Euler's Eyes
2026-10-15
History of Mathematics
Page 164 of 191
Image credits
Historical images and photographs
All come from Wikimedia Commons. We use the thumbnails provided by Commons, unedited.
- Portrait of Abel, drawing by Johan Gørbitz, Paris, 1826: source page · public domain.
- First volume of Crelle’s Journal, Berlin, 1826: source page · public domain.
- Abel’s grave at Froland, photo by Karl Ragnar Gjertsen: source page · CC BY 4.0.
- Abel monument in Oslo, sculpture by Gustav Vigeland, photo by Wolfmann: source page · CC BY-SA 4.0.
Blog figures
The figure of the lemniscate divided into eight equal arcs is an original illustration. The points were computed with the formula $r=\sqrt{\sqrt2-1}$ derived in the post. The figure has no text and serves every language of the site.
Record
The file data/abel_imagens.json records the origin, licence, verification date and SHA-256 hash of each downloaded image. The historical sources for each topic appear 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/abel_imagens.json.
- Gjerstad church and rectory (c. 1890): Peder Bentsen Melaas · Wikimedia Commons · public domain
- Norwegian stamp of 1929: Norwegian Post · Wikimedia Commons · public domain
All topics on Niels Henrik Abel · ← The legacy of Niels Henrik Abel