From: jimruttshow8596
The conceptualization of time has evolved significantly across different cultures and periods, often influenced by the prevailing technology of the era [00:03:46]. Early forms of timekeeping relied on natural phenomena like sand, wind, and shadows [00:03:54].
Historical Perspectives
Newtonian Clockwork Universe
The advent of mechanical clocks led to Isaac Newton’s “clockwork universe” concept, where time was envisioned as an ultimate, external clock through which the universe moved [00:04:01]. Newtonian mechanics proposed that time was reversible, meaning processes could work equally well forwards and backwards [00:07:22].
Einstein’s Block Universe
Albert Einstein’s work on relative time introduced the idea of the block universe [00:04:16]. In this view, all moments in time exist simultaneously everywhere, and the sensation of passing through time is an illusion [00:08:00], [00:08:34]. This perspective implies that novelty and free will do not exist, as all events are already predetermined within this “block” [01:03:01], [01:03:09].
Sarah Walker, an astrobiologist and theoretical physicist, regards Einstein’s Universe as a “dead Universe” due to its lack of inherent directionality, especially concerning phenomena like life [00:09:07], [00:09:01]. Lee Cronin, a chemist, questions the testability of the block universe concept [00:09:30].
The Arrow of Time
The apparent irreversibility of time, often called the “arrow of time,” has several proposed explanations:
- Thermodynamic Arrow: Based on the second law of thermodynamics, this suggests that the increase of disorder (entropy) in the universe provides time with a direction [00:11:04]. A classic example is a dropped egg splattering – the process cannot be reversed naturally [00:10:55]. Lee Cronin argues that if the second law lacks a fundamental basis or mechanism, it becomes a “religious doctrine” [00:06:13].
- Cosmological Arrow: Related to the universe’s expansion from a singularity, this implies a direction from a small, ordered state to a larger, more expanded state [00:11:21].
- Causal Arrow: This theory posits that the sequence of causal relationships defines time’s direction, as events happen one after another [00:11:43]. Sarah Walker notes that irreversibility in this context needs to be an emergent property, requiring mechanisms that cause processes in only one direction, which may involve memory in complex systems like biological ones [00:13:03]. Lee Cronin adds that causation itself is evidence of time [00:14:19].
- Particle Physics (Kaon Decay): A rare, irreversible decay of the kaon subatomic particle that breaks CP symmetry [00:07:31]. Lee Cronin points out that particle physics already indicates intrinsic asymmetry through CP violation [01:05:21].
- Quantum Decoherence: The collapse of quantum states into classical states may contribute to the apparent arrow of time [00:12:31].
A common criticism of traditional theories of time is that they do not treat time as a property of objects or as having any materiality [00:04:25], [00:04:36].
Assembly Theory: A New Conceptualization of Time
Sarah Walker and Lee Cronin propose Assembly Theory, which fundamentally redefines time by treating it as an object with materiality, embedded in the structure of physical objects [00:04:25], [00:04:36], [00:04:39].
Core Principles
Assembly Theory originated from experimental measurements and seeks to bridge abstract concepts with lab-measurable phenomena [00:26:56], [00:27:09]. It proposes that time is an intrinsic physical attribute of an object, captured by the “minimal set of causal pathways” required to make it [01:00:14], [01:00:07]. This means objects are extended in time as recursive, hierarchical, modular structures that encode their own memory [01:00:02], [01:00:12], [01:00:37].
The theory measures the “assemblyness” of an object based on two key components [00:14:49], [00:14:59]:
- Number of Parts (Steps): The shortest number of causal steps required to form an object, allowing for the reuse of components [00:25:31], [00:25:37]. A higher number of steps indicates a greater improbability of formation by random chance [00:26:37]. This is distinct from traditional complexity measures (like Kolmogorov complexity) which focus on program size or computational complexity [00:18:22], [00:19:09]. Assembly Theory focuses on the physical process of construction within the universe’s laws [00:19:06].
- Number of Copies: The abundance of identical objects [00:15:23]. If an object with many parts also exists in many identical copies (e.g., ten identical iPhone 14s), it strongly suggests non-random formation [00:16:33], [00:16:37].
The assembly equation unifies these two components, giving a higher weighting to the assembly index (number of steps) [00:34:46], [00:35:13].
Memory and Selection
A key concept in Assembly Theory is that beyond a certain level of complexity, memory is crucial for an object’s creation [00:32:03]. This memory can be embodied in various forms, such as the deep genetic memory in DNA or the local metabolic memory within a cell, which are prerequisites for building complex organic molecules [00:32:26], [00:33:00].
Assembly Theory proposes that selection must predate biology [00:36:52]. Complexity does not arise randomly; it is built in steps, with the universe itself creating mechanisms for memory and selection [00:37:06], [00:37:11]. Life, in this context, acts as a “selection amplifier,” an autocatalytic network with closure that resists entropy [00:37:43], [00:37:49].
The theory suggests a sharp phase transition between non-biotic (inorganic chemistry) and biotic chemistry at a certain assembly threshold (around 13-14 steps, with 15 steps and above strongly indicating biotic origin) [00:40:28], [00:40:40], [00:41:27], [00:41:30]. While life can produce low-assembly objects, high-assembly objects require the physics of life (selection) to be present [00:43:30], [00:43:57].
Time as Depth
Assembly Theory views complex objects as having “depth in time” [01:05:41], [01:06:02]. For example, a cell implies a lineage stretching back billions of years, representing the accumulated causal steps and memory [01:05:50]. This perspective means that Assembly Theory is fundamentally incompatible with Einstein’s block universe, as it asserts that some things must happen before others [01:02:01], [01:02:09], and that novelty genuinely emerges [01:03:01].
Implications
Philosophy of Consciousness and Choice | Novelty and the Expanding Universe
The universe’s expansion signifies an increase in available options, meaning more possibilities exist in the future than in the past [01:04:03], [01:04:06]. This aligns with Assembly Theory’s focus on novelty and the building of complexity, which contradicts the static nature of the block universe [01:03:01], [01:03:09].
Emergence of Intelligence and the Fermi Paradox
Assembly Theory provides a framework for addressing the Fermi Paradox, which questions the absence of observable extraterrestrial intelligence [01:06:16].
- The Great Perceptual Filter: Sarah Walker suggests that the “great filter” might not be alien extinction, but rather our own undeveloped “technology of perception” [01:08:27], [01:08:52]. We may not recognize alien life or technology because we lack the physics to understand what life truly is or how technology evolves beyond our current understanding [01:09:00], [01:09:03]. Just as gravitational waves existed for billions of years before we developed the theory and instruments to detect them, alien phenomena might be similarly imperceptible to us [01:09:04], [01:09:10].
- Technosignatures: The theory proposes looking for “technosignatures” – evidence of massive technology, such as Dyson shells or other structures that cannot be explained by abiotic or simple biological physics [01:06:40], [01:06:55].
- Detecting Complexity Remotely: Future efforts using telescopes like the James Webb Space Telescope could seek complex molecules in exoplanetary atmospheres that exhibit high assembly numbers, indicating the presence of life or technology [01:10:11], [01:14:07]. This requires developing planetary models based on Assembly Theory to detect a planet’s “memory of past states” and its “structure of evolving complexity” [01:14:31], [01:14:39].
Probability of Life’s Evolution
Assembly Theory shifts the perspective on the probability of life’s evolution [01:18:00]. While individual events in Earth’s history might seem improbable, the entire causal chain of life is a single, interconnected structure [01:18:50], [01:19:00]. The key question becomes how much selection is required for the transition to life [01:21:28]. The theory aims to make predictions about the ease or difficulty of this transition by quantifying the conditions under which it can occur [01:19:11], [01:19:46]. Until the physics of this transition is solved, bounding the probability of alien life remains speculative [01:20:14]. Lee Cronin believes that selection is as fundamental for the emergence of biology as gravity is for the emergence of stars [01:22:38], [01:22:46].