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Self taught rocket launcher - Failure waiting to happen... 1

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I think that if there was any hint of a doubt of the actual existence of a westward path to Asia, the royals would not have funded three ships. They clearly expected the ships to bring back goodies, which is what actually happened, eventually, with the gold that the Spaniards pillaged from the South America. Ironically, Spain managed to squander all the wealth anyway.

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@IRstuff:
"The biggest error was that the Greeks grossly underestimated the diameter of the Earth."

Actually, Eratosthenes did a remarkably good job of calculating the circumference of the Earth in the third century BC:

... Taking the Earth as spherical, and knowing both the distance and direction of Syene, he concluded that the Earth's circumference was fifty times that distance.
His knowledge of the size of Egypt was founded on the work of many generations of surveying trips. Pharaonic bookkeepers gave a distance between Syene and Alexandria of 5,000 stadia (a figure that was checked yearly).
...
Some claim Eratosthenes used the Olympic stade of 176.4 m, which would imply a circumference of 44,100 km, an error of 10%,but the 184.8 m Italian stade became (300 years later) the most commonly accepted value for the length of the stade, which implies a circumference of 46,100 km, an error of 15%.

 
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Yes, but, if the Spaniards really knew this, they would not have funded Columbus, since westward distance from Spain to China was over 22,000 km, for which the ships that sailed had nowhere near sufficient rations and water. They had barely enough provisions to get to the Caribbean, which was not even 7000 km.

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IRstuff said:
Ironically, Spain managed to squander all the wealth anyway.
Click to expand...
Easy come, easy go?
LittleInch said:
How do they answer the question that when at sea, where the surface is super flat spherical [FIFY], you still can't see anything more than 20-30 miles away on the clearest day in history??
Click to expand...
...don't need an ocean, on any decent sized lake, e.g. Lake Winnipeg, any of the Great Lakes or any of the larger lakes around the world, the curvature of the horizon is evident, as is the recedence of land or floating bodies near and beyond the horizon.


"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz
 
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IRstuff,

The problem was that in the 1400s, estimates of longitude were not very good, Estimates for the longitude of East Asia had it quite a lot further east than the real figure, Columbus was also using an under-eastimate for the circumference of the Earth - he really did believe he could sail to Japan, but as luck would have it, he found the Caribbean islands just when he expected to reach Asia.

There's a good succinct account here:

 
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I've been on Lake Winnipeg often and have viewed Lake Superior often. I have never noticed the 'curvature'... looked pretty flat, but, then wasn't looking for the curvature. Wave 'set-up' may have obscured that.

Dik
 
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the class room story I recall was that Columbus observed the ship gradually disappear while the mast and sails remain visible for some time after, thus observing the curvature as objects went over the horizon.
 
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Julian, that was my point exactly, the sailing speed of his largest ship was around 90 miles per day, so if the Europeans knew the correct circumference within 15%, they would have expected a minimum of 154 days of sailing from Spain, not the 49 days sailing distance to the Caribbean they wound up with. They, Columbus, immediately assumed that they arrived in India, when they made landfall in the Caribbean.

So, either the Europeans misinterpreted the Greeks' Earth circumference, or the Greeks made a mistake.

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My eyesight has never been good enough to distinguish between a boat and the mast and sails in a distance... once out of sight, I just assume they have 'dropped off'.

Dik
 
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"The issue in the 1490s was not the shape of the Earth, but its size, and the position of the east coast of Asia, as Irving in fact points out. Historical estimates from Ptolemy onwards placed the coast of Asia about 180° east of the Canary Islands. Columbus adopted an earlier (and rejected) distance of 225°, added 28° (based on Marco Polo's travels), and then placed Japan another 30° further east. Starting from Cape St. Vincent in Portugal, Columbus made Eurasia stretch 283° to the east, leaving the Atlantic as only 77° wide. Since he planned to leave from the Canaries (9° further west), his trip to Japan would only have to cover 68° of longitude.
Columbus mistakenly assumed that the mile referred to in the Arabic estimate of 56⅔ miles for the size of a degree was the same as the actually much shorter Italian mile of 1,480 metres (0.92 mi). His estimate for the size of the degree and for the circumference of the Earth was therefore about 25% too small. The combined effect of these mistakes was that Columbus estimated the distance to Japan to be only about 5,000 km (or only to the eastern edge of the Caribbean) while the true figure is about 20,000 km."
Ref:





 
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Seems odd to me that Ferdinand wouldn't have had his own naval experts check Columbus' math, particularly for a rather expensive and risky (even without falling off the edge of the Earth) venture.

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Christopher Columbus mission cost was probably under $1M USD. The ships were rentals, not purpose built. Then there were the crews and provisions costs. Conversions are very difficult because the currency and relative values of the various portions have changed such that scaling no longer works. Also, Columbus seems to have contributed 1/3 of the funding through other sources and the Crown didn't finance the entirety of the rest.

He scored the big contributions when he returned with evidence of finding a new place.

has an accounting view of the voyage but doesn't suggest a converted value.

CONCLUSION
It has been reported that Columbus may have been one of the best dealmakers in history. He really did not know where he was going, and even after four voyages, he never really got there. He convinced others to finance his adventure into the unknown, and when he got there, he did not know where he was. Yet, when he returned to Spain, he was able to obtain monies to finance a second trip with 17 ships and over 1200 people.
 
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According to this: Columbus actually didn't use Eratosthenes' measurement, he used Posidonius' which was grossly in error, and then Columbus used an incorrect value for the mile in Pierre d’Ailly's translation of the Greek writings. Net result, Eratosthenes' successors did measure the circumference incorrectly, which was what Columbus used, coupled with an incorrect value for the Arabian mile, resulted in a substantially shorter distance to Asia. So, it's possible that others using the same source wound up with similar estimated distances to Asia.

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The Brit's actually tried very hard to measure the earth's curvature using the "absolute flat" water in their longest-straightest canal possible back in the early Industrial Revolution period. Depending on the test, they were either able to prove it was flat, or prove it was round. The instruments available and the lengths of the canal sections were simply not able to generate enough precision to overcome the prejudices of each different judge and each different circumstance.

They were attempting to use the same principle as watching a boat's mast disappear: Measure the height of a marker on the boat as it moved away from the observer down the calm water of the canal. Today, with a laser line from a gravity-balanced level and today's telescopes and mounts, could the experiment be tried again successfully?
 
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Just to illustrate the importance of side effects, Columbus also calculated the food supplies based on the estimation of the journey. Where's that, "half of the way", that was the question.

So, after launching that rocket it is just common sense to demand that it gets the passenger back on the ground in one piece. Else we're ripe for gladiator games (again). Such handling of reality as one of many alternative facts will harm, hurt or worse, one day or other.

Roland Heilmann
Lpz FRG
 
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Well, I'll add my 2 cents to the divergence this thread has taken from the OP. The Norse were visiting the actual North American continent ~500 years prior to CC making it almost there. I don't know what all of the fuss is about. We'd have stayed and settled longer, but the skraelings were a very unfriendly lot.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.
 
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ornery: What do you mean, almost there... we had Viking settlements in Newfoundland...

Dik
 
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dik, please re-read my post. Absolutely there were settlements on the mainland. It was Christopher Columbus (CC) that almost made it to the North American continent. The Norse, in fact, were there 500 years prior. IRstuff, they did, in fact, make it to Minnesota in the 14th century. I'm 100 miles south of where the Kensington Runestone was originally found. It's a genuine artifact. The debunkers have been debunked many times. Linguists have affirmed that the subtle intricacies of the runic characters inscribed on the stone weren't known in the timeframe that the stone was unearthed. A forgery using the characters as they were known in the 1890's would have had tell-tale differences to expose it, were it faked.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.
 
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