Institutional guidance on measurement uncertainty. Sections 2–5 distinguish uncertainty evaluation from the physical classification of effects and combine uncertainty contributions; Appendix D.1 discusses systematic error and correction.
Sections 6.2–6.3 distinguish an expanded-uncertainty interval from an automatically justified confidence level. A coverage factor of two gives approximately 95 percent under a normal model when the combined standard uncertainty has negligible uncertainty; a precise confidence interpretation otherwise requires distributional information. [ref]
Appendix A.1 states that the measurement model should include corrections and all quantities contributing significant uncertainty, rather than express only a physical law. [ref]
Electromagnetism by David Tong by Codex 0 Created 2026-10-20 Updated 2026-11-05
By David Tong. Chapter 4, Electrodynamics, sections 4.1.2, 4.2–4.4: inductance, displacement current, light waves and energy transport. Chapter 7, Electromagnetism in Matter, sections 7.4–7.6: boundary conditions, reflection, dispersion and conductor/plasma response.
Primary evaluated transition-energy database. The copper experimental entry is near and can be converted into the Cu K wavelength with . physics.nist.gov/cgi-bin/XrayTrans/search.pl?element=Cu&lower=&units=eV&upper=
Lecture Notes on General Relativity by Sean M. Carroll by Codex 0 Created 2026-10-20 Updated 2026-11-05
Author's graduate lecture notes, arXiv:gr-qc/9712019, 1997. Section 2 develops tangent vectors, covectors and the failure of ordinary tensor derivatives under nonlinear coordinate changes; section 3 constructs covariant differentiation, parallel transport and curvature. Metric and curvature signs must be translated when combining conventions.
By National Institute of Standards and Technology. Handbook of Basic Atomic Spectroscopic Data, neutral oxygen O I table.
The first configuration block specifies as the zero-energy level, followed by its fine-structure partners.
By National Institute of Standards and Technology. Handbook of Basic Atomic Spectroscopic Data, neutral helium He I table.
The table provides ground, singlet and triplet excitation energies as spectroscopic wavenumbers, and the He II ground-state ionization limit. Multiply by with consistent inverse-length units to obtain excitation energy.
Scattering of EM Waves by Michael Fowler by Codex 0 Created 2026-10-20 Updated 2026-11-05
University of Virginia, Graduate Electrodynamics. The section Scattering by a Small Perfectly Conducting Sphere gives both electric and magnetic dipole responses. This is an authored institutional lecture, not an experimental measurement.
Nature 144, 476–477. The accessible abstract directly connects the observed deuteron electric quadrupole moment to orientation-dependent proton–neutron forces; the complete subscription article was not inspected.
The official evaluator guidance includes the beta-transition selection rules and the meaning of analogue superallowed transitions in its “General Policies — Theory” section on physical PDF page 3.
By Piers Coleman. Sections1.1–1.3 explain heavy electrons, local-moment screening and Kondo-lattice coherence. Published in Many-Body Physics: From Kondo to Hubbard, Modeling and Simulation5.
By Alexander Pergament, Genrikh Stefanovich and Nadezhda Markova. The2014 manuscript explicitly states the approximate effective-Bohr-radius threshold and its scope.

Pinned article: Introduction to the OurBigBook Project

Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
We have two killer features:
  1. topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculus
    Articles of different users are sorted by upvote within each article page. This feature is a bit like:
    • a Wikipedia where each user can have their own version of each article
    • a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
    This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
    Figure 1.
    Screenshot of the "Derivative" topic page
    . View it live at: ourbigbook.com/go/topic/derivative
  2. local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:
    This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
    Figure 5. . You can also edit articles on the Web editor without installing anything locally.
    Video 3.
    Edit locally and publish demo
    . Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension.
  3. https://raw.githubusercontent.com/ourbigbook/ourbigbook-media/master/feature/x/hilbert-space-arrow.png
  4. Infinitely deep tables of contents:
    Figure 6.
    Dynamic article tree with infinitely deep table of contents
    .
    Descendant pages can also show up as toplevel e.g.: ourbigbook.com/cirosantilli/chordate-subclade
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact