Situation: Aliens attacked earth. They used a weapon which produces waves, say "destorymachinewaves". It destroys the machines and takes them to space. So every machine on the earth was Destroyed. Destroyed machines were flew to space from earth. All the technology was gone, From super computer to your wrist watch. Not even a electrical bulb exist on earth. We are only left with technology on the paper.

TODO: How many years it is going to take to retain the same technology and all machinery to the world? In the process of retaining the technology do we invent any new technology or machines. For instance, microtechnology or a suit which fly by itself if you wear it.

  • $\begingroup$ If everyone wants to become mechanic, then the only issue left isn't about time but how much resources are available. My estimate based on the best case scenario is within decades, give the scientists some times to reverse engineer the alien tech then we can turn the table around.👽 $\endgroup$ – user6760 Aug 14 '15 at 11:53
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    $\begingroup$ I think we need a working definition of "machine". Does anything with wheels count (like a horse-drawn cart)? Does anything with moving parts count (like a human-powered water pump with a hand crank or foot pedal)? Do bicycles count? On the other hand, I think it's a stretch by any definition to call a light bulb a machine. $\endgroup$ – Charles Burge Oct 25 '16 at 18:38

Possibly never.

It's questionable whether we'd be able to regain it at all.

If every machine on earth was powedered and spirited away into space not only would we lose the technology, we'd lose the materials. We've already used most of the most easily accessible ore deposits and the most easily accessible fuel deposits and you can't get to the deep stuff without equipment and you can't make the equipment without ore/metal/material.

Every single bit of knowledge stored only on computer would be gone. Society would collapse into a terrible famine as all the farming infrastructure would be totally gone. For a long time people would just be trying to survive. It's hard to maintain libraries when the librarians are starving to death.

Knowledge of how to build tractors isn't a great survival skill in a world where there's almost no metal to build them with nor fuel to run them and there's going to be a lot of cannibalism.

It's hard to even have an iron age when the easiest surface iron deposits are already gone and without that there's little hope of climbing higher since you need to be able to free up enough people to have a scholar class and that may never happen. Without that society can remain totally static without notable scientific discovery.

There's even a danger that even if society did start to climb again, that people would develop a worldview where useful knowledge can only come from some golden age in the past which could further cripple any attempt to reestablish a scientific community.

  • $\begingroup$ The good news is we still have the knowledge, for a while at least. You certainly shouldn't expect flying suits to miraculously appear though. $\endgroup$ – Tim B Aug 14 '15 at 11:08
  • $\begingroup$ Good answer @Murphy. Actually I thought that it would take decades. I will explain why. We have come to this time from a time where we did not have a language to communicate. where we used to fight with nature for food, Where we used to cover our bodies with leaves. From that time to reach this time it took some decades. But now we have the knowledge and know how to retain metal from ground earth. So i thought so. But with the points you mentioned and as bowlturner said, Billions would die from starvation. So i would agree with your answer 'Possibly never'. $\endgroup$ – Mr ASquare Aug 17 '15 at 6:19
  • $\begingroup$ Basic materials could be reused from structures and basic survival level argiculture only requires manual tools (sure this can't be ultra industrial but if everyone had their own, or worked together on plots, it could sustain humanity until we mine deeper. $\endgroup$ – John Hon Oct 25 '16 at 11:59
  • $\begingroup$ How many libraries survive when the heating, AC, and wiring get pulled from the walls? $\endgroup$ – SRM Dec 19 '16 at 15:15
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    $\begingroup$ @Clearer Not to mention landfills, it's a common fallacy to imagine that everything humanity has 'used' is gone somehow from the world. Besides, we get much of our chemical production from sustainable sources(which would be reduced certainly given irrigation & transportation difficulties) Think it's also worth pointing out that most of the technology we'd lose is stuff we couldn't reproduce easily without international cooperation, whilst what came before (even up to the 1900s) could relatively easily be reconstituted even given just theoretical knowledge anybody who paid attention at $\endgroup$ – Giu Piete Mar 3 '19 at 9:45

As Murphy pointed out. First we would have chaos. Billions would die from starvation. We can't sustainably feed our numbers without equipment to produce (much less transport) food we need. Refrigerators/freezers are gone and all that food will spoil. So people will starve to death in every advanced nation on Earth. Rural places will fair a little better. Indigenous peoples will have minimal issues.

So first we'd fall, rapidly. We won't have the ability to communicate over any distance that doesn't involve someone walking or riding a horse. All 'governments' would be reduced to local city officials. With luck there might be a few beacons of light scattered throughout the globe.

Quite likely the survivors will actually have myths about technology and might even try to avoid it since 'dependency' on it caused such misery. So I would go with at least 1,000 years to have a chance of reaching something similar to our current state. If the libraries are actually preserved and not used as fuel or are burned in protest or rage then we have a chance of turning around our dark age in a few hundred years (but still need a lot more to reach the industrial revolution).


I do not believe it will as grim as others put it. After all, this is like starting over a game, but with all the cheat codes memorized.

We still have all of our structures which don't require constant machines to function (at least residential ones) and basic materials could be reused from structures (such as construction steel and copper used for communications) and basic survival level agriculture only requires manual tools (sure this can't be ultra industrial but if everyone had their own, or worked together on plots), it could sustain humanity until we collectively can try again.

  • $\begingroup$ I think you're missing just how much we depend on transportation technology to eat. Every city would suddenly have no food, and no way to get food since the farms that supply it are hundreds or thousands of miles away. NYC would be an absolute madhouse. "Civilization is only 3 meals away from anarchy." On top of that, probably 90% (or more) people (in the US, anyway) only know how to do jobs that require technology, and will be absolutely useless in an agrarian society. Think farmers are going to give them food for free? $\endgroup$ – Azuaron Oct 25 '16 at 13:26
  • $\begingroup$ @Azuaron "absolutely useless in an agrarian society" - I can teach you farming in 5 minutes - take hoe and work $\endgroup$ – MolbOrg Dec 18 '16 at 23:29
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    $\begingroup$ @MolbOrg I can pretty much guarantee you are not a farmer. Weather patterns, land rotation, seed storage, water irrigation construction, fertilizer rates... the farmers in my family know a whole lot of critical stuff that I am only aware enough of to know I couldn't learn it in a day. $\endgroup$ – SRM Dec 19 '16 at 7:38
  • $\begingroup$ @SRM True, I'm not a farmer. fertilizer - forget it, the only fertilizer available in this situation will be manure. Vaccines - forget it, only vaccines available will be the pray and common sense(isolation, alcohol disinfection, selection). Interesting channel Urban Farmer Curtis Stone - even that will be too advanced. The point is - there two distinctly different approaches, how 3% of population make the food for everyone, and how everyone will make food for them self. land rotation - forget it, rotate crops. Hard work and pray. $\endgroup$ – MolbOrg Dec 19 '16 at 11:07
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    $\begingroup$ @SRM, as an agricultural student, i do agree, there is plenty to learn and its even harder to apply it correctly, especially when your livelihood and financial stability actually will depend on it, however, basic level agriculture can be achieved if the government distributed this knowledge as well as instructions to keep calm. Everyone would be issued new roles perhaps in society, but everyone would be given the knowleadge on how to correctly and efficently as possible farm the land (in a somewhat consise manner i guess since it is for the general public) $\endgroup$ – John Hon Dec 19 '16 at 13:37

There is some basic agriculture level that requires only domesticated animals, crops and very basic tools that were made by the farmer from wood. I think civilization is unlikely to degrade below that level. It may be actually higher as smiths can forge plows and scythes from rusting machines.

Farmers may not be able to produce enough food for sale but probably will manage to grow enough food for own families. They are in danger of angry crowds running from the dying cities, but without transportation these crowds may die out before destroying every remote farm.

In general monkey business for the Aliens, the humanity will completely recover in a few thousand years that is a very short time in a cosmic scale.


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