Endel Lippmaa

His father Teodor Lippmaa (1892–1943) was a botanist and plant geographer: a Tartu natural sciences graduate in 1925, docent from 1926, professor from 1930, director of the Institute of Botany and of the Botanical Garden. Eesti Entsüklopeedia counts him among the founders of the synusia method and credits him with Estonia’s vegetation classification of 1933 and its plant-geographic regionalisation of 1935. His mother’s father was the writer Jakob Mändmets. Two very different Estonian traditions in one household: village prose on one side, university botany on the other.

On 27 January 1943 a bomb from a Soviet aircraft hit the Lippmaa flat in the Tartu Botanical Garden. Professor Teodor Lippmaa, his wife Hilja and their daughter Siiri were killed. Endel survived because he was not at home. Aleksander Rebane and Raivo Stern’s obituary in Physics Today (2016) dates the bomb to 1942 and adds that the boy was at a film in town; Estonian sources and Wikipedia date it firmly to 27 January 1943 and say only that he was away. No other source that reached this page confirms the cinema, and the page leaves it open.

A week later, on 3 February 1943, Postimees carried an item on Teodor Lippmaa. Estonia’s digitised newspaper archive still holds it. The archive could not be opened from the environment this research ran in, so the item’s date and title are established and its contents are not — one of those places where the evidence exists and is out of reach.

What falls between those two dates — January 1943 and finishing Nõmme Gymnasium in 1948 — is in none of the sources reached here. Where he lived, with whom, what school he attended before Nõmme: the Academy of Sciences obituary gives the year and the school and says nothing else about those five years.

Eesti Teaduste Akadeemia: Endel Lippmaa (1930–2015) · Eesti Entsüklopeedia: Teodor Lippmaa · Wikipedia: Teodor Lippmaa · Estonian Writers Online Dictionary: Jakob Mändmets · Aleksander Rebane, Raivo Stern: Endel Lippmaa. Physics Today 69 (8), 65–66 (2016) · DIGAR: Postimees, 3 February 1943 (unopened)

Oil shale was the Tallinn Polytechnic Institute’s own subject. The Estonian encyclopaedia article on oil-shale chemistry counts Paul Kogerman, Agu Aarna and Endel Lippmaa among the field’s leading names — which places his early career inside an established Tallinn research tradition rather than in isolation. Whether Kogerman, of the older generation, ever taught him personally is not stated there.

Rebane and Stern’s obituary in Physics Today names Agu Aarna, the leading Estonian oil-shale chemist of the period, as his supervisor. No Estonian source reachable here confirms the supervision, and the same English text renders the Soviet candidate’s degree loosely as a PhD — so this page reports the claim with that caveat.

From 1956 to 1961 he worked at the Tallinn Polytechnic Institute as a senior lecturer and then as a docent. These are the years of his late twenties, in which he stepped out of oil-shale chemistry — and they are the least documented part of his career in every source read here.

Õpetajate Leht’s obituary states the turn plainly: after the oil-shale work of his candidate’s degree, Lippmaa turned to an entirely new field, nuclear magnetic resonance spectroscopy, in which he then worked for roughly half a century. Why he turned, or who showed him the technique, the obituary does not say. The thirteen years between his candidate’s and doctoral degrees span exactly that change.

Eesti Teaduste Akadeemia: Endel Lippmaa (1930–2015) · Õpetajate Leht: suri akadeemik Endel Lippmaa · Estonian Wikipedia: oil-shale chemistry · Aleksander Rebane, Raivo Stern: Endel Lippmaa. Physics Today 69 (8), 65–66 (2016)

The obituary does not assert the priority flatly, it hedges it — and this page repeats that caution. What he did is not in dispute: vacuum tubes, an electromagnet, and an instrument that produced spectra. In what room, with which magnet and to what resolution, no source reached here gives; the only hard instrument figures found are from 1978, not from the home-built machine.

In the autumn of 1961 a physics sector was set up at the Institute of Cybernetics, and it came to be called the Lippmaa sector. He headed the institute’s physics division from 1961 to 1980 — nineteen years in which the NMR group grew. The Institute of Cybernetics itself had been founded on 1 September 1960.

In 1969 he defended a doctorate in physics and mathematics in Moscow, at the USSR Academy of Sciences’ Institute of Chemical Physics, on “The Overhauser nuclear effect and the structure of organic compounds”. Thirteen years after oil shale. In 1971 he became professor of chemical physics and physical chemistry, in 1972, at forty-one, he was elected a corresponding member of the Estonian Academy of Sciences, and in 1975, at forty-four, a full academician — so the Academy’s chronology has it; the memorial notice and the obituaries say simply that he was elected a member in 1972. Either way, young by the standards of the Soviet academy system.

One story from those years survives without any instrument figures at all. ERR reports that the first NMR transmitter was a shortwave radio set. And the Japanese magnets are said to have been so heavy that the laboratory needed double floors. Neither can be checked; both are here because they describe what doing front-rank physics in Tallinn in the 1950s and 1960s meant.

Aleksander Rebane, Raivo Stern: Endel Lippmaa. Physics Today 69 (8), 65–66 (2016) · Eesti Teaduste Akadeemia: Endel Lippmaa (1930–2015) · Õpetajate Leht: suri akadeemik Endel Lippmaa · ERR: akadeemik Endel Lippmaa · Substantia: Estonian scientist in USSR (2020) · Estonian Academy of Sciences: the Academy’s chronology

What it showed is easy to say and was hard to do. The chemical shift of silicon-29 in a silicate depends on how many neighbouring silicon tetrahedra are joined to it through oxygen: Q0 an isolated tetrahedron, Q1 one neighbour, up to Q4 with all four corners shared. Those five states give separate lines across a window of roughly −60 to −120 ppm. Which means a powder can be read for how polymerised its silicate is — without breaking the crystal.

Three things had to work at once: spinning at the magic angle, which removes the chemical shift anisotropy; a high enough spinning rate, for which the spinners were built in Tallinn; and an instrument sensitive enough, because silicon-29 is only 4.7 per cent of natural silicon. The third author was the twenty-four-year-old Ago Samoson, whose speciality spinning speed then was and remained.

It was not one laboratory’s work. The co-author Günter Engelhardt worked in East Berlin, at the GDR Academy of Sciences’ central institute of physical chemistry, and that institute’s history of zeolite research credits him with starting, by working with Lippmaa in Tallinn, ten years of international work on the NMR of solid inorganic silicates, zeolites above all. The fifth author, A.-R. Grimmer, published a German parallel paper the same year on chemical shift anisotropy in thaumasite.

Writing in Physics Today on 21 August 2015, Charles Day calls it his most cited paper and gives 969 citations on Google Scholar — the only concrete figure that reached this research, and a count as of that day. The claim that it is the most cited scientific paper ever produced in Estonia was found in no source at all, and this page does not make it. But what the Q labels were built for lives on elsewhere: cement chemistry uses the same vocabulary to follow hydration, the Q0 clinker signal giving way to Q1 end groups and Q2 middle groups as the calcium silicate hydrate chains grow.

Mindat: the full citation of the 1980 JACS paper · Günter Engelhardt, Hubert Koller: 29Si NMR of Inorganic Solids. Solid-State NMR II, Springer, 1994 · Charles Day: Endel Lippmaa. Physics Today online, 21 August 2015 · Cement and Concrete Research: Q states in hydration · Zeolite research at the GDR’s central institute of physical chemistry · Estonian Wikipedia: Ago Samoson

What came out of it was bigger than one paper. In 1988 Samoson, Lippmaa and Alexander Pines published double rotation — DOR — in which the sample spins about two different axes at once: an outer rotor at 54.74 degrees, an inner one at 30.56 degrees to the outer axis. One angle removes the second-rank interaction; two angles remove the fourth-rank one as well, which is what broadens the lines of quadrupolar nuclei.

The same year brought another route: Llor and Virlet published dynamic-angle spinning, in which one rotor is turned in turn to two different angles. In 1989 DAS and DOR appeared side by side in Nature as oxygen-17 spectra. Neither contradicted the other — this research found no priority dispute between them. And in 1995 multiple-quantum MAS undercut both: the same result with an ordinary single rotor and no special hardware.

Spinning rate is the number this field is measured by, and Tallinn is on its graph throughout. MAS began at 7 kHz in seven-millimetre rotors. In 1999 a two-millimetre rotor in Tallinn reached 50 kHz; the sources disagree on whether the first 40–50 kHz probe was finished in 1999 or 2001. In 2020 a 0.5-millimetre prototype from Tallinn gave 150 kHz. Today’s ceiling for cylindrical rotors is about 170 kHz — which is over a hundred thousand revolutions a second.

The institute itself survived the reorganisation of the Academy in the 1990s and got its own act of parliament in 1998. Nine academicians, Lippmaa among them, came out of the Institute of Cybernetics it grew from, as Estonian World Review counts them. Today the building at Akadeemia tee 23 holds four Bruker spectrometers, including an 800 MHz machine from 2007, and the Estonian Magnetic Laboratory works at 18.8 tesla; it gets through ten thousand litres of liquid helium a year. Lippmaa was director from 1980 or 1982 — the sources give both — until 2001.

Estonian Wikipedia: KBFI · Aleksander Rebane, Raivo Stern: Endel Lippmaa. Physics Today 69 (8), 65–66 (2016) · Samoson, Lippmaa, Pines, Molecular Physics 65 (4), 1013–1018 (1988) · ISMAR: Andy Byrd, Endel Lippmaa passed away (1 August 2015) · Estonian World Review: Küberneetika Instituut 50 · Postimees: KBFI ehk Eesti kõige-kõigem instituut

The problem was not the text. Photocopies of the pact and the protocols had been known since 1945: Karl von Loesch had buried microfilms of them, at the end of that May he met the head of the British documents team and the films passed to the Allies, and English translations were published in Washington in 1948. The problem was proof. With no certified originals to set beside them, Moscow could dismiss the copies as Western forgeries — that is how Charles Day states the difficulty in Physics Today. This page’s own conclusion: what was decisive was not the text but the certification.

On 2 June the Congress held a long and sharp debate over whether the commission was needed at all, and Lippmaa put the Estonian position from the floor. Estonian accounts credit his active work with Mikhail Gorbachev in the Congress presidium with getting it through — one account says he had himself been elected to the presidium, which is what put him within reach of Gorbachev. The commission had 26 members, chaired by Alexander Yakovlev. Who the Estonians on it were is not settled: one list gives Lippmaa, Gräzin and Lauristin, another adds Savisaar.

And then the part that is exactly one scientist’s own. Permitted to travel west, Lippmaa went to a scientific conference in the United States, selected the suitable documents — the Estonian émigrés Ann and Arno Liivak had found them in a US archive — and had them reproduced at his own institute, KBFI. On 11 December, 2 250 pink booklets were driven in two cars to the Palace of Congresses in the Kremlin and handed out to the deputies. Where exactly the copy came from is not settled: several Estonian summaries say the US National Archives, Ivar Raig’s detailed account says the State Department archive.

On 23 December the commission’s resolution was voted down at the first attempt. At Arnold Rüütel’s insistence an emergency meeting was held, at which F. Kovalyov produced copies of the protocols together with documents recording their transfer, and it was decided to make them public in Moscow and to demand a fresh debate and vote. On 24 December 1989 Yakovlev reported the results and the resolution passed in a roll-call vote, 1 432 for and 252 against. The Congress declared the Molotov–Ribbentrop Pact and its secret additional protocols legally baseless and void from the moment of signing.

Ivar Raig Postimehes: MRP tühistamine riiklikuks tähtpäevaks · Riigikogu Toimetised: Ivar Raigi käsitlus · Charles Day: Endel Lippmaa. Physics Today online, 21 August 2015 · Lituanus 35 (1), 1989: The Molotov-Ribbentrop Pact: The Documents, editor’s introduction (issue editor Saulius Sužiedėlis) · “Eesti iseseisvus võideti Moskvas”, edited by Andres Adamson (Argo, 2016)

On 11 March 1990 he chaired the opening session of the Estonian Congress. He was a member of the Estonian Committee from 1990 to 1992 and a minister without portfolio in Edgar Savisaar’s government and in Tiit Vähi’s second and third — two titles, East Minister and Euro-Minister, which give the range of his politics in one line. In March 1995 he was elected to the VIII Riigikogu on the list of the Coalition Party and the Rural Union, which won 41 seats.

He was not pleased with every victory. On 28 June 1992 he campaigned against the constitution; the referendum passed it by about eleven to one. That is where the two Lippmaas argue with each other: the sovereignty fighter who insisted restoration run through 1940 citizenship and nothing else, and the Euro-Minister who spoke of Estonia’s place in the European Union. The sources give both and do not join them up.

The honours came from both sides. The AMPERE Prize in 1994; the Order of the National Coat of Arms, second class, and the Estonian National Science Prize in 2000; the National Thought Prize in 2006; the Order of Holy Bishop Platon in 2013. Three honorary doctorates: Jyväskylä 1975, Tallinn 1991, Tartu 1999. Foreign academies: Finland from 1990, Sweden from 1992. In 1999 he was voted one of the hundred great Estonians of the twentieth century.

He died on 30 July 2015, aged eighty-four, and is buried at Tallinn’s Forest Cemetery. On the day of the funeral ERR carried Ilves’s words that he was never comfortable. A post by the journalist Anneli Reigas on the blog News from Estonia (27 August 2015) carries the words “Estonia’s silenced hero” in its headline, implying his part in the pact affair was under-acknowledged at home — which sits badly beside the presidential tribute and the state funeral coverage of the same weeks, and this page does not settle it.

Vaba Eesti Sõna: lahkus akadeemik Endel Lippmaa · Õpetajate Leht: suri akadeemik Endel Lippmaa · Eesti Teaduste Akadeemia: Endel Lippmaa (1930–2015) · Groupement AMPERE: the Ampere Prize laureates, 1990–2014 · ERR: Akadeemik Lippmaa saadetakse homme viimsele teekonnale · ERR: photographs of the farewell to Endel Lippmaa (5 August 2015) · The elections archive: the referendum of 28 June 1992 · Estonian Wikipedia: the Coalition Party and Rural Union