Information as a Building Block
Information as substrate: Shannon to emergence to it-from-qubit.
Why this path exists
The thesis: your intuition is correct and supported by serious literature — information is not just a useful description; it appears to be physically fundamental. Boltzmann's entropy is missing information. Shannon's entropy has the same mathematical form. Landauer showed erasing a bit costs energy. Bekenstein showed a region of space has a maximum information content. Wheeler conjectured "it from bit." Current quantum-gravity research literally derives spacetime geometry from entanglement structure. This is real, live, and not mysticism.
The warning that pays for the whole path
The word information does four different jobs, and most exciting claims ride on sliding between them:
- Shannon information — probability distributions, bits. Rock-solid.
- Algorithmic information — shortest program length. Precise, non-computable.
- Physical information — Landauer, Bekenstein — bits with thermodynamic or spatial cost.
- Semantic information — meaning. No settled formal definition; where most "the universe is information" claims secretly live.
When a podcast guest says "the universe is information," ask which kind. That one piece of hygiene is worth more than any book on this path.
Honest warnings
- Wolfram, pan-computationalism, and the simulation hypothesis are tempting sinks. Engage as provocations, not conclusions.
- Emergence is the most abused word in this vocabulary. Weak emergence is real and ubiquitous; strong emergence is a live philosophical question; "everything emerges, man" is noise.
- The origin-of-life field is genuinely unsettled. Assembly theory, the free energy principle, dissipative adaptation — live hypotheses, none settled.
- Popular information books slide into awe. Fine in small doses; bad as a diet. Gleick is the gold standard; Davies sometimes overclaims; Chaitin is eccentric.
- No physics degree needed for the core units; the it-from-qubit extension is the only place you'll feel the ceiling of popular writing.
How this path connects
Algorithmic information is where the Math path's Gödel/Turing material fuses with information theory. The shared quantum-information unit is the bridge to the Quantum path. IIT and consciousness-as-information belong to the Mind path — this path points, doesn't cover.
Suggested sequence
Shannon first — a strict prerequisite for everything. Then thermodynamics, algorithmic information, quantum information, or emergence in any order; the life unit wants thermodynamics and emergence first; it-from-qubit wants quantum information. Quickest taste of the whole: Colah's essay + Mitchell's Complexity + Anderson's "More Is Different" — three weeks, and you'll know whether you want more.
The mathematical foundation. Shannon's 1948 paper turned information from a vague word into a measurable quantity with units and theorems; this unit gets you fluent in that language.
Boltzmann, Maxwell's demon, Landauer, Bennett: erasing information has a thermodynamic floor — while logically reversible computation has none (real machines still dissipate; the zero is an ideal limit). Reversible gates (Toffoli, Fredkin), Bennett's compute-copy-uncompute trick, and the demon finally exorcised by its own memory. The hinge that makes information physical, not just mathematical.
Kolmogorov, Chaitin, randomness: the information content of a string is the length of the shortest program that produces it, connecting information theory to computation (Turing) and Gödel-style undecidability — including Chaitin's Berry-paradox proof of incompleteness: a system with M bits of axioms cannot prove any string has complexity much beyond M.
Reconstruction programs, qubits, entanglement: quantum information reframes QM as a theory of a different kind of information, with entanglement as a resource and its own theorems. Reconstructions of QM try to derive quantum mechanics from a few information-theoretic axioms.
The thing that makes information interesting: emergence and complexity, from Anderson's More Is Different through chaos theory and the Santa Fe Institute to the current frontier (causal emergence, scaling laws, networks). Needs a critical posture — weak emergence, strong emergence, and emergence-as-mysticism must be kept distinct.
Wolfram's cellular automata and the two claims worth taking seriously: simple rules generate irreducible complexity (Rule 30's randomness, Rule 110's universality — proved by Cook), and the conjecture that for such systems there is no shortcut — that the fastest way to know step N is to run all N steps. (Universality is proved; irreducibility-in-general is Wolfram's proposal, not a theorem.) Where irreducibility differs from chaos and from undecidability, what the Principle of Computational Equivalence actually claims, and why "the universe cannot predict itself" is partly theorem and partly speculation. Read Wolfram critically — the ideas outrun the salesmanship both ways.
Biology, origin of life, assembly theory: life resists entropy by feeding on negative entropy from the environment. Covers current attempts — assembly theory, the free energy principle, dissipative adaptation — to give life an information-theoretic foundation.
Optional extension, only if Units 4 and 5 leave you hungry — this is where current theoretical physics thinks reality might actually live: Bekenstein's black hole entropy, the information paradox, the holographic principle, AdS/CFT, and spacetime from entanglement.