Euler's Eyes
2026-10-11
Image credits
Historical portrait
The portrait attributed to Rolland Lefebvre comes from Wikimedia Commons and is in the public domain. We use the thumbnail provided by Commons, without editing, and the caption keeps the attribution given by the collection.
Blog figures
The cover and the refraction sketch are original illustrations. The interactive figures for remainders of powers, the area of rectangles and the division of the interrupted game were created for this trail. They are teaching aids and do not reproduce Fermat’s manuscripts. The division figure, for example, assumes independent rounds and players with equal chances.
Record
The file data/fermat_imagens.json records the source, licence, verification date and SHA-256 hash of the portrait. The historical sources for each topic are listed at the end of each post.
Additional historical images
These images come from Wikimedia Commons. The source, licence and SHA-256 hash of each one are recorded in data/fermat_imagens.json.
- Diophantus’s Arithmetica (1670), problem II.8 with Fermat’s note: Diophantus, ed. Samuel de Fermat (1670) · Wikimedia Commons · public domain
- Diophantus’s Arithmetica (1670), page 339, the proof by infinite descent: Diophantus, ed. Samuel de Fermat (1670); restored by Leonid 2 · Wikimedia Commons · public domain
- Title page of Diophantus’s Arithmetica (Toulouse, 1670): Bernard Bosc, Toulouse (1670) · Wikimedia Commons · public domain
- Monument to Fermat in Beaumont-de-Lomagne: Didier Descouens · Wikimedia Commons · CC BY-SA 4.0