Let's say that you find yourself in the ideal situation for this thought experiment. The world as we know it as ended, and the vast majority of humanity is gone. There has been a period of turmoil after the apocalypse, but order has now been restored by a ruler. You are a member of a surviving community of a few thousand people, in a largely peaceful society. Given the appropriate guidance, what do you think is the quickest that such a society could progress from rudimentary means to a technologically competent civilisation with, say, electricity, radio, and engines?
Sadly, I think that the ideal situation is one of pure fantasy. It feels like the only way the scenario could occur is if there was some group of people actively preserving the knowledge needed to rebuild society and then doling out the wisdom when we were ready for it again.
-Read a A Canticle for Leibowitz.
Let's look at the world today and why it dims our chances.
1. Very, very little is actually built to last.
- What's left after 20, 50 or 100 years of decay? By that time what machinery/technology would be left that could be revived through some blood, sweat and tears? Pre-plastics revolution machinery and mechanically powered machinery is gone. Capitalism, or what we perceive to be capitalism has created such fast production cycles for nearly everything in society that nothing built now is meant to last beyond the next cycle or 2. Keep them buying to keep them happy....
2. No minerals, oil, metal ore is abundantly available from surface collection.
-As mentioned elsewhere, all fossil fuels have been surface mined decades ago. Without advanced technology we cannot dig deep enough to mine ore, or fossil fuels with pre industrial revolution methods.
3. Majority of the developed world inhabitants are too specialized in their knowledge base/education
- Not enough people will survive with knowledge and skills required to fix anything, build anything or that know how to live off the land.
4. Books containing knowledge on building or repairing machinery etc.. will be extremely difficult to find intact as the libraries that house them will have most likely been ransacked or decayed into ruin. The books will have probably been burnt for heating/cooking.
5. Much of the world's most fertile land will be ruined because it's also where we have built all of our cities and industry. It will be covered in large swaths of pollution from decayed industrial sights, untreated sewage and polluted waterways, nuclear fallout(either from war or from reactor failures), fossil fuel spills(destroyed oil rigs, tankers and pipelines)
Lastly, although I am sure that others may want to chime in on my fatalistic views, I'd like to turn it over to Thomas Hobbs,http://plato.stanford.edu/entries/hobbes-moral/
There would be “no place for industry, because the fruit thereof is uncertain; and consequently no culture of the earth; no navigation, nor use of the commodities that may be imported by Sea; no commodious Building; no Instruments of moving and removing such things as require much force; no Knowledge of the face of the Earth; no account of Time; no Arts; no Letters; and which is worst of all, continuall feare, and danger of violent death; And the life of man, solitary, poore, nasty, brutish, and short.” If this is the state of nature, people have strong reasons to avoid it, which can be done only by submitting to some mutually recognized public authority, for “so long a man is in the condition of mere nature, (which is a condition of war,) as private appetite is the measure of good and evill.”