William Ockham c 1285 1349 is remembered as

William Ockham (c. 1285– 1349) is remembered as an influential nominalist but his popular fame as a great logician rests chiefly on the maxim attributed to him and known as Occam's razor: Entia non sunt multiplicanda praeter necessitatem or "Entities should not be multiplied unnecessarily. " The term razor refers to the act of shaving away unnecessary assumptions to get to the simplest explanation. Hanlon’s Razor: "Never attribute to malice that which can be adequately explained by stupidity".

Image source: Wikipedia. Image source: Word. Press blog. Eratosthenes (b. 276 BC- d. 194 BC) calculated the radius of the Earth. He was a librarian in Alexandria, Egypt. He made the measurement without leaving home (but getting information from travelers)

Credit : Inter-University Centre for Astronomy and Astrophysics, Pune.

One needs two measurements to calculate radius of the Earth: angle & distance meter stick height Image from Wikimedia Commons, courtesy of John O’Neill A C shadow length angle Image of protractor from Wikimedia Commons. B distance

Credit : Inter-University Centre for Astronomy and Astrophysics, Pune. h θ x

Image source: Wikipedia. A note of interest: Eratosthenes was known as “beta” because he was always second best at things.

Sun Foci Earth Draw 4 Earths on the orbit, labeling the dates in the year they are in that position.