Re: [asa] Rudwick does it again (back to Adam)

I may have missed something in this thread, which I've not carefully
followed.

Merv wonders about this:

What fascinates me is the reasoning (was it the early Greeks?) in which
they favored the ball because a sphere is the only simple shape that
wouldn't involve sudden discontinuities of contour somewhere (like a
flat disk or a cylinder would --giving you edges to contend with).

My recollection (which I haven't checked before writing this) is that
Aristotle argued for the earth's sphericity based on the following types of
evidence:

--the set of visible constellations changes a bit as you go north or south
(which Greek traders did)
--the shadow of the earth, during an eclipse of the moon, is round (recall
that Aristarchus later used this fact as part of his calculation of the
distances to the sun & moon)
--ships vanish over the horizon and return
--the horizon from mountaintops is extended further out

Smart guys, those Greeks.

Ted

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Received on Tue Aug 19 20:57:44 2008