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-----Original Message-----_______________________________________________
From: phys-l-bounces@carnot.physics.buffalo.edu [mailto:phys-l-
bounces@carnot.physics.buffalo.edu] On Behalf Of curtis osterhoudt
Sent: Thursday, September 16, 2010 12:23 PM
To: Forum for Physics Educators
Subject: Re: [Phys-l] H. Sapiens
Remember the simple rule-of-thumb: If something is growing at x% per
time y, the
doubling time is roughly 70/x to double in y units. That is, a
percentage growth
rate of (say) 1% leads to a doubling of population in about 70 years.
That's
_scary_ to me, for _any_ population.
/**************************************
"The four points of the compass be logic, knowledge, wisdom and the
unknown.
Some do bow in that final direction. Others advance upon it. To bow
before the
one is to lose sight of the three. I may submit to the unknown, but
never to the
unknowable." ~~Roger Zelazny, in "Lord of Light"
***************************************/
________________________________
From: Bernard Cleyet <bernardcleyet@redshift.com>
To: Forum for Physics Educators <phys-l@carnot.physics.buffalo.edu>
Sent: Thu, September 16, 2010 11:15:34 AM
Subject: Re: [Phys-l] H. Sapiens
Contrary to what I presume many think, Mexico is less adding to that
problem:
"Throughout most of the twentieth century Mexico's population was
characterized
by rapid growth. Even though this tendency has been reverted and average
annual
population growth over the last five years was less than 1%, the
demographic
transition is still in progress, and Mexico still has a large cohort of
youths."
http://en.wikipedia.org/wiki/Demographics_of_Mexico
bc
Demographic transition:
http://anthrocivitas.net/forum/showthread.php?t=1539
On 2010, Sep 11, , at 20:15, ludwik kowalski wrote:
Actually, I was wrong about the "less than 20 years, as you can seeat:
double
http://en.wikipedia.org/wiki/World_population
Ludwik
= = = = = = = = = = = = = = = = = = = = = = = = = = =
On Sep 11, 2010, at 11:05 PM, ludwik kowalski wrote:
On Sep 11, 2010, at 10:49 PM, brian whatcott wrote:
There are less than 8 billion people presently on Earth. . . .
This is about four times more than when I was a kid. It will probably
future ofagain in less than 20 years. How can one be optimistic about the
sapients?
Ludwik
http://csam.montclair.edu/~kowalski/life/intro.html
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Ludwik
http://csam.montclair.edu/~kowalski/life/intro.html
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