Human Exploration of Mars

Eric Chomko wrote:

: Easily. Africa alone could feed 15 billion people at currently achievable crop
: yields.

What? 15 billion people on what? Most people in Africa eat much worse than
the rest of the world. If what you say is true (and I doubt it), then it
is a sad statement about humanity in general regarding our ability to feed
ourselves.

Crop yields in Africa currently suck. Little use of fertilizer, or irrigation,
or any of a number of known techniques. Africa is actually rather sparsely
populated. What malnutrition is there is a consequence of poverty and social
breakdown, not populations exceeding what could be supported.

Elsewhere in the world, the 'problem' has been continued overproduction of
food. Prices of crops have been in long term decline (with the occasional
blip marked by yet-another-this-is-the-end proclamation by Lester Brown.)


: The UN gives population projections quite frequently; go look at them. While
: rediction is always difficult, there are strong trends around the world toward
: lower birth rates, falling below replacement in nearly all industrialized countries.
: As the populations age (and this happens automatically after the birth rates
: decline) the death rate begins to increase, so after coasting on "demographic
: momentum" the population will begin to fall.

I have heard about this decline. But I have never actually seen an example
of it.

The predictions of decline are near-deterministic consequences of the age
structure of populations. Unless birth rates radically increase, populations
will be declining soon in many industrialized countries.

If by 'never actually seen an example' you mean you haven't seen this demographic
data, I recommend you go to the UN web site and look for it.

Paul

: Look at any reputable set of projections, e.g. the ones discussed in
: Cohen, "Human population: the next half century", Science 14 Nov, p. 1172.

Available at http://www.atmo.arizona.edu/students.../pdf/Cohen.pdf

In article ,
Henry Spencer wrote:

Quite misleading numbers in the case of Canada, and probably Australia as
well. Much of Canada's land area is borderline uninhabitable; the bulk of
Canada's population is in a thin strip along the border. (And something
like a quarter of it, if dim memory serves, is in a very thin strip along
the north shore of Lake Ontario... which is where I happen to be. There
are 7 people within 20ft of me.)

60% of us live somewhere between Windsor and Montreal, ims.

Which doesn't contradict what you said, I know.

The odd thing about CDN population distribution is that
BC, with its soft effete coastal climates, is not more heavily
populated.
--
"The Union Nationale has brought [Quebec] to the edge of an abyss.
With Social Credit you will take one step forward."

Camil Samson

(James Nicoll) wrote:

The odd thing about CDN population distribution is that
BC, with its soft effete coastal climates, is not more heavily
populated.

Because the area with said climate is actually rather small. The
interior of BC, and by far the vast majority of the surface area,
isn't a particularly clement clime.

D.
--
The STS-107 Columbia Loss FAQ can be found
at the following URLs:

Text-Only Version:
http://www.io.com/~o_m/columbia_loss_faq.html

Enhanced HTML Version:
http://www.io.com/~o_m/columbia_loss_faq_x.html

Corrections, comments, and additions should be
e-mailed to , as well as posted to
sci.space.history and sci.space.shuttle for
discussion.

On Sun, 7 Dec 2003 08:43:56 GMT, in a place far, far away,
(Henry Spencer) made the phosphor on my monitor
glow in such a way as to indicate that:


I think you confuse immigration rates with population growth.

You think incorrectly.

A good general statement.

Those are net population growth rates. Many more
of the advanced countries would have negative rates already if not for
immigration; the average children per woman in those countries is 1.6 now
(although that is temporarily low because of Baby-Boom-related timing
effects -- it'll be 1.8 or so by 2050, still below replacement levels).

Yup. Italy is now paying women to have children.

On Sun, 7 Dec 2003 04:29:26 +0000 (UTC), in a place far, far away,
(Eric Chomko) made the phosphor on my monitor
glow in such a way as to indicate that:

Paul F. Dietz ) wrote:
: Eric Chomko wrote:

: Could the world's population of today (~6.3 billion) fit inside the world as we
: knew it back in 1492 (Asia, Europe and Africa)? Or, did we need to find the New
: World to expand mankind?

: Easily. Africa alone could feed 15 billion people at currently achievable crop
: yields.

What? 15 billion people on what? Most people in Africa eat much worse than
the rest of the world. If what you say is true (and I doubt it), then it
is a sad statement about humanity in general regarding our ability to feed
ourselves.

It's mostly a sad statement about malgovernance in Africa.

On Sun, 7 Dec 2003 04:35:36 +0000 (UTC), in a place far, far away,
(Eric Chomko) made the phosphor on my monitor
glow in such a way as to indicate that:

: Or, did we need to find the New World to expand mankind?

: Probably not, but we did need it to have a social laboratory to let
: society and technology evolve to do that comfortably.

But I think you do see the need for more room for humans as we increase
our population.

That's not a problem.

: Tell me about that crystal ball you own that lets you see a decline in the Earth's
: population. When is the population going to start decreasing and at what rate?
: Also where?

: Go ask the UN. It's their prediction, not mine.

Cite please, UN and future population trends.

Go do your own research. People have offered you plenty of pointers.

(Henry Spencer) wrote in message ...
In article ,
George William Herbert wrote:
That mission is one which has constituent tasks which are not
currently feasible to do in any fashion using robots.
Drilling both for fossils and for possible remaining
subsurface life, and the more complex surfaces (cliffs,
holes, etc) geology, are missions which at our current
level of technical prowess require humans to do them.

As a data point here, a few years back Greg Benford asked Hans Moravec
(who is one of the more far-thinking robotics guys, and *not* noted for
being a pessimist about robot capabilities, quite the contrary...) how
soon he could build a robot that could climb down a geothermal vent on
Mars. The answer was "half a century".

He's getting cautious with age, apparently. A few years ago he was
predicting computers with full-human cognitive abilities within a few
decades.

Shermanlee

"Paul F. Dietz" wrote in message ...
Michael Walsh wrote:

I note that James Van Allen has been a consistent and vocal opponent of
manned space flight for many years.

I imagine he is feeling rather vindicated by how it has all turned out.

Paul

It hasn't 'turned out' since the test period is barely begun. If
nothing has come of it 200 years from now (yes, I said 200 years), he
can maybe consider his views vindicated.

Shermanlee

Johnny1A wrote:
(Henry Spencer) wrote:
George William Herbert wrote:
That mission is one which has constituent tasks which are not
currently feasible to do in any fashion using robots.
Drilling both for fossils and for possible remaining
subsurface life, and the more complex surfaces (cliffs,
holes, etc) geology, are missions which at our current
level of technical prowess require humans to do them.

As a data point here, a few years back Greg Benford asked Hans Moravec
(who is one of the more far-thinking robotics guys, and *not* noted for
being a pessimist about robot capabilities, quite the contrary...) how
soon he could build a robot that could climb down a geothermal vent on
Mars. The answer was "half a century".

He's getting cautious with age, apparently. A few years ago he was
predicting computers with full-human cognitive abilities within a few
decades.

The advance in computing power has been significantly faster
than the advance in robotic motion and tactile capabilities.
And they are separate topics. We could well reach computing
device capacities approximating those of the human brain before
we have the general purpose / high mobility robot problem solved.


-george william herbert