{"query": "Build a Crystal Radio", "count": 20, "results": [{"id": "card_n_072d00893a26", "title": "Build a Crystal Radio", "shelf": "maker", "surface": "secular", "snippet": "A working radio with no batteries — runs on the energy of the radio waves themselves. The first DIY electronics project a generation of American kids built.", "authority_tier": "external_aligned", "source": "Popular Science, March 1922 (and many others)", "readable": false, "generated": false}, {"id": "card_theory_electromagnetic_spectrum", "title": "The electromagnetic spectrum & modulation (radio to gamma, one axis)", "shelf": "theories", "surface": "secular", "snippet": "The electromagnetic spectrum & modulation (radio to gamma, one axis) — an engine domain that can touch it: physics. Calibration: seals — c = fλ, photon energy E = hf, and bandwidth relations all recom", "authority_tier": "reference", "source": "The Theory Assay — calibrated, not judged (docs/THEORY_CATALOG.md)", "readable": false, "generated": false}, {"id": "card_theory_third_law_of_thermodynamics", "title": "Third law of thermodynamics", "shelf": "theories", "surface": "secular", "snippet": "Third law of thermodynamics — an engine domain that can touch it: thermodynamics. Calibration: map-only — a limiting statement, not a computation. As temperature approaches absolute zero, the entropy ", "authority_tier": "reference", "source": "The Theory Assay — calibrated, not judged (docs/THEORY_CATALOG.md)", "readable": false, "generated": false}, {"id": "card_src_book_26622", "title": "How to Read the Crystal; or, Crystal and Seer — Sepharial", "shelf": "gutenberg", "surface": "secular", "snippet": "How to Read the Crystal; or, Crystal and Seer, by Sepharial. Subjects: Crystal gazing. Read the full text (public domain): https://www.gutenberg.org/ebooks/26622", "authority_tier": "reference", "source": "Project Gutenberg (public domain)", "readable": true, "generated": false}, {"id": "card_src_word_crystal_microphone", "title": "crystal microphone", "shelf": "dictionary", "surface": "secular", "snippet": "crystal microphone: (noun) a microphone in which sound waves vibrate a piezoelectric crystal that generates a varying voltage — syn: crystal mike", "authority_tier": "reference", "source": "WordNet 3.0, Princeton University (WordNet License)", "readable": false, "generated": false}, {"id": "card_src_word_crystal_mike", "title": "crystal mike", "shelf": "dictionary", "surface": "secular", "snippet": "crystal mike: (noun) a microphone in which sound waves vibrate a piezoelectric crystal that generates a varying voltage — syn: crystal microphone", "authority_tier": "reference", "source": "WordNet 3.0, Princeton University (WordNet License)", "readable": false, "generated": false}, {"id": "card_src_book_44192", "title": "The Crystal Palace — Peter Berlyn", "shelf": "gutenberg", "surface": "secular", "snippet": "The Crystal Palace, by Peter Berlyn. Subjects: Crystal Palace (Great Exhibition, 1851, London, England). Read the full text (public domain): https://www.gutenberg.org/ebooks/44192", "authority_tier": "reference", "source": "Project Gutenberg (public domain)", "readable": true, "generated": false}, {"id": "card_src_book_43954", "title": "Practical Psychomancy and Crystal Gazing — William Walker Atkinson", "shelf": "gutenberg", "surface": "secular", "snippet": "Practical Psychomancy and Crystal Gazing, by William Walker Atkinson. Subjects: Magic; Crystal gazing; Clairvoyance. Read the full text (public domain): https://www.gutenberg.org/ebooks/43954", "authority_tier": "reference", "source": "Project Gutenberg (public domain)", "readable": true, "generated": false}, {"id": "card_src_book_53934", "title": "The Sabbath and the Crystal Palace — Anonymous", "shelf": "gutenberg", "surface": "secular", "snippet": "The Sabbath and the Crystal Palace, by Anonymous. Subjects: Sunday; Sabbath; Crystal Palace (Sydenham, London, England). Read the full text (public domain): https://www.gutenberg.org/ebooks/53934", "authority_tier": "reference", "source": "Project Gutenberg (public domain)", "readable": true, "generated": false}, {"id": "card_src_book_62220", "title": "The New Crystal Palace and the Christian Sabbath — John Weir", "shelf": "gutenberg", "surface": "secular", "snippet": "The New Crystal Palace and the Christian Sabbath, by John Weir. Subjects: Sunday; Crystal Palace (Sydenham, London, England). Read the full text (public domain): https://www.gutenberg.org/ebooks/62220", "authority_tier": "reference", "source": "Project Gutenberg (public domain)", "readable": true, "generated": false}, {"id": "card_src_book_58235", "title": "Beach Rambles in Search of Seaside Pebbles and Crystals With Some Observations on the Origin of the Diamond and Other Precious Stones — John George Francis", "shelf": "gutenberg", "surface": "secular", "snippet": "Beach Rambles in Search of Seaside Pebbles and Crystals With Some Observations on the Origin of the Diamond and Other Precious Stones, by John George Francis. Subjects: Precious stones; Mineralogy; Pe", "authority_tier": "reference", "source": "Project Gutenberg (public domain)", "readable": true, "generated": false}, {"id": "card_src_book_62202", "title": "The Sabbath, the Crystal Palace, and the People — James Baldwin Brown", "shelf": "gutenberg", "surface": "secular", "snippet": "The Sabbath, the Crystal Palace, and the People, by James Baldwin Brown. Subjects: Sunday; Crystal Palace (Sydenham, London, England); Sunday legislation. Read the full text (public domain): https://w", "authority_tier": "reference", "source": "Project Gutenberg (public domain)", "readable": true, "generated": false}, {"id": "card_src_book_63755", "title": "A Few Words on the Crystal Palace Question — C. J. (Charles John) Vaughan", "shelf": "gutenberg", "surface": "secular", "snippet": "A Few Words on the Crystal Palace Question, by C. J. (Charles John) Vaughan. Subjects: Crystal Palace (Sydenham, London, England); Sunday legislation -- Great Britain. Read the full text (public domai", "authority_tier": "reference", "source": "Project Gutenberg (public domain)", "readable": true, "generated": false}, {"id": "card_src_book_62203", "title": "The Divided Sabbath remarks concerning the Crystal Palace now erecting at Sydenham — William Jowett", "shelf": "gutenberg", "surface": "secular", "snippet": "The Divided Sabbath remarks concerning the Crystal Palace now erecting at Sydenham, by William Jowett. Subjects: Crystal Palace (Sydenham, London, England); Sunday legislation -- Great Britain; Sabbat", "authority_tier": "reference", "source": "Project Gutenberg (public domain)", "readable": true, "generated": false}, {"id": "card_src_book_62206", "title": "A few lines against the opening of the Crystal Palace on the Sabbath day — John Elwin Wrench", "shelf": "gutenberg", "surface": "secular", "snippet": "A few lines against the opening of the Crystal Palace on the Sabbath day, by John Elwin Wrench. Subjects: Sabbath -- Poetry; Crystal Palace (Sydenham, London, England) -- Poetry. Read the full text (p", "authority_tier": "reference", "source": "Project Gutenberg (public domain)", "readable": true, "generated": false}, {"id": "card_src_book_63257", "title": "An Apology for the Colouring of the Greek Court in the Crystal Palace — Owen Jones", "shelf": "gutenberg", "surface": "secular", "snippet": "An Apology for the Colouring of the Greek Court in the Crystal Palace, by Owen Jones. Subjects: Crystal Palace (Sydenham, London, England); Architecture, Greek; Decoration and ornament -- Greece. Read", "authority_tier": "reference", "source": "Project Gutenberg (public domain)", "readable": true, "generated": false}, {"id": "card_n_cdb747a427d2", "title": "Electronics — the resonant chain, from Ohm's law to the radio wave", "shelf": "science", "surface": "secular", "snippet": "One sealed chain runs the whole bench: Ohm's law (V = I·R), the capacitor's\nexponential clock (one time constant → 63.2% charged), the diode's exponential gate (current\ndoubles every ln2·nVT ≈ 17.9 mV", "authority_tier": "engine_derived", "source": "Concordance assay — 2026-07-09", "readable": false, "generated": false}, {"id": "card_src_lex_g2930", "title": "G2930 — κρύσταλλος (krustallos): crystal", "shelf": "lexicon", "surface": "secular", "snippet": "κρύσταλλος (krustallos), Strong's G2930: crystal. κρύσταλλος , -ου, ὁ (κρύος, frost), [in LXX: Job.38:29 , Psa.147:17 , Eze.1:22 (קֶרַח), etc. ;] crystal : Rev.4:6 22:1 .† (AS)", "authority_tier": "reference", "source": "STEPBible TBESH/TBESG — Extended Strong's lexicon (CC-BY, Tyndale House)", "readable": false, "generated": false}, {"id": "card_src_word_crystal_lattice", "title": "crystal lattice", "shelf": "dictionary", "surface": "secular", "snippet": "crystal lattice: (noun) a 3-dimensional geometric arrangement of the atoms or molecules or ions composing a crystal — syn: space lattice, Bravais lattice", "authority_tier": "reference", "source": "WordNet 3.0, Princeton University (WordNet License)", "readable": false, "generated": false}, {"id": "card_src_word_crystal_oscillator", "title": "crystal oscillator", "shelf": "dictionary", "surface": "secular", "snippet": "crystal oscillator: (noun) an oscillator that produces electrical oscillations at a frequency determined by the physical characteristics of a piezoelectric quartz crystal — syn: quartz oscillator", "authority_tier": "reference", "source": "WordNet 3.0, Princeton University (WordNet License)", "readable": false, "generated": false}]}