Monday, May 11, 2009

It's later than you think

It’s 11:00 PM. One bacterium sits alone in a jar. At 11:01 PM, the bacterium splits in two. Then these two bacteria split again at 11:02 PM, becoming four bacteria; then these four divide at 11:03 PM, becoming eight bacteria; and each resulting bacterium splits every minute until the jar is totally filled up at midnight.

When the jar is half full, what time is it?

11:59 PM.

It’s later than you think.

Assume you are a bacterium in this colony and you just realize your jar is a quarter full. Not to worry. The remaining open volume is triple the space of what your colony now occupies. Right?

What time is it?

11:58 PM.

Again, it’s later than you think.

The clock has struck midnight and your jar is completely full. Luckily, exploring bacteria have found another jar in which to continue growing and save your colony from decimation.

What time is it when your colony fills up the second jar?

12:01 AM.

But wait! A miracle happens. Two more jars suddenly materialize, an incredible volume of space for your ever growing colony. You are saved, again!

What time is it when your colony completely fills up these next two jars?

12:02 AM.

Dr. Bartlett drove home the overpopulation dilemma with this type of story at the 2009 EntConnect conference. In his “Arithmetic, Population and Energy” speeches over the years, he considers the greatest challenge facing humanity as overpopulation and promotes sustainable living.

Next time you read an article about a new housing growth rate of, say, 7% per year, consider this. When half the area of a desirable open space has been populated, what time it is?

11:59 PM.

Next doubling time, 10 years, the open space will be urban sprawl.

Joni Mitchell sang it best in “Big Yellow Taxi” – “They paved paradise and put up a parking lot.”

EntConnect website:

Dr. Bartlett links:

Photos from
Bacteria in a petri dish:
Ticking clock:


  1. What a great illustration of exponential growth.
    I do have an issue with scientists being concerned by overpopulation. When God created the earth and Adam and Eve he gave them direction "Be fruitful and multiply; fill the earth and subdue it." Genesis 1:28 NKJV. He didn't say fill it to only this many million, he just said fill the earth. When I drive in the U.S., it has not been filled. I have been in several other nations and they have not been filled. I know that there is a concern for food and energy supplies to sustain the growth but God would not say to fill it but not take into consideration what it would take to sustain the population. He will give us creative ideas to generate all that we need. He is a God of more than enough.
    Thanks for sharing this.

  2. Thanks for sharing, Diana. You point definitely needs to be heard.
    I was presenting the key arguments of a talk given by a physicist, which had sound arithmetic behind it and should be thoughtfully considered.
    But you have hit the nail on head in that most scientists leave God out and He is the most important factor.