The cubit, measured

A research archive on the cubit: how ancient builders measured it, what its length means in physics, and the copper models we design from it. Facts are sourced, calculations are shown, and hypotheses are labelled as hypotheses.

palm 1palm 2palm 3palm 4palm 5palm 6palm 7 52.32 cm 0
One royal cubit = 7 palms = 28 digits. Long ticks mark palms, short ticks mark digits.

Start here

  • History of the cubit

    The Egyptian royal cubit, Norse ells and the 83 cm unit of Teotihuacan, with sources.

  • Sacred Cubit

    52.32 cm, and why a 2-metre band antenna is almost exactly one royal cubit long.

  • Tensor Coil

    How the copper rings are built and how to measure their resonance with a NanoVNA.

How every model page is written

Each model page has the same five parts, so you always know what kind of statement you are reading.

  • 1. EvidenceHistory and archaeology, with a source for every fact.
  • 2. CalculationFrequency and geometry, with every formula shown.
  • 3. SpecificationCopper, gauge, length and measured resonance.
  • 4. HypothesisThe researcher's model, kept separate from the facts.
  • 5. RelatedLinked models and further reading.

Models

Cubit instruments on this site are research and design objects. Nothing here is medical advice, and no page claims that a cubit treats, prevents or cures any condition.

Published monographs · 研究专著与公开方案

Monographs on this site's subject, published with DOIs

The Sacred Cubit and Resonant Geometry神圣肘尺与谐振几何

Measuring the Egyptian Royal Cubit, the Quarter Wave and the Bifilar Ring · 古埃及肘尺、四分之一波长与双绞铜环的测量研究

Five measurable questions about the royal cubit: museum rod lengths, λ = c/f resonances, twisted copper rings, orthogonal ring geometry, and a home bench with NanoVNA and RTL-SDR. Predictions are stated in advance and raw data are published as measured.

从都灵、卢浮宫、大英博物馆的肘尺实物出发,用可复现的测量回答五个问题;预测事先写明,原始数据原样公开。

Fan Yafu 范雅福 · 5D Library, 5DL-B-003 · version 1.0.0, 2026 · Preface + 5 chapters · 序 + 五章 · free to read, CC BY-NC-ND 4.0

Disclosure: this site and 5D Library are run by the same group, which makes and sells the rings and coils discussed in the book. The book makes no health or medical claims. 说明:本站与 5D Library 同属一个集团,集团制作并销售书中讨论的铜环与线圈;本书不作任何健康或医疗声称。

Crystal Piezoelectricity, Iron-Nickel Meteorites and Photobiomodulation晶体压电性、铁镍陨石与光生物调节

Alpha-Quartz, Tourmaline Pyroelectricity, Widmanstätten Diffusion and Near-Infrared Cytochrome c Oxidase

The real physics behind stones and light, and how large it is: the piezoelectricity of quartz and the quartz resonator, the pyroelectricity of tourmaline, the Widmanstätten pattern as a record of cooling over millions of years, light in tissue and the biphasic dose of red and near-infrared light, the Schumann resonances and earthing, with four physical checks and a double-blind trial against a heat-matched sham.

石英压电与谐振器、电气石热释电、魏德曼花纹记录的百万年冷却、组织光学与红光近红外的双相剂量、舒曼共振与接地,附四项物理检测与等热量假照射双盲试验。

Fan Yafu 范雅福 · 5D Library, 5DL-B-009 · version 1.0.0, 2026 · Preface + 8 chapters · 序 + 八章 · free to read, CC BY-NC-ND 4.0

Not medical advice; the book claims no healing power for any stone, meteorite, earthing product or light device. Disclosure: this site and 5D Library are run by the same group, founded by the author. 非医疗建议;本书不声称任何石头、陨石、接地产品或光照设备有疗效。说明:本站与 5D Library 同属作者创办的集团。

The Default Mode Network, the Entropic Brain and Neural Oscillations默认模式网络、熵脑与神经振荡

5-HT2A Receptor Kinetics, Pineal Calcite Microcrystals and the Computational Neuroscience of Meditative Attention

The resting brain's energy budget and network hubs, the Kuramoto model of synchrony, the entropic brain hypothesis with the risks and limits of the clinical trials, meditation and mind-wandering, the pineal gland, and the evidence on 40 Hz stimulation and binaural beats, read beside the Diamond Sūtra and the Platform Sūtra, with a pre-registered trial comparing breath-focused listening with binaural beats.

大脑静息能量预算与网络枢纽、库拉莫托同步、熵脑假说及临床试验的风险局限、禅修与走神、松果体,以及 40 Hz 与双耳节拍的证据,与《金刚经》《坛经》并读,附专注听息对照双耳节拍的预注册试验。

Fan Yafu 范雅福 · 5D Library, 5DL-B-008 · version 1.0.0, 2026 · Preface + 8 chapters · 序 + 八章 · free to read, CC BY-NC-ND 4.0

Not medical or legal advice. Disclosure: this site and 5D Library are run by the same group, founded by the author, who teaches the listening method discussed in the book. 非医疗或法律建议。说明:本站与 5D Library 同属作者创办的集团,作者教授书中讨论的聆听方法。