rsc2a said:
Increased food production, better medicine, sanitation improvements, increased human lifespan, industrialization, the Black Death, WWI, WWII.....
It's not as simple as y=Ae^rt
Then give us the formula you think is better suited to it.
Do you agree with Nye that man has been on the earth for 30,000 years?
Dr. Henry Morris put it this way...
To illustrate the problem, assume that the human population increases geometrically. That is, the increase each year is equal to a constant proportion of the population the previous year. This relationship can be expressed algebraically as follows:
(1) Pn = P (l + r)n
in which P is the population at any certain time, r is the proportionate annual increase in population, and Pn is the population n years later. For example, if the present population is 3.5 billion and the planet's permissible population is 50 billion, the number of years before this number will be reached at the present 2% annual increase can be calculated as follows:
50 x 109 = 3.5 x 109 (1.02)n
from which
log 50/3.5 = n log 1.02
and
n = 1.156/0.0086 = 135 years
We have already discussed this result, however. Looking toward the past, instead of the future, equation (1) will also indicate how long it would take to produce the present population at 2% growth per year, starting with two people. Thus:
3.5 x 109 = 2 (1.02) n
from which
n = 9 + log 3.5 /2 = 1075 years
log 1.02
That is, an initial population of only two people, increasing at 2% per year, would become 3.5 billion people in only 1075 years. Since written records go back over 4,000 years, it is obvious that the average growth rate throughout past history has been considerably less than the present rate.
As a matter of interest, we can also use equation (1) to determine what the average growth rate would have to be to generate the present population in 4,000 years. Thus:
3.5 x 109 = 2(l + r)4000
from which
r = (1.75 x 109)1/4000-1 = 1/2%
Thus, an average population growth rate of only (1/2)% would generate the present world population in only 4000 years. This is only one-fourth of the present rate of growth.
Now, although it is obvious that the present rate of growth (2%) could not have prevailed for very long in the past, it does seem unlikely that the long-time growth rate could have averaged significantly less than (1/2)%. Very little is known about the world population in earlier times, but everything that is known indicates the population has steadily increased throughout recorded history.
http://www.icr.org/article/67/
