Irony of Rheya’s “rebirth”
The clone of Rheya created by Solaris is formed from Kris’s thoughts, no different from all the other Visitors the ocean-being created, however his thoughts regarding Rheya are closely tied to guilt and thoughts of resentment as these bitter memories have been in Kris’ mind for years. Because of this the simulacra that Solaris creates is an echo of those negative thoughts: the clone Rheya is extremely emotionally needy and her desire to be constantly near Kris is smothering, suffocating experience. The slightest hint of being abandoned she immediately turns suicidal. It is ironic that what should have been a means of finding some closure for the emotional turmoil of the past turns into a nightmare and he experiences reliving Rheya’s suicide over and over again as the simulacra, though she hurts herself in the worst ways possible, is virtually indestructible, regenerating from injuries as superhuman speed.
Irony of Clone Rheya's “life”
Over time Kris learns to appreciate the clone Rheya, seeing the appearance of this simulacra of his deceased wife as a chance to make things right and he eventually falls in love with the clone Rheya. When the clone Rheya however realizes she is but a clone of the original Rheya, she experiences an existential identity crisis. Considering her life and existence a great lie and she sinks into depression and asks to be destroyed. Again, Kris is subjected to the pain of losing Rheya.
Irony of Kris Kelvin
Kris, despite being the protagonist and narrator of events for most of the novel, is a tabula rasa in that apart from his profession there is nothing more known about him. Even if he is the protagonist he is mostly an observer and chronicler of events around him and this task is carried out with a cold, distant lack of involvement. He is mostly defined through his interactions with Rheya his wife, through flashbacks, then later on through his quasi-romantic interludes with the clone Rheya.
Irony of Expeditionary Teams journals
The expedition team on Solaris meticulously keep archives full of information of what they’ve observed from the planet. The notes vary greatly as the observers as scientists coming from various disciplines. However varied their notes are one common thread binds all of it: their voluminous collection of data provides no answers. Solaris, the mimoids, the Visitors—all completely inscrutable mysteries—and all the scientists have achieved on their long stay on the alien world is a great collection of observations, nothing more.
Irony of Earth Science
The scientists are a motley crew of highly trained individuals from various disciplines. Earth science however seems to be completely inadequate to understand the the enigma of Solaris and the phenomena it creates. Traditional biology cannot explain how the Visitors are created, psychology can give no answers to how the planet-being can see into the crew’s innermost thoughts. Earth science, at best, helps the crew frame their observations of Solaris, and nothing more.