Facts:

- A generation = 25 years (using the highest number in lieu of 20, the number of years for earlier generations)
- 2⁴⁰ = 1,099,511,627,776
- 40 X 25 = 1,000

Given the above, a thousand years ago I had over a trillion grandparents. Correct?

Question: What was the population of the Earth a thousand years ago? Was it over a trillion?