Thread: All Water on Earth as One Sphere

That's 1.386×10^21 liters!

I wonder if there are spheres of h2o floating in space somewhere out there...

I'm gonna have to call BS on this, it's based off of a book written in 1993. If you expect me to believe we had the capability to quantify the amount of water in the entire ocean (we don't even have a completely detailed map of the ocean floor, let alone what lies in subterranean lakes and this is 2012) you've lost your mind.

Are you aware that it is impossible for us to even decide on how long a country's coastline is? Do you know why that is? Because each measurement is off by thousands of miles depending on how detailed in you go. The reason behind this (and how it relates to water) is in the detail. If you were to take a general outline that is technically considered "correct" by topographical standards you might get one measurement, while ignoring smaller tributaries and offshoots of water into the shore.

Take a look at this picture:


all three of those are correct measurements of that coastline, and as you start cutting out those tiny details on each coast you would lose millions of gallons of water (just on America's coastline alone). Now extrapolate that. That's a coastline we can see, imagine how much detail is cut off from three dimensional topography of what we theorize the map of the ocean floor looks like, or the bottom of a lake. How much detail gets cut off there? I'd gather more than we can even fathom. Just some food for thought.


EDIT:

to further prove my point here are three separate "correct" measurements for the US coastline:

CIA: 19,924 km
NOAA: 12,479 miles
NOAA: 95,471 miles

if you noticed that two of those are the same agency, congratulations, you've just further proved my point. The same agency recorded the shore line as two seperate quantities. And before you say it's because technology advanced, that longer measurement was done by hand in the late 1930s, the shorter was done in 1975.

I've got nothing but my gut, but this seems wildly unprobable. I hope!

Originally Posted by DocDoom

I'm gonna have to call BS on this, it's based off of a book written in 1993. If you expect me to believe we had the capability to quantify the amount of water in the entire ocean (we don't even have a completely detailed map of the ocean floor, let alone what lies in subterranean lakes and this is 2012) you've lost your mind.

Are you aware that it is impossible for us to even decide on how long a country's coastline is? Do you know why that is? Because each measurement is off by thousands of miles depending on how detailed in you go. The reason behind this (and how it relates to water) is in the detail. If you were to take a general outline that is technically considered "correct" by topographical standards you might get one measurement, while ignoring smaller tributaries and offshoots of water into the shore.

Take a look at this picture:


all three of those are correct measurements of that coastline, and as you start cutting out those tiny details on each coast you would lose millions of gallons of water (just on America's coastline alone). Now extrapolate that. That's a coastline we can see, imagine how much detail is cut off from three dimensional topography of what we theorize the map of the ocean floor looks like, or the bottom of a lake. How much detail gets cut off there? I'd gather more than we can even fathom. Just some food for thought.


EDIT:

to further prove my point here are three separate "correct" measurements for the US coastline:

CIA: 19,924 km
NOAA: 12,479 miles
NOAA: 95,471 miles

if you noticed that two of those are the same agency, congratulations, you've just further proved my point. The same agency recorded the shore line as two seperate quantities. And before you say it's because technology advanced, that longer measurement was done by hand in the late 1930s, the shorter was done in 1975.

You remind me of this math "problem":
Koch snowflake - Wikipedia, the free encyclopedia

Say this is a coast line, as you can see it's infinite, or is it ?



Yes this problem bewildered humanity for centuries.

No measurement is accurate, there will always be a relative error and if the error is a few units off it usually so small that it doesn't really matter.

For example, I weigh about 68 kg, you think I care if the weight is off by a few hundreds of grams ? and that's a very large amount of error, I don't care because I know my estimated weight and it's enough for me.

In our case, we had the satellites and the tech to measure the volume of water back in the 90s, it's more of an applied math and physics problem than tech problem actually.

Notice what I said before:

Originally Posted by LabChimp

That's 1.386×10^21 liters!

I wonder if there are spheres of h2o floating in space somewhere out there...

Try to subtract a few millions of liters of water from that number and see what happens.

More on infinite series:
https://secure.wikimedia.org/wikiped...d_the_tortoise
Geometric series - Wikipedia, the free encyclopedia

Originally Posted by LabChimp

In our case, we had the satellites and the tech to measure the volume of water back in the 90s, it's more of an applied math and physics problem than tech problem actually.

Satellites wouldn't be able to figure out how much water there was, if you really took the time to carefully use the images they might capture you could possibly get pretty close to the total perimeter of all the bodies of water on the earth, but satelites wouldn't be able to calculate depth into the water, and we still can't do that today en mass. What i'm saying is on a 2 dimensional plane, sure we could probably get a ballpark of how much water there is on the earth, we might even be able to make wild accusations as to the average depths in the area and tick the rest off into our margin of error, but the point of my example of coastline measurements is that those small errors add up to huge amounts even just on the scale of the 2 dimensional coastline of the USA. You can call that miniscule but we're talking about unfathomable amounts of water being written off as a "margin of error".

And again, this still doesn't take into account the subterranean lakes. Where you aware we don't even know how big most of the ones we've actually discovered are? And that's not including the ones we haven't discovered yet.

To anyone daft enough to think we have the technology to map the entire ocean floor, let alone what lies beneath it, ask yourself why the oil companies still have to make educated guesses as to where oil might be buried.