And now a controversial look back… way back.
Physicist Amelia Sparavigna recently identified an artifact in a Turin museum as the world’s first known protractor. Sparavigna argues that the artifact’s ornate decoration, which resembles a compass rose with 16 evenly spaced petals surrounded by a zigzag with 36 corners, was used in combination with a plumb line to measure the slope angle of an object beneath it.
