Tsiolkovsky and extraterrestrial intelligence

Where is everybody? Fermi’s famous question about the apparent absence of evidence of extraterrestrials and the answers to it offered by Ball, Kuiper and Morris during the search for extraterrestrial intelligence (SETI) debates of the 1970s were anticipated in the writings of the pioneering Russian space theorist Konstantin Tsiolkovsky. Although Tsiolkovsky is most widely known for his work on spaceflight theory and his visions of humans living in space, he was also a dedicated monist who believed life existed throughout the cosmos and that we were surrounded by extraterrestrial species far more intelligent than us. To explain why advanced extraterrestrials had not made their presence known to us, or, more importantly, had not interfered with our evolution to raise us to their own level, Tsiolkovsky proposed that they were deliberately leaving us alone in the hope that we might develop “a new and wonderful stream of life that will renew and supplement their already perfected life”.