## Doubling Time

To work out the doubling time of an annual percentage growth, divide it into (100 ÷ ln(2)) = 70 e.g. 7% ⇒ 70 ÷ 7 ⇒ 10 years to double. So, for example, when electric power consumption was growing at 7% a year, we had to come up with double the generating capacity every decade. Further, every decade consumed more power than in all previous history combined. These are the consequences of simple arithmetic.

~ Roedy (1948-02-04 age:70) see lecture by Dr. Albert A. Bartlett