the doomsday argument

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You are missing my point. At one point there were 1 billion total humans. If no time is special, can they not expect to be somewhere near the middle, too, like we can? Or are we special?

they could've, yes, and yes, they would've been wrong if they thought up the doomsday argument, but like i said there is something to be said about us NOT being one of those first one billion.
you realize we're in the time where there's the most people ever alive in history? by a LARGE margin? you think that's coincidence?
i'm not missing your point i just don't think it's a valid one.
they were special in that they existed in a very unlikely period in human history, but due to the improbability, here we are all these years later instead of back then throwing spears at mammoths or something.

Of course it's not a coincidence that the time we're in now has the most people alive in history. But that in no way makes this time any more special than when the total amount of humans was 1 billion. They could of just as easily said that "there's the most people alive now in history". Well, maybe back then the population went up and down, instead of just up, and at 1 billion total humans, there wasn't the most people alive in history. But we could just pick another time.

Edit: we could just pick a time in the future, too. There will be more people alive then, so it would appear that you would consider that time more special than now. Also, when i first mentioned a time in the future, you did not argue against it.

"when dealing with these kind of numbers, a factor of a bit more than two isn't saying much lol.. but i guess when you go from 10,000 years to ~30,000 it's pretty relevant as that's relatively a lot of time."

So you only have a problem with past times?

I never said "the theory just means that the further in time you go the closer the end is"..

What I said was that the finite timeline that the human race will exist will get shorter if our numbers go up at one particular time (according to what you said that the theory said).

If our numbers were still low we would still have a long future. But if our numbers were low we wouldnt even think to have this conversation for some statistical reason.

I said that the distance in time to the end of the human race shrinks if population grows. The higher the vertical population goes on the vertical line on the graph the shorter the horizontal time line will be (but the area contained in the graph will be the same) because thats what you are in effect saying.

I said exactly what you just now said that the theory says: (A) we are the random balls pulled out of the urn because the urn is skewed to our own time because we now have a higher population then ever before. Ergo (B).the human race will end soon. The reason A means B is because only a finite number of humans will ever live. So if we have a high populaton density now... our gas tank of humans will get used up faster because there are more of us around now.

Isnt that what you are saying that the theory says?

If that is what the theory says then how is not ridiculous?

If that is not what your understanding of the theory is then what is your undertanding of it?

yes there will be more people in the future, but you can't presuppose there will be very many without properly debunking the doomsday argument, if there turned out to be a large civilization sustained for a long time then the argument says we would be very 'special' in being around in the transitioning phase when the population has sky-rocketed at an unprecedented rate rather than after, when it calms down and then keeps going forward.
of course the argument doesn't work for people in the very early period in human history, but it doesn't need to work for everyone, just most.
the fact is that it was very 'unlikely' to have been them, and if we happen to be in a special period too, then that just means we beat the odds, which is even more significant considering the total number of present observers.
the odds are that we are the 'most', unlike 'adam and eve' for instance.
it's a 'probabilistic' argument for a reason, it's not making any claims of certainty just that it's much more likely that it's true than not.

i don't really know what you're getting at at the end there, but yes you can pick a time in the future, just not one that's too far into the future. numbers matter.

finally, even if i'm not the best to explain this, let me just say that there's not a super long wikipedia page on it with scholarly sources for no reason, and if something's wrong and been refuted wikipedia will usually make it abundantly clear.

oh okay, yes that's correct, sorry for misunderstanding you if that's what you were getting at.
population growth is obviously a big factor, and i factored that in, but based on the projections it should stabilize soon at around 10 billion people.

i don't think you're representing the theory to 100% accuracy but it's something close.
the number of people isn't so important to the concept a priori, the main thing to understand is that just by being born at any particular time you can make a good bet in predicting when the species will end when you factor in the numbers.
you're wrong in saying that if our numbers were still low we wouldn't have a problem, as if we were living while the numbers were low like 1 billion total ever born with stable birthrates then we'd (wrongly - it's not going to work for everyone, just most people) predict that humanity was never going to get to 100 billion people where we are now.
the problem may not be so pronounced for them though since like you said they wouldn't be experiencing a drastic population boom like we are, which will 'empty the tank' faster, as you put it.

you can't just say it's ridiculous and dismiss it without providing a counterargument.. just because it may sound crazy to you at first, doesn't mean it is.
i don't see what's ridiculous about it at all. i can see why people wouldn't like it though, and maybe be more inclined to put it in the same box as conspiracy theories or something and call it a day.

Last edited by schopenhauer with a keyboard on 09 Dec 2016, 5:58 pm, edited 2 times in total.

I agree that if something's wrong and been refuted, wikipedia will usuallu make it clear.

Why doesn't the argument work for very early people in human history? Evidence please.

"yes you can pick a time in the future, just not one that's too far into the future."

"when dealing with these kind of numbers, a factor of a bit more than two isn't saying much lol.. but i guess when you go from 10,000 years to ~30,000 it's pretty relevant as that's relatively a lot of time."

^ when using my 800 years into the future example. So it seems you agree that going 800 years into the future is fine; the argument still works. So now we have increased the time in years to reach the number of total humans at which we have a 95% chance of going extinct before, from 10,000 to ~30,000, as you said yourself. Now, as we have given ourselves more time, we can go another 800 years into the future. Then we get 20*260 billion = 5.2 trillion. That adds an extra ~20,000 years. Then another 800 years into the future; 20*360 billion = 7.2 trillion. Another ~20,000 years. We can do this forever.

for one thing, people back then wouldn't even be thinking of this kind of thing let alone have the numbers at hand to make worthwhile predictions, but i didn't say it 'doesn't work' (unless i did, in which case i probably shouldn't have), just that it doesn't have to work for them.
say if you define the first and last 5% of humanity's people as 'special'.. that still leaves 95% of people who the doomsday argument works for to varying extents (the math gets complicated but you get the idea) (the last people are by definition about to suffer an impending doom).
it's still more likely that it's true for us, even if it didn't work for the (much fewer) people back then.

and why can you keep adding 800 years indefinitely? i never said you could do that.
that would end up making our current situation too improbable to be viable.
adding 800 years from now doesn't though, it just puts us at a theoretical 25% into human history as opposed to 50%.

"of course the argument doesn't work for people in the very early period in human history, but it doesn't need to work for everyone, just most."

You can add 800 years indefinitely, because of why you believe you can't pick a time "that's too far into the future" (assuming i know why you believe that correctly. You didn't say why, but i think i know why). If you go ~10,000 years into the future, then if you use Leslie's figure, there's a 95% chance we'd be extinct by then. But if you just add on 800, like you said, it would add on ~20,000 years. Why can you then not add on an extra 800? And again? Etcetera.

i told you why.
because of the unprecedented birthrates that aren't looking to drastically turn around any time soon, even adding on another 800 on top of the first one puts us at around the first 15% if the people 1,600 years into the future considered themselves to be born on the most average time in history and were right.
we just get squashed too far into the beginning of human history for it to be the likely scenario.

Why would us being squashed far into the beginning of human history be an unlikely scenario?

The closer the total amount of humans so far gets to N-1, the higher the chance of us going extinct, correct?

Well, there's the more common idea that as many humans will be born, or as many apes, or as many plankton will be divided off, is how many you'll have and that will go on until such a time when there's no environment left clement to that particular animal, or us, procreating anymore.

My more fundamental critique of what you're describing is that it reminds me of two tantamount paradoxes; Zeno's arrow and the tortoise and Achilles:

https://en.wikipedia.org/wiki/Zeno's_paradoxes

One of the things that boggles my mind with the tortoise and Achilles is it seems to treat two objects moving like a turn-based roleplaying game where the moment one catches up to the other turns switch. Nothing of a kind happens. It's like saying that it's impossible to run an 800 meter dash because you'll run half of it, ie. 400 meters, then another 200, ie. 600 meters total, and that you'll keep progressing in halves and get closer and closer to the finish line but that it'll be impossible to reach.

The obvious refutation to the above - who set the 800 as the limit? What if a mile were half? A lightyear half? Half of what? Who knows! Half the distance to a completely imaginary asymptote!

To figure that the median person to ever be born tells us how many billions of people will be able to be born and that once that last person whose born whose 2n of their place in line n - good luck ever settling on a fixed n! If you took this measurement a few million years ago n could have been less than a million and less than 2 million births to solidify the end of the world!

You could rinse and repeat that but this mathematical construct you're looking at is like a rainbow - every time you take a step toward it it will receed one step further away, because it's a filter with no fixed n and therefore no fixed end.

it by definition is unlikely.
how can't you see that being in the first 5% of humans for instance is less likely than being ANYWHERE ELSE on the spectrum.
i thought i'd explained this more than thoroughly enough.

and yes that's a given regardless of the argument. what do u mean exactly?

so we'll exist as a species until our environment won't allow it? not only does that sound closed-minded, but it's not mutually exclusive to the doomsday argument. doomsday doesn't have to be all flash and bang.

and i've responded to the latter objection already in the thread i think to adequate satisfaction.
the easy answer is that the argument doesn't have to work for all people, but it will for most.
it's easy to say 'look at the first million people, if they used the argument and it was valid we wouldn't be here to talk about it!'.. but for one thing, we are not those first people for a reason, it is very unlikely to be them and they arrived on the scene at a peculiar time.
for another, after all is said and done, the argument will have worked for most people in the history of a species.
the first lot obviously not so much, but for us it's still more likely than not that the argument holds up.

I shall put Techstepgenr8tion's point into a mathematical form.

We shall go with 50% instead of 95%.

n₁ = 60 billion = total amount of humans born so far,
N = 2n₁ = the number of total humans to be born that we have a 50% chance of going extinct before we reach.

People will continue to be born, which will increase n. Let's call this new number, n₂. Let's call the new people born, x. n₂ = n₁ + x. In the case where x = 0, n₂ = n₁.

N = 2n₁ + 2x

2n₁ + 2x > n₁ + x

Therefore:
n₁ + x < N


Let's go with 40% now.
N = (1+⅔)n₁
N = (1+⅔)n₁ + (1+⅔)x
(1+⅔)n₁ + (1+⅔)x > n₁ + x
For x = 0, N = 100 billion and n₁ + x = 60 billion. That's a 40 billion difference. 40% chance of going extinct by the time we reach N - 1.

In my first example, with x = 0, N = 120 billion, n₁ + x = 60 billion. 60 billion difference. 50% chance of going extinct by the time we reach N - 1.

If you keep going, you'll find that the difference between N and n₁ + x increases exponentially as you increase the chance. Obviously, this means that the difference between N - 1 and n₁ + x also increases exponentially as you increase the chance.

50% chance.
n₁ + x = 70 billion. Therefore N = 140 billion. Now there is a 70 billion difference. The difference between N with x = 0, and N with x = 10 billion, = 20 billion, as N with x = 0 is 120 billion. Therefore as x increases, the difference between N - 1 and n₁ + x increases.

"And yes that's a given regardless of the argument, what do you mean exactly". So seeing as the closer the total amount of humans gets to N - 1, the higher the chance of us going extinct, the further away the total amount of humans gets from N - 1, the lower the chance of us going extinct (according to you and the Doomsday argument).

However, as you can see, the difference between N and n₁ + x increases as the chance increases. However, this is a misinterpretation. That percentage increasing as the difference increases relies on N being static, which it evidentally isn't.

To the middle of that I'll admit that I tend not to read debates after a while, particularly if it gets to five-layer quotes. If you want to quote yourself in response to this that's fine. Other than that I still don't understand what the objection would be unless I'm really not understanding the doomsday scenario to begin with. If there's a whole other factor than median person born (of which we only can contemplate in terms of the median person 'to date') let me know - in that case I misunderstood the source mechanics of it. Otherwise, like I said before, it's a view that's chasing a number that never stays the same and, like the American protestant apocalypse, it's a black rainbow that hangs like a dangling 70th week of Daniel and seems to always be just beyond reach but never actually occuring (again - much like you can chase a rainbow and the light-refraction will change to accommodate your angle between the rain and the sun).

Also I don't think closed-mindedness can really factor into this. There are either arguments that have solid anchors that can be falsified (and in the case of a strong argument proven true). Again, maybe I did miss the strong arguments in some of the follow-ups to follow-ups, feel free to cut, paste, and quote yourself. Any which way if the theory is correct and we're all wrong you have to be able to state your case well.


Can you state that reason, or what in this equation makes it more likely to be us and not some person making this measurement a million years from now aside from that we're alive and we can think of things like the doomsday argument?



If this whole thing was a big stilted joke suggesting that no one will live to be 1000 years old or something like that (ie. most people in human history born over 100 years ago and all over 120 years ago) then I'd have to commend you for your determination to faithfully carry the punchline until the bitter end. Otherwise I can't make sense of this sentence in the context you provided it.


If you're saying we'll all eventually be dead someday (excluding our progeny) then sure.