- Warming stripes
- A visualization that encodes each year's average temperature as a coloured bar, from cool blues to hot reds. Invented by climate scientist Ed Hawkins, it shows a warming trend at a glance without axes or numbers.
- Precession
- The slow, 26,000-year wobble of Earth's rotation axis. It gradually shifts where the Sun appears against the constellations, which is why the astrological signs assigned 2,000 years ago no longer match the sky.
- Ophiuchus
- The thirteenth constellation the Sun passes through each year, between Scorpius and Sagittarius. Traditional astrology skips it, so people born from late November to mid-December get a true-zodiac answer they've never seen in a horoscope.
- CSPRNG
- A cryptographically secure pseudo-random number generator, meaning randomness strong enough for encryption keys. Browsers expose one as crypto.getRandomValues, and it's what fair digital coins and dice should be built on.
- Rejection sampling
- A technique that discards random values falling outside an evenly divisible range instead of wrapping them around. It removes the small bias that naive approaches introduce when mapping random bytes onto things like a six-sided die.
- Runs test
- A statistical test that counts unbroken streaks in a sequence. Too few runs means suspicious alternation, the classic human tell. Too many means suspicious clustering. Real randomness sits in a predictable band between them.
- Gambler's fallacy
- The belief that past random outcomes change future odds, as if five heads in a row make tails due. A fair coin has no memory. The streak analysis in these tools exists partly to make that visible.
- Continuous performance task
- An attention-research format where you respond to targets over a sustained run rather than a single trial. It measures speed, consistency, and impulse control, which gives a richer read than one-tap reflex tests.
