Dark Matter and Cosmic Web Story

by Einasto, Jaan

  The next IAU General Assembly I participated was held in Grenoble, France, in 1976. The President of the Commission 33 Luboŝ Perek asked me to organise a session of the Commission to discuss dark matter, in particular its possible stellar origin. But I had a problem. I was member of a Soviet delegation, which this time was formed through Intourist, a Soviet organisation that manages foreign visits of Soviet citizens and foreign visitors in the USSR. The organisation was controlled by the KGB, and there were strict rules for participants of the delegation. The visit was made according to the standard itinerary of tours to France, which meant that most of time was allocated to Paris. To attend the IAU General Assembly, only a few days were reserved. The second rule for the Soviet delegates was — everybody must always be together with the rest of the delegation. The session where I had the talk on dark matter was outside the time-slot allocated for the Soviet delegation in Grenoble. Thus I contacted Luboŝ Perek and explained to him my problem. Perek understood the problem, and rearranged the timetable of Commission 33 Meetings, so that the session with my talk was shifted to the time-slot where I could participate in the session. Perhaps the most import result of this talk was that at least some astronomers started to understand that the corona is a new population with strange properties, not just an extended halo of faint stars. The other result of this visit was the meeting of the Scientific Organising Committee of the IAU Symposium on Large Scale Structure, to be held next year in Tallinn.

  Surely the most important international astronomical conference in Estonia was the 1977 Symposium, discussed elsewhere. After the Symposium we got a number of invitations to visit observatories outside the Soviet Union. During the preparations for the Symposium we had frequent contacts with the Foreign Affairs Office of the USSR Academy of Sciences. We discovered that the head of the division of the Office responsible for handling the reception of foreigners was an Estonian, a very friendly man. He gave us advice on how to prepare applications for foreign visits in such a way that there was more chance of success. First of all, it was possible to send applications from the Estonian Academy directly to the Office, which meant that the Astronomical Council as a filter is eliminated. Second, we had to follow very accurately all the stupid rules for foreign visits. Then we have in reality much more freedom. One of important rules was: we must follow exactly the dates of the visit. Actually we needed visas not only from countries we planned to visit, but also permissions from Soviet ‘competent organs’ to visit a particular country for a fixed period. An additional rule was, soon after the visit we had to give a detailed report on the results of the visit, with recommendations on how to use the results of the visit to improve the Soviet science system.

  The first person who used our new ‘system’ for visit applications was Enn Saar. He had received an invitation from Beatrice Tinsley, who was Director of the Astronomy Department atYale University. I had with Beatrice already many years of mail exchange. She was the referee of one of my papers on the star formation rate in the Andromeda galaxy. I was very interested in details of her galaxy evolution calculations, and she sent me her PhD Thesis, which contained much more technical information than the published paper in Astrophysical Journal.

  Enn had a very successful half-year visit to Yale. This was just the time when Bob Kirshner and his collaborators discovered the Bootes void. When Enn saw their results he told them that we had known and had described such big voids already several years ago (Jõeveer et al., 1977; Jõeveer & Einasto, 1978; Jõeveer et al., 1978). One of the large voids we found is located behind the Perseus–Pisces supercluster. To find a good title for the paper Yale authors even asked advice from an advertising company, who suggested “A million cubic megaparsec void in Bootes” — a really striking title. From now on voids were taken seriously by the astronomical community.

  But Enn made a mistake. A conference on the structure of galaxies and the Universe was scheduled to place just after the period fixed for his visit, but Enn wanted to attend the conference. So he applied an extension of the USA visa, but forgot to ask an extension from Soviet authorities. After his return he was accused of violating important rules for foreign visits, and was banned from future visits. The ban was canceled only 7 years later.

  I had also an accident in one of my visits. When I was a guest of the Astronomy Department of UCLA all my documents were stolen. I kept them in a wallet which was in my bag in my office. I went out from the office for only a minute. When I returned I discovered that my bag was open and the wallet and a pocket computer were gone. I purchased a new computer next day. I also searched together with George Abell all rubbish bins nearby in the hope that the thief might throw away documents he did not need, but futilely. Then I phoned the Estonian Academy and asked advice on what to do. I got an answer only a few days later. As I was told after my return, Academy officials initially suggested that I must return immediately, but then realised that it is more useful for me to continue the visit as planned. So they told me that the Soviet consulate in San Francisco is informed and shall give me a new passport. I had to go there and write an application with an explanation how my passport was stolen. After my return I had to explain the story to the Office of Foreign Affairs of the Academy in Moscow. And again in Tallinn to the Office of the Estonian Academy. I also got a ban for foreign visits. The President of the Estonian Academy asked to cancel the ban next year, so it was not so severe as in the case of Enn’s visit. But from now on I had to describe in detail the story whenever I wrote a new application for a foreign visit.

  My visits to Cambridge in 1980 and ESO in 1981 and 1985 are described elsewhere. But I would like to add a few words on some later visits. In summer 1988 a workshop on cosmology was held in Krakow, and a fairly large group of Tartu astronomers attended. We all got conference badges. I cannot remember who was the first to cross out the word ‘USSR’ and replace it with ‘Estonia’, but then we all changed our country name. One of the participants was our good friend Gustav Andreas Tammann. Many years later in one of our meetings he told me that he was very surprised at our courage in doing this. In all subsequent conferences we attended we did the same.

  In summer 1988 we had a visitor from USA: Joel Primack with his wife Nancy Abrams got permission to come to Tartu. The situation was a bit freer than in previous years, and they had the chance to stay in the Observatory for several days. We had a lot of time to discuss various topics from cosmology to the political situation in Estonia. His wife is a social scientist and a musician who likes singing. So we had in the Observatory a small concert where she among other songs performed a new song dedicated to our freedom movement. I drove them back to Tallinn, and during the trip we had time to exchange impressions on the visit. Nancy said that she had the possibility of meeting our social scientists. In her opinion our politicians were not aware how policy making worked, thus their activity looked like an amateur enterprise. Perhaps she was right. But, on the other hand, our situation was very unique, and the fall of an empire like the Soviet Union was completely different from the fall of other empires. Thus action in the style of trial-and-error was probably the only way to proceed.

  Next year there was in Heidelberg an IAU Symposium on galaxy dynamics, and Enn and I had the chance to attend. One of the participants was Ivan King. During a break we had time to discuss cosmology and more general topics. Ivan praised the Soviet Union for the perestroika policy. Then I asked: “What do you think, who is the actual initiator of perestroika?” Ivan replied: “Of course Gorbachev”.Then I answered: “ I think that the actual initiator was Ronald Reagan. He pushed Soviet Union to the corner with his Star Wars program, what Russians could not follow. So an economic collapse followed, and the only way out was to change the policy of Cold War.“ Ivan thought a bit and then agreed. Now this point of view is well recognised, but at the time not; it seems to me that I came to this conclusion independently.

  In 1989 I had an invitation to visit the Institute of Astronomy in Cambridge. Together with me were se
veral of my colleagues: Enn Saar, Ants Kaasik, and Mikhail Babadzanjants from Leningrad University Observatory. At this time events in the Baltic countries were quite often in the headlines of newspapers, and often I was asked what was actually happening. Then I decided to answer these questions openly in a seminar talk. So I did, and slides of the talk What Is Happening in Baltic Countries are still in my archive. I said that this was not a problem of Baltic countries, but the whole Soviet Empire had started to collapse. I gave an overview of the thousand year history of the Russian Empire. The Russian Empire was the successor of the Roman and Mongolian Empires. The Mongolian Empire had as its goals to expand its territory “to the last ocean”. The Russian Empire got first access to the Arctic Ocean near the White Sea. The next goals were to get access to the Baltic Sea and the Pacific Ocean. These attempts succeeded when Peter I won The Great Northern War, and Cossacks arrived in the Pacific. After the Russo–Turk wars Russia got access to the Black Sea. After World War II the Soviet Empire consisted of many layers like an onion: the central core was the Russian Federation, the next layer consisted of Soviet Republics, then came ‘Socialist Countries’ in East Europe, followed by ‘friendly’ countries like China, North Korea, Vietnam and Cuba. The last layer was formed by some African and Asian countries which were economically dependent on the USSR. Soviet leaders tried to control all these countries, but this was impossible, and now the disintegration of the Empire had started, similar to the disintegration of European Empires after WWI and II. The process was slow and painful since the Soviet Empire was a continental empire, which is easier to control than empires that consisted of a European core and overseas colonies.

  To my surprise one of the listeners asked the question: Why do you want to secede when we here build up a joint Europe? To give a fair answer I should describe the terror regime of the Soviet System, with massive killings, deportations etc. But at this time I was not ready to do this. I just described succinctly what ‘evil empire’ actually means. In contrast, representatives of small nations, such as Danes, Dutch, Finns and Swedes, understood our problems much better.

  In autumn 1989theAustralianAcademy of Sciences arranged a jointAustralia–Soviet seminar on cosmology. In the invitation Australian astronomers specially asked that observational cosmologists such as our Tartu team should participate in the seminar. So Enn and I were included in the Soviet delegation. We had the possibility of visiting all Australian astronomical facilities, both optical and radio observatories. At the end of the visit, Australian astronomers arranged an official reception, where the Diplomatic Corp was also invited. An intensive discussion started. Around Enn and me many participants gathered, they wanted to know what is happening in our countries. The most detailed questions were asked by an elderly gentleman. Finally he asked directly: What you actually want? Enn answered succinctly: Freedom. Later we were told that this gentleman was the USSR Ambassador in Australia.

  Next day the head of the Soviet delegation, Igor Novikov, and I were invited to the Embassy of USSR. Here again the main questions were on what news there was from Moscow and the Baltic countries. Novikov spoke of the latest developments in Moscow. But most questions were addressed to me. The Embassy staff was very educated; they asked matter-of-fact questions, in particular questions about the culture, education and traditions in Estonia. I explained that one of our goals was to develop scientific terms in practically every field, since education in schools and in the university was in Estonian. Then one of the Embassy staff members, a Ukrainian, said that in Ukraine higher education was in Russian because the development of all terms in Ukrainian was too costly and time-consuming. My answer was, this was really a problem in Estonia too, but our own terminology is an essential feature of our culture, so we do this.

  In the late 1980’s when I was at the ESO, Sir Fred Hoyle had a talk on the origin of life on Earth. In his opinion the seeds for life can come from space where numerous organic molecules form in gaseous nebulae: the panspermia hypothesis. In his opinion “The notion that not only the biopolymer but the operating program of a living cell could be arrived at by chance in a primordial organic soup here on the Earth is evidently nonsense of a high order”. After the talk ESO Director Harry van der Laan invited the speaker and some astronomers to a dinner. I was happy to be one of astronomers to be invited. After some time Fred started to ask for news on the independence movement in Estonia. Some years later, when Estonia was already free, we met again in Cambridge. We looked back on our earlier discussion, and I explained all the difficulties we had during this process. But luckily everything happened quietly without bloodshed. I am not a supporter of his Steady State Universe and panspermia hypotheses, but he was an extremely interesting and inspiring astronomer. A few years later he together with his coauthors Geoff Burbidge and Jayant Narlikar revised their Steady State model taking into account new observational facts.

  About ten years later I got an invitation from the Director of the Inter-University Centre for Astronomy and Astrophysics, Prof. Jayant Narlikar, to attend a small conference in Calcutta, and to visit thereafter the Centre in Pune University. So far I had had no chance to visit India, so I was happy to accept the invitation. The flight itself was interesting. Tallinn airport had at the time direct flights to Vienna, and from Vienna there was a direct flight to New Delhi, so I used this route. All local costs were covered by the Centre, so I was met at the New Delhi airport, a taxi brought me to a hotel, and very early in the next morning back to the airport. I had a first class ticket. The flight to Calcutta itself was very beautiful — to the left the whole range of Himalayas was seen on the horizon. Flights of bigger airplanes in India are scheduled for night, early morning or late evening hours. When I asked about this, it was explained to me that the runways are in daytime too hot for heavy planes to land or takeoff.

  Indian cities were completely different from everything I had seen before. Streets were full of people, cars, bicycle and auto rickshaws. In every corner I saw tiny shops for food or small items; the noise was earsplitting. Cars looked like those in Europe some 50 years ago, and almost all were rather broken. I was warned that to eat on such street places can be hazardous, because Europeans are not accustomed to Indian micro-organisms. The food for us was served in the guesthouse — a large apartment was used for this purpose. The food itself was basically vegetarian and very tasty.

  Among foreign participants invited to the small conference were Geoffrey Bur- bidge, Halton Arp and me. How I was included into this coterie I do not know. All of us had talks in the conference; Geoff was also invited to give a public lecture at the Birla Planetarium. One talk was Geoff’s presentation of his picture on the structure and evolution of the Universe. My understanding of these phenomena is different, but it is always interesting to listen to arguments from the other side.

  The trip from Calcutta to Pune was also interesting. The flight Calcutta-Mumbai was again very early in the morning, first class as in previous flight. Next was a trip by SUV to Pune, which is about a half day’s drive away. It was interesting to see — everywhere in India we saw building works, new houses, roads, airports that were rather modern. The Astronomy Center was built in 1992 following the initiative of Jayant Narlikar. The Center is located in the Pune University park, at a very quiet location. Here we had plenty of time for discussions in a relaxed atmosphere. I discovered that Geoff Burbidge is an excellent story-teller. He told us how the organisation of science in USA works, how university committees function etc.

  Of special interest to me were his recollections of galaxy rotation measurements he made together with his wife, Margaret Burbidge. The actual observer was Margaret; Geoff was assisting. The first thing to do was to find a powerful spectrograph. One unused spectrograph was found in a cellar of an observatory, and a lot of effort was needed to get it mounted at the prime focus of the 82-inch McDonald Observatory in Texas. They succeeded, and soon papers with galaxy rotation data started to appear in Astrophysical Journal. Once an accident occurr
ed — one night Margaret fell from the observing platform and was injured. But her bones were not broken, and on the next night she was observing again. So the first large collection of galaxy rotation curves was obtained. Unfortunately, the equipment they used was not sensitive enough to see outlying sections of rotation curves, thus these observations did not yield hints of flat rotation curves, which a decade later were found in many galaxies by optical and radio observations.

  Fig. 8.8 Visiting North Holland with Adriaan Blaauw, December 2006 (author’s photo).

  8.5.2 Collaboration with other centres

  During the Soviet period our cosmology team collaborated with several other astronomers. The most active collaboration was with the Zeldovich group in Moscow. Now the former Zeldovich team is spread over many different countries: Rashid Sunyaev is in Garching, Germany; Sergei Shandarin, Anatoly Klypin and Andrei Linde are in the USA; Igor Novikov and Andrei Doroshkevich in Copenhagen. Aleksei Starobinsky is still mostly in Moscow, and we have continued the collaboration with him. He is one of the best specialists in early Universe physics, and we have made use of his knowledge. One of our young collaborators, Gert Hütsi, did his PhD in Garching with Rashid Sunyaev; this collaboration is continuing.

  During the Soviet period some collaboration also started with astronomers from Western countries. The most important of these had its beginning in the visit of Enn Saar and myself to Nordita in 1987. With Bernard Jones and Vicent Martinez we started to investigate the fractal nature of galaxy distribution. This led to several publications (Einasto & Saar, 1987; Jones et al., 1988). Presently Enn is a visiting Professor at Valencia University. With Vicent Martinez and other astronomers Enn started to explore in more detail the application of statistics to the study of the galaxy distribution. The most important results of this collaboration is realised in the monograph by Martinez & Saar (2002).