DANGEROUS THOUGHTS Memoirs of a Russian Life By Yuri Orlov Translated by Thomas P. Whitney Morrow. 348 pp. $21

FIVE BILLION VODKA BOTTLES TO THE MOON Tales of a Soviet Scientist By Iosif Shklovsky Translated by Mary Fleming Zirin and Harold Zirin Norton. 268 pp. $19.95

A WESTERN colleague once asked the brilliant Soviet physicist and democrat Andrei Sakharov how his countrymen ever managed to achieve scientific advances in such a stifling political atmosphere. "Advances?" Sakharov retorted. "For every important scientific paper published by a Soviet, there are 30 published in America."

As always, Sakharov had a point. For a nation of the Soviet Union's vast size and talent, advances in science and technology have been far fewer than statistics might predict. What successes there have been have emerged despite all but impossible odds against the expression of not just scientific innovation but indeed any sort of creativity: a hermetic ideology; a hypercentralized and massively bloated bureaucracy; secrecy verging on absurdity; restrictions on travel and on communications technologies; and anti-Semitism -- all this on top of material privation and a shortage of living and working space so desperate that everyone knows exactly how many square meters is allotted to each of his neighbors.

It is not just individual talent that the Soviet regime has stifled, either; against a background of repression that has continually sapped the scientific community, periodic convulsions of larger proportions have sundered any sense of intellectual continuity. From early on, the regime destroyed countless scientists, first as bourgeois atavists and later as "smugglers of enemy {i.e., German or Jewish} ideas." Persistently, moreover, the authorities suppressed scientific theories (among them relativity, quantum physics, psychoanalysis, cybernetics and

genetics) that failed to accord with scientific materialism -- the state-enshrined philosophy that all reality resides in observable physical matter.

In Dangerous Thoughts and Five Billion Vodka Bottles to the Moon, Yuri Orlov, an emigre physicist and longtime central figure in the dissident movement, and Iosif Shklovsky, an iconoclastic astrophysicist who died in Moscow in 1985, respectively document not just their own sad, if spirited, personal histories but also, more broadly, their country's staggering, self-defeating history of squandering -- indeed cannibalizing -- its native resources of intellect and energy. Even of those scientists who were not executed, or exiled to Siberia or imprisoned, or confined to psychiatric facilities, or deprived of citizenship, many have emigrated. Even thinkers whose fate has been less calamitous have suffered losses of productivity and potential -- if not at the hand of politics directly, then starved intellectually under the society's countless impediments to the free exchange of ideas.

Yuri Orlov, a founder of the Soviet Amnesty International and Helsinki Watch groups, not only suffered many such ravages to his scientific productivity; it was precisely because he dared address their nature and origin in his "13 Questions to Brezhnev" in 1972 that the authorities consigned him to an ever-deteriorating hell of harassment, interrogation and hard labor. His ordeal ended 14 years later, in 1986, thanks only to the bizarre "spy-for-dissident" swap that freed U.S. journalist Nicholas Daniloff.

Because Orlov's life coincides more or less with the history of Soviet power (he was born in 1924) and because he has "traveled," as he puts it, "through nearly every layer" of the society -- from peasant to factory worker to army officer, Party member, high-level scientist, prisoner and exile -- inevitably Dangerous Thoughts stands up as more than just his own story: It is a testimony of countless many millions of lives that have been abused by Soviet totalitarianism.

Orlov writes his history brilliantly. A captivating storyteller, he depicts his childhood in his country's heartland with a skill that rivals that of the classic Russian novelists. With a few strokes he sketches his simple peasant uncles, rendering through them the brutality of the Revolution and the savagery of the Civil War that preceded the cruelty of collectivization -- and the destruction of individuality, erosion of trust, extinction of compassion and hypertophy of hatred that followed it. For all the poverty of pre-Revolutionary life, Orlov seems to suggest, there was a warmth and richness about it, like a pot of borscht simmering over an old Russian stove; under the Soviets, that same life acquired the tepid, soulless consistency of a thin prison gruel.

To all of this reportage, Orlov applies a capacity for clearheaded political analysis, and offers concrete democratic remedies. But life in the Soviet Union has taken its inescapable toll: While he has survived to continue in the West his work in both science and human rights, Orlov admits he has been left "a prisoner of time, with too few years left for science." Likewise "Russia," he writes, "is almost used up." MUCH AS conditions conspire to undermine effective science in the U.S.S.R., next to the humanities and social sciences many of the "hard" disciplines have been relatively free of ideology. For this reason, many Soviet researchers say, even when their first love was in the arts, they chose careers in science.

Often, fortunately, their original talents endure. In his youth, for example, the great radio astronomer Iosif Shklovsky writes in Five Billion Vodka Bottles to the Moon, he wanted to be a portraitist, but threw it aside in favor of physics. Always a vivid and amusing raconteur, toward the end of his career in the early 1980s he undertook to commit to paper a series of portraits of his life in science.

More quirky than dissident, a self-described "free spirit" and a stinging wit, Shklovsky rose from a poor Jewish childhood in the Ukraine to chair, by 1972, the astronomy program at Moscow's famed Institute for Space Research. Imbued with his country's culture, combining an almost pre-Revolutionary manner and an old-guard idealism, he presented no danger to the system. Still the state, in its perverse insistence on control, deprived him of the one thing he ever wanted: the freedom to travel abroad at will. In science, at least, Shklovsky writes, he could feel "like an adventurer paving the way into an unknown . . . land." Allowed to visit New York in 1967, he experienced a thrill at meeting his peers from abroad that is especially poignant.

It was a simple thrill, and it could only have benefitted his homeland as well. Today, as Soviets attempt to remake their society -- "tacking between old dreams and new realities," as Orlov puts it -- it is vital that they see that their worst enemy has always been not the spirit of inquiry, but the ultimately doomed impulse to suppress it. Glenn Garelik writes frequently about science and scientists in the Soviet Union.