THE SOLAR SYSTEM
eight planets · size, distance, year and day
DEVELOPMENTAL MILESTONES · YEAR ONE
2, 4, 6, 9, 12 months per the CDC checklists (2022 revision): 59 milestones that at least 75% of children reach by each age
DEVELOPMENTAL MILESTONES · YEAR TWO
15, 18, 24 months per the CDC checklists (2022 revision): 41 milestones that at least 75% of children reach by each age
SIZE CHARTS
shoes, tops, bottoms — and a centimetre under every grid
AI MILESTONES
ten tasks, the year of each, the system, the figure — and the human it was measured against
AUDIO FORMATS
who published each standard, when, what it does to the sound, and how many bits per second it allows
BIG-O NOTATION
the seven growth classes: how many steps, how long they take and how far each one lets you go
THE CRON EXPRESSION
the five schedule fields: what each one means, what values it takes, and how to read stars, lists and steps
A NUMBER IN 32 BITS
sign, exponent and significand: what actually sits in a float and what does not
IPv6 ADDRESS NOTATION
eight groups of sixteen bits, the double colon, and one canonical spelling out of thousands
MARKDOWN SYNTAX
headings, emphasis, lists, links and code per the CommonMark 0.31.2 specification — the core all dialects share
MEDIA TYPES
2322 registered subtypes under 11 top-level types, and how to read one you have never seen
REGULAR EXPRESSIONS
anchors, classes, quantifiers and groups: what a pattern is made of and how it reads, token by token
TIMESTAMPS
date, time and offset from UTC in one string: what it is made of and what it is not
SEMANTIC VERSIONING
what each of the three numbers means, what may follow them, and the order versions stand in
ARABICA AND ROBUSTA
two species, six varieties, one difference
MATCHA GRADES
ceremonial, premium, culinary — what is behind the words
SPIRIT HOMELANDS
where the law lets Scotch, bourbon, cognac and tequila be made — seven spirits, three scales of place: a country, a part of one, a drawn zone
SPIRIT RAW MATERIALS
what the law lets whisky, rum, brandy and tequila be distilled from — ten spirits, seven raw materials, two regulations
YELLOW TEA
yellowing under a cover · the step no other tea has
THE 9 MAJOR FOOD ALLERGENS
the foods US law singles out by name, and the two ways a label is allowed to say so
CULINARY KNIFE CUTS
julienne, brunoise, bâtonnet and the family of dice — the Culinary Institute of America dimensions, drawn to true scale
PROTEIN IN FOODS
grams per 100 g · animal and plant · and the state each one was weighed in
ENGLISH PUNCTUATION
twelve marks and the three strokes: a name, a job and one working example for each
THE COLLATZ CONJECTURE
halve the even, triple the odd and add one: the road of 27, the record holders and a problem nobody has solved
NUMBERS 1 TO 100
the hundred chart · primes picked out in colour
LEAP YEARS
one rule, a cycle of four hundred years and the ninety-seven extra days in it
MULTIPLICATION TABLE
1 to 12 · colour intensity = size of the product
CURWEN HAND SIGNS
one hand for each degree of the scale, with the mental effect John Curwen gave it
EQUAL TEMPERAMENT
how many cents each interval misses the pure one by, and why exactly that much
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
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
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