Columbus Day Virtual History

[oldpop2000]

In honor of Columbus Day on Monday, this bit of virtual history. The Greek scholar Eratosthenes was the father of Geography. He was able to determine by close approximation,  the circumference of the earth; off by 100 miles. He calculated that one degree on the earth was equal to 70 miles, close since it now known to be 69 miles. For Claudius Ptolemy, however, this was wrong. He calculated the earth circumference at 18,000 miles. He used one degree equals 50 miles and this meant the Asian continent was 180 degree in width, as opposed to its actual 130 degrees. This greatly underestimated the distance over the Atlantic Ocean from Spain to India. Spain was of course, the departure point for Columbus and he relied on Ptolemy's maps, not Eratosthenes.

Now the virtual history; had Columbus relied on the latters maps, Asia would have been over 2500 miles farther and one wonders if he would have made the trip and whether his benefactors would have posted the funds for it. Probably doesn't matter, the Vikings were here at L'Anse Aux Meadows in about 1001 AD on the northern tip of Newfoundland. But it is interesting to consider this bit of virtual history.

Note: Yes, I am aware that the degrees of longitude converge at the poles and that the degree of latitude has a range of 68.703 at the equator to 69.407 at the poles. The degrees of longitude vary from 69.172 at the equator to zero at the poles. At 40 degrees north or south the actual distance is 53 miles. So, Ptolemy wasn't that far off if we just consider longitude..... which we can't because Columbus was moving east to west.

[fredsanford]

Would the marginal cost of the additional trip length really have been a deal-breaker? Assuming that the expedition would have obtained supplies for the return trip in "Asia", and say a 100 mile/day average rate of advance, would another 25 days worth of supplies been that hard to swallow? I'm sure some ghosts of native Americans would hope so, but I'm not sure.

[oldpop2000]

Oct 14, 2013 15:07:45 GMT -6 fredsanford said:

Would the marginal cost of the additional trip length really have been a deal-breaker? Assuming that the expedition would have obtained supplies for the return trip in "Asia", and say a 100 mile/day average rate of advance, would another 25 days worth of supplies been that hard to swallow? I'm sure some ghosts of native Americans would hope so, but I'm not sure.

 I think it probably would have been a game changer. As we know, on October 10th, 1492 there was almost a mutiny and Columbus had to  bargain that if within three days, they had not sighted land, they would have gone home.  If he had used the true figures from Eratosthenes, then not only would the timeframe have increased but the cost that the Spanish monarchy would have to accommodate. We know that the North American continent was in the way, but he and no one else did except the Vikings and Eric the Red. Hard to speculate how good a con man Columbus might have been. He might have chosen Ptolemy because his maps showed a shorter journey.

[fredsanford]

You may be onto something with that last sentence. According to Wikipedia, he was turned down by the Portuguese twice, and the Castilians once, because they thought he was underestimating the distance.

At any rate, if Columbus didn't make the voyage, somebody would have sooner or later.