[extropy-chat] Population Densities (was Panicmongering)

[Lee Corbin]

Damien S. writes

> > Let's see what population densities that might be. Suburbs currently 
> > run at about 10,000 people per square mile, or 6000 per square
> > kilometer.

I was remembering San Francisco's as 15,000; BTW, that's closer to 3500
per square kilometer unlike what I wrote.

> Where do you get those numbers?
> http://www4.wittenberg.edu/academics/urban_studies/BFINALEC.html
> gives 2000 people per square mile.
> 
> Some numbers I have burned into my memory:
> Manhattan 65,000
> NYC 25,000
> (Outer boroughs 15,000)

I recall reading many, many years ago that in 1900 New York City's
lower east side attained a density of 600,000 people. (Probably an
Edward T. Hall book.) Seem possible to you? Know how to check that?
The author claimed that this was the highest density for humans
in all history, and considering that modern sanitation and
construction might be required, it didn't seem impossible.

> San Francisco 16,000
> Chicago 12,000
> LA 9,000
> Berkeley, Pasadena 5,000 [could be wrong about Berkeley]
> Dallas 3,000
> 
> http://www.perc.org/perc.php?id=374
> "only half of Americans live in 2,000/mile^2 or higher" -- Indianapolis
> or Tulsa densities.
> 18% at 5,000 or more.  1/3 at 3,000 or more.  And that's the central
> cities.

Yes, thanks for the research.  Since I did say "suburb" my figures
are inappropriate. 

> > but are vacant now. Food production has increased per acre by
> > about a factor of 5 since 1950, while the population has only
> 
> It's not clear that's sustainable, given energy inputs to corn from
> petroleum-made fertilizers comparable to the energy inputs from the sun.

I don't know what the assumed crops were. 

> Area of San Antonio: 1000 km^2.
> Solar energy input estimate: 3e11 watts.
> Energy consumed by US human bodies: 3e10 watts
> 
> You'd need 10% energy capture when plants tend to get 1%.  Okay, 8% at
> the high end of algae or growing sugar cane.  Where's the beef?  Not to
> mention the electricity.

The city he mentioned turns out to be Austin, not San Antonio (my 
error). Sunlight isn't used; as one on-line reference puts it
"Energy for artificial light is the key raw material in state-of
-the-art hydroponics . Even at present electricity costs,
PhytoFarm is profitable ..."

Anyway, here is Julian Simon's chapter on hydroponics:

http://www.juliansimon.com/writings/Ultimate_Resource/TCHAR06.txt

Lee