The Great Filter is a proposed explanation for the Fermi Paradox. Robin Hanson coined the term in his 1998 essay The Great Filter. The titular Filter refers to whatever forces prevent the development of an interstellar civilization. These forces might be present at any stage of development, i.e. an "early filter" which prevents the formation of life, a "middle filter" which prevents life from attaining sentience, or a "late filter" which prevents sentient life from spreading beyond its home planet. Any of these filters could account for the lack of visible evidence for extraterrestrial life. Hanson argues that our lack of knowledge regarding the position of the filter should make us more cautious, as a "late filter" would imply that we have low odds of successfully colonizing space and our survival may be in danger.
- Very Bad News by Robin Hanson
- An empirical test of anthropic principle / great filter reasoning by James Miller
- SIA won't doom you by Stuart Armstrong
- Late Great Filter is not bad news by Wei Dai
- Planets in the habitable zone, the Drake Equation, and the Great Filter by JoshuaZ
- Beware Future Filters by Robin Hanson
- Hanson, Robin (1998) The Great Filter - Are We Almost Past It?
- SIA Doomsday: The filter is ahead by Katja Grace