{"id": "card_floor_acoustics", "kind": "note", "title": "Acoustics — waves, loudness, and harmonics", "body": "The physics of sound and hearing, standing between matter and mind. Sound is a pressure wave in a medium (v = f lambda); loudness is logarithmic (the decibel); pitch is frequency and timbre is the harmonic series; a moving source shifts pitch (the Doppler effect, the acoustic cousin of the redshift). Four pillars rest on chemistry (the medium), the mind (perception), quantum mechanics (phonons), and relativity (Doppler). The stick (stick_acoustics_waves_loudness_and_harmonics) seals concert A's wavelength, a 30 dB ratio, and a third harmonic (tools/seed_acoustics.py).", "source": {"label": "Narrow Highway — acoustics", "url": "", "authority_tier": "engine_derived", "ref": "stick_acoustics_waves_loudness_and_harmonics"}, "shelf": "codex", "box": "acoustics", "bands": ["floor", "acoustics", "sound", "decibel", "harmonics", "one map"], "subject": "Acoustics — waves, loudness, and harmonics", "connections": [{"to_card_id": "card_acoustics_the_wave", "relationship": "has_part", "evidence": "a pillar of acoustics (The wave)"}, {"to_card_id": "card_acoustics_loudness", "relationship": "has_part", "evidence": "a pillar of acoustics (Loudness)"}, {"to_card_id": "card_acoustics_harmonics", "relationship": "has_part", "evidence": "a pillar of acoustics (Harmonics)"}, {"to_card_id": "card_acoustics_doppler", "relationship": "has_part", "evidence": "a pillar of acoustics (The Doppler effect)"}, {"to_card_id": "card_k_floor_of_discovery", "relationship": "part_of", "evidence": "the physics of sound on the one map"}], "author": "engine", "created_at": 0.0, "updated_at": 0.0, "visibility": "public", "lifecycle_stage": "public", "volatility": "permanent", "surface": "secular", "generated": false, "call": "codex.acoustics", "facets": {"subject": ["decibel", "floor", "harmonics", "one map", "sound"]}, "presentation": {"glyph": "•", "kind_label": "acoustics", "by": "Narrow Highway — acoustics", "authority": "engine_derived", "posted": "", "standing": ""}, "neighbors": [{"id": "card_acoustics_the_wave", "title": "The wave — v = f lambda", "relationship": "has part", "why": "a pillar of acoustics (The wave)", "href": "/card/card_acoustics_the_wave", "resolved": true}, {"id": "card_acoustics_loudness", "title": "Loudness — the decibel, a logarithm", "relationship": "has part", "why": "a pillar of acoustics (Loudness)", "href": "/card/card_acoustics_loudness", "resolved": true}, {"id": "card_acoustics_harmonics", "title": "Harmonics — pitch, timbre, phonons", "relationship": "has part", "why": "a pillar of acoustics (Harmonics)", "href": "/card/card_acoustics_harmonics", "resolved": true}, {"id": "card_acoustics_doppler", "title": "The Doppler effect — the acoustic redshift", "relationship": "has part", "why": "a pillar of acoustics (The Doppler effect)", "href": "/card/card_acoustics_doppler", "resolved": true}, {"id": "card_k_floor_of_discovery", "title": "The Floor of Discovery — one floor, and by its design the fear of God", "relationship": "part of", "why": "the physics of sound on the one map", "href": "/card/card_k_floor_of_discovery", "resolved": true}], "house": {"door": "FIND", "kind": "card", "trail": "connections", "seal": "/card/card_floor_acoustics", "next_step": {"do": "follow a connection: what this card rests on, and what rests on it", "door": "FIND", "tool": "card_connections", "params": {"id": "card_floor_acoustics"}}, "ends": "a verdict or a card · the trail · a seal · one next step"}}