Re:Perspective: All of Earth's Water in a Single Sphere
by kijin on Saturday May 05, 2012 @07:45PM
(#3933640)
Those numbers don't make any sense. 2,250,000,000 cubic miles is ~100 times the volume of a sphere with a diameter of sixty leagues. It's also over 6 times the volume cited in the article, while having only twice the weight. That can't happen unless water's density varied dramatically.
So Verne both overestimated and underestimated, and didn't bother to check if his numbers were consistent with one another.
Re:Perspective: All of Earth's Water in a Single Sphere
by yew on Saturday May 05, 2012 @09:32PM
(#3933847)
I can't speak for this estimate in particular, but Verne usually did his (quite extensive) calculations in metric units. Many older translations of his work swapped in imperial or US customary units without adjusting the values for the 'benefit' of English-speaking readers.
Re:Perspective: All of Earth's Water in a Single Sphere
by kijin on Saturday May 05, 2012 @10:43PM
(#3933976)
Aha, that might actually explain the inconsistency between the volume and weight. Imagine that the volume was originally stated as 3.6 billion cubic kilometers, which would actually weigh around "three quintillion tons" (actually close to four, but let's forgive that). A translator might have turned that into 2.25 billion cubic miles, thinking that one mile = 1.6 kilometers. But of course, non-mathematical types usually don't notice that one cubic mile = 4.1 cubic kilometers.
Re:Perspective: All of Earth's Water in a Single Sphere
by simias on Sunday May 06, 2012 @11:40AM
(#3935361)
I've looked up the original text and it uses the same units except for the weight which is expressed in "tonneaux" instead of metric tons: "[...] dont le poids serait de trois quintillions de tonneaux." So they basically swapped the units without bothering to calculate the correct value.
Now how much a tonneau weights is left as an exercise to the reader...
Re:Perspective: All of Earth's Water in a Single Sphere
by sliverstorm on Saturday May 05, 2012 @07:20PM
(#3933600)
Well, the ice caps hold a TON of water.
"THE PART OF THE planet earth that the seas occupy has been assessed at 3,832,558 square myriameters, hence more than 38,000,000,000 hectares. This liquid mass totals 2,250,000,000 cubic miles and could form a sphere with a diameter of sixty leagues, whose weight would be three quintillion metric tons."
According to Google and Frink, 60 leagues is less than 1/4 of the 860 miles estimated here; I'm not sure how much of that is due to the smaller scope of the estimate in Verne's book.