893: 65 Years
In this comic, over 65 years, Randall is projecting the number of living humans who have walked on another world, counting the Moon as a 'world'. He is using actuarial tables or life tables which shows for each age the probability that a certain person will be alive by their next birthday. Although not named, the graph refers to the 12 Apollo astronauts who landed on the Moon between 1969 and 1972.
This comic assumes that no one else is going to walk on another world going forward into the future which, as is mentioned in the image text, is a terrible idea for the future of the human race. If the human race only exists on one planet — one disaster can destroy the whole race. However, if humans extend their society to other planets, they lessen the risk of complete extinction.
- [A graph titled 'Number of Living Humans Who Have Walked on Another World' — its y-axis is numbered 5, 10, 15; its x-axis increments every ten years from 1960–2040. The line of the graph has a bracket above it that says '65 Years', starting at 1969, ending in 2034.
- The line starts at 1969 and increases steeply to 12 by 1972. It then plateaus until 1991, then declines in three steps to 9 by 1999, and then plateaus again.
- From 2011–2035, which is labeled 'Projected Actuarial Tables', the line branches into three and begins to decline more steeply to zero. The first is labeled '5th percentile' and the third is labeled '95th percentile'; the middle is presumably for the 50th percentile. The area between the lines is shaded. The lines reach zero between about 2022 and 2034, indicating that there is less than a 5% chance that anyone in the group will be alive after that ... unless new people are added.]