"in a single sphere"---- shows three spheres
All of Earth's water in a single sphere (2019)
191–200 of 290 posts
Re: All of Earth's water in a single sphere (2019)
#192Earlier quoted context omitted.
Humans are notoriously terrible about estimating volumes when things are curved and volume functions are exponential. A great example of this done in 8th grade science classes across the US is to put 100ml of water in a 100ml graduated cylinder, 150ml in a 1L beaker, and ask the class which has more. Humans are awful at estimating how much volume the increased radius adds, and usually will say the 100ml. The problem…
Volume functions are not exponential. They are polynomial. (Fair point that people are lousy at estimating even polynomial functions, though...)
Thanks for adding the mathematical definition!
You might be interested to know that the first definition of "exponential" is "of or relating to an exponent". The second definition is, as you say, "involving a variable in an exponent". https://www.merriam-webster.com/dictionary/exponential
As this is an internet forum and not a rigorous mathematical setting, I assert that my use of "exponential" is correct in context and to claim otherwise is incorrect. :)
Re: All of Earth's water in a single sphere (2019)
#193Earlier quoted context omitted.
"Polynomial" meaning x^n. "Exponential" meaning e^x. Exponentials eventually grow much faster than polynomials, no matter what the exponent is. I mean, look, in v = x^3, the "3" is an exponent. But it's not an exponential function because the variable isn't in the exponent.
> Exponentials eventually grow much faster than polynomials, no matter what the exponent is. Since we're being pedantic, that last clause should be: "as long as the exponent is greater than 1."
We can go a step further with the pedantry, and say that the commenter above is using an unreasonably narrow definition of the work "exponential" and that there are others which allow x^2 to be described as "exponential".
Re: All of Earth's water in a single sphere (2019)
#194NB: The infographic and articles are based on a 1993 publication. More recent research, from about 2017, suggests that there's about as much water in Earth's mantle as in all the oceans, so we either need another drop roughly the volume of the first, or the second drop should be greatly expanded. See: "There’s as much water in Earth’s mantle as in all the oceans" (2017) https://www.newscientist.com/article/2133963-th…
> second drop should be greatly expanded
Radius of said sphere would only increase by ∛2. ;)
Re: All of Earth's water in a single sphere (2019)
#195Earlier quoted context omitted.
> Exponentials eventually grow much faster than polynomials, no matter what the exponent is. Since we're being pedantic, that last clause should be: "as long as the exponent is greater than 1."
We can go a step further with the pedantry, and say that the commenter above is using an unreasonably narrow definition of the work "exponential" and that there are others which allow x^2 to be described as "exponential". https://www.merriam-webster.com/dictionary/exponential
Or one step further
https://www.merriam-webster.com/dictionary/exponent
which is how I was taught. I only went to CalIII back in the early 90s, so who knows what's being taught now???
Re: All of Earth's water in a single sphere (2019)
#196I long assumed that the Earth is a "water planet" because water is mostly what you see from a distance. It wasn't until I did the math that I realized that is really about wet rocks in space vs dry rocks in space. Earth isn't made of water, it's just a damp rock. Or a bowling ball that you squirted a dozen times with a spray bottle.
rock that moves and is hot inside so a magnetic fields generates from its motion and protect us from the sun particles
Re: All of Earth's water in a single sphere (2019)
#197IIRC water in earth's mantle is magnitudes greater than the volume contained in our oceans. I think only part of Earth's H2O story is illustrated by this graphic.
Re: All of Earth's water in a single sphere (2019)
#198What a coincidence, One hour before reading this article I was thinking of it! I was imagining that how the sphere will look like if made of oceans and seas' water. Now I got to know it :D
Re: All of Earth's water in a single sphere (2019)
#199I long assumed that the Earth is a "water planet" because water is mostly what you see from a distance. It wasn't until I did the math that I realized that is really about wet rocks in space vs dry rocks in space. Earth isn't made of water, it's just a damp rock. Or a bowling ball that you squirted a dozen times with a spray bottle.
> Earth isn't made of water, it's just a damp rock. Or a bowling ball that you squirted a dozen times with a spray bottle. Yeah, the image with the oceans being dry is wow-inducing... On further thought, of course it'd be very close a sphere, because gravity forces it to be. A sphere where e.g. a slice of it is water (imagine a clementine with one of its segments being water) would be very wobbly if even possible at…
Yup, the mere fact that we can have oceans and continents on a planet means we can only have so much water, lest we become a water world or something more like mars.
I do wonder if the OP includes water locked away in rocks though, to my understanding the majority of the water is in the mantle and not even the oceans, but my source is my butt for that one
Re: All of Earth's water in a single sphere (2019)
#200Earlier quoted context omitted.
They mean in terms of the ratio of water to rock.
Well, the spray bottle was more to spread the water out into a thin layer as opposed to something like crashing an icy asteroid in at one spot. I have a mental image of a gigantic cosmic being grabbing the Earth, wiping off the wet stuff with a rag, and bowling it at Proxima Centauri.
Reminds me of the ending of Men In Black (1997).