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All of Earth's water in a single sphere (2019)

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Re: All of Earth's water in a single sphere (2019)

#111

Post by nwiswell »

oorza wrote: post #98
sfink wrote: post #59

I 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.

Closer to a bowling ball that picked up a drop of beer from your hands.

This didn't sound right, so I did the math.

The volume of all water is 1,386,000,000 km^3, which is then 1.386e+21 liters, or right about the same number of kilograms.

The mass of Earth is about 5.972e+24 kg. So the percent fraction by mass is 0.0232%.

A "drop" is typically estimated at 1/20th of one mL, which is then 0.05 grams. We can estimate the mass of a small-ish bowling ball at 5kg, or 5000 grams. 0.05 / 5000 * 100 = 0.001%.

So it's an order of magnitude shy, but that's still closer than I expected! It's about 1 ml of beer on a bowling ball - a small splash. Or maybe a very large drop.

Re: All of Earth's water in a single sphere (2019)

#114

Post by Intralexical »

sfink wrote: post #59

I 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.

"Squirt with a spray bottle" is a nice euphemism for throwing asteroids at.

https://en.wikipedia.org/wiki/Origin_of_water_on_Earth#Aster...

Re: All of Earth's water in a single sphere (2019)

#115

Post by [deleted] »

nightpool wrote: post #20
mensetmanusman wrote: post #7

Can’t help but want to build that. Apparently all the mined gold in the world would fit inside a 5 m diameter sphere. Spheres are suspicious in hiding weight.

The World Gold Council says: > If every single ounce of this gold were placed next to each other, the resulting cube of pure gold would only measure around 22 metres on each side So that can't possibly be right, you must be off by a factor of 10 or so at least—Wolfram Alpha says a 30m diameter sphere.

[deleted]

Re: All of Earth's water in a single sphere (2019)

#116

Post by zamadatix »

ars wrote: post #105
sfink wrote: post #59

I 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 even really a "rock", it's mostly a ball of iron. It's a ball of iron covered with rocks (i.e. metal oxides) cover with water (i.e. hydrogen oxide).

I don't buy it. Even allowing counting iron as separate from what rocks can be composed of (and using mass instead of volume) you still have 30.1%+15.1%=45.2% of the Earth as oxygen and silicon (which are most certainly part of what makes a rock) at which point you've already disproved the claim Earth is more a ball of iron than a ball of rock.

A ball of iron covered with a ball of rocks is a more fair statement though, and I'd agree with that. It's just that center ball isn't most of what makes up the Earth (by any measure).

Re: All of Earth's water in a single sphere (2019)

#117

Post by ianburrell »

Sparkyte wrote: post #76
kevinkeller wrote: post #32

Largest ocean in our solar system isn't even on Earth, apparently: > ... Ganymede’s ocean is even bigger than Europa’s—and might be the largest in the entire solar system. “The Ganymede ocean is believed to contain more water than the Europan one,” he says. “Six times more water in Ganymede’s ocean than in Earth's ocean, and three times more than Europa.” https://www.scientificamerican.com/article/overlooked-ocean-..…

We could probably terraform Mars if we crashed Europa into Mars.

It would make Mars warmer. It would melt all the ice and CO2. It would give Mars an ocean. Of liquid rock. This is assuming that it doesn't destroy Mars completely. There might be enough fragments to make Solar System dangerous place and destroy life on Earth.

Europa is the size of our Moon. Colliding it with Mars would be similar to the collision that formed our Moon.

Re: All of Earth's water in a single sphere (2019)

#120

Post by rising-sky »

digging wrote: post #71
rising-sky wrote: post #48

Pretty interesting juxtaposition considering water makes up about 71% of the Earth's surface, while the other 29% consists of continents and islands!

Well, spill a glass of water on your kitchen counter and you'll find it suddenly makes up a large percentage of the counter's surface as well!

I'm aware, notice my comment specifically states "the Earth's *surface* " not just "the Earth". However, my kitchen counter is a flat surface, it's common knowledge the Earth isn't flat and the average ocean depth is 3,682 meters
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