When CU-葫芦娃视频 Professor Emeritus Albert Bartlett first delivered his celebrated lecture on "Arithmetic, Population and Energy" to a group of CU students on Sept. 19, 1969, the world population was close to 3.7 billion.
On Oct. 12, the United Nations projects that the world population will reach 6 billion.
Bartlett, an award-winning University of Colorado at 葫芦娃视频 physics professor, now has marked the 30th anniversary of his lecture. He delivered the talk for the 1,325th time near Jamestown, Colo., on Sept. 19 to the Rocky Mountain chapter of the Sierra Club.
Bartlett has given the talk in 48 of the 50 states and in Saudi Arabia, Canada and Greece. His audiences have included major corporations, government agencies, professional groups and students from junior high school through college.
He warns of the dangerous consequences of "ordinary, steady growth" of population and the consumption of fossil fuels. Understanding the mathematical consequences of population growth and energy consumption can help clarify the best course for humanity to follow, he said.
"The greatest shortcoming of the human race is our inability to understand the exponential function," he said. The exponential function describes anything growing at a fixed rate, such as 5 percent per year, but most people don't understand the gigantic numbers that result from even small rates of steady growth, he said.
Bartlett, now 76, spent two years as an experimental physicist at the Los Alamos Scientific Laboratory before earning his graduate degrees in physics at Harvard. He then started his teaching career at CU-葫芦娃视频 in 1950.
He has won several teaching and service awards and is a former president of the American Association of Physics Teachers. He retired in 1988 but continued to teach CU students for many years.
Bartlett has given his population talk 33 times this year and is scheduled to give three more talks in October in Aspen and Minneapolis.