Sunday, July 10, 2011

Numbers

I like numbers.  They are factual.  They can tell a story.  They can remove emotion and commentary from sensationalistic journalism.  They unlock secrets and give new insights into the universe.  However, numbers can also be twisted to tell lies and manipulate public opinion.  Like Homer says, "People can come up with statistics to prove anything, Kent. 14% of people know that."

Here's some numbers I found intriguing.  Some may be true.

7 000 000 000 - earth's population by the end of 2011
6 000 000 000 - earth's population at the end of 1999
5 000 000 000 - earth's population at the end of 1987
4 000 000 000 - earth's population at the end of 1974
3 000 000 000 - earth's population at the end of 1960
2 000 000 000 - earth's population at the end of 1927
1 000 000 000 - earth's population at the end of 1804

What does that mean?  
Currently there are more people alive now than the sum total of every person who ever lived on earth before them. Human population up until the early 1800's was rather linear.  Boring.  However, from 1800 it only took 123 years to double to 2 billion.  After that it was a mere 47 years to double to 4 billion.  Earth's current population took about 40 year's to double from the 1970's.  Expressing the growth as a function is boring but the truth the numbers tell when graphed show that earth's population is heading for (what calculus would call) a limit where earth's population doubles faster and faster until it reaches infinty around the year 2350.  Of course there are natural limits to the sustainability of the human population and the rate of reproduction which would never allow for that, such as disease, nutrition, and gestation.  However, if those issues didn't exist, mathematically by 2350 there would be an infinite amount of people in the world.  We would not have enough room to breathe, literally.  

Realistically, seeing as only half the world's population are women (approx), that gestation is around 9 months, most pregnancies lead to one child and that only 60% of women are of child bearing age at any given moment there is a biological limit that trumps the mathematical limit for reproduction. That's the fancy way of saying the least amount of time possible for the human population to double is about 3 years. So, instead of running out of room on planet earth by 2350 we're probably good until 2500. Whew!

              1 400 000 000 - China's population
              1 200 000 000 - India's population
                 400 000 000 - Facebook's population
                 310 000 000 - United States' population
                 230 000 000 - Indonesia's popultation
                   35 000 000 - Canada's population
                   35 000 000 - Estimated population of the world in 2000 BC
                        600 000 - Aproximate population flying at any given time
1 400 000 000 000 000 - Aproximate population of ants in the world

0.5% - Canada's share of the world's population

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