4 AUG 2026

Day 216

He who has a why to live can bear almost any how.

Friedrich Nietzsche · Twilight of the Idols

A large dark mezzotint of an executioner with a sword and the severed head of John the Baptist; a name is inscribed along the blade.

I · THE OBJECT · BRITISH MUSEUM

The Great Executioner

1658 · Prince Rupert of the Rhine · Mezzotint print

A soldier-prince finished a mezzotint of John the Baptist’s execution in 1658. His name runs along the blade. Who invented the technique is still debated.

Enter lesson 6 MIN

II · THE IDEA · ARTIFICIAL INTELLIGENCE

Differential Privacy by Noising Gradients

training · differentially private SGD · Gaussian on clipped gradients

Training can leak individual records through the gradients. Clipping each example’s contribution and adding Gaussian noise turns that leakage into a measurable privacy budget.

Enter lesson 7 MIN

Tiny ivory head in three-quarter view: smooth face with clear brow and nose, a patterned hood or hair above, and a rough broken edge at the neck.

III · THE WORK · ART HISTORY

Venus of Brassempouy

Gravettian · Mammoth ivory · 36.5 mm (1.44 in)

A scrap of mammoth ivory, only 36.5 millimetres (1.44 in) high, holds what may be among the earliest surviving attempts to model a human face in three dimensions.

Enter lesson 6 MIN