APOD: All the Water on Planet Earth (2016 Sep 11)

[bmander]

Puts things in perspective, doesn't it?

[starbrush]

It's a fine and poignant image, and I'm all for describing phenomena, processes and quantities in different ways, because these can then give access to fresh ways of looking at other, er, spheres! Otherwise, why pay any attention to a bored Swiss patent clerk chasing torch beams?

[DavidLeodis]

This link (brought up through the "featured illustration" link) brings up among other things an even more informative illustration of Earth's surface water distribution. http://water.usgs.gov/edu/gallery/globa ... olume.html.

The "If you put a (big) pin to the largest bubble showing total water, the resulting flow would cover the contiguous United States (lower 48 states) to a depth of about 107 miles" information through the link is quite staggering (well it is to me ).

[neufer]

What may be more interesting to know is what average depth of water would occur everywhere if the entire surface of earth was quite flat and covered with all the water calculated here.

Just under 3 kilometers...or slightly less than the current average ocean depth.

As a GAS, the atmosphere (on Earth) has more depth, considerably more....

As a GAS, half the atmosphere (on Earth) lies below 5.5 kilometers.

[Chris Peterson]

how big would this sphere be if you take the volume of every inhabitant of the Earth and create a sphere representing this volume ?

All of humanity would fit in a volume of about one cubic kilometer. Smaller than a pixel in this image.

The internal temperature from metabolic heat would be high enough to initiate thermonuclear fusion.

I agree on the size, but the core metabolic heat would dissipate rather quickly, as everyone was crushed and/or suffocated to death. Lovely thought.

Of course, such a thing couldn't be constructed. It's just an illustration of the temperature that would (theoretically) result given packing in a bunch of 100 watt emitters (humans) in a confined space.

But how much volume does every living thing on Earth take up?

The usually quoted value for the volume of the biosphere is a sphere approximately 20 km in diameter.

[Chris Peterson]

It is just plain dumbed down anti-science to entertain the silly notion of the Earth's water bundled into a little ball. You may as well bundle the whole crust beyond the depth man has ever ventured and roll it into a ball, it is about as arbitrary, useful and misleading a comparison!

Your point entirely escapes me. But I do recognize that you're missing the point of this APOD. Badly.

[rstevenson]

how big would this sphere be if you take the volume of every inhabitant of the Earth and create a sphere representing this volume ?

You could also take all the human inhabitants and relocate them to the Hawaiian islands with some room to spare

This concept was the starting point for a 1968 science fiction novel called Stand on Zanzibar, by John Brunner. From its Wikipedia article...

The primary engine of the novel's story is overpopulation and its projected consequences, and the title refers to an early twentieth-century claim that the world's population could fit onto the Isle of Wight – which has an area of 381 square kilometres (147 sq mi) – if they were all standing upright. Brunner remarked that the growing world population now required a larger island; the 3.5 billion people living in 1968 could stand together on the Isle of Man (area 572 square kilometres (221 sq mi)), while the 7 billion people who he (correctly) projected would be alive in 2010 would need to stand on Zanzibar (area 1,554 square kilometres (600 sq mi)). Throughout the book, the image of the entire human race standing shoulder-to-shoulder on a small island is a metaphor for a crowded world.

As I recall, at the end of the book the outermost people were likely to be ankle deep in the sea, an image that has stuck with me ever since.

Rob

[BMAONE23]

It was an interesting read though.
The current estimated population of 7.45 Billion would have approx 40sq' each or 5' x 8' on Hawaii
Who wants the Beach Cubicles??

[chuckster]

You may as well bundle the whole crust beyond the depth man has ever ventured and roll it into a ball,

I think gravity did that already, about 4 billion years ago. It's what the water's sitting on.

[longtry]

I have a hypothetical scenario. Supposed that in some magical way all the water on Earth (minus that in living things - biosphere) collects into that ball. What will happen next?

But my main question is: is this forum, particularly this topic, the place where I should ask this kind of query? If not, where would be the most appropriate place on the internet?