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