It makes me sad for a couple of reasons, the first being that it just underscores how little people paid attention in school. (or have forgotten) The story of Eratosthenes, for instance, is taught at least twice in high school: once in science class, and once in geometry. It's a basic use case for both the position of the sun relative to the surface of the earth, and how to best compute the circumference of a sphere.
The second reason is that these articles are usually presented as either "Look at this brand new thing that we just discovered about old timey stuff!" or, even more depressingly, "Look! Someone was smart back when people were stupid!" The assumption that, just because there were no smartphones, game stations or cars 500, 1000 or 5000 years ago that the human mind must have been small and unsophisticated is maddening.
Thank you #businessinsider for once again stooping to click bait.
How Eratosthenes calculated the Earth's circumference - Business Insider http://www.businessinsider.com/how-greek-eratosthenes-calculated-earth-circumference-2016-6