I guess that by today you all know about the catastrophic earthquake that struck Chile last Friday. My colleague, ESO astronomer Michael Dumke has already published a post about this.

I have been living in Chile for two years, working as a postdoctoral fellow in La Silla, and I have many colleagues and friends that live there. I just had a long phone call with my old friend and best man Giovanni Carraro, whom I know since the years of university in Padua. He is now in Cerro Paranal, observing at UT2. He tells me ESO observatories do not report any damage. They were out of phone/internet reach for some time, but now things are back to normal. At the time of the quake he was at the telescope, but he did not feel the ground shaking. The VLT control building is in fact very elastic. He became aware of the catastrophe only twelve hours later, fortunately. By that time, in fact, some of the connections were fixed and he could talk to his family in Santiago. The situation was chaotic, but none of ESO people was injured. No internet and normal phone connection, problems with drinkable water, chaos in the supermarkets to buy food and so on. With the airport closed and many roads seriously damaged, connections to Santiago are very difficult. Although the situation is still critical, I now feel a bit better. When I got the bad news I was in Italy, in my home village. We were struck by an earthquake in 1976, which caused about 1000 dead, 40 on my village. And that was only 6.3 Richter. I was only ten at that time, but I have a very vivid recollection of what happened. In a few seconds I could see all those apocalyptic scenes. Smoke and dust, screams, and most scaring of all, the continuous growls coming from the depths. And I was imagining the anxiety of my colleagues up on the mountain, 1200 km away from their families living in Santiago, with no news about their conditions and thereabouts. It must have been terrible…

All our thoughts now go to the Chilean population, especially the poor people in Concepcion and in the towns which have been devastated by the tsunami wave on the Chilean coast.

Willy Benz at ESO.

Every week, on Thursday afternoons, ESO hosts the Munich Joint Astronomy Colloquium. This is organized by all the astronomical institutes in the Munich area (there are quite a few). The idea is to invite leading scientists to give an overview on a specific field of astrophysics. Yesterday it was the turn of Willy Benz, professor at the University of Bern. Willy is an expert in numerical simulations. I remember the first time I met him, at a NATO school in Spain, back in 1995. At that time he was doing Smoothed Particle Hydrodynamics (SPH for short) simulations of supernova explosions. However, if you look at his publications, you will see that he has done lots of work in the planet formation field, where he has applied his hydrodynamical models to study the accretion of planetesimals, impacts, crater formation and stuff like that. And, in fact, the title of yesterday’s talk was “What have exoplanets told us about planet formation?”.

Willy Benz explaining the Neptune-Peak. In the plot you can see the broad Jupiter-Peak (which Willy is indicating), the Neptune-Peak (in the middle) and the Earth-like peak (to the left).

As expected, given the appealing subject, the auditorium was full. Willy has started giving an introduction on the planet formation basics, as we understand them now. He started off saying that for many, many years, before the discoveries of exo-planets, it was believed that big planets (Jupiter-like) do not form close to their central star. Joking, Willy said this was based on many, many years of observations and studies on one single case (our Solar system). As it often happens in science, the first exoplanet, which was discovered in 1995 by Michel Mayor and Didier Queloz using ESO telescopes, destroyed this castle of ideas in one single shot. “This is one of those cases” - said Willy - “where one observation is sufficient to blow up a theory“. Since then, more than 400 exo-planets have been found, and the vast majority of them populates what was believed to be a forbidden region. Part of this is certainly due to an observational bias, in the sense that with the current instrumentation it is easier to discover massive planets that move fast (i.e. are very close to the central star. This is why they are also called hot-Jupiters).

What Willy and his collaborators have done, is to produce with hydro simulations synthetic populations of planets, and compare them to observations. The experimental data we have for each single exo-planet does not tell us very much in itself. The real power comes from statistics: that is the place where theoretical models and observations can be compared. “The discovery of the whole population of exoplanets is essential to provide important constraints on planet formation models” - said Willy. Although the planet formation field is still driven by observations, theory is starting to make some quantitative predictions. “If you believe the models (which you probably shouldn’t) - joked Benz - “we expect to see the Neptun-Peak coming up and, in the future, the big peak of Earth-like planets“. In fact, their models predict that the number of planets having characteristics similar to our Neptune (10 AU distance from the central star and Neptune mass) should be rater large (there the name of Neptune-Peak). From the observational point of view, unveiling this kind of planets requires a very high precision. Now we can measure velocities up to about 1 meter per second accuracy, with instruments like HARPS. In the future, we will be able to go down to 10 cm per second. The new high resolution spectrograph ESPRESSO is designed exactly for that purpose. This will allow us to detect planets well below the 10 Earth masses limit, and give us the opportunity to see whether, indeed, Earth-like planets are rare or not.

What I liked in Willy’s talk, besides of course the underlying physical robustness of his science, is his way of presenting things, always cum grano salis and within a wide astrophysical context, not too detailed but also not too generic.

Great speaker, great talk, great science.

Science Day at ESO

The staff of the European Organization for Astronomical Research (ESO) includes people coming from very different fields. Given the fact that we design, build and operate telescopes and instruments, our teams are composed by a mixture of mechanical, optical, electronic and software engineers plus, of course, some astrophysicists. These have a double life within the organization, since they do functional work for the organization, but also their own research (up to 50% of their working time). The purpose of this is rather clear: if the organization wishes to keep scientifically linked to the community it is serving, than at least a fraction of its staff must be active in research. By construction, since ESO is not a university, there are no large scientific groups and most of us are part of large international collaborations. Also (and this is done on purpose), the scientific staff of ESO covers a wide spectrum of astrophysical fields, so that within the organization is rather rare to have two people working on the same subject.

Exactly because of this, it often happens than one does not exactly know what the guy sitting in the next office is doing in her/his science time. With the purpose of reducing this potential problem and to stimulate possible collaborations within the staff, the Office for Science at ESO organizes every year the so called Science Day, where everybody is given the opportunity of telling the others what she is doing. And this is what happened yesterday. The overall organization has been growing significantly during the last ten years, so that now what we call the ESO Faculty includes more than 80 scientists, ranging from PhD students to full astronomers. So, in order to fit more than 80 talks in about 8 hours, we were given 4+1 minutes for our presentations. The sessions were chaired by some of our post-doc Fellows.

It is always amazing to see how many different and interesting topics one can work on in astrophysics (I guess the same is true, though, for any other scientific discipline). We heard about the contribution of comets to the content of water on Earth, methane on Mars, very old stars in the Galaxy, stellar seismology, optical interferometry… you name them.

Besides giving old farts the chance to see what the youngsters are doing and where astrophysics is moving to, it was also a good opportunity for the young researchers to get familiar with presenting their work in front of a large audience. An exercise which might turn to be very useful for their future careers. Well done, lads.

The SW embankment of the castelliere in Galleriano (photo by F. Patat).

As I discovered in the initial phases of the study, the issue about the orientation of these sites had been already raised by other researchers. The first written reports (in the ’40s of last century) were mentioning that they all had the vertexes aligned along the cardinal axes. The same conclusion was reported also in several archaeological studies. But, most important of all, a more astronomically-oriented analysis had been published in 1986 by Aveni and Romano on the Journal for the History of Astronomy. Anthony Aveni is one of the most famous researchers in Archaeoastronomy and he has written many papers and books on this subject. This was more than sufficient to stimulate my curiosity, besides being a clear challenge. The first step was to establish a contact with archaeologist Dr Susi Corazza, who is working at the Laboratory of Protohistory at the University of Udine. She gave me several reports of archaeological digs carried out in these sites in the last ten years and she also invited me to visit an open excavation in Galleriano, one of the three well preserved sites.

Archaeological dig in Galleriano. Well visible is the cross section of the embankment.

There I was exposed to a completely new way of doing research. I could walk over the embankment, watch the stratigraphic sections, have samples of earth in my hands, smell the freshly excavated soil… a contact to objects which is forbidden to astrophysicists. And, most important of all, having to do with human artifacts. The excavation campaign, supervised by Susi, was conducted by undergraduates, PhD students and post-docs, under the hot sun of August. I must say I felt several times overwhelmed by emotions.

Two of the sites had been surveyed from the ground by the University using a classical ground-based total station, while for the third (Savalons) nothing was available. For this one I had a different idea. In fact, there is now the possibility of getting a 3D mapping of a site using an airborne laser device. This is typically used for civil purposes, like topography and the like, bit it has been used also for archaeology.

3D rendering of LIDAR elevation data for Savalons (Credit F. Patat).

The concept is very simple. A laser beam is sent down, reflected by the soil and received back by the device, which is capable of measuring the time it takes the signal to come back, with extremely high accuracy. If you then know precisely where your device is, you can then reconstruct the elevation profile of any 3D structure, with centimeter accuracy. Easy, uh? Well, yes, but it requires some expensive equipment and an helicopter. This is why I contacted HELICA, a local company, which is specialized in this kind of work. “We have never done this before” - said to me Diego Plos, Helica’s Director - “so we’ll give it a try and see what comes out of it”. And, yes, they did it. In a matter of a few seconds the LIDAR (that is the name of the device) has collected about a million points, spaced by about 30 cm. Amazing! A ground based survey of these structures takes many days, to collect a thousand points at most. Not only, but based on the properties of the reflected light, during the post-processing phase one can distinguish between ground and false-ground data (produced for instance by foliage). The data are so good that you can see the signs of cultivations in the fields.

Aerial view of Savalons (orthophoto - credit Helica).

But most interesting of all, the geometry of the site (approximately 180m on a side) appears very clearly. Clearly, the orientation analysis with digital, geo-referenced data is just a matter of computer skills and the smell of the archaeological digs is already far away.To complete the analysis (terrain slope, horizon) I also made use of the Shuttle Radar Topography Mission, which is essentially based on the same principle and it uses a radar instead of a laser. With this, for instance, I can check whether a site has been aligned along the direction of maximum slope, something which was typical in the Roman centuriation to favor the draining of rain water. Or I can try to see whether the orientation was done along the direction to some remarkable structure on the natural horizon, like a far, high mountain peak.

In fact, in archaeoastronomy is rather easy to be carried away and see alignments everywhere. This is actually a bit of a plague in this field, and the enthusiasm brought about by the findings in Stonehenge and the like has created a generation of improvised researchers, who have not exactly followed scientific criteria in their studies. Therefore, more than a grain of salt is necessary. And this actually makes the whole thing attractive for a scientist. The analysis is almost over and I am now convinced that there is no alignment to astronomically significant directions in these proto-historical sites. Even the orientation to cardinal points, suggested by early investigations (and reported more by tradition than by measurement), does not hold. At this point you might wonder whether the disproval of previously reported “facts” is really useful. Well, yes, it is. Here in archaeo-astronomy as well as in astrophysics or in any other science, for that matter.

The human skeleton found below the mound close to Savalons (credit University of Udine).

Meanwhile the archaeological digs have continued. Most remarkably, Susi and her collaborators have opened the mound close to Savalons, finding a human body deeply buried under it, which has now been dated around 1800 b.C. You can watch a movie about this finding here on YouTube.

If they’ll keep finding tombs like this (this is the 3rd one), we will be in the condition of starting an analysis about the orientation of proto-historical graves in the High Friulian Plain. This is another interesting topic connecting human life (well, actually human death) with astronomy. An example study can be found here.

In a subsequent post I will report a bit more in detail about the kind of analysis I have performed on the three sites.

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Map of St. Martin (Artegna-Italy).

I like astronomy very much at the level that I can say mine is not a profession, is rather a passion. But there are gray areas here and there. One of them, maybe the most important, is the level of abstraction it brings about. Having to deal with very far things, far in space and time, with no possibility to touch them, adds to the generic frustration that any scientist, if you look deeply enough, has to deal with. In astronomy, the closest you can get to your “object” is working on Solar System bodies. In some cases, you can even hope to get some extra-terrestrial piece of matter in your hands, dissection it, run chemical and physical analysis. But this is rather the [extraordinary] exception than the rule. For extra-galactic guys, like me, no way. Well, yes, maybe when a close-by Galactic Supernova will go off then we will have the chance of receiving even particles. But that might be the last thing we do

More seriously, at some point in my life, just before leaving for Chile, I started feeling a strong need for reconnecting to reality, to the day-to-day world, to humanities. How a supernova guy would do that without abandoning his profession was not clear for quite a while.

Sunset at St. Martin (Artegna-Italy) ten days after Vernal Equinox.

But the quest brought me somewhere. I have quite strong roots deeply planted in my homeland. And in the months preceding my departure to Chile (at that time I had no clue about how long I would stay there), I started reading all the books about the history of my small village. The eldest thing we have there is an ancient church, dedicated to St. Martin. When the Longobards  entered the Italic soil, they established in that area their first Earldom and, having a long knight tradition, they devoted many a church to St. Martin, S. George and St. Michael, all coming from a military tradition or having something to do with horses and knights. In one of the books there was a mention about the fact that St. Martin, rising on top of a prominent hill, like many ancient buildings, was oriented along the east-west axis. That was the start of it, because my attitude to measure things immediately generated the question about the accuracy of such an alignment.

Measuring the natural horizon at St. Agnes - Gemona del Friuli.

So, using rather simple methods, I measured the azimuth of the church’s axis, finding that it deviated  only 0.7 degrees from the geodetic E-W line. At that time I had not so much money, I was just out of my PhD and we had a 3 months baby. Chile was appearing close to the horizon and so I postponed any further study in that direction. But for the two following years I nursed this idea and I started a self-training in this discipline, which was indeed bringing me back to man through astronomy. I had finally found a way to reconnect to reality without giving up or betraying my “credo”. When, two years after, I got a position here at ESO-Garching (Germany), those places were much closer. I had some more money and I could afford buying a second hand Zeiss theodolite and a GPS receiver (at that time not so diffused as they are today). Equipped with this, a background in spherical astronomy, some home made software and lots of good will I started getting acquainted with the required techniques. I first started with ancient churches in Friuli, some of which were originally built around the V-VI century a.C., all erected on high hill tops. And something interesting indeed came out of it, bringing about a new kind of emotions, which my main research field could not have given me, by construction.

Castelliere (artist's impression).

Encouraged by the results I then moved one step further, and I started an orientation study on three proto-historical sites (about 1800-1500 b.C.) in the High Friulian Plain, in collaboration with the Laboratory of Proto-History of the University of Udine. These are large (150-200 m on a side) earthworks, usually called castellieri, with embankments that can reach 5 meters in elevation above the surrounding plane, and base widths reaching 20 meters. Imposing manufacts, indeed. If you know where they are you can easily see them in GoogleEarth (see the pictures below). Their purpose is not really clear, but the archaeologists think they were used as fortified villages. Although in the High Friulian Plain there are remnants of many such sites, only three are rather well preserved. The others have been leveled mostly  during the intensive agricultural activities that took place last century. These three sites have a roughly quadrangular form, in contrast to other similar structure seen for instance in Istria, which had a circular shape. This of course offers the possibility of running an orientation analysis. I will tell more about this in the next post.

The castelliere of Savalons (GoogleEarth).

The castelliere of Galleriano (GoogleEarth).

This has nothing to do with Astronomy (or maybe it does, but this it is not so important). I am just back from the Prinzregenten Theater in Munich, where David Fray gave a very impressive concert, playing Schubert and Bach. What amazes me is how actual and vivid Bach can sound in the hands of Fray. All that geometry transfigured into passion… Have a look to this and you’ll tell me. Certainly the guy is eccentric (and a beautiful man, ladies tell me), but when he plays Bach he brings about something I had never heard before. Bach and Astronomy are so strictly related in my own experience that I could not resist to share this with others.

Good night.