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
THE BEAUFORT SCALE
thirteen forces of wind — from water like a mirror to a wave of fourteen metres
THE EIGHT BLOOD TYPES
three antigens, eight types — and the one rule the whole table of compatibility follows from
RED CABBAGE pH INDICATOR
the purple juice that changes colour: acid or base, without asking a book
THE TEN CLOUD GENERA
three levels of the troposphere to one scale, and the ten genera that live in them
COLOUR GAMUTS
sRGB, Display P3, Rec. 2020 and ProPhoto RGB on the CIE 1931 chromaticity diagram
THE COMPASS ROSE
the sixteen compass points with exact bearings: four cardinal, four intercardinal, eight in between
THE VERTICAL PLANET
from the Challenger Deep to the summit of Everest · one scale, nothing compressed
TN, VA, IPS AND OLED
what differs inside the cell · and a paper describing each mode
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
THE FUJITA SCALE
six categories of tornado damage — and the two different winds assigned to them
GREEK LETTERS IN SCIENCE
10 capitals with a shape of their own, 14 twins of Latin letters, and what each one stands for
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 MOHS HARDNESS SCALE
ten reference minerals and five household probes: who scratches whom
THE MOMENT MAGNITUDE SCALE
what a single step hides: ×10 in recorded amplitude and roughly ×32 in released energy — drawn to true scale
THE PERIODIC TABLE
all 118 elements: symbol, atomic number and IUPAC atomic weight in every cell — blocks in colour, lanthanoids and actinoids offset below
BASIC PHYSICS FORMULAS
fifteen formulas · every letter explained beneath it