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