This equation states that the number of civilizations (N) in our galaxy that we might able to communicate can be determined by multiplying the average rate of star formation in our galaxy (R*), the fraction of those stars which have planets (fp), the number of planets that can actually support life (ne), the number of planets that will develop life (fl), the number of planets that will develop intelligent life (fi), the number civilizations that would develop transmission technologies (fc), and the length of time that these civilizations would have to transmit their signals into space (L). Mathematically, this is expressed as: space science and universe science on space to know science
N = R* x fp x ne x fl x fi x fc x L
Dr. Sandberg is no stranger to the Fermi Paradox, nor is he shy about attempting to resolve it. In a previous study, titled “That is not dead which can eternal lie: the aestivation hypothesis for resolving Fermi’s paradox“, Sandberg and his associates proposed that the Fermi Paradox arises from the fact that ETIs are not dead, but currently in a state of hibernation – what they called “aestivation” – and awaiting better conditions in the Universe. space science and universe science on space to know science
In a study conducted back in 2013, Sandberg and Stuart Armstrong (also a research associate with the FHI and one of the co-authors on this study) extended the Fermi Paradox to look beyond our own galaxy, addressing how more advanced civilizations would feasibly be able to launch colonization projects with relative ease (and even travel between galaxies without difficulty).
As Dr. Sandberg told Universe Today via email:
“One can answer [the Fermi Paradox] by saying intelligence is very rare, but then it needs to be tremendously rare. Another possibility is that intelligence doesn’t last very long, but it is enough that one civilization survives for it to become visible. Attempts at explaining it by having all intelligences acting in the same way (staying quiet, avoiding contact with us, transcending) fail since they require every individual belonging to every society in every civilization to behave in the same way, the strongest sociological claim ever. Claiming long-range settlement or communication are impossible requires assuming a surprisingly low technology ceiling. Whatever the answer is, it more or less has to be strange.”