Just wondering… (and, yes, it is ok to stack everyone on top of each other to the top)
Many times over.
Volume of the Grand Canyon is 5.45 trillion cubic yards, more or less. (Figure acquired off the internet and probably reasonably accurate.)
The volume of the average person is less than one cubic yard. Maybe even 1/3 cubic yard. So you could fit between 1000 and 3000 times the current population of the Earth into the Grand Canyon.
But let’s get a bit fancier here. The average depth of the GC is one mile. Average width is 10 miles.
Unless I’ve screwed up the math, there are 5,451,776,000 cubic yards in a cubic mile. So you could cram all 8 billion people in the world in a section of the Grand Canyon less than 1/10 mile long. Probably a lot less if you allow for squishage.
I don’t think you appreciate how huge the Grand Canyon is. From this site:
Let’s put the numbers into cubic feet. (For convenience, let’s say that it is one mile deep and only 4 miles across)
(277 x 5280) x (4 x 5280) x 5280 = 861,143,346,708,480,000 cu. ft.
People are 6 x 2 x 1 = 12 cu. ft.
12 x 6,000,000,000 = 72,000,000,000 cu. ft. of people.
That means you could fit all the people on earth into the Grand Canyon more than 12,128,779 times over. And since it is much wider in spots, that severely underestimates the case.
Ever been to Loch Ness? That quote about fitting the population of the Earth in the Loch is thrown around by every tour guide and Exihibition Centers.
Loch Ness itself is a mile wide , 24 miles long and up to 700’ deep, so since you could fit quite a few Loch Ness’s into the Grand Canyon, easy to say that even a hundred years in the future we all could still fit in the GC.
OK
World Population is 6,214,891,000 (2002 Numbers eek! pdf file)
Grand Canyon is 1,217,403 acres (Park Service
That would mean you’d have to put a little over 5105 people per acre. An acre is 43,560 square feet. That would be 1 person ever 8.5 square feet (I think).
Not comfortable, but theoretically possible.
(Please check my math!)
OK, I say we do it!
Group photo!!!
Yeah right. Like half a billion people aren’t going to have their eyes closed.
I didn’t check your math, but I just wanted to point out that according to your numbers, you could fit everyone in without even having to stack them. Everyone gets standing room.
Particularly given that 100 years in the future the human population will still be less than 9 billion people.
How do you figure that? The conventional wisdom is that the population doubles every 35 years.
It used to be said that there is enough standing room for the Earth’s population on the Isle of Wight - I’m not sure if this is possible with today’s population and besides, I think the locals might object.
In the 1968 sci-fi novel Stand on Zanzibar, John Brunner predicted a world population of 8 billion in 2010, which would require an island the size of Zanzibar for standing room:
Not sure who subscribes to that convention, but it is anything but wise.
With room for errors in censuses etc, world populaton was about about 4 billion in 1968 and now 35 years later we have a total of about 6 billion. Not close to a doubling. Not only that but within 50 years the population will plateau at C9 billion ad then begin to fall. ( http://www.un.org/News/Press/docs/2003/pop850.doc.htm )
There may have been one very specific period in the early-mid 20th century when population doubled in one 35 year period. But anyone who has told you this has been true at any other point in time, or whpo has been telling you it has been true in the last 30 years has been telling you porkies.
Nope. Can’t be done. At any given time, 204 million people are in meetings and can’t be reached. Countless pretty young women have other plans. A billion or so children have to go to the bathroom or are afraid of canyons. Teeming millions cannot be pried from their computers. 84 million people have to stay home and wait for the cable guy, who will be there sometime before five. Seven or eight million bouncy, chattering little folks can’t go because they’re waiting in line for Justin&Christina tickets. Billions of Chinese citizens are atop chairs, waiting for the signal to jump. Two point four billion people are on hold, waiting for tech support. Eighteen hundred people are actually talking to tech support. 105,071 hearing-impaired folks thought you said “band candy,” and they slammed the door. I can’t go. I’m, uh, busy.
The real question: what would happen if they all jumped up and down at the same time?
Not a chance. We’ve been trying to set up a dinnerparty at my house with 12 guests. It’s taken over three months to agree on a date when we can all be there. Good luck trying that with 6 billion people!
Besides… you wouldn’t be able to get enough toilet-facilities either. So I for one would refuse to go in anyway. Plus, I can only make it on Saturdays.
Okay, who wants to tackle the corollary question:
Can you fit all living things on Earth into the Grand Canyon?
Yes, that means plants, too.
Planning the mother of all mass executions or something? Who’s gonna run the bulldozers, chimps? 
To start, this site gives the total biomass of the Earth as 1851 X 10[sup]9[/sup] tons. Assuming that the density of the biomass is approximately that of water (probably not to bad a guess), then one ton = one cubic meter, and total biomass = 1.851 X 10[sup]12[/sup] cubic meters.
For the Grand Canyon, Finagle gives 5.45 trillion cubic yards = 4.14 X 10[sup]12[/sup] cubic meters. Exapno Mapcase gives something roughly the same (although looks like he mismultiplied: should be 163 trillion cubic feet = 4.56 X 10[sup]12[/sup] cubic meters).
So looks like all life will fit in about half the volume of the Grand Canyon. I get dibs on the top layer, though.
zut, my hat’s off to you! Thanks for the analysis.