Our civilization lifespan as per Copernican Principle

[Genady]

The Copernican Principle, officially described by Richard Gott (J. Richard Gott III | Department of Astrophysical Sciences (princeton.edu)) in 1993, basically says, "I'm not special." It can be applied for statistical predictions in cases where our place in space or time may be considered random. E.g. the fact that I was born in this specific time in the history of human civilization seems to be random, i.e. I could be equally likely born in any other time of that history. 

Now, the human civilization, with towns, writing, some kind of machines, etc. exists about 10,000 years. My random place in it is - with 95% confidence - inside the middle 95% interval of its lifespan. It could be just in the beginning of this interval, in which case the 10,000 years is 2.5% of the lifespan and we have 97.5% still to go, 390,000 years. It could be just at the end of that interval, in which case the 10,000 years is 97.5% and we have only 2.5% left, 256 years. 

So, with 95% confidence we can say that our civilization will last no less than 256 years and no more than 390,000 years.

Some estimates to consider when discussing big issues, I think.

[MigL]

That seems rather ambiguous/inexact, as there are no other civilizations for comparison.
One could argue that we are not fully 'civilized', and may be at the 0.01 % of our civilization lifespan.
One could also make the argument that intelligence will have an effect on civilization lifespan, for better or for worse.
It may mke our civilization last forever, even expanding to other star systems, or, it may lead to our early demise.
You need a definition of 'civilization' and 'intelligence', for comparison purposes; and there are none for comparison to.

Statistical analysis with too many unknowns, such as with the Fermi Paradox, usually lead to invalid conclusions.

Edited January 2, 2022 by MigL

[Genady]

This is indeed a factor that makes Copernican principle inapplicable, if civilization changes its own lifespan one way or another, because we can't talk then about a pre-existing, albeit unknown, statistical distribution. However, if we're just at the .01% of the span, it would make me /you "special" - that's why we have 95% rather than 100% confidence. If we are not "special" we should be in the 2.5% -- 97.5% interval.

Regarding the Fermi Paradox, BTW, here is a quote from Gott:

At lunch one day in Los Alamos in 1950, the noted physicist Enrico Fermi asked a famous question about extraterrestrials: “Where are they?” The answer to Fermi’s question, provided by the Copernican principle, is that a significant fraction of all intelligent observers must still be sitting on their home planet, just like you; otherwise, you would be special.

Gott, J. Richard. Time Travel in Einstein's Universe: The Physical Possibilities of Travel Through Time (p. 237). 

[joigus]

Other questions that make the argument very little compelling, if at all, are: how do we define civilization? Do we all belong to the same 'civilisation': Sumerians, Etruscans, Egyptians, and so on?

It has been argued that civilisation defined by cities, writing, and monumental architecture, came about as a consequence of the end of a glaciation.

Civilisations in a narrower sense like, e.g., the Minoans, probably disappeared because of a volcanic eruption. Others, like the Egyptians, because of people from the seas invading lands that were essential to their trade; as to the Mayas, it's debatable, but climate change may have played a role. It could also be for internal reasons... Earthquakes, meteorites, you name it.

I concur with @MigL  that there are too many unknowns.

Also, I know you pitched this topic for applied mathematics, but we should try to make these ideas falsifiable, because we're concerned with science. You cannot experiment with civilisations as a subject of study in real time.

1 minute ago, Genady said:

This is indeed a factor that makes Copernican principle inapplicable, if civilization changes its own lifespan one way or another, because we can't talk then about a pre-existing, albeit unknown, statistical distribution.

(My emphasis)

This is funny, because --and I think it's happened before-- you've made a good argument, but it seems to me that it works against your idea. How can we surmise that probability distribution?

On other threads I've argued that the word 'random' in itself doesn't mean much. You would have to make a statistical hypothesis => probability distribution.

Equiprobability doesn't apply in general.

[Genady]

Regarding too many factors /unknowns, it's good, the more the better. That is where statistics works the best. Of course civilization will not die because of the statistics - something will cause its death. But there are so many different possible somethings, that we can apply statistics. Not to figure, what will kill it, but to make statistical estimates, e.g. when it is likely to happen.

I am not sure we need to be concerned too much with a definition of civilization either. It is enough to say, some version of human lifestyle that started about 10,000 years ago. we make an estimate about that lifestyle.

We can apply the Copernican principle to a better defined thing, like human species. Here is Gott again:

Our species, Homo sapiens, has been around for about 200,000 years. If there is nothing special about our time of observation now, we have a 95 percent chance of living sometime in the middle 95 percent of human history. Thus, we can set 95 percent confidence level limits on the future longevity of our species. It should be more than 5,100 years but less than 7.8 million years (5,100 years is 1/39th of 200,000 years and 7.8 million years is 39 times 200,000 years). Interestingly, this gives us a predicted total longevity (past plus future) of between 0.205 million and 8 million years, which is quite similar to that for other hominids (Homo erectus, our direct ancestor, lasted 1.6 million years, and Homo neanderthalensis lasted 0.3 million years) and mammal species generally (whose mean longevity is 2 million years). The average, or mean, duration of all species lies between I million and 11 million years.

Gott, J. Richard. Time Travel in Einstein's Universe: The Physical Possibilities of Travel Through Time (p. 210). 

 

I just saw you comment about a shape of distribution. Assuming uniform distribution is more optimistic in this case. If it is more Gaussian-like, the confidence interval will only decrease since you /me will have a higher probability to be closer to the center.

[zapatos]

1 hour ago, Genady said:

E.g. the fact that I was born in this specific time in the history of human civilization seems to be random, i.e. I could be equally likely born in any other time of that history. 

I know this is a tangent, but I think you are wrong. You are the product of a specific egg and sperm. The time you were born is the ONLY time you could have been born in history.

[Peterkin]

1 hour ago, Genady said:

Some estimates to consider when discussing big issues, I think.

Which big issues do you wish to discuss? The time estimate of 256 years [to the end of all civilization - or just Eurocentric western civilization, or what?] is rather loose; it allows for any number of scenarios. The most likely snuffers-out of our civilization (either way) are super-storm, super-bug or super-bomb.  That is: climate change, pandemic or nuclear war.

That's the optimistic version: with a bang.

The pessimistic: with a whimper, looks more like economic collapse, accompanied by continued unchecked population growth, in the presence of climate change, plague and threat of nuclear war, petering out in a protracted series of migrations, wars, floods, fires and famines. 

[Genady]

9 minutes ago, zapatos said:

I know this is a tangent, but I think you are wrong. You are the product of a specific egg and sperm. The time you were born is the ONLY time you could have been born in history.

This is fine. It is just like in statistical mechanics. We consider a position of any specific molecule random, in spite of the fact that it certainly has had a certain specific dynamic history. A big number of molecules allows this approach. A big number of eggs and sperm and me / you / he / she etc. allows it here.

[Peterkin]

11 minutes ago, zapatos said:

The time you were born is the ONLY time you could have been born in history.

This is true, but not germane to the topic, since Genady's presence or absence from any particular time period is irrelevant. Unless he's the emperor of a great and powerful global empire, his(?)  statistical significance is 0.000,000,007.

[Genady]

6 minutes ago, Peterkin said:

Which big issues do you wish to discuss? The time estimate of 256 years [to the end of all civilization - or just Eurocentric western civilization, or what?] is rather loose; it allows for any number of scenarios. The most likely snuffers-out of our civilization (either way) are super-storm, super-bug or super-bomb.  That is: climate change, pandemic or nuclear war.

That's the optimistic version: with a bang.

The pessimistic: with a whimper, looks more like economic collapse, accompanied by continued unchecked population growth, in the presence of climate change, plague and threat of nuclear war, petering out in a protracted series of migrations, wars, floods, fires and famines. 

In another response above I've clarified, "Not to figure, what will kill it, but to make statistical estimates, e.g. when it is likely to happen."

1 minute ago, Peterkin said:

This is true, but not germane to the topic, since Genady's presence or absence from any particular time period is irrelevant. Unless he's the emperor of a great and powerful global empire, his(?)  statistical significance is 0.000,000,007.

Thank you, I agree. Yes, it's "his".

[beecee]

13 minutes ago, Peterkin said:

Which big issues do you wish to discuss? The time estimate of 256 years [to the end of all civilization - or just Eurocentric western civilization, or what?] is rather loose; it allows for any number of scenarios. The most likely snuffers-out of our civilization (either way) are super-storm, super-bug or super-bomb.  That is: climate change, pandemic or nuclear war.

That's the optimistic version: with a bang.

The pessimistic: with a whimper, looks more like economic collapse, accompanied by continued unchecked population growth, in the presence of climate change, plague and threat of nuclear war, petering out in a protracted series of migrations, wars, floods, fires and famines. 

Or super cosmological catastrophe?

[zapatos]

14 minutes ago, Peterkin said:

This is true, but not germane to the topic

I know. That's why I started the post by saying "I know this is a tangent..."

[MigL]

If we don't agree on the meaning, or even if we are, a 'civilization, how can we establish that we are in the 5-95% of the Gaussian distribution ?

Intelligence, or lack thereof, also tends to alter the distribution curve, as our 'evolution' is not solely controlled by environmental forcings, once we have the ability to control our environment ( to an ever increasing degree ).

[Peterkin]

17 minutes ago, Genady said:

when it is likely to happen."

What does that matter? 20 years, 200 years.... The process is what we'll be aware of, not the duration.

 

11 minutes ago, beecee said:

Or super cosmological catastrophe?

I'd call that another kind of bang - possibly followed by a drawn-out whimper.