From: jimruttshow8596
The Jim Rutt Show, with guests Sarah Walker and Lee Cronin, delves into the implications of Assembly Theory for understanding and potentially discovering extraterrestrial life. The discussion touches on the Fermi Paradox, SETI (Search for Extraterrestrial Intelligence), and the likelihood of life evolving on other planets [01:06:13].
The Great Perceptual Filter and the Fermi Paradox
Sarah Walker introduces the concept of the “great perceptual filter,” suggesting that the Fermi Paradox — the apparent contradiction between the high probability of extraterrestrial civilizations and the lack of evidence for them — is not about aliens going extinct, but rather about humanity’s inability to perceive them [01:07:35]. Technology, including our sensory perceptions, evolves over time [01:07:47]. For example, early cells had single photon receptors, evolving into multicellular eyes, and then human societies developed telescopes and microscopes [01:08:10].
Walker posits that we may not have developed the necessary “perceptual apparatus” to discern the “physics of life” itself [01:08:28]. The analogy is made to gravitational waves, which permeated the universe for billions of years but could only be detected after Einstein’s theory predicted their existence and technology was developed to sense them [01:09:04]. To make “first contact” with extraterrestrial phenomena, new “technology of perception” is required [01:09:16].
Assembly Theory and Life Detection
Assembly Theory offers a new framework for detecting extraterrestrial life by grounding the concept of complexity in measurable physical properties [01:14:07].
Key implications:
- Techno signatures: Assembly Theory proposes looking for “techno signatures” beyond conventional radio waves, such as Dyson shells around stars [01:06:40].
- Detecting Complexity: The theory suggests that life and technology produce objects with a higher “assembly index” (number of steps required for their formation) than those produced by random chance [00:34:36]. This means a sharp “phase transition” is observed between non-biotic and biotic chemistry, typically around 15 steps of assembly [00:40:25].
- Life can produce low assembly objects, but high assembly objects definitively indicate the presence of “living physics” or “selection” [00:43:30].
- This boundary is a constraint where selection mechanisms must be in place to observe high assembly objects [00:43:48].
- Technological Signatures: Lee Cronin speculates that there might be another phase transition between biology and technology/intelligence [01:00:27], which can create molecules with even higher assembly indices than biology alone [00:48:08]. This suggests that future SETI efforts could look for chemical signatures indicative of advanced technology [01:07:07].
- Remote Sensing: Researchers are actively working on how to model a planet’s evolution and detect “how much memory a planet has in it of past states” or “the structure of evolving complexity” remotely using telescopes, such as the James Webb Space Telescope [01:14:12]. The goal is to detect a biosphere or technosphere rather than individual instances of life [01:14:45]. This means moving beyond simple biosignatures like oxygen or methane to look for more complex chemical arrangements [01:16:36].
- Laboratory Creation: A radical approach to “first contact” might be evolving alien life in the laboratory from scratch. This would provide a deep understanding of the “physics of life” and offer new “lenses” to interpret observations of the universe [01:09:34].
Probability of Life Evolving
When discussing the probability of life evolving on an otherwise suitable planet, Sarah Walker and Lee Cronin offer insights from Assembly Theory:
- The “Origin of Life” Problem: Walker states that statements about the likelihood of life cannot be made until the origin of life problem is fully solved. She acknowledges that while Earth-like environments might be abundant, if the probability of origin of life is extremely low (e.g., one in trillions of planets), then abundance alone doesn’t guarantee life [01:19:51]. For Walker, the alien life problem and the origin of life problem are fundamentally the same [01:20:16].
- Selection as a Universal Process: Cronin argues that selection predates biology and occurs throughout the universe [01:21:19]. He suggests reframing the question to “how much selection is required” to initiate the transition to life [01:21:28]. The universe continually undergoes selection, driving matter towards complexity [01:21:57].
- Unique vs. Common Events: While specific events on Earth might seem unique (e.g., the emergence of eukaryotes), the underlying process of persistent selection leading to complexity is common [01:21:52]. The long timescales for events like photosynthesis or the emergence of eukaryotes on Earth might suggest a “low global IQ” for Earth’s early history, implying other planets might develop intelligence quicker depending on conditions like gravity [01:22:10].
- Cosmological Context: Lee Cronin suggests that the universe has grown in “capability” over time, meaning that the first instance of intelligence might have appeared when the conditions were just right, implying that humans might be among the first to achieve this [01:10:33]. The formation of stars and heavy elements was a prerequisite for the chemistry required for life [01:11:00].