Given that there are 6.5 x 10 to the power 9 people alive to day.
How many people have ever been born ?
2006-08-31 09:37:49 · 19 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
Let's say that, on average, each couple has 2.2 kids. That's 1.1 offspring per person, and thus each generation is therefore 1.1 times as large as the previous one, or equivalently that each generation is 10/11 the size of the next.
Let's also say that the 6.5*10^9 people alive now constitute a bit over 3 generations worth of people, so that one generation's worth is n=2*10^9.
Thus, the number of people born is approximately n + n(10/11) + n(10/11)^2 + ..., or (pardon the notation):
n * sum[x=0,inf]((10/11)^x)
The sum of (10/11)^x from 0 to infinity is 11, so I'd estimate that there have been about 2.2*10^10 births.
2006-08-31 10:17:52 · answer #1 · answered by Anonymous · 1⤊ 0⤋
Lets say that the average age of all those alive is 30 (going by demographics in each country and averaging u can arrive at a more precise figure but just for simplicity, assume this)
So, we can safely assume that all these people have been born in the last 40 years and all before are dead.
i.e. Now we just need global birth rates until 1965.
Lets say that on an average, so far a child has been born in this world every 2 second since for the last 2000 years. (1700 to 1965 rates would be much much less and before that more...so we can assume 1 second for simplicity)... (today the birth rate is around 2 every second)
Now, 2000 years x 365 days x 24 hrs x 60 minutes x 60 seconds / 2
= 3.15 x 10^10 people have been born in the last 2000 years.
Before that, lets say mankind started another 2000 years back and the birth rate was 0.2 per second i.e. 1 child every 5 seconds
so, this is = 2000 years x 365 days x 24 hrs x 60 minutes x 60 seconds/ 5
= 1.21 x 10^10
So, till date number of births has been
3.15 + 1.21 + .65 = 4.91 x 10^10 = 49.1 x 10^10
2006-08-31 09:59:37 · answer #2 · answered by DG 3 · 0⤊ 0⤋
10 x 10 to the 9
2006-08-31 09:58:13 · answer #3 · answered by j_son_06 5 · 0⤊ 0⤋
Well the last common Y-chromosome was alive in 60Ka ie 60,000 years ago. Hence, I think if you count up all the Y chromosomes alive today, multiply by the number of generations since 60Ka and then multiple that by two, that will give you a rough enough answer. Of course you'd also need to add how ever many people never had children though how you'd figure that out is beyond me.
2006-08-31 10:01:03 · answer #4 · answered by bur667 2 · 0⤊ 0⤋
Although there are 6.5 x 10^9 alive, many have been born and have died since the beginning of time.
So this cannot be calculated.
2006-08-31 11:11:54 · answer #5 · answered by Kemmy 6 · 0⤊ 0⤋
Better watch the simple equations for extrapolation. If you do the radius of human flesh will start to expand at a speed faster than the speed of light.
2006-08-31 10:05:03 · answer #6 · answered by Scott S 4 · 0⤊ 0⤋
8.5 x 10^9 -2
2006-08-31 10:13:41 · answer #7 · answered by a_ebnlhaitham 6 · 0⤊ 0⤋
I've heard it said that for every person alive today, there are 30 who are dead. Whether it's true or not, I don't know (and frankly, don't want to know).
2006-08-31 09:44:36 · answer #8 · answered by The_Mystic 3 · 1⤊ 1⤋
not as many that are living to day,
2006-08-31 09:45:43 · answer #9 · answered by kmc1169 2 · 0⤊ 0⤋
Substantially less than double that. Exponential (i.e. natural) growth. There are more living than dead. Freaks me out.
2006-08-31 09:39:26 · answer #10 · answered by wild_eep 6 · 1⤊ 1⤋