Today’s guest post in our Limits to Growth 40th anniversary series is courtesy of Tom Murphy. Tom is an associate professor of physics at the University of California, San Diego. He has simultaneously posted this entertaining conversation on his popular blog, Do the Math. More about Tom after the conversation. While there are economists, like Herman Daly, who believe there are limits to economic growth, there are many more, such as the infamous Julian Simon, who do not. That ratio is, I believe, in the process of changing. We hear from both Daly and the late Simon in the GrowthBusters film. It’s pretty entertaining. But I have to hand it to Tom Murphy. He shares with us here an enlightening and engaging conversation with an economist of Simon’s ilk. Enjoy and learn! – Dave Gardner
author: The Population Bomb
First, let’s pick up our exponential growth demonstration. If you’ll recall, we began with a single grain of wheat in a beaker. Each day of the demonstration, we double the amount of wheat in the beaker. This is equivalent to a growth rate of just under 3% per hour. This makes it a good fast-track demonstration of what’s happening in the real world. 3% annual growth is a common economic objective. About 15 nations have annual population growth rates near or above 3%. Las Vegas, Nevada was growing faster than 3% annually until the housing bubble burst. Last week we left off at Day Nine, with 256 grains of wheat. Today let’s double that:
