This is a 80-minute lecture on Arithmetic, Population, and Energy by Dr. Albert A. Bartlett. It is uploaded into eight 10-minute long video in Youtube. Even though the lecture was made in around 1999/2000, you should definitely take your time to watch through all the presentation as it is very fascinating and still relevant to today (as of 2009)!

The opening statement for the lecture is "The Greatest Shortcoming of the Human Race is our Inability to Understand The Exponential Function".

A couple of fascinating quote from the professor.
1) To calculate the doubling time for exponential function
Time = 70 / % growth per unit time

For example, a town population of 100,000 people with a growth rate of 7% per year, will take 10 years to grow to 200,000 people, another 10 years to grow to 400,000 people, and another 10 years to grow to 800,000 people.

T = 70/7 = 10 years

2) An analogy of the bacteria in a bottle (from part 3/8 of the video)
Imagine bacteria growing steadily in a bottle. They double in number every minute. At 11:00 am there in one bacteria in the bottle. At 12:00 noon the bottle is full.
Question 1: At what time was the bottle half full?

Suppose that at 11:58 am some of the bacteria realize that they are running out of space. So, they launch a great search for new bottles. They search offshore on the outer continental shelf, in the overthrust belt and in the arctic, and they find THREE NEW BOTTLES.
Question 2: How long can the growth continue as a result of the discovery of three new bottles; this quadrupling of the proven resource?

Highlight this page to see the answer. (or press both the CTRL and A on your keyboard)

Answer 1:
11:59 am
11:54 am 1/64=1.6%full 63/64empty
11:55 am 1/32=3.1%full 31/32empty
11:56 am 1/16=6.3%full 15/16empty
11:57 am 1/8=12.5%full 7/8empty
11:58 am 1/4=25%full 3/4empty
11:59 am 1/2=50%full 1/2empty
12:00 noon 100%full

Answer 2: 12:02 pm
11:59 Bottle 1 is half full
12:00 Bottle 1 is full
12:01 Bottle 1 & 2 full
12:02 Bottle 1, 2, 3 & 4 are full

The First Law of Sustainability
Population growth and/or growth in the rates of consumption of resources CANNOT BE SUSTAINED!

Watch this interesting video! It will stimulate your mind and definitely one of the best 80 minutes in your life!!!