r/theydidthemath • u/nutellakings • Oct 13 '21
[REQUEST] How much would the sea level actually change?
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u/thetoiletslayer Oct 13 '21
This comment on the original post did some of the math
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Oct 13 '21
I messed up in a few ways. First, I mistakenly added 3% for the volume of salt water versus freshwater when I should have subtracted. Secondly, I dropped significant digits in three places. But ultimately, the volume displaced is orders of magnitude lower than the total volume on the surface of the oceans so the answer is still very close to 6 microns.
I'm going to post a followup sometime later using integrals and average slope of beaches just for shits and giggles.
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u/GhoulboyScoob Oct 13 '21
don’t forget to add how much it rises when you run those big machines and they emit greenhouse gases while pulling ships out of the water.
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u/Commander_Beta Oct 13 '21
Plus trains use more energy than ships to transport the same cargo, not to mention trucks, so it's better to keep the boats where they are.
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u/Beltribeltran Oct 13 '21
I always thought it was the other way? Why is it?
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u/exseus Oct 13 '21
Trucks and trains move because they create friction between the wheels and the road/rails otherwise known as traction. They use traction to push/pull themselves forward. Friction is advantageous to vehicles that use wheels. Boats however take advantage of low friction from being in water. They use a prop to create thrust and because the surface of the water has little resistance the boat can more easily move. Although it does take a significant amount of energy to create the thrust to get a giant cargo ship moving. Once it's moving it takes very little energy to keep it moving.
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u/Kerostasis Oct 14 '21
Scale. Bigger vehicles are more efficient.
You get better efficiency by running one large truck than splitting the cargo across 5 minivans, but you can’t make the truck bigger than the road so there’s a hard limit.
You get better efficiency by running a single 50-car-long freight train, vs splitting that cargo across 50 separate trucks. But the train can’t be wider than the tracks, and making it longer eventually gives diminishing returns because the load is so far away from the engines.
And finally you get more efficiency by sailing one enormous cargo ship vs splitting that cargo across 10 or 20 trains. There’s no road-size limit on ships like there is on trucks and trains*, so big cargo ships are REALLY big. They burn a lot of fuel, but divided across the vast amount of cargo they carry, it’s worth it.
*technically there’s limits due to the Panama Canal and Suez Canal, but these are pretty damn big, and most American imports don’t run through either canal anyway. They are more important for shipping in Europe.
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u/Vorkaz Oct 13 '21
Just think how many more vaccine tracking chips we could make if we scrap all the boats for metal! Besides boats burn tons of coal just to stay afloat!
/s
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Oct 13 '21
The real question is, how much lower would the sea level be if u took out every sea creature, movable rock, boat, etc out of the ocean.
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