Home > Astronomical History, Ephemeris Program > 10/13/2015 – Ephemeris – Columbus was wrong!

10/13/2015 – Ephemeris – Columbus was wrong!

October 13, 2015

Ephemeris for Tuesday, October 13th.  The Sun will rise at 7:55.  It’ll be up for 11 hours and 6 minutes, setting at 7:02.   The Moon, 1 day past new, will set at 7:35 this evening.

Yesterday I recounted that Christopher Columbus was able to extort supplies from the native Jamaicans by using an eclipse table to predict a lunar eclipse.  But let’s face it Columbus was lost.  He wasn’t in India as he thought.  He based his voyage on the erroneous belief that the Earth was less than 19,000 miles in circumference, when it’s actually 25,000 miles, which was the prevailing view of the day.  That the Earth was round was known from the 3rd century BC, and measured quite accurately by Eratosthenes.    Of course with the varieties of distance units of the day it was no wonder an error of that magnitude could be made.  Of course did anyone think to remeasure the circumference of the Earth?  Apparently not.  Nowadays no scientist thinks of taking only one measurement. Columbus was lucky a continent was here, or no one would have heard from him again.

Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.


1474 map of the Atlantic Ocean

A map of the western ocean (Atlantic Ocean) by Paolo dal Pozzo Toscanelli about 1474 which may have influenced Columbus. North America is superimposed at the proper longitudes. Credit: A literary and historical atlas of America, by Bartholomew, J. G. via Wikipedia.  Click to enlarge.

Note that Cathay is China and Cippangu represents Japan.  It was thought back then that the Eurasian continent spanned 180 degrees of longitude at the latitude of Spain, rather than 130 degrees it actually does  Japan was thought to be bigger and farther off the Chinese coast.  The phantom island of Antillia seems to date back to stories from Spain of the 8th century.

%d bloggers like this: