EQUAL TEMPERAMENT
how many cents each interval misses the pure one by, and why exactly that much
AMP MIC POSITIONS
where to place a mic in front of a guitar cab and how each spot sounds — after the Shure chart
ACOUSTIC BODY SHAPES
what each one was made for · from the front room to the stage, at true scale
NOTES ON THE FRETBOARD
standard tuning E A D G B e · first twelve frets
STRING MATERIALS
what they are drawn from, how one wrap differs from another and what of that is audible
TONEWOODS
density, hardness, export · what is measured kept apart from what is taste
MICROPHONE TYPES
what picks the sound up and where it stays deaf — five patterns from one formula
THE SEVEN MUSICAL MODES
the same white keys · a different root
NOTE VALUES
from whole to thirty-second · how many fit a 4/4 bar
DADGAD
D — A — D — G — A — D
DROP D
one string down · everything else unchanged
HALF STEP DOWN
every string down a semitone · same shapes
OPEN C
the deepest of the open tunings
OPEN D
the open strings are already D major
OPEN G
the open strings are already G major
UKULELE CHORDS
the first twelve chords · standard tuning G C E A
RED CABBAGE pH INDICATOR
the purple juice that changes colour: acid or base, without asking a book
THE COMPASS ROSE
the sixteen compass points with exact bearings: four cardinal, four intercardinal, eight in between
MAMMALS IN TIME
from the first synapsid to us · 320 million years on one axis
VERTEBRATES IN TIME
when each group appeared · five hundred million years on one axis
USDA HARDINESS ZONES
the 13 zones by average annual extreme minimum — each range in °F and °C, with the a and b half-zones
THE MOMENT MAGNITUDE SCALE
what a single step hides: ×10 in recorded amplitude and roughly ×32 in released energy — drawn to true scale
BASIC PHYSICS FORMULAS
fifteen formulas · every letter explained beneath it
PLASTIC RESIN CODES
the seven codes on the bottom of an article per ASTM D7611: which resin each number names and what it means for sorting
SPEED THRESHOLDS
six thresholds where a different physics begins · every figure computed, not typed
ANIMALS
the main branches — from comb jellies to chordates · who is actually related to whom
VERTEBRATES
from lamprey to bird · and why "fish" and "reptiles" are not groups
CROCHET SYMBOLS
the standard chart symbols, abbreviations and US/UK name differences — per the Craft Yarn Council standards
MORSE CODE
26 letters and 10 digits · dot, dash
THE BASKETBALL
four FIBA sizes with their circumference and mass — and why the rules set a bounce, not a pressure
BALLS BY THE RULES
eleven sports at true relative size — circumference, mass, pressure, and who sets them
IMPERIAL UNITS
convert in your head · without a calculator
CURRENCY MINOR UNITS
178 codes in the standard: 139 currencies divide by 100, 17 do not divide at all, 7 divide by 1,000 — and 25 codes are not money you can spend
APERTURE, SHUTTER, ISO
one stop is twice the light: three scales with the same step on each
SI UNITS WITHOUT NAMES
the endless rest: assembled from the base and the named units, and never with a factor
THE TALLEST BUILDINGS
the ten tallest at true scale — and where the floors in them end
THE WORLD'S TIME OFFSETS
37 offsets from UTC−11:00 to UTC+14:00 — a spread of 25 hours over a 24-hour day
BICYCLE CLASSES
frame, wheel by ISO 5775 and handlebar — three signs of a class, and what the frame is rated for
CAR CLASSES
segments A to F by length and bodies by box count — how to name any car you see
MOTORCYCLE CLASSES
rake, trail, wheelbase and seat height — six classes drawn at one scale
THE RACING LINE
one corner, three apexes, the time computed
TYRE SIZE
what the sidewall marking is made of and what it works out to