What This Site Is Not

A trustworthy reference needs boundaries. This page says what the project deliberately avoids so that the main pages can stay useful, sober, and maintainable.

For the positive statement of purpose, see What This Site Is. For the editorial policy behind these choices, see Editorial Philosophy.

Not a Hype Site

Quantum mechanics is profound enough without inflated language. Pages should not imply that quantum mechanics is magic, that every hard problem becomes easy on a quantum computer, or that every advanced technology is quantum in the same sense.

When a topic is technologically important, the page should say what is known, what assumptions enter the model, what engineering constraints matter, and what remains difficult. Enthusiasm is welcome; overclaiming is not.

Not a Replacement for Every Textbook

This resource should be useful for learning, review, and reference, but it cannot replace every textbook, lecture course, problem set, laboratory, or research monograph.

Good pages should point outward:

• textbooks for sustained pedagogy;
• monographs for depth;
• review articles for mature research areas;
• primary papers for historical or technical priority;
• computational references for algorithms and reproducibility.

The goal is to make the landscape navigable, not to pretend that one resource can contain the whole subject at full depth.

Not a Personal Blog of Unreviewed Claims

Speculation, interpretation, and research taste have legitimate places in physics. They become a problem when they are presented as settled formalism.

Pages should distinguish:

Kind of claim	How it should be labeled
Standard theorem or textbook result	State assumptions and cite stable sources.
Convention	Link to the convention page and translate alternatives when needed.
Approximation	State regime, error scale, or failure modes where possible.
Active research	Label as active and cite review or primary literature.
Speculation	Keep it out of core explanatory pages unless clearly identified and justified.

For claim-strength language, see Evidence Labels.

Not a News Feed

The site is intended to be durable. It should not chase every announcement, preprint, device claim, or media cycle. Research-frontier pages can be updated, but they should synthesize stable patterns rather than mirror a timeline.

Recent developments belong only when they clarify a lasting concept, update a settled reference, correct an error, or belong in a clearly labeled frontier page.

Not a Formula Dump

Formulas without assumptions are dangerous. A useful formula page should explain notation, units, domains, conventions, validity conditions, derivation links, examples, and common mistakes.

For example, the expression

$$E_n=\hbar\omega\left(n+\frac12\right)$$

is not just a line to memorize. It assumes the one-dimensional quantum harmonic oscillator with Hamiltonian

$$H=\frac{p^2}{2m}+\frac12m\omega^2x^2,$$

with the usual self-adjoint realization and $\omega>0$. The surrounding assumptions are part of the knowledge.

Not an Interpretation Tribunal

Foundations and interpretations matter, but core calculation pages should not pretend to settle them when the formalism does not.

A page may say that the Born rule gives probabilities, that a state-update rule is conditional on an outcome, or that decoherence suppresses locally observable interference. It should not silently turn those statements into a proof of one interpretation unless the page is explicitly about that interpretive program and labels the claim accordingly.

Not a Particle-Data Table

Quantum mechanics connects to atomic, molecular, nuclear, condensed-matter, and particle physics, but this reference is not a replacement for specialist databases. Precise constants, particle properties, material parameters, spectral lines, and experimental limits should be cited from authoritative data sources when needed.

The Reference can provide model cards, symbols, formulas, and convention translators. It should not try to become a comprehensive data archive.

Not a Shortcut Around Prerequisites

The pages should be accessible where possible, but real quantum mechanics uses linear algebra, complex numbers, probability, differential equations, Fourier analysis, and classical mechanics. Avoiding those tools would make the subject less clear, not more clear.

Use Prerequisites Overview and Mathematical Toolkit to repair gaps. A page is doing its job when it states its prerequisites honestly.

Not a Duplicate of Canonical Pages

The one-canonical-home rule matters. If a page needs the spectral theorem, the Born rule, the harmonic oscillator spectrum, or the density-operator trace rule, it should link to the canonical explanation rather than rederive the same material every time.

Duplication makes errors harder to find and maintain. Cross-linking makes the structure visible.

Common Mistakes

• Mistaking sobriety for lack of ambition.
• Treating a draft page as a final reviewed authority.
• Asking a reference entry to do the job of a full derivation.
• Treating a preferred interpretation as if it were a standard postulate.
• Adding a formula without its assumptions, units, conventions, or validity range.
• Importing fast-moving claims into durable pages without clear labels.

References

• P. A. M. Dirac, The Principles of Quantum Mechanics, 4th ed., Oxford University Press, 1958.
• A. Peres, Quantum Theory: Concepts and Methods, Kluwer, 1995.
• L. E. Ballentine, Quantum Mechanics: A Modern Development, 2nd ed., World Scientific, 2014.
• Committee on Publication Ethics, Core Practices, for general correction and integrity principles.