Geodesic

The idea

A geodesic is the shortest path across a curved surface. On a sphere it is an arc of a great circle, which is why long-haul flight paths look bent on a flat map. Seen straight on, a great circle can only be the globe's rim, a straight line through its centre, or an ellipse touching the rim at two opposite points. Every stroke in Geodesic is one of those, so every stroke can be described by four numbers.

Capitals are the Earth seen from above New York (17.46° N on New York's meridian). From that viewpoint the equator dips by exactly the amount of the crossbars in the original drawing. Lowercase letters are the Moon passing in front of the Earth, which sets the x-height.

Origin

Around 2012 I was editor-in-chief of Wander: Brandeis Abroad, a journal of writing and photography by students studying abroad, and drew this lettering by hand for its masthead. At the time I asked whether the curves could be plotted as real flight paths. They could, but by hand it would have taken far too long, so I eyeballed them.

In 2026 I rebuilt it with Claude: tracing the old drawing, fitting every stroke to a true great circle, and extending the same rules to a full alphabet with lowercase, figures, and punctuation.

What the page does

• Type tester. Set any text in six weights, upright and italic. The italic is the same view rolled 12° about the line of sight, so every globe stays round.
• Fly it. Planes draw each letter stroke by stroke along its great circle.
• Turn the world. Drag any globe and every letter turns with it, with the routes staying on the map.
• Show the math. Each glyph lists its flights, formulas, and distances, and a side-by-side slider compares the 2012 drawing with the fitted curves.