Yosyp Samuilovych Shklovskyi was born in Hlukhiv, Ukraine, on July 1, 1916. He dedicated his entire life to the field of astrophysics. Nevertheless, it was his research into the possibility of extraterrestrial life that gained him international recognition.
Astrophysics in Stalin’s USSR
If one were to briefly describe the life of the eminent astrophysicist Yosyp Shklovskyi, it would resemble Liu Cixin’s “The Three-Body Problem.” This astrophysicist, who miraculously survived Stalin’s purges, dedicated his studies to radio signals from space, eventually developing an interest in the search for extraterrestrial life. He authored a book on this subject and successfully organized an international conference comprising scientists committed to this field. However, subsequent to these endeavors, the Soviet authorities prohibited him from traveling abroad.
None of this constitutes fiction. Yosyp Samuilovych Shklovskyi was born on July 1, 1916, in the Ukrainian city of Hlukhiv. His parents were ordinary local Jews, adherents of the culture celebrated by the writer Sholem Aleichem.
These were challenging times: World War I was ongoing. When Shklovskyi was two years old, the Soviet-Ukrainian War commenced, although it might be more precise to state that during that period, various armed factions traversed Ukrainian territory, and nearly all of them deemed it appropriate to perpetrate pogroms.
The Shklovskyi family endured those times; however, when Yosyp was six years old, his father passed away. Until 1930, he resided with his mother in Hlukhiv, where he pursued his education. Subsequently, his mother remarried a railroad worker, leading to his relocation to the Far East. Nevertheless, he retained a fond remembrance of his periods in that Ukrainian town throughout his life.
Following the completion of seven years of academic studies, Shklovskyi served for two years as a foreman on a railroad construction project. Subsequently, he enrolled in the Physics and Mathematics Department at the Far Eastern Institute; after two years, he transferred to the same program at Moscow State University. It was at that institution that he commenced his serious study of astrophysics. It appeared that everything was progressing as smoothly as possible.
Nevertheless, the period was once again marked by terror. The year was 1937. Roommates, students, and postgraduate students were sequentially disappearing. At the Pulkovo Observatory in Leningrad, more than a dozen scientists were apprehended. Moreover, Shklovskyi was known to be candid in expressing his opinions. He was not inherently opposed to Soviet authority; however, when a minor party official persistently issued directives, Shklovskyi referred to him as a fool.
A Communist subsequently authored a denunciation against him, accusing him of disseminating slander regarding the Soviet regime personally. Shklovskyi may have never graduated from Moscow State University; however, the official managed to meet him once more to induce his “repentance.” The future scholar then composed a statement in his own name, asserting that he was a fool.
An ardent Communist hurriedly proceeded to the party gathering to present his “evidence.” There, they examined the “certificate,” observed him, and finalized that Shklovskyi’s statements did not constitute defamation against the Soviet government, as the individual referred to as a fool genuinely was one. The matter was therefore concluded.
This was the reality for astronomers residing in Stalin’s USSR. Subsequently, the situation deteriorated further. Hitler’s invasion of the USSR compelled undergraduate and graduate students specializing in astronomy to engage in trench digging outside Moscow. Subsequently, most of these students were deployed to the front lines, from which the vast majority never returned. Shklovskyi, who was already pursuing postgraduate studies at that time, was not conscripted into the military due to significantly poor eyesight. Consequently, in 1944, he successfully defended his doctoral dissertation on the topic of “Electron Temperature in Astrophysics.”
From the Sun to the interstellar hydrogen
Yosyp Shklovskyi was, first and foremost, a theoretical astrophysicist. He began his scientific career at a time when astrophysics was undergoing a real revolution. Scientists were increasingly aware that stars were not just red-hot balls of gas, but complex plasma systems in which thermonuclear processes, electromagnetism, and hydrodynamics were closely intertwined. Shklovsky devoted his first studies to the Sun.
In 1947, the Soviet Union dispatched a substantial expedition of astronomers to Brazil to observe a total solar eclipse observable from that nation. Shklovskyi had the privilege of participating in this scientific endeavor. Naturally, the expedition was assisted by Soviet intelligence agents and became entangled in espionage activities. Nevertheless, Shklovskyi, who vividly recounted these events in his memoirs, focused his interest on the solar corona. The occurrence of the total solar eclipse facilitated the observation of this phenomenon. Based on the data obtained from these observations, Yosyp Samuilovych deduced that magnetic fields played a crucial role in the corona’s extraordinary heating. He conducted comprehensive investigations and descriptions of the emission lines within the radio spectrum, which enable scientists to ascertain the composition of the corona.
Upon returning from the expedition, Shklovskyi defended his doctoral dissertation on radio emissions from the solar corona. However, circumstances became challenging once more. As he aged, Joseph Stalin exhibited a shift from being a communist towards embodying a more Russian imperialist chauvinist attitude.
In the USSR, a campaign against cosmopolitanism was initiated, which effectively constituted an anti-Semitic witch hunt. Jewish individuals were systematically dismissed from the Sternberg State Institute based on fabricated charges. Notably, Shklovskyi was among those affected; however, his dismissal lasted only two weeks, after which he was reinstated.
By then, he was already working in a new field. Radio astronomy was just getting off the ground, and Yosyp Shklovskyi was one of its pioneers. Based on his own research on the Sun, he knew better than anyone that it is a source of radio waves that carry information about the processes taking place inside it.
If the Sun emits such radio waves, then it is reasonable to posit that every star within the galaxy does so as well. We observe the Milky Way as if from the inside, so it is not easy to assess its structure as a single system. Radio telescopes have greatly facilitated this task. Most of the interstellar matter in the Galaxy is atomic hydrogen, which emits a characteristic radio line with a wavelength of 21 cm. Shklovsky was one of the first to appreciate how important this radiation is for studying the structure of the Milky Way.
Subsequently, this specific wavelength emerged as the predominant one for the study of our galaxy and others. Nonetheless, Shklovskyi did not cease his efforts there. He theoretically predicted what the spectral lines of hydroxyl (OH) and some organic molecules should be in the radio range, laying the foundation for their search in the interstellar medium.
It must be taken into account that not only stars emit radiation within the radio spectrum, but also, for example, clouds of ionized gas and supernova remnants. During the 1950s and 1960s, Shklovskyi endeavored to demonstrate that sources of radio signals in the sky correspond to specific objects observable in the optical spectrum.
Moreover, it was revealed that radio waves can be produced even in ostensibly empty regions, which occasionally stretch over tens of light-years. This phenomenon is attributable to these regions being filled with an extremely tenuous gas. During the 1970s and 1980s, Shklovskyi persisted in his investigation of the radio emissions originating from pulsars, quasars, and other celestial objects, the existence of which was still entirely unprecedented at the time. However, his primary research focus had once again shifted.
Universe. Life. Intelligence
The most interesting thing about Yosyp Shklovskyi’s story is that he became world-famous not because of his academic work, but because of a popular science book. However, it’s worth noting that the path to writing it was quite a long one. Even as a student, he displayed a wide range of interests, particularly in history, and was a talented artist. On one occasion, a portrait he painted of a fellow student turned out to be the only image of that student after he was killed in action.
Following the conclusion of World War II, Shklovskyi dedicated significant efforts to the promotion of scientific knowledge. He delivered lectures, acted as a consultant for the production of feature films and the composition of articles, and authored press materials. One notable instance involves an article on Venus, wherein he strategically incorporated a segment of a poem by Nikolai Gumilyov, a poet executed by the Soviet authorities and whose works were prohibited.
From popularizing science, Shklovskyi transitioned to investigating controversial scientific issues. For instance, as early as the 1950s, he suggested that mass extinctions on Earth could have been caused by nearby supernova explosions. Today it is known that the Cretaceous-Paleogene extinction event was almost certainly caused by the impact of a large asteroid, so this hypothesis has lost relevance for this specific event. At the same time, nearby supernova explosions are still considered one of the potential cosmic factors that can significantly affect the Earth’s biosphere.
In 1959, two American physicists, Philip Morrison and Giuseppe Cocconi, published an article on the search for extraterrestrial intelligence, and Shklovskyi, after reading it, became interested in the subject.
Shklovskyi possessed a superior understanding of the characteristics of natural radio signals compared to others. Consequently, he was capable of offering a thoroughly scientific explanation of the expected appearance of artificial signals, identifying searching locations, and recognizing potential challenges involved. Unlike many of his predecessors, he demonstrated a profound comprehension of the scientific worldview, which enabled him to identify where extraterrestrials could feasibly fit within it.
As early as 1960, Yosyp Shklovskyi remarked in a public discourse that there are approximately one billion planets within the Milky Way galaxy orbiting stars akin to the Sun or smaller. Notably, the initial exoplanets outside the Solar System were not identified until the 1990s. Moreover, estimates concerning their overall quantity — closely aligning with those provided by the astrophysicist from Hlukhiv — did not gain widespread acceptance until the year 2010.
Shklovskyi articulated his insights on the quest for extraterrestrial life in 1962 within the popular science publication “Universe. Life. Intelligence.” This publication provides a succinct yet adequately comprehensive overview. It commences with an exposition on essential knowledge pertaining to stars, nebulae, and galaxies, aimed at equipping an extraterrestrial investigator with sufficient understanding to prevent ridicule from astronomers. Subsequently, the discourse progresses to examine life as a phenomenon within the specified universe. The text culminates with an analysis of intelligence as a manifestation of life, capable of conveying its presence through various signals.
The book remains relevant even now, sixty years after its publication. However, the most intriguing aspect pertains to a different matter. Published during the peak of the Cold War, it nevertheless reached the United States, where it was read by a young physicist named Carl Sagan — who, incidentally, was a descendant of Ukrainian Jews.
The book profoundly impacted Sagan. He subsequently published it in English, authored several of his own books on the same subject, dedicated his life’s work to the search for extraterrestrial civilizations, and gained widespread recognition for his efforts.
Incidentally, Sagan was not the only scientist who, influenced by Shklovskyi, began to explore the question of extraterrestrial intelligence and gained prominence as a result. Mykola Kardashov, the author of the renowned Kardashov scale, is also among his students.
Civic stance
It is often argued that scientists should refrain from engaging in political activities. A distinction is generally recognized between rigorous academic research and various forms of volunteer work, outreach initiatives, and similar pursuits.
Yosyp Samuilovych Shklovskyi is an individual whose very existence contradicts this assertion. He never once indicated any discontent with the Soviet regime. Instead, he merely acknowledged when its representatives conducted themselves foolishly or unjustly, identifying such actions accurately.
Following the events of the 1930s, there were no formal accusations levied against him. However, informally, he was regarded not only as unreliable but also as having generated numerous adversaries within the Soviet scientific community and among its particular members.
All of this culminated in Shklovskyi, at the height of his triumph — when “Universe. Life. Intelligence” became known throughout the world — being simply barred from leaving the USSR. This restriction lasted for nearly two decades, until 1979. In effect, they tried to cut him off from the rest of the scientific world. However, even the Soviet authorities had to allow the Burakan Symposium on the Problems of Extraterrestrial Life to be held in the USSR in 1971. It was a unique event at which Shklovskyi himself, Kardashov, Sagan, Morrison, Freeman Dyson, Marvin Minsky, and many other scientists spoke about the search for extraterrestrial life.
In 1979, Shklovskyi was finally permitted to participate in an international conference. During the event, his international colleagues advised that he refrain from returning to the USSR, yet he declined. He passed away in 1985.
