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Something vaguely related I've been thinking about: When looking at the timeline of life (link below), humans are a completely negligable slice of history. Dinosaurs survived for about 170M years, modern humans have existed for just 200K, civilization for about 10K, and the technological boom has been here for roughly 100 years.

Can this be seen as evidence that the timeline of humanity will be relatively short in the big picture? Because it would seem like a strange coincidence to be born at the beginning of it. This is even more true for the survival time of humans with modern technology. Assuming the era of technologically advanced humans will last for, say 200M years, it's extremely unlikely to be born at the first 100 years (0.00005 %).

It's interesting to think about how civilization would develop over hundreds, thousands or thousands of thousands years. There have been some pretty significant changes in just the last 100 years, what could happen in millions of years? Civilisation is not a stable system, it seems to be quite volatile. And unlike before, changes and disruptions are not as locally constrained. Perhaps after many thousands of years, there will come a low-probability event that civilization won't recover from.

https://en.wikipedia.org/wiki/Template:Life_timeline




It's a nonsensical idea.

Imagine you are a soul, in limbo, somewhere outside the universe and elsewhere in another part of reality the universe is progressing through its motions as time goes on. You are an other-reality-style being, yet somehow still allocated as "going to be a homosapiens on Milky Way\Sol\Earth", and your birth will be random during the era of homo sapiens.

Now you can argue about the likliehood of where this random birth happens.

On the other hand, take away the other place, and the souls, and the spooky assignment of types, and just look at the universe as a thing of matter and energy. Some configuration of matter was born to your parents, from their DNA. It is intimately connected to its surroundings by a continual stream of light, heat, air pressure, physical pressure; over millions of seconds it learns. It learns the patterns of air pressure that correspond to other people talking to it, and it learns what things it can and can't push by trying, and what other people talk about.

And it says "isn't it unlikely that I was born here and now, instead of some other time?"

And the question makes no sense. _What_ could have been born somewhere else? or somewhen else? Without its parents DNA, without its particular twenty continuous years of sensory input that it learned from, it would not be itself.

Some other matter, born to other parents, with other DNA, and other childhood experiences, and other knowledge patterns. It would be someone else. Entirely someone else. And ... that happens, we call it "other people".

If you don't believe in a soul, or something like it, what does it mean for you to possibly "be born somewhen else"?


The question is, what is the probability that a person picked at random from the human population, would be born during a technological era. We can work this out. Then, what is the probability that the part of the technological era they were born in was the first 100 years. This is easier to work out, it's 100/L_years(technological_era) but, unfortunately that's also the probability they are born in the second 100 years of a technological era of the same length, the third 100, the last 100 etc. so I don't think it gives us any predictive power?


No, the question asked by the parent poster is "what is the probability that I would be born at this time in a long time frame".

Which is what I was answering. You can't pick a human at random including from the future, unless you're outside the system somehow.


That just leads you down the road of discarding probabilities. Since something either happens or doesn't happen, the probability is either 100% for the things that will happen or 0% for those that do not. This is not a helpful position to take, although it is technically correct, in some not very useful sense.

Humans are good at dealing in counterfactuals. 'What would have happened if I hadn't missed the bus?' is a useful question to ask, even if you did miss the bus. What would I be like if I hadn't gone to university/had taken that job/never killed my parents? Obviously the 'I' in those questions cannot be you, exactly, since you did or didn't do those things. But it's still a useful concept or thought experiment, and can give us valuable insights.

The commenter is using 'I' in that counterfactual sense. And certainly, I understood what they meant by it, so they were successful in communicating (at least, to me) which is what matters with language.


>it's extremely unlikely to be born at the first 100 years (0.00005 %).

similar example - throw a coin 21 time and record result. Now look at that recorded result and behold how unlikely that result is, like one in 2^21 (0.00005%), yet you got it despite the odds :)


Yeah of course, but... all results are equally likely, but some are "interesting" or "meaningful", like all tails or all heads. If it's 21 tails, it's pretty much certain that something is not right, that it's not a fair coin.

In a Bayesian point of view, let's pick some prior probability distribution over lengths of human survival and consider the current age of humanity as a random variable. This gives the posterior probability over lengths of human survival.


Apparently this is called the Doomsday Argument: https://en.wikipedia.org/wiki/Doomsday_argument


I'm having trouble writing out a detailed refutation, but it seems highly speculative to deduce much solely from the notion that "it is very unlikely one would be born in in the first few years of a long technological age".

I do think that analyzing the stability and trajectory of civilization is very interesting.




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