Here’s a document called “Upper and lower bounds for Alien Civilizations and Expansion Rate” I wrote in 2016. Hanson et al. Grabby Aliens paper was submitted in 2021.
The draft is very rough. Claude summarizes it thusly:
The document presents a probabilistic model to estimate upper and lower bounds for the number of alien civilizations and their expansion rates in the universe. It shares some similarities with Robin Hanson’s “Grabby Aliens” model, as both attempt to estimate the prevalence and expansion of alien civilizations, considering the idea of expansive civilizations that colonize resources in their vicinity.
However, there are notable differences. Hanson’s model focuses on civilizations expanding at the highest possible speed and the implications of not observing their visible “bubbles,” while this document’s model allows for varying expansion rates and provides estimates without making strong claims about their observable absence. Hanson’s model also considers the idea of a “Great Filter,” which this document does not explicitly discuss.
Despite these differences, the document implicitly contains the central insight of Hanson’s model – that the expansive nature of spacefaring civilizations and the lack of observable evidence for their existence imply that intelligent life is sparse and far away. The document’s conclusions suggest relatively low numbers of spacefaring civilizations in the Milky Way (fewer than 20) and the Local Group (up to one million), consistent with the idea that intelligent life is rare and distant.
The document’s model assumes that alien civilizations will become spacefaring and expansive, occupying increasing volumes of space over time and preventing new civilizations from forming in those regions. This aligns with the “grabby” nature of aliens in Hanson’s model. Although the document does not explicitly discuss the implications of not observing “grabby” aliens, its low estimates for the number of civilizations implicitly support the idea that intelligent life is sparse and far away.
The draft was never finished as I felt the result wasn’t significant enough. To be clear, the Hanson-Martin-McCarter-Paulson paper contains more detailed models and much more refined statistical analysis. I didn’t pursue these ideas further.
I wasn’t part of the rationality/EA/LW community. Nobody I talked to was interested in these questions.
Let this be a lesson for young people: Don’t assume. Publish! Publish in journals. Publish on LessWrong. Make something public even if it’s not in a journal!
Here’s a document called “Upper and lower bounds for Alien Civilizations and Expansion Rate” I wrote in 2016. Hanson et al. Grabby Aliens paper was submitted in 2021.
The draft is very rough. Claude summarizes it thusly:
The draft was never finished as I felt the result wasn’t significant enough. To be clear, the Hanson-Martin-McCarter-Paulson paper contains more detailed models and much more refined statistical analysis. I didn’t pursue these ideas further.
I wasn’t part of the rationality/EA/LW community. Nobody I talked to was interested in these questions.
Let this be a lesson for young people: Don’t assume. Publish! Publish in journals. Publish on LessWrong. Make something public even if it’s not in a journal!