Sources & notes

About the outlines

Dashed guides group scattered islands that share a name; they are not political borders or territorial waters. Tiny islands are emphasized in map mode and outline previews so they stay visible. Zooming in shows their true scale; satellite emphasis is subtler.

Neighboring land borders use a shared boundary dataset. Coastlines and imagery can differ with survey date, tides and display scale. Hatching marks disputed claims.

The night sky

Star positions and magnitudes: HYG v4.1, David Nash / Astronomy Nexus, CC BY-SA 4.0. The sky is turned by the Earth’s real sidereal time, so the stars over each place are the ones overhead there right now. Daylight follows your view so the facing side of Earth stays illuminated.

Constellation lines, names, IAU boundaries, the Milky Way and Hipparcos star positions: d3-celestial, Olaf Frohn (BSD-3-Clause). Constellation drawings: Johan Meuris, from the Stellarium modern sky culture (Free Art License 1.3; data CC BY-SA 4.0). Sun, Moon and planet positions: Astronomy Engine, Don Cross (MIT).

Test scores and IQ

Test scores are the World Bank’s Harmonized Learning Outcomes, which put PISA, TIMSS, PIRLS and regional student tests on one scale. Canadian provinces and Spanish regions use PISA 2022; U.S. states use NAEP 2024, coloured against each other because NAEP has its own scale.

The Median IQ (estimated) layer uses David Becker’s NIQ dataset (2019), a revision of Lynn and Vanhanen’s national IQ data. It is shown because people ask for it, but it is not reliable: many countries’ figures come from one or two small, unrepresentative samples, sometimes a few dozen children in one town, tested decades ago with foreign tests. Researchers have found that better samples raise many scores by 10 points or more, and the original authors have been criticised for their views on race. Please read it as a rough and disputed estimate, never as a fact about a people. Mean and median are the same on an IQ scale. Countries without data stay gray rather than being guessed from neighbours.

More

Geography & data sources
Map sources & boundary notes
Illustration credits