Solaris chronicles the ultimate futility of attempted communications with the extraterrestrial life on a far-distant planet. Solaris, with whom Terran scientists are attempting communication, is almost completely covered with an ocean that is revealed to be a single, planet-encompassing organism. What appear to be waves on its surface are later revealed to be the equivalents of muscle contractions.
Kris Kelvin arrives aboard the scientific research station hovering (via anti-gravity generators) near the oceanic surface of the planet Solaris. The scientists there have studied the planet and its ocean for many decades, a scientific discipline known as Solaristics, which over the years has degenerated to simply observe, record and categorize the complex phenomena that occur upon the surface of the ocean. Thus far, they have only achieved the formal classification of the phenomena with an elaborate nomenclature — yet do not understand what such activities really mean in a strictly scientific sense. Shortly before psychologist Kelvin’s arrival, the crew has exposed the ocean to a more aggressive and unauthorized experimentation with a high-energy X-ray bombardment. Their experimentation gives unexpected results and becomes psychologically traumatic for them as individually flawed humans.
The ocean’s response to their aggression exposes the deeper, hidden aspects of the personalities of the human scientists — whilst revealing nothing of the ocean’s nature itself. To the extent that the ocean’s actions can be understood, the ocean then seems to test the minds of the scientists by confronting them with their most painful and repressed thoughts and memories. It does this via the materialization of physical human simulacra; Kelvin confronts memories of his dead lover and guilt about her suicide. The torments of the other researchers are only alluded to but seem even worse than Kelvin’s personal purgatory.
The ocean’s intelligence expresses physical phenomena in ways difficult for their limited earth science to explain, deeply upsetting the scientists. The alien (extraterrestrial) mind of Solaris is so greatly different from the human mind of (objective) consciousness that attempts at inter-species communications are a dismal failure.