If all our technology disappeared, how long would it take to make a smart phone?

Question

Suppose all of technology in existence disappeared overnight, except for the clothes everyone is wearing. No houses, man-made structures of any kind, just the land as it was say 60,000 years ago. All of our technology is gone, but everyone retains their knowledge. People know how to make a fire, the contractors know how to build a house, the scientists still know science, the tech people know how to make phones and computers, everyone still believes the same religion they believed in previously, etc.

With modern-day know how and experience, how long would it take to manufacture a smart phone as they exist today? Assume that it is the goal of humanity to rebuild itself as fast as possible.

And by the way, I use the smartphone as an example. As a bonus answer, try to make a speculative timeline of which technologies are achieved and when (for example houses/buildings, cars/planes, rockets/satellites, computers, vaccines/antibiotics/heart surgery.

Answer 1

TL;DR 2000 years

The only historical example that we have shows that going from late iron-age technology (the rest describes why iron age) to smartphones has taken around 2000 years.

Progress isn't a priority

The immediate result of such an event is that most of humans will die. Ignoring the other possible effects (housing - in many climates lack of proper housing means death during the first year), medicine, conflicts) the agricultural efficiency would drastically fall. If we're unable to get up a running industry to make a very, very large amount of tools we wouldn't even be able to harvest the existing ripe crops. We would be unable to quickly match medieval technology due to lack of large numbers of load-pulling animals - draft horses and oxen. Even if we'd immediately get up our technology level up to year 1800, that would allow us to feed a billion people, leaving the other 6 billion to starve.

That magnitude of death will not happen easily or peacefully - it means that immediate survival will be a complete priority and preservation of long-term knowledge (as well as anything long-term) will be an unaffordable luxury.

Most of the skills are immediately useless

Contractors know how to build a house using tools, concrete, screws, drywall and straight and even-sized planks - none of which exist nor will exist soon. People who know how to make screws and tools know how to make them using machines and metal that doesn't exist and will not exist soon. People who know how to make metal and alloys know how to make them using machines that don't exist and a large quantity of ore - that needs to be mined and transported using nonexistent infrastructure. The currently available sources for mining ore generally are miles deep and are unusable without modern machinery.

This goes on for pretty much everything - in an USA-like society, almost the only useful skills will be ones that are used as part of unconventional hobbies - recreating stone-age tools, open-air fireplace blacksmithing, pottery and basket weaving.

Progress comes at stages

You can't start modern society before having a lot of functioning industrial-age tools and processes, no matter how good knowledge you have.

You can't start industrial age manufacturing before having a lot of functioning iron age tools and processes, no matter how good knowledge you have.

You can't even start iron age manufacturing before having a lot of functioning stone age tools and processes, no matter how good knowledge you have - you'd need charcoal which requires felling of decent-sized trees, you'd need to obtain ore which will also require tools, and you'd need to survive which would require housing, farm tools and weapons.

If you're unable to make the first tools at scale - millions and millions of them - then your society won't be able to progress beyond that and your knowledge of industrial processes will be irrelevant.

Underdeveloped societies will be leading the pack

I would expect that societies which are currently underdeveloped would fare the best in this scenario. They are less dependent on infrastructure, and the skills they have are more useful in both immediate survival and in recreating low-tech infrastucture. Also, they often are located in places more suitable for survival. Places like Canada or northern Europe simply aren't habitable without any technology, you'd need at least a supply of good stone axes for firewood, spears and a lot of huntable wildlife to enable survival of small bands of hunter-gatherers there - totalling thousands, not millions. After such an event, sub-Saharan Africa would clearly be in a better position. The immediately sustainable level of technology will be the one that currently some nomadic herder communities have, since they will be pretty much the only communities that will be able to keep their food security, lifestyle and avoid absolute chaos.

Answer 2

Simple answer : never

For one simple reason.

When any technology started to flourish (metal working, steam power, etc..) it was driven forward by easily accessible raw resources. When people first started working metals, they mostly picked the raw ores from the ground or made really shallow mines. Industrial revolution was driven by coal, that was mostly in top layers of soil. First pertroleum drills were really shallow and some was even found on the surface.

The problem is that all of those easily accessible resources are long gone thanks to modern excavation. We need to put lots of effort, tools and knowledge in finding and excavating new resources.

But if we lost all of that tools and knowledge, it would be almost impossible to find and excavate new deposits. And humanity would develop in completely different way than what we saw in history.

Answer 3

You'll have to be far more precise about what you are imagining. Let's take wheat. It is, like corn, a product of selective breeding, as are virtually all of our other food crops. So, no field crops. Take coal mines. The mine is obviously technological. So, what happens to the hole? Magically get filled in? Similarly with other open pit and underground mines. What happens to the materials making up the concrete, steel, copper, etc., etc.? You state the land would magically revert to "as it was say 60,000 years ago." Does that mean the climate will be the same? That mastodons will roam North America? That rivers magically assume their courses, desserts appear (and disappear)? Roads disappear, land (and water and rock) is magically resculpted into the way it "was" 60,000 yrs ago? The ancestors of maize and potato and wheat and rice revert to their native habitats? All this while 7½ billion people are killing one another (and anything else that moves) for food?

Answer 4

The single biggest problem then would be survival. Our technology is what is keeping the vast majority of us alive today. Just feeding everyone needs a huge level of tech. Most people don't have enough skills to survive several months without a grocery store and the wild does not have enough supplies to feed everyone. So the first problem would be survival and my guess better than %90 of the human population would be dead in less than a year.

At this point the survivors will have made shelters and have figured out some subsistence living. If the group is really lucky they might have some skilled members of the group, hunters, farmers, craftsmen, ie. blacksmiths, carpenters etc.

But I would expect at least 1000 years if not a LOT longer because we really would be starting over and by the time things settled down most of the people with needed knowledge would be gone and in two or 3 generations most of what we had would be relegated to myths and legends.

Answer 5

The largest issue should be that the people alive today with the knowledge of how to work on the tech in smartphones would die long before the infrastructure that would be needed to produce the materials to make the phone. And I doubt the people with the knowledge of "smartphone" building would want entrust their children with the important task of know how to build a smartphone when there much greater needs at the time (e.g food, clean water, shelter). So the knowledge that will be passed down to the future generations will not include how to build a smartphone. That being said the time it would take to produce a new smartphone has to be 2000 years at the minimum and with the possibility that it never gets built at all, with another technology that provides what is necessary at the time

Answer 6

I agree it could be much longer than 2000 years. Imagine the world as a video game. First you must find clues and pick up objects that will help you on the next level and so-on. If we started again, we would not find our clues on top of the ground because they would have been wiped out by the older civilization. We won't be able to easily make tools from easy to get to resources. How are we going find and recover deep underground ore without the start up equipment need. The reason we know so much about ancient history is because we were able to recover tablets used as we use paper today. So when we die everything goes with us because paper, CD Roms, books even cellphones aren't going to last long after we go

Answer 7

Minimum 100 years, maximum 2,000 years

Maximum is easy - already stated in several other answers based on the past 2,000 years of Earth history.

Minimum is where it gets interesting. Infrastructure and knowledge are the keys. You are starting with near-100% knowledge, but 0% infrastructure. If you can do the following, you could have most of today's key infrastructure in about 100 years:

• Immediately recognize the problem and start writing everything down, which means...

• While other people are foraging, farming, hunting, etc., a group of people needs to start right away on recording information. My best guess is papyrus or similar - less work to produce than modern paper, but more information dense than stone tablets. Understanding that it will take 100 years to be able to actually use all the available information, writing it down is absolutely crucial so that the next generation will have the knowledge it needs.

• Work on a long-term (100 years, not 1 year or 5 years) for recreating the infrastructure needed for a modern society. Key elements will be:

  • Metalworking - iron (which leads to steel), copper, aluminum - mine, refine, manufacture useful produces
  • Woodworking, masonry - for building structures
  • Tools - Starting with hand tools, but with machine tools (water power, electric, etc.) in mind
  • Chemistry - Needed for refining metals, developing batteries, medicines, etc.
  • Electricity - a lot of other pieces need to be done first, but this will be vital and early development of even basic electrical infrastructure will dramatically improve productivity

and a bunch of other things. It will be a huge team effort. If society can stay together long enough to write down a substantial part of modern knowledge and start on the necessary infrastructure without having to go through 1,000 years of scientific development, we could have modern technology in 100 years.

On the other hand, if famine, war or other problems result in delays in the infrastructure or in the loss of information (e.g., burning the only copy of vital information 20 years in when many of the key people have already died), then you're back to 2,000 years.

Answer 8

I would assume around 500 years. Surriving population will verbally pass down some important knowledge like woodworking, ore refinement, irrigation, basic chemistry, physical formulas, toolmaking and most importantly scientific methods. Some of these will be immediately useful and next generations will keep this knowledge, this will allow us to skip or at least fast forward stone, bronze and iron ages.