More stuff I never knew.......................

     Aristotle, a leader of Greek learning with a passion for encyclopedic knowledge, described the earth as unmoving.  Even so, the Greeks soon discovered that the earth was not what it seemed.  They found that the earth was a sphere, and that was a big surprise.  The Greeks also knew quite accurately just how big our sphere is.
     The Greeks noticed that the slant of the sun's rays changed as one moved from north to south.  The difference of the angle at two points on earth, one directly south of the other, could be easily observed at noon during the summer solstice (when the sun appears to come as far north as it ever does).  If one knows this angle and the distance between the points of measurement, on can determine the circumference of the earth.  Eratosthenes is credited with originating this principle and first applying it.  To measure the angle, he used a perpendicular stick in Alexandria and a well with vertical walls in Syrene (modern Aswan).  The stick in Alexandria cast a shadow that indicated the sun was 7° 12' from the vertical.  At the same time, the sun was shining directly down the wall at Syrene.  The distance between the well and the stick was 493 miles. Since 7° 12' is 1/50 of 360°, the circumference of the earth was calculated to by 50 x 493, or 24,661 miles.  This is only about 150 miles less than today's best measurement.

-Edward Teller,  The Pursuit of Simplicity

Geography quiz.......................................

Can you name 39 countries bigger than Texas (without looking at a globe).   I only got twenty, but if you've studied up on Africa you should be able to score in the 30's.  Test is here.

Not sure that it is working............................

Pin the tail on Ukraine.......................

We found that only one out of six Americans can find Ukraine on a map, and that this lack of knowledge is related to preferences: The farther their guesses were from Ukraine’s actual location, the more they wanted the U.S.  to intervene with military force.

Full post is here

thanks tyler

Betcha didn't know.....................

Today's geography question:   How big is Africa?

BIG

Larger that the combination of the United States, India, China, Japan and most of Europe.  Enlargeable map is here