How Eratosthenes measured the earth: part 4 of 4.

The angle of the sun is the last hurdle Eratosthenes had to overcome with his data collection methods.

Here we review the popularly believed story -- measuring shadows of sticks -- before looking at a more likely and methodologically simpler alternative.

Concludes with a bibliography.

(Reading time: 15 minutes)
#ancientscience #eratosthenes #geography #ancientgreece
https://kiwihellenist.blogspot.com/2023/07/eratosthenes-4.html

How Eratosthenes measured the earth, part 3 of 4: distance.

How did Eratosthenes find out the distance from Syene to Meroë? What units did he use, and what do they mean in modern units?

(Reading time: 18 minutes)
#ancientscience #eratosthenes #geography #ancientgreece
http://kiwihellenist.blogspot.com/2023/06/eratosthenes-2b.html

The ongoing story of how Eratosthenes measured the earth, based on ancient evidence. Part 2b: distance.

How did Eratosthenes find out the distance from Syene to Meroë? What units did he use, and what do they mean in modern units? What's the difference between the 'metrological stadion' and the 'itinerary stadion'? (And how do they compare to the kilometre and the 'itinerary kilometre'?)

(Reading time: 18 minutes)
#ancientscience #eratosthenes #geography #ancientgreece
https://kiwihellenist.blogspot.com/2023/06/eratosthenes-2b.html

How Eratosthenes measured the earth: an account grounded in ancient evidence.

Part 2a explains the basic idea underlying the measurement, and begins to look at the hurdles involved in obtaining observational data.

Parts 2b and 2c will look at what we know about measuring overland distances, and 2nd century BCE instrumentation for observing the angle of the sun.

(Reading time: 16 minutes)
http://kiwihellenist.blogspot.com/2023/06/eratosthenes-2a.html
#ancientscience #eratosthenes #geography #astronomy #egypt #ancientgreece

How Eratosthenes measured the earth. Part 2a.

The ongoing story of Eratosthenes' measurement, grounded in ancient evidence.

Part 2a: the basic principle of the measurement; an introduction to the technological hurdles; and the problem of simultaneous measurements.

(This was _not_ a problem to be solved by two sticks!)

(Reading time: 16 minutes)
#ancientscience #eratosthenes #geography #ancientgreece
https://kiwihellenist.blogspot.com/2023/06/eratosthenes-2a.html

How Eratosthenes measured the earth. Part 1: the discovery of the earth's shape.

Before 400 BCE, everyone was a flat-earther. Afterwards, it gets hard to find people who weren't aware that the earth is round.

A look at early Greek thought on the shape of the cosmos, the earth's location, and the angle of the ecliptic, leading up to the first estimate of the earth's size in Aristotle.

(Reading time: 18 minutes)
https://kiwihellenist.blogspot.com/2023/04/eratosthenes-1.html
#ancientscience #eratosthenes #geography #ancientgreece

I found a truly amazing reading of an English translation of De Rerum Natura, by Titus Lucretius!

https://www.youtube.com/watch?v=wurOQffA6pE&t=5062s

#Philosophy #Epicureanism #AncientScience

The problems with ancient abortifacients wasn't that they were necessarily ineffective, but that they're all poisonous to some degree--especially, it seems, they're neurotoxic.

It's got me wondering about the state of Ophelia's health in the last scene where we see her alive. Are we supposed to understand that she has been dosing herself--that she was, or feared she was, pregnant?

#ancientscience #classics #Shakespeare

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