The Library
Where the portraits came from
Why this page has no clickable links
This app never sends a child to another website. The sources below are listed as plain text so a grown-up can look them up themselves — by typing or pasting them into a separate browser tab. We do this on purpose: it keeps the app a quiet place to learn, with no ads, no trackers, and no surprise pages.
Portrait sources
Every portrait in the Library is an artwork in the public domain in the United States — all pre-1928, with the artist's rights expired. No attribution is legally required. We list the sources anyway, for transparency.
- Robert Recorde(c. 1512 – 1558)
- Anonymous oil portrait, c. 1900; National Library of Wales, Welsh Portrait Collection.
- Retrieved 30 May 2026imagined portrait, 1900
- Emmy Noether(1882 – 1935)
- Anonymous photograph, c. 1900-1910; reproduced on Wikimedia Commons (PD-anon-expired).
- Retrieved 30 May 2026
- René Descartes(1596 – 1650)
- After Frans Hals, c. 1649; Musée du Louvre, INV.1317.
- Retrieved 30 May 2026
- Hypatia of Alexandria(c. 360 – 415)
- Jules Maurice Gaspard illustration, 1908; from Elbert Hubbard's *Little Journeys to the Homes of Great Teachers*.
- Retrieved 30 May 2026imagined portrait, 1908
- Isaac Newton(1643 – 1727)
- Godfrey Kneller, oil portrait, 1689.
- Retrieved 30 May 2026
- Gottfried Wilhelm Leibniz(1646 – 1716)
- Christoph Bernhard Francke, oil portrait, c. 1695.
- Retrieved 30 May 2026
- Ada Lovelace(1815 – 1852)
- Margaret Sarah Carpenter, oil portrait, 1836; held in the UK national art collection (GAC).
- Retrieved 30 May 2026
- Archimedes of Syracuse(c. 287 – 212 BCE)
- Domenico Fetti, "Archimedes Thoughtful," oil on canvas, 1620; Gemäldegalerie Alte Meister, Dresden.
- Retrieved 30 May 2026imagined portrait, 1620
- Augustin-Louis Cauchy(1789 – 1857)
- Rudolf Hoffmann, lithograph, 1856 (after a photograph by Bertsch).
- Retrieved 30 May 2026
- Joseph Fourier(1768 – 1830)
- Engraving by Geille, c. 1823, after a drawing by Julien-Léopold Boilly.
- Retrieved 30 May 2026
- Sophie Germain(1776 – 1831)
- Berthe Chégaray, posthumous medallion portrait, 1896.
- Retrieved 30 May 2026imagined portrait, 1896
- Grace Hopper(1906 – 1992)
- James S. Davis, US Navy official photograph of Commodore Grace M. Hopper, c. 1984; Wikimedia Commons (PD-USGov-Military-Navy).
- Retrieved 31 May 2026
Mathematicians shown as symbols
For these mathematicians no historical likeness exists in a form we can show here, so the Library card carries their defining mathematical symbol instead.
- Muhammad al-Khwarizmi — symbol shown:
x^2 - Maria Gaetana Agnesi — symbol shown:
2x + b - Bonaventura Cavalieri — symbol shown:
\dfrac{a^3}{3} - Rafael Bombelli — symbol shown:
i - Bhaskara II — symbol shown:
\dfrac{a}{b} - Liu Hui — symbol shown:
+ - Aryabhata — symbol shown:
10^n - Brahmagupta — symbol shown:
-n - Alicia Boole Stott — symbol shown:
V-E+F - The Egyptian rope-stretchers — symbol shown:
3,4,5 - Marjorie Rice — symbol shown:
\bigtriangleup - Heron of Alexandria — symbol shown:
A=bh - Karen Uhlenbeck — symbol shown:
\triangle - al-Karaji — symbol shown:
x^n - Hertha Ayrton — symbol shown:
e^x - Leonhard Euler — symbol shown:
e - Eratosthenes of Cyrene — symbol shown:
p - William Rowan Hamilton — symbol shown:
\vec{v} - Luca Pacioli — symbol shown:
p\% - Stella Cunliffe — symbol shown:
P(E) - Pythagoras of Samos — symbol shown:
1{:}2 - John Horton Conway — symbol shown:
\square - Blaise Pascal — symbol shown:
\triangle - Niels Henrik Abel — symbol shown:
x^{5} - Thales of Miletus — symbol shown:
h{:}s - Zu Chongzhi — symbol shown:
\pi - Florian Cajori — symbol shown:
(\,\bullet\,) - Florence Nightingale — symbol shown:
\bar{x} - Benoît Mandelbrot — symbol shown:
z \to z^2 + c