4.A. Drake and Fermi

Location

Student Union 323-A

Start Date

8-3-2022 9:00 AM

End Date

8-3-2022 10:30 AM

Description

  1. The Fermi Paradox and Doomsday: Arguments for the Prioritization of Resources / Keith Abney
    Recent work on the Fermi Paradox (e.g., by Milan Ćirković) attempts to weigh the likelihood of 'neocatastrophic' explanations for the Great Silence versus other explanations. Neocatastrophic explanations include technological civilizations becoming self-destructive, or their destruction by other causes, such as natural catastrophes like a large meteor/comet or gamma ray burst, or by attack by aliens, most likely their killer robots.
    The other explanations include several categories: first, what Ćirković terms solipsism: that reality is not what it seems, such as the simulation hypothesis or the zoo hypothesis. Second, rare-earth: the conditions that led to the development of technological life on Earth are unique, or close to it. Or third, logistic: advanced civilizations maintain themselves in places we don't see. My presentation critically assesses the relative likelihood of each category of explanation both now and in the near to medium-term future (by 2050). Implications for existential risk (the probability of Doomsday) over that timeframe will be highlighted, with corollary arguments for how we should prioritize resources in SETI (and METI) as a result.
  2. Fermi and fiction / Walter Barta
    In the Remembrance of Earth’s Past trilogy, Cixin Liu forwards a potential solution to the Fermi Paradox. What he dubs the “Dark Forest Theory” suggests that the galaxy is teeming with advanced civilizations, but that they are too afraid to contact each other, for fear of existential threat. Emerging from the concept of the “State of Nature” in the philosophy of Thomas Hobbes, this state of affairs is a trap intrinsic to competing rational agents: the mutual fear of attack leads to preemptive attack. This unfortunate scenario may be seen as game theoretically inevitable if the conditions of the game, in this case the cosmos, are setup right. Certain indelible features of space and time (for example, the speed of light, and interstellar distance, the finitude of habitable planets, etc.) could provide the right incentive structure. Certain features of history and civilization (for example, exponential growth) could exacerbate the severity of attack while discounting the possibility of cooperation. The solution to the problem in Hobbes is the production of a sovereign power with authority over all subjects. Such is the dream of other science fictions: Star Trek’s Federation, the Star Wars’ Republic, Foundation’s or Dune’s Galactic Empire, etc.. Under the “Dark Forest” model, in the event that we are the first interplanetary civilization, establishing galactic sovereignty would be imperative; or, if we are not the first, a galactic sovereignty may have already been established. But, given the state of the universe, is such statecraft too unwieldly to be viable? Or, are there other solutions to the “Dark Forest”?
  3. Interplanetary transport and the Drake equation / Margarida Hermida
    It is generally accepted in astrobiology that more planets are habitable than those which are inhabited by any form of life. Consider the classical formulation of the Drake equation: N=R*fpneflfifcL where ne is the number of habitable planets per solar system and fl the fraction of those on which life actually originates. Planets with environments suitable for life are likely to vastly outnumber planets with conditions for abiogenesis, which probably requires very specific conditions. The number of planets where life originates is a fraction of the latter. But habitable planets on which abiogenesis does not or cannot occur may still become secondarily inhabited through interplanetary transport.
    While the extent to which interplanetary transport occurs is unknown, it is certainly more probable than interstellar transport. It can include not only technological transport but also unintentional dispersal by organisms capable of surviving vacuum exposure and atmosphere re-entry (for instance, endolithic life forms). Since interplanetary transport is an additional factor which conditions the overall number of inhabited planets, it should be incorporated into the Drake equation.
    Let fo be the fraction of habitable planets with abiogenesis conditions and ft the fraction of habitable planets which become secondarily inhabited through interplanetary transport within a solar system. Then in the Drake equation, nefl can be replaced with: nefofl (primarily inhabited planets) + nefofl(1-fofl)ft (secondarily inhabited planets). Furthermore, interplanetary transport is also likely to increase the average life span of life forms and civilizations, since being present in more than one planet plausibly reduces extinction risk.

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Mar 8th, 9:00 AM Mar 8th, 10:30 AM

4.A. Drake and Fermi

Student Union 323-A

  1. The Fermi Paradox and Doomsday: Arguments for the Prioritization of Resources / Keith Abney
    Recent work on the Fermi Paradox (e.g., by Milan Ćirković) attempts to weigh the likelihood of 'neocatastrophic' explanations for the Great Silence versus other explanations. Neocatastrophic explanations include technological civilizations becoming self-destructive, or their destruction by other causes, such as natural catastrophes like a large meteor/comet or gamma ray burst, or by attack by aliens, most likely their killer robots.
    The other explanations include several categories: first, what Ćirković terms solipsism: that reality is not what it seems, such as the simulation hypothesis or the zoo hypothesis. Second, rare-earth: the conditions that led to the development of technological life on Earth are unique, or close to it. Or third, logistic: advanced civilizations maintain themselves in places we don't see. My presentation critically assesses the relative likelihood of each category of explanation both now and in the near to medium-term future (by 2050). Implications for existential risk (the probability of Doomsday) over that timeframe will be highlighted, with corollary arguments for how we should prioritize resources in SETI (and METI) as a result.
  2. Fermi and fiction / Walter Barta
    In the Remembrance of Earth’s Past trilogy, Cixin Liu forwards a potential solution to the Fermi Paradox. What he dubs the “Dark Forest Theory” suggests that the galaxy is teeming with advanced civilizations, but that they are too afraid to contact each other, for fear of existential threat. Emerging from the concept of the “State of Nature” in the philosophy of Thomas Hobbes, this state of affairs is a trap intrinsic to competing rational agents: the mutual fear of attack leads to preemptive attack. This unfortunate scenario may be seen as game theoretically inevitable if the conditions of the game, in this case the cosmos, are setup right. Certain indelible features of space and time (for example, the speed of light, and interstellar distance, the finitude of habitable planets, etc.) could provide the right incentive structure. Certain features of history and civilization (for example, exponential growth) could exacerbate the severity of attack while discounting the possibility of cooperation. The solution to the problem in Hobbes is the production of a sovereign power with authority over all subjects. Such is the dream of other science fictions: Star Trek’s Federation, the Star Wars’ Republic, Foundation’s or Dune’s Galactic Empire, etc.. Under the “Dark Forest” model, in the event that we are the first interplanetary civilization, establishing galactic sovereignty would be imperative; or, if we are not the first, a galactic sovereignty may have already been established. But, given the state of the universe, is such statecraft too unwieldly to be viable? Or, are there other solutions to the “Dark Forest”?
  3. Interplanetary transport and the Drake equation / Margarida Hermida
    It is generally accepted in astrobiology that more planets are habitable than those which are inhabited by any form of life. Consider the classical formulation of the Drake equation: N=R*fpneflfifcL where ne is the number of habitable planets per solar system and fl the fraction of those on which life actually originates. Planets with environments suitable for life are likely to vastly outnumber planets with conditions for abiogenesis, which probably requires very specific conditions. The number of planets where life originates is a fraction of the latter. But habitable planets on which abiogenesis does not or cannot occur may still become secondarily inhabited through interplanetary transport.
    While the extent to which interplanetary transport occurs is unknown, it is certainly more probable than interstellar transport. It can include not only technological transport but also unintentional dispersal by organisms capable of surviving vacuum exposure and atmosphere re-entry (for instance, endolithic life forms). Since interplanetary transport is an additional factor which conditions the overall number of inhabited planets, it should be incorporated into the Drake equation.
    Let fo be the fraction of habitable planets with abiogenesis conditions and ft the fraction of habitable planets which become secondarily inhabited through interplanetary transport within a solar system. Then in the Drake equation, nefl can be replaced with: nefofl (primarily inhabited planets) + nefofl(1-fofl)ft (secondarily inhabited planets). Furthermore, interplanetary transport is also likely to increase the average life span of life forms and civilizations, since being present in more than one planet plausibly reduces extinction risk.