I found the “let’s assume humanity remains at a constant population of 900 million” notion particularly interesting. On some level I still have this (obviously wrong) intuition that human knowledge about its history just grows continuously based on what happens at any given time. E.g. I would have implicitly assumed that a person living in 1888 must have known how the population numbers have developed over the preceding centuries. This is of course not necessarily the case for a whole bunch of reasons, but seeing that he wasn’t even aware that population growth is a thing was a serious surprise (unless he was aware, but thought it was close enough to the maximum to be negligible in the long term?).
It’s funny how he assumes a generation would span 31.125 years without giving any explanation for that really specific number. Maybe he had 8 children at this point in time, and took e.g. his average age during the birth of all of them?
And lastly, he as well as any readers of this letter would have greatly benefited of the scientific notation. Which makes me wonder what terrible inefficiencies in communication & encoding / expressing ideas we’re suffering from today, without having any inkling that things could be better… :)
I think constant population assumption is honestly pulled out of thin air and is just to simplify calculations – not because he thinks it actually makes sense. What’s much more relevant to his calculation is how long the world will last. Why assume that it will last one million years in total and not ten thousand?
It’s also interesting that he assumes that everyone is going to heaven and doesn’t even call out that assumption. Whether he was a universalist (believing everyone would go to heaven) or not, the fact that he fails to mention this assumption makes me question the seriousness of this letter. I wouldn’t read too much into this letter as evidence of how naive we could be.
Pointing out more weirdnesses may by now be unnecessary to make the point, but I can’t resist: the estimate also seems to equivocate between “number of people alive at any moment” and “number of people in each generation”, as if the 900 million population was comprised of a single generation that fully replaced itself each 31.125 years. Numerically this only impacts the result by a factor of 3 or so, but it’s perhaps another reason not to take it as a serious attempt :)
This is great, thanks for sharing!
I found the “let’s assume humanity remains at a constant population of 900 million” notion particularly interesting. On some level I still have this (obviously wrong) intuition that human knowledge about its history just grows continuously based on what happens at any given time. E.g. I would have implicitly assumed that a person living in 1888 must have known how the population numbers have developed over the preceding centuries. This is of course not necessarily the case for a whole bunch of reasons, but seeing that he wasn’t even aware that population growth is a thing was a serious surprise (unless he was aware, but thought it was close enough to the maximum to be negligible in the long term?).
It’s funny how he assumes a generation would span 31.125 years without giving any explanation for that really specific number. Maybe he had 8 children at this point in time, and took e.g. his average age during the birth of all of them?
And lastly, he as well as any readers of this letter would have greatly benefited of the scientific notation. Which makes me wonder what terrible inefficiencies in communication & encoding / expressing ideas we’re suffering from today, without having any inkling that things could be better… :)
I think constant population assumption is honestly pulled out of thin air and is just to simplify calculations – not because he thinks it actually makes sense. What’s much more relevant to his calculation is how long the world will last. Why assume that it will last one million years in total and not ten thousand?
It’s also interesting that he assumes that everyone is going to heaven and doesn’t even call out that assumption. Whether he was a universalist (believing everyone would go to heaven) or not, the fact that he fails to mention this assumption makes me question the seriousness of this letter. I wouldn’t read too much into this letter as evidence of how naive we could be.
Pointing out more weirdnesses may by now be unnecessary to make the point, but I can’t resist: the estimate also seems to equivocate between “number of people alive at any moment” and “number of people in each generation”, as if the 900 million population was comprised of a single generation that fully replaced itself each 31.125 years. Numerically this only impacts the result by a factor of 3 or so, but it’s perhaps another reason not to take it as a serious attempt :)