Tech levels and the end of the universe

[Mustrum_Ridcully]

At what tech level can I travel back in time to avert my death after I died?
At what tech level can I travel back in time to avert having being erased from existence?

Instinct versus science, round two. Fight!



That's not really relevant to what's there. The idea that humans would leave the Earth at some point would adjust the particulars of the DA only in that it'd increase the total capacity for how many humans would be alive at once (e.g. 20 billion people collectively supported across two planets, rather than 10 billion people supported across one). In that case, you simply adjust the calculations and modify the final results accordingly.



It's not an inevitability by the terms of the article, just a likelihood (e.g. 95%). Given that it's plausible to state that only a finite number of humans will be born - rather than an infinite number - the premise of the article certainly seems reasonable.



I'd say that it's option B, since it's not particularly concerned with questions of how humans would theoretically come to an end. It is, as you note, a purely mathematical construct, which is sort of the point. If you presume (as noted above) that there won't be a unlimited number of humans, then it's a question of trying to make a construct to guess how many there will be, and working backwards from there.



I suspect that the hubris is in assigning humanity "infinite possibilities of the future" and in presuming that even loose models of statistical analysis don't apply to us, but that's just me.

Stupid question:

If I'd plug in the numbers of 3150 B.C., will I get the same results as you get with the current numbers? Or will it be lower?

Isn't math one of the sciences? Or is science one of the maths? I can never keep them straight.



See below for why I don't think this is actually a factor.



The problem here is that none of the potential variables you're throwing out are meaningful, with regards to colonizing other planets and such. It's an Occam's Razor thing: when you have competing hypotheses, the one with the fewest assumptions should be selected.

Presuming that a probabilistic model of the timeline of human extinction is flawed because it doesn't take into account an assumption of planetary colonization is backward, because it posits an event that has no particular model for suggesting, however remotely, that such a thing will happen.

You're saying that because something could theoretically happen, we can't make a prediction as to what might happen. That's the equivalent of not planning out your week because you can't be certain that the world won't suddenly combust. You make predictions with the best data you have on hand, and discount the things that don't have some suggestion of likelihood.

But aren't there problems here - could Earth have supported 6 $Billion humans without advances in agriculture? What about our lifespan expectations? Didn't they change over time.

The problem is that we know that such things can happen. We cannot presume that planetary colonization will happen, but we could also never presume that we would come up with better agricultural technology, or antibiotics. I am not convinced it's a good use of Occam's Razor to assume stagnation when we have plenty of examples against stagnation. That would be using the razor and cutting off parts we know we need. You will likely have to reconsider the confidence of certain assumptions made (like how many people can we sustain, how long do humans live..).

 

[Janx]

Electricity. Telephones. You know an iPhone is still a telephone, right?

My reference to 'evidence has existed' referred to large-scale galactic engineering projects that one might expect to be visible in the universe.

Then as I said, go back farther in time, until there is no supporting science/technology to make it evident that such is possible.


By itself "evidence it has existed" is a weaker argument than your other prior points.

Since our observation is constrained to light speed, we are stuck looking at stale information. The universe may already be saved by FTL beings, but the light from their humongotronic device hasn't reached us yet. Or they have saved us by creating an artificial reality, and thus there is no structure to see, barring glitches in the matrix.

 

[Alzrius]

Stupid question:

If I'd plug in the numbers of 3150 B.C., will I get the same results as you get with the current numbers? Or will it be lower?

That's actually a bit more complicated than it appears, since even leaving aside the questions of what exactly the population was then (the actual numbers used matter, here), you have to cite whether you'd be using the numbers including the subsequent population statistics we know now, or if you were using only what was known then.

The latter part is important because it brings up the refutation mentioned in Caves' rebuttal, which is that when you apply the Copernican principle, it looses some of its applicability due to not knowing exactly when to place it (which was discussed above).

As the Wikipedia article mentions, this can be refined via Nick Bostrom's refinement: "Knowing the absolute birth rank must give no information on the total population (N)."

But aren't there problems here - could Earth have supported 6 $Billion humans without advances in agriculture? What about our lifespan expectations? Didn't they change over time.

Yes, but that's not a guess as to what might happen, it's a notation of what actually did. The the difference between the two are not simply that the former is in the future and the latter is in the past.

The problem is that we know that such things can happen. We cannot presume that planetary colonization will happen, but we could also never presume that we would come up with better agricultural technology, or antibiotics. I am not convinced it's a good use of Occam's Razor to assume stagnation when we have plenty of examples against stagnation. That would be using the razor and cutting off parts we know we need. You will likely have to reconsider the confidence of certain assumptions made (like how many people can we sustain, how long do humans live..).

It's something of a stretch to say that "we know such things" as terraforming "can" happen, since that presuming a level of technical knowledge that goes beyond the hypotheses and vague blueprints that we have now. Ideas alone are far from certainty.

There does need to be a reconsideration of confidence here, but I believe that it's with regards to your near-certainty that such things will happen. Likely, there will be some sort of technological advances over time that change various paradigms for everyone across the world, but even if such changes do happen, their paradigm-changing nature makes them very difficult to predict at all, let alone measure changes of when they'll happen and what the ripple effects will be.

Given that, there can be no such presumption of radical changes occuring when trying to make any kind of scientific or mathematical measurement regarding how a given system will change over time. There's no other way to remain credible except to take a conservative approach, particularly since most of the time these major changes don't happen, which makes the conservative approach the one that's usually correct. If such a change does happen, then you just scrap the now-obsolete model and make a new one to account for what's happened.

Otherwise, you're the guy saying that the end of the world will happen next Friday...which means that you have quite a bit of explaining to do on Saturday morning.

 

[Mustrum_Ridcully]

That's actually a bit more complicated than it appears, since even leaving aside the questions of what exactly the population was then (the actual numbers used matter, here), you have to cite whether you'd be using the numbers including the subsequent population statistics we know now, or if you were using only what was known then.

The latter part is important because it brings up the refutation mentioned in Caves' rebuttal, which is that when you apply the Copernican principle, it looses some of its applicability due to not knowing exactly when to place it (which was discussed above).

As the Wikipedia article mentions, this can be refined via Nick Bostrom's refinement: "Knowing the absolute birth rank must give no information on the total population (N)."



Yes, but that's not a guess as to what might happen, it's a notation of what actually did. The the difference between the two are not simply that the former is in the future and the latter is in the past.



It's something of a stretch to say that "we know such things" as terraforming "can" happen, since that presuming a level of technical knowledge that goes beyond the hypotheses and vague blueprints that we have now. Ideas alone are far from certainty.

Yes. But the idea that we could immunize ourselves against several terrible diseases was also not a certainty, but affected our lifetime expectations.

There does need to be a reconsideration of confidence here, but I believe that it's with regards to your near-certainty that such things will happen. Likely, there will be some sort of technological advances over time that change various paradigms for everyone across the world, but even if such changes do happen, their paradigm-changing nature makes them very difficult to predict at all, let alone measure changes of when they'll happen and what the ripple effects will be.

Given that, there can be no such presumption of radical changes occuring when trying to make any kind of scientific or mathematical measurement regarding how a given system will change over time. There's no other way to remain credible except to take a conservative approach, particularly since most of the time these major changes don't happen, which makes the conservative approach the one that's usually correct. If such a change does happen, then you just scrap the now-obsolete model and make a new one to account for what's happened.

What does "most of the time, these major changes don't happen"? What is "most of the times" in this context? It seems they happened often enough for humanity so far to matter for usnig this method. That tells me that the method is not all that useful, and merely a conversation piece you can ponder about.

 

[Alzrius]

Yes. But the idea that we could immunize ourselves against several terrible diseases was also not a certainty, but affected our lifetime expectations.

Which isn't a helpful point to make, as there was no way of predicting that this would happen, for which diseases, how effective they'd be, etc.

What does "most of the time, these major changes don't happen"? What is "most of the times" in this context? It seems they happened often enough for humanity so far to matter for usnig this method. That tells me that the method is not all that useful, and merely a conversation piece you can ponder about.

"Most of the time" in this context means exactly what it sounds like, particularly when applied to timeline as well as the question of whether they exist or not. The previous generation thought we'd be living like the Jetsons by now, or that we'd all have rocket packs and be taking meetings on the Moon. Fossil fuels use was graphed to end right at the turn of the millenium. Nuclear war with the Soviets was once at the proverbial "two minutes to midnight," etc.

You seem to be saying that any model for what happens to humanity needs to take into context major changes. Can you offer any sort of model for what changes will happen, when they'll happen, and what their major effects will be? (Hint: the correct answer is "no.") Hence why the more rational approach is to leave these assumptions out of models that do try to estimate changes to the systems that we can see and measure now.

 

[Mustrum_Ridcully]

Which isn't a helpful point to make, as there was no way of predicting that this would happen, for which diseases, how effective they'd be, etc.



"Most of the time" in this context means exactly what it sounds like, particularly when applied to timeline as well as the question of whether they exist or not. The previous generation thought we'd be living like the Jetsons by now, or that we'd all have rocket packs and be taking meetings on the Moon. Fossil fuels use was graphed to end right at the turn of the millenium. Nuclear war with the Soviets was once at the proverbial "two minutes to midnight," etc.

You seem to be saying that any model for what happens to humanity needs to take into context major changes. Can you offer any sort of model for what changes will happen, when they'll happen, and what their major effects will be? (Hint: the correct answer is "no.") Hence why the more rational approach is to leave these assumptions out of models that do try to estimate changes to the systems that we can see and measure now.

No, I obviously cannot point to such models, I am not Hari Seldon .

But sometimes you have to face with the fact that the only models you have are not useful either, conservative assumptions or no conservative assumptions.
Especially since this model has no way of being falsified except "wait a few millenia, if humanity is gone by then, it worked!"

 

[Alzrius]

No, I obviously cannot point to such models, I am not Hari Seldon .

Hence why guesswork for the future needs a strong foundation (see what I did there?).

But sometimes you have to face with the fact that the only models you have are not useful either, conservative assumptions or no conservative assumptions.
Especially since this model has no way of being falsified except "wait a few millenia, if humanity is gone by then, it worked!"

That depends on how you define "useful," I suppose. Obviously, this isn't something that can be objectively verified beyond waiting to see if we're still here 9,100 years from now. That said, it's not meant to be definitive; it's a probabilistic argument, which attempts to set some parameters to give us a framework, based on everything we know now, for making an educated (rather than wild) guess.

 

[Storminator]

Meh. Even if I cannot predict what advances will happen, when, and who will invent them, I am reasonably confident that advances will happen. Given the last 1000 years to look at, it is reasonable to conclude we will see more advances in the future than we've seen in the past. Ray Kurzweil would argue here that exponential growth in technology is an overly conservative estimate.

And given that the conservative estimate has been wrong 98% of the time, how can you justify continuing to use it?

PS

 

[Alzrius]

Meh. Even if I cannot predict what advances will happen, when, and who will invent them, I am reasonably confident that advances will happen. Given the last 1000 years to look at, it is reasonable to conclude we will see more advances in the future than we've seen in the past. Ray Kurzweil would argue here that exponential growth in technology is an overly conservative estimate.

Which misses the point - I'm saying that the unpredictable nature of such changes makes it a fool's errand to try to incorporate them into any predictive models (and, equally, that they're not sufficient justification for eschewing any and all such models).

And given that the conservative estimate has been wrong 98% of the time, how can you justify continuing to use it?

I suspect that your 98% statistic is one of the 84% of all statistics that have been made up.

In answer to your question: for the same reason that you look at the weather report, despite it having been "wrong" in the past. It's not a binary "right/wrong" guess - it's predicting a range, and is close to what happens more often than not.

Current predictions include an 80% chance of weather-anecdote related jokes in the next ten posts, for (not really an) example.

 

[Sword of Spirit]

Here's a thought for the doomsday deal. Take specific points in the past and and apply the formula based on what was known at the time. Ie, if you had the exact same formula as you do now, but you were in the 15th century, for instance (and had an accurate knowledge of the current and past population at that point). Then determine how much the estimates have changed based on unforseeable events and major changes to human civilization. Then develop a formula to take that into account and estimate how much change potential events and major changes we can't actually foresee might affect the formula.