How small population can maintain contemporary technology level

Antiphon

Assume 1/10th of all technical experts have most of the expertise of the other 90%. Then assume that the technical literatti is 0.1% of the world population.

Next assume that the know-how is fully concentrated (as the above fraction) in a single highly industrialized country like Japan.

Then 0.1% / 10 * 300M = 30,000 very very carefully chosen people.

r4z0r84

Like they did with the 2012 movie, the ships were apparently designed to sustain life and re populate the world after an apocalyptic accurance. They had to pay extreme amounts of money to be allowed access, or be very select few individuals that are required to keep the technology.

According to the bureau of statistics the estimate is 127,570,000 people in japan as o the 1st of august 2012, this is taking account of all ages, if we were to select a certain age range the number would be lower again also roughly 7 million people are required for 0.1% of the worlds population.

im not sure how you get 30,000 from calculating your above equation you get 300,000 unless im doing something wrong.

Nimbian

The Above equation uses 300,000,000 not 300,000

The US has a Population of 314 Million plus as of 2011

0.1% = 0.001
0.001/10 = 0.0001
0.0001*300,000,000 = 30,000

Antiphon

This is correct; I incorrectly assumed Japan has about 300 million people. Using the US instead you'd get my estimate of 30,000 people.

Borek

30k people calculation is missing the point of the question. You can select such people for a first generation, but I doubt in their ability to pass the knowledge.

Ryan_m_b

That's an interesting attempt at an answer but it has a few flaws. The intitial premise that a fraction of experts will know almost everything is flawed. If anything it is more like a bell curve with experts knowing a lot about related fields and less about fields further away. So the knowledge and skills of a cardiologist might be 80% similar to a hepatologist but 1% similar to a mechanic.

Also whilst your attempt takes into account skilled labour we are still going to need unskilled labour to carry out many of the tasks. Possibly this could be done by idle skilled labourers from other fields but it would be interesting to know how many man hours in each field are needed each day to keep society going.

Czcibor

Just to get some hard data, I suggest a following reasoning:
1 million population
I use my country (Poland) as a benchmark. Because our public health care is so great... No, because it still haven't collapsed this year. ;) So according to our statistical yearbook of 2011 (data from 2010) for 1 million people, we have:
2082 doctors, of whom:
194 are surgeons
54 are neurologists

Thus I think that population should be able to keep a few neurosurgeons. (especially if just in case some surplus is taken at start) Also assuming that one have to train every year 1/30 of of whole doctors pool one would have to train as doctors 70 medical students every year.

I'm not sure about very narrow professions though it seems that anyway that should be enough doctors not to have learn neurosurgery from books.

As you probably see from my language I'm not a native speaker, though I understood what you meant. Nevertheless, chance for understanding term "pain" here literally was to funny for me to ignore.

Good guess - GURPS 4- very flexible for worlds with different technology. Maybe I should note it TL(8-1) ;) - devices look like modern, though under closer inspection show quality matching that from the cold war. ;)

I see that everyone tends to be very careful about giving exact numbers. OK, maybe I'd change a bit the direction.

How in practice would look like reduction of dependency on big economy and looking for simpler substitutes? And what outcome (popular device) that would lead to? Mobile phones with lead-acid battery? ;) (I fully understand the general trend, though I'm curious about practical examples)

Would a tidally locked planet try to adjust itself so that on the part closest to the star and the part exactly opposite a landmass would be more likely than in other places?

Nimbian

As a way of putting it into perspective the above example of 2082 Doctors for 1 Million people means the percentage of Doctors is 0.208% of one million people are doctors.

Antiphon

You misread what I meant. Let's talk about herpetology only. I assert that if you lost the bottom 90% of herpetologists, the remaining 10% who were the best of them would be able to preserve almost all of the art and science that is herpetology.

You would not need any skilled or unskilled labor to preserve herpetology; you would need it to build a herpetology center where it could be practiced. That's not the same thing as preserving the know-how.

The calculation of ~.2% of the population being physicians means my guess of 0.1% is in the right order of magnitude.

Borek

Now I have no idea what your number - 30000 - represents. Is that number of people required to preserve the knowledge? Who is going to feed them?

Antiphon

Yes, preserve mainly and practice to small degrees.

I think the OP was wondering how small he could shrink a society that could maintain a high level of operating technology. My estimate didn't account for long-term sustainability of the equation. That would require things like schoolteachers, farmhands and bricklayers and not just technocrats.

Borek

OK. But the question IS about long-term sustainability.

Nimbian

lol, yet at the same time it provides a reasonable starting point.
An Irony that is not lost on me since I suggested at the low end of my post that 300,000 people of which 5-10% are specialist would be necessary.

How ever it would also mean that one bad virus could send the entire population back to the stone age.

Ryan_m_b

+100000000. Size = redundancy and this should be taken into account as well. It's all very well that the exact minimum population of 11,632,742.6 people trained to various levels in various specialities with strict work schedules is shipped to Planet X but one bar fight, one bout of flu, one fire etc and the whole thing comes crashing down.

Obviously I exaggerate for effect but it is a really interesting point because it has really important implications for the socioeconomic models that the society will adopt. As a very simple example a society with too much personal freedom might leave itself open to accidental self destruction (think tragedy of the commons), too little freedom might create escalating social tension ending in bloody revolution.

Czcibor

One car from which a few friends came from work crashed. I understand consequences.

But I started to wonder - wouldn't industrial base be the more limiting factor. When I tried to look for industrial output, for ex. mobile phones:

Randomly chosen, unrepresentative example with actual data - one line - 3 mln mobile phones per year, whole, finished factory 10 millions mobile phones per year. Wouldn't economics of scale be a bigger problem?

http://www.chinascopefinancial.com/news/post/15411.html

Nimbian

Industrial base is scalable thou. In the above example they make 10 million phones because they belive they can make a profit off 10 million phones.

In a Colony situation, certain things will be majorly scaled down.
EX. there is no need to make 1 million phones a year for a population of 1 million, likely only a few thousand a year to make replacements and for the colonist's children. It would likely be made of identical or nearly identical design.

Large production run type industrial base. would be reserved for things the colony regularly consumes in quantity, is necessary for survival and/or can be stockpiled.

Ryan_m_b

That's all well and good but the point is to consider economics of scale. Making 10 million phones isn't necessarily 10 million times more expensive than making 1. This has an interesting effect economically on our smallest group because it may be that they are less efficient than a slightly larger group. This line of thinking pretty much follows the thread because for the last few posts we've been talking optimum number rather than straight minimum.