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Related: https://en.wikipedia.org/wiki/Doomsday_argument https://en.wikipedia.org/wiki/Doomsday_argument This is worth a read for those unfamiliar with this ar

by cgh 3y ago

Related: https://en.wikipedia.org/wiki/Doomsday_argument https://en.wikipedia.org/wiki/Doomsday_argument This is worth a read for those unfamiliar with this argument. Essentially, it’s a way to make a probabilistic guess for when humans will go extinct based on the number of humans that have been born. There are several variants and as far as I know, the argument’s premise has never been conclusively refuted.

feoren 3y ago
I think the biggest problem with this utter nonsense is this: > In other words, one can assume with 95% certainty that any individual human would be within the last 95% of all the humans ever to be born "any individual human" really means "a human chosen at random" from all humans who will ever live. Then they go on to assume that this is representative of the humans who have already lived. But clearly there's a problem there. They find a statistic that is true of all past-and-future humans and then assumed it must be equally true of all past humans as well. In fact we've exactly chosen the subset (past humans) as those that are least likely for this statistic to apply. It'd be like deriving some statistic about being 95% sure any given human can run a mile within 10 minutes, and then applying that statistic specifically to those humans with no legs. It's that dumb -- clearly past humans are fundamentally different from past-and-future humans in exactly the property they're sampling. You can easily see this problem by simply going back in time and applying the same argument at any point in history. At some point, the total number of humans who had ever been born was 1 billion. At that point, we would have been 95% sure that the total number of humans would never exceed 20 billion. Oops! In fact, we would have been 99% sure that the total number of humans would never exceed 100 billion. Double oops! Go back to when the total number of humans who had ever been born was 1 million. We would have been 99.999% sure the total number of humans would never exceed 100 billion. Triple oops! It's a nonsense argument.
AbrahamParangi 3y ago
There are a number of counter arguments that I don’t see represented in this article. For instance: 1) this argument makes the implicit assumption that the “number of years before a species goes extinct” is anti-correlated with “the present population of the species” meaning that the greater the present population in comparison to the historical population, the less time we should expect the species to survive for. This is already a contradiction because in reality it is the opposite. Species abundance is directly correlated with species longevity. Necessarily so! In order for a species to go extinct all members must die! 2) there’s no particular reason you should take the emergence of anatomically modern humans as the start point. We represent a continuous lineage of related animals going back to the last universal common ancestor of all life. By naive copernican principal, you may expect our lineage to go on for another 4 billion years! This is not to say that this is likely, just that the copernican principal is entirely subject to what you consider the starting point to be. If you say you care about “homo sapiens and their direct descendants” rather than “homo sapiens” you get a very different answer.

by cgh 3y ago

feoren 3y ago

I think the biggest problem with this utter nonsense is this: > In other words, one can assume with 95% certainty that any individual human would be within the last 95% of all the humans ever to be born "any individual human" really means "a human chosen at random" from all humans who will ever live. Then they go on to assume that this is representative of the humans who have already lived. But clearly there's a problem there. They find a statistic that is true of all past-and-future humans and then assumed it must be equally true of all past humans as well. In fact we've exactly chosen the subset (past humans) as those that are least likely for this statistic to apply. It'd be like deriving some statistic about being 95% sure any given human can run a mile within 10 minutes, and then applying that statistic specifically to those humans with no legs. It's that dumb -- clearly past humans are fundamentally different from past-and-future humans in exactly the property they're sampling. You can easily see this problem by simply going back in time and applying the same argument at any point in history. At some point, the total number of humans who had ever been born was 1 billion. At that point, we would have been 95% sure that the total number of humans would never exceed 20 billion. Oops! In fact, we would have been 99% sure that the total number of humans would never exceed 100 billion. Double oops! Go back to when the total number of humans who had ever been born was 1 million. We would have been 99.999% sure the total number of humans would never exceed 100 billion. Triple oops! It's a nonsense argument.

AbrahamParangi 3y ago

There are a number of counter arguments that I don’t see represented in this article. For instance: 1) this argument makes the implicit assumption that the “number of years before a species goes extinct” is anti-correlated with “the present population of the species” meaning that the greater the present population in comparison to the historical population, the less time we should expect the species to survive for. This is already a contradiction because in reality it is the opposite. Species abundance is directly correlated with species longevity. Necessarily so! In order for a species to go extinct all members must die! 2) there’s no particular reason you should take the emergence of anatomically modern humans as the start point. We represent a continuous lineage of related animals going back to the last universal common ancestor of all life. By naive copernican principal, you may expect our lineage to go on for another 4 billion years! This is not to say that this is likely, just that the copernican principal is entirely subject to what you consider the starting point to be. If you say you care about “homo sapiens and their direct descendants” rather than “homo sapiens” you get a very different answer.