All thinkers

Johannes Kepler: 3 ideas and puzzles worth knowing

3 ideas and puzzles from Johannes Kepler, each explained in a minute and credited to the original work. Free on Savvy.

• Planets don't move in circles — one astronomer proved they trace ellipses

  Using decades of naked-eye observations inherited from Tycho Brahe, Johannes Kepler discovered that planets sweep out equal areas in equal times along elliptical, not circular, orb…

  — Johannes Kepler, Astronomia Nova

• A wine merchant's lazy pricing trick turned out to be nearly impossible to cheat

  Austrian wine merchants priced a barrel by pushing a measuring rod diagonally through the bunghole to the far bottom rim, and charging purely by that one length -- never mind the b…

  — Johannes Kepler, Nova Stereometria Doliorum Vinariorum

• Is stacking oranges like a grocer does really the tightest way to pack spheres?

  Stack identical spheres as densely as possible, the way a grocer piles oranges into a pyramid. Is there any arrangement, however irregular, that packs them more tightly than that i…

  — Johannes Kepler, Strena Seu de Nive Sexangula

Five ideas worth knowing, every week

The week's best cards and a puzzle, credited as always. Free, unsubscribe any time.

Subscribe