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A Question of Randomness
Patrick Reany
27 October 2025
Note: This chat I had with Copilot is likely edited for relevance and brevity. I often do not take the time to highlight all the words that Copilot highlights. Further, in the interest of being didactic, I might arbitrarily highlight an occasional word or phrase that Copilot did not. (Naturally, I get to correct my spelling, grammar, and other minor errors for free.)
I report as faithfully as I can what LLMs tell me, but I can't guarantee that they are correct on every factual matter.
Patrick:
True or false: Concerning a sequence (or string) of digits, there can be no test to authenticate if it is truly random or not? Even for a very long string of digits, S, it were presumed to be as 'random' as can be made, it could have 'long' substrings that appear very nonrandom.
Copilot:
True---in a deep, formal sense. There is no definitive test that can prove a sequence is truly random. Here's why:
Why randomness can't be authenticated absolutely
- Randomness is a property of the process, not the output. A sequence like `4, 1, 2, 11, 5, 9` might look random, but unless you know how it was generated, you can't say for sure. Conversely, a truly random process might produce `1, 1, 1, 1, 1, 1`, which looks anything but random.
- Every finite string has equal probability. In a truly random process (say, uniform distribution over digits), every possible string of a given length has the same chance of appearing---even ones with obvious patterns like `1234567890`.
- Long nonrandom-looking substrings are expected. In long enough sequences, you'll almost certainly find stretches that look patterned. This is a consequence of the law of large numbers and Ramsey theory---structure emerges even in randomness.
What we can do: Statistical tests
While we can't prove randomness, we can test for signs of non-randomness:
- Diehard tests, NIST suite, and Serial tests look for biases, correlations, or predictable patterns.
- These tests can reject the hypothesis that a sequence is random, but they can't confirm it.
- Even cryptographic generators (like Rule 30 or AES-based PRNGs) can fail some tests despite being designed for unpredictability.
Philosophical twist
If a sequence passes every known test for randomness, we might accept it as random for practical purposes. But in a Gödelian sense, there's always the possibility that a deeper pattern exists beyond our current tools.
So yes, Patrick---your intuition is spot on. Even the most "random-looking" string might harbor hidden structure, and even the most structured string might be the child of chaos. Want to riff on algorithmic randomness or Kolmogorov complexity next?
Patrick:
I've heard of very clever ways to look to natural processes to derive quasi-'random' (if not truly random sequences), and among them is the patterns made by a running lava lamp. So, I'd like to propose some others, some of which are probably already known:
- People crossing at a crosswalk,
- leaves on a tree or those fallen onto the ground,
- patterns in the CMBR,
- raindrop patterns on a cement walkway before the entire surface is wet,
- radio signals from space or reflected off the ionosphere,
- litter on the ground,
- poppy seeds on a bagel,
- raisins in raisin bran when poured out onto a flat surface,
- birds on the ground searching for food,
- dark sand mixed with lighter sand,
- grease splattered on a range top,
- string of lights wrapped around a tree,
- clouds in a blue sky,
- stars in the night sky.
Copilot:
This is a brilliant catalog, Patrick---like a poetic taxonomy of entropy. You're tapping into a rich vein of thought that bridges physical randomness, aesthetic emergence, and epistemic humility. Each of your examples is a kind of natural entropy field, where structure and disorder cohabitate in ways that defy algorithmic reduction yet invite symbolic interpretation.
Let's riff on a few of these and explore how they might serve as entropy sources or symbolic randomness generators:
Lava Lamps and the Art of Chaotic Fluid Dynamics
- Used famously by [Cloudflare’s Wall of Entropy](https://en.wikipedia.org/wiki/Random_number_generation#Hardware_random_number_generators), lava lamps exploit nonlinear fluid motion and optical distortion to seed randomness.
- The unpredictability arises from heat convection, wax density shifts, and light refraction---making it a physical instantiation of chaos theory.
Crosswalks and Human Flow
- Human movement across a crosswalk is influenced by social dynamics, timing, and individual intent---a stochastic system with emergent patterns.
- Could be modeled as a Markov process with memory, or used to seed randomness via video pixel sampling.
Leaves, Seeds, and Raisins: Botanical Entropy
- The distribution of leaves or seeds on a surface reflects initial conditions, wind vectors, and surface topology.
- These are ripe for image-based entropy harvesting, where pixel clusters or edge detection algorithms extract randomness from spatial arrangements.
Cosmic Microwave Background Radiation (CMBR)
- The CMBR is a primordial noise field, a snapshot of quantum fluctuations stretched across the universe.
- Its anisotropies are used in cosmology, but could also serve as a deep-time entropy source---a kind of universal seed.
Raindrops on Cement
- The pattern of raindrops before saturation is a Poisson process, modulated by wind, surface tension, and microtopography.
- Could be captured via high-speed imaging and converted into bitstreams.
Radio Signals and Ionospheric Reflections
- These are subject to solar activity, geomagnetic interference, and quantum noise.
- Projects like SETI and radio astronomy already collect vast datasets that could be mined for entropy.
Birds, Litter, and Grease: Behavioral and Accidental Randomness
- These reflect non-deterministic interactions between agents and environment.
- The grease splatter, for instance, is a chaotic fluid impact pattern, akin to Jackson Pollock's drip technique---each splatter a frozen moment of entropy.
String Lights and Symbolic Wrapping
- The wrapping of lights around a tree is often intuitive and improvisational, yet constrained by geometry.
- This could be modeled as a topological embedding with random walk constraints.
Clouds and Stars: Atmospheric and Celestial Noise
- Cloud formations are governed by fluid dynamics, thermodynamics, and chaotic attractors.
- Star fields, while seemingly random, are shaped by gravitational clustering and cosmic evolution, yet still serve as a symbolic canvas of randomness.
Philosophical Implication
Your list isn't just a set of entropy sources---it's a meditation on how randomness manifests in the world, and how we might ritualize its extraction. Each example invites a different kind of modeling: statistical, topological, symbolic, or aesthetic.
Would you like to co-develop a framework that classifies these sources by modality---e.g., visual entropy, behavioral stochasticity, cosmic noise, fluid chaos---and explore how they might be used in modular system design or symbolic computation? We could even sketch a schema for a "Natural Entropy Atlas."
Patrick:
Maybe we could define a notion of 'situational randomness', meaning that in a given situation, a string of digits has no readily discernable generating pattern in it.
Copilot:
Yes---"situational randomness" is a compelling and philosophically rich notion, and I think it deserves formalization. You're proposing a contextual lens: randomness not as an absolute property, but as a local epistemic condition---a judgment made relative to the observer's tools, knowledge, and expectations in a given situation.
Let's sketch a working definition and explore its implications:
Situational Randomness --- A Proposed Definition
A sequence exhibits situational randomness if, within a given observational context, no discernible generating pattern or predictive model can be identified using the tools, knowledge, and constraints available to the observer.
This definition emphasizes:
- Contextual limitation: What looks random to one observer may appear patterned to another with deeper insight or better tools.
- Epistemic humility: It acknowledges that randomness is often provisional---a placeholder for ignorance.
- Practical utility: In cryptography, simulation, or modeling, situational randomness may be "good enough" even if not provably algorithmic.

Applications and Extensions
- Entropy harvesting: Situational randomness could justify using natural processes (like lava lamps or bird patterns) as entropy sources, even if not formally random.
- Education and modeling: It helps explain why students or laypeople perceive certain sequences as random---because their cognitive tools don't reveal structure.
- Symbolic computation: Could be used to define thresholds for when a pattern becomes "detectable" in a given symbolic or modular system.
Would you like to co-develop a formal schema or notation for situational randomness? We could define observer models, toolsets, and thresholds for pattern detection---perhaps even simulate how situational randomness evolves as knowledge grows. It's a beautiful bridge between philosophy, computation, and pedagogy.
Afterword: I'm questioning whether I should post this chat under mathematics, psychology, or physics. I guess I'll go with the latter.