Say, are you over age 40? If so, then the world's population has more than
doubled in your lifetime. Think about the meaning of that!!
The lead article in the June 22 SCIENCE NEWS is about population growth and
the consequent strains on natural resources. Mentioned are the following:
- The world's population grew by 87 million last year, with 80 million of
these people being in developing nations.
- One third of the world's cropland has been abandoned since 1955 due to
overuse.
- Demand for food in developing countries is expected to double by 2025.
Yet the per capita availability of cereal grains, the source of 80% of the
world's food, has been declining for 15 years. The US provides the largest
share of grain exports.
- In the US, demand for food will double in 60 years if the population
keeps growing steadily; there will be no grains left to export. Food could
cost half of each paycheck. etc.
It sounds terrible. And what happens after 200 years? I hope to have
great grandchildren, and I want them to have a healthy world to live in.
It troubles me, and I urge all of us physics teachers to think deeply about
how we can educate our students to the facts and the dangers of
environmental dis-ease.
I can see two direct links between population growth and physics education.
First, the arithmetic connection: the meaning of steady growth (exponential
growth). Second, the impact on energy use.
As Al Bartlett says, "The greatest shortcoming of the human race is our
inability to understand the exponential function." His 1994 video entitled
ARITHMETIC, POPULATION AND ENERGY explains doubling time and shows how you
can predict the consequences of steady growth in population, inflation,
energy use, etc. It's powerful! It can be ordered for $35 from the U of
Colorado TV, Academic Media Services, CAmpus Box 379, Boulder, CO
80309-0379.
I used Al's video every year in my courses for science majors and non
science students at the community college, and followed it with a
discussion on what they could do personally; and then had them do a lab on
doubling time, in which groups of students measure out a drop of water, and
then double it, etc. They predict how many doubling times are needed before
the water fills a wastebasket, and then test their prediction. The lab
manual that comes with the Hewitt book includes this idea.
If you go to the AAPT Summer meeting in College Park on Aug.5 - 10, be sure
to attend the plenary session on Wednesday: "Earth on Fire: the
Atmospheric, Climatic, and Biospheric Implications of Global Burning". The
abstract reads, "Recent satellite measurements ...suggest that on the
global scale, biomass burning is much more extensive and widespread than
previously thought....Biomass burning may be an important driver for global
atmospheric and climatic change."
Of course you all know that last year was the warmest year in the 130 years
of record-keeping. The global warming is even more alarming when you look
at the trend on a graph.
On Wed P.M. at the AAPT meeting is our session on "Incorporating
Environmental Issues into Physics Curricula". Many good talks!
Unfortunately, we couldn't find many teachers who are incorporating
environmental issues in courses specifically for science majors. I'm
concerned; we could do much better! The science majors are the ones who can
make the biggest difference, it seems to me, so we should be teaching them
well on environmental issues which involve physics.
One more important related thought: for the first time in history, a
sizable proportion of young people don't think we have a future. How
disempowering! What to do about it? Educate them to the facts, the dangers,
and the possibilities for their actions to make a difference. One of the
best trends I see is service learning, and environmental issues are a
natural for service learning in a physics class.
Cheers,
Jane Jackson
Jane Jackson, Prof. of Physics, Scottsdale Comm.College (on leave)
Box 871504, Dept. of Physics, Arizona State Univ., Tempe, AZ 85287-1504.
phone:(602) 965-8438 fax: 965-7331 e-mail: jane.jackson@asu.edu
Modeling Workshop Project: http://modeling.la.asu.edu/modeling.html