The point of the Doomsday argument as I understand it is that we should expect to be near the median of (human?) *births*. If so, then only about the same number of births as have already happened should be expected to happen in the future. This doesn't mean there will be no individuals living far into the future, just that there will only be a certain total number of lives in all of time (200 billion by the numbers below). So, rather than a continuing exponential growth of population across the asteroid belt, never mind across the galaxies, something drastically less profligate has to happen, that's the "doom". I am not smart enough to understand why this is not nonsense. For instance, does the outcome change with each change I make to the definition of my affinity group? E.g. conscious entities, original templates of consciousnesses, copies of consciousnesses, contiguous-over-spacetime graph structures of protoplasm (e.g. my family tree), waking days, etc? Some of the people who make the Doomsday argument also make the Simulation argument (we should expect that we are in a simulation), and I don't see how they can be reconciled or combined. Is what counts the number of different personalities, or the number of copies of people summed across all simulations, or what? Do these differences all cancel out, or what? (For the Akond of Swat.) --Steve p.s. I was going to ask whether it matters whether I later become a genetic reengineeree, cyborg, or upload. I got zero hits on google for "reengineeree," except from autospam "search for <what you searched for>" sites, so I claim the word for Spain. On 9/15/15 9:59 PM, math-fun-request@mailman.xmission.com wrote:
Date: Tue, 15 Sep 2015 14:12:03 -0400 From: Warren D Smith <warren.wds@gmail.com>
From: Charles Greathouse <charles.greathouse@case.edu> The doomsday argument suggests considering oneself as a random sample from the total number of humans to be born. Estimating the number of humans born so far at 100 billion and the number of annual births at ~0.13 billion per year (assuming stabilization around 10 billion, if current trends continue) a 95% confidence interval suggests that humans will be around at least 20 more years but not more than 30,000 years. Adjust assumptions to suit. --That argument yields very different conclusions if we assume that future "humans" (which by the way might not be considered human) will have much longer lifespans.
For example I think cybernetic "life" organisms will become important and their lifespans could be comparable to the lifespans of stars. In that case, assuming you are near-median chronologically does NOT at all imply that intelligent life will end in the next 100K years.