What's the ideal era for harvesting resources by an advanced society?

It's 2100-ish and we're experimenting on our new time travel device, or let's say time travel bunker. What we gathered of information so far are:

• We can't really go back in time, literally. Every time we visited the past, we got into a new dimension identical to ours to the point the visitor arrived. Then, it just changes direction chaotically, but nothing really changes on our timeline.
• Huge amounts of energy are used to visit this new dimension for the first time, although revisiting it demands a lot less.
• Weirdly enough, it's cheaper to explore this new dimension than to explore space and new planets.
• We can bring back goods from that dimension as efficiently as we can carry stuff there.
• We can't go forward, no matter what we try to do.

The higher ups are not that happy. They hoped they could win the lottery a few times I guess. The board members were afraid we would get shut down and devised a plan to rescue all the investments made on the project.

As we know now where all the natural resources are we could just go there and get it. And let's be fair, we could use some. Since the construction of the mega cities started, we've been on a major shortage. The thing is, when should we go? I mean, to what age should we go harvest resources?

It would be easy to say "just go now and gather that brand new duplicated nuclear frost free refrigerator", but I don't think we would be welcomed there. I mean, I would shoot dead anyone trying to rob my toaster and I don't think the military would allow any of that. It would be a large scale war between two identical forces.

We need to think of a time where resources were readily available and we could outmatch the military. The balance on that question is the answer.

Valuable goods: almost anything goes. Think of what is valuable today, as in high price stuff. More readily resources like already processed steel and gold ingots. Also art, high tech computers (large amounts as in warehouse full of it), uranium ready rods, etc. The thing is, the more advanced the better resources we can find, but it'll be harder to harvest since the military would be a hard match to overcome. Not limited to those, you get the idea I hope.

• What resources are valuable to this future society? – Cort Ammon Oct 26 '18 at 4:13
• Pretty much this concept was explored in Frederick Pohl's The Coming of the Quantum Cats (1986). Lots of paratimes where humans died out for one reason or another. Harvest there. – user535733 Oct 26 '18 at 4:59
• Voted unclear, because it's hardly answerable if we don't know what resources they might need, as @CortAmmon said. – Mołot Oct 26 '18 at 5:21
• Obligatory xkcd: https://xkcd.com/1191/. – Jordi Vermeulen Oct 26 '18 at 9:37
• "Huge"? How huge, in absolute (Joules) and relative (percent of world energy budget)? The first tells us if there are more efficient alternatives, the second determines what strategies are reasonable. Second, is it a "teleport" or a "portal"? Can you build pipelines? – Yakk Oct 26 '18 at 14:09

18 Answers

The thing is the massive amount of energy. Sure you could go back and collect iron, coal, oil, etc but is it worth the expense?

Raw materials can be collected from space by asteroid harvesting and the energy to rip a hole in the fabric of time/space just to mine I suspect will be far greater than asteroid mining.

Now where you make your money is collecting unique things. Think Jurassic Park except you don't need to find DNA or clone anything. Think all the Van Gogh painting he burnt because his painting were worthless at the time. Think about all the books and scrolls burnt in the Library of Alexandria. Da Vinci first draft drawings. The items that were robbed from the Pharaoh's tomb and melted down.

The next thing is recordings of events. The Parthenon filmed just after construction. Life in Pompeii. The burning of Rome.

Finally you have the recording of crime. Who actually shot JFK? Who was Jack the Ripper actually? What happened to missing people? Where is the missing body?

All these things can make a huge amount of money far greater than any lottery.

• Your corporate board may be leery of getting involved with contraversial history — birth of Christ might not be virginal; JFK might not have been shot by Ted Cruz’ father; etc. Might piss people off. But winning class action lawsuits? You could know if Exxon really suppressed climate change research or whether Big Tobbacco ignored cancer warnings. And you wouldn’t need a subpoena. In fact, you could spy on all sorts of goings-on, right up to the present day. See “The Dead Past” by Isaac Asimov for more on that. – SRM Oct 26 '18 at 12:11
• See also Kage Baker’s “Company” series of seven novels for harvesting rare materials from the past ideas. – SRM Oct 26 '18 at 12:14
• @Thorne Perhaps all the items you cited such as Van Goph burning his paintings, the scrolls in the Library of Alexandria etc. were all elaborate cover ups planted by time travellers from other dimensions because they stole our priceless works!! :o hang on, I have a YouTube conspiracy rant and a badly designed website I need to go make... – Trotski94 Oct 26 '18 at 12:46
• @SRM I'm imagining the legal argument there... "you went back in time and recorded a board meeting where x was said, but that dimension's timeline was already in chaos from your presence...". There might need to be some legal precedent set maybe? – PeterL Oct 26 '18 at 22:51
• @PetetL True! “Your honor, the Jones recording was the first incursion into that time stream. This Smith recording was made barely two weeks later, across the country. While theoretically within the time-light cone, our expert physicists will testify about the extreme unlikelihood of any divergence. Also, your honor, we made recordings at your home address on both occasions so you could see for yourself that nothing diverged in the second recording... and we think you’ll rule in our favor unless you want those recordings made public...” – SRM Oct 27 '18 at 13:53

If length of time isn't a factor, you could always go back to before humanity evolved. I'm aware this is basically the plot of Terra Nova, but it means that you don't have to deal with any real resistance.

Homo Sapiens only evolved as a separate species in the last 300,000 years or so, and would only present serious resistance to a modern military sometime in the last 100-150 years. The Earth is 4.5 billion years old - even if travelling further back requires more energy, it's only in the last 100,000 years that humans managed to colonise most of the planet

Sure, you lack the benefit of preexisting mines and infrastructure, but if you don't care about preserving the world or timeline, you can basically strip mine the planet with no care for collateral damage. It also brings up the possibility of retrieving extinct species of plants and animals for studies - who knows what medicines could be found in the jungles of the Jurassic?

As an alternative approach - why do the work yourself? You presumably have access to highly advanced technologies, knowledge, and medicines. Travel back only a few hundred years - perhaps to the end of the industrial revolution - and trade with the inhabitants of the new world for resources. You could charge exorbitant prices in raw materials for mere pittances. If it's possible to travel back to several locations within the same parallel reality, you could start a bidding war between the nations of the time.

• +1 for trade. Furthermore, it could set a good precedent for people in the future of other dimensions coming to your one. – Pere Oct 26 '18 at 12:19

You really need to read Charles Stross's Merchant Princes series, which has a very similar premise. To my knowledge, he's the only author that's really leveraged inter-dimensional travel between more/less advanced societies for its logical economic conclusions. (And social conclusions, but that's where the plot lies.)

The key concepts are uplift and technology transfer. No, you can't win the lottery. You may be able to win by betting on a sporting event, because those are slightly less random. But you can reliably make your fortune by teaching less-advanced people skills which will build their society and put yourself in the position of being the supplier of those technologies. If you could be a combination of Newton, Newcomen, Stephenson, Faraday, Davy, Edison, Marconi, (extend as appropriate), then you can drip-feed their society advances in technology at a rate they can handle, and be in a position to reap the profits of being the person at each step who gets "first mover" advantage.

And not only that, but knowing the direction of travel, you can make sure you've acquired the relevant assets ahead of time while they're still cheap. Say you're going to give them the Newcomen beam engine for pumping out mines. You can buy up flooded mines for a pittance, and of course when the pumping technology exists then they're profitable again. Thinking about building railways, canals or turnpikes? Buy land along the route before the technology exists. Internal combustion engine? Expand your empire to the Middle East. Mobile phones? Expand your empire to the Congo for coltan mines.

Don't forget general society as well. It's tempting to just look at railways and bridges as the big legacies of the Victorian era, but arguably the biggest advance was installing proper sewers and water supplies so that people didn't die of preventable diseases. As those people survive, you've got more workers for your businesses, and more consumers. Hospitals too - don't forget to pass on lessons from Pasteur and others. And by doing this, you shift the public perception of yourself from industrialist robber-baron to benevolent protector of the nation. It's hard for Luddites to find much traction when you're the reason their families have toilets and running water in their houses, and their children were born safely in your hospitals, and their grandparents are being looked after in their old age by your nurses. Victorians like Rowntree can serve as useful examples if you discard their religion and moralising.

• This. You beat me to it, +1 :D – Ruther Rendommeleigh Oct 26 '18 at 10:43
• Asimov’s “And Eternity” is the same trading among times, but comes to a very different conclusion. – SRM Oct 26 '18 at 12:18
• There is another series whose author I am forgetting. I know one of the books is the disunited states of America or some other way of saying disunited. – Tanzanite Dragoness Dec 30 '18 at 11:57

There are probably 3 main times that you want to go back, if you just want to steal the resources sitting there. I'm not sure of the actual time, so I'll outline the transition stage and why.

Right before the rifle was invented (1840). The invention of the rifle meant that instead of muskets, people now had guns that were accurate. If you want to have the lowest risk possible, hit them right before they have accurate guns and you don't have to worry much about losing anyone.

Before the Invention of the Machine Gun (1880). The invention of the machine gun. The machine gun marked a huge change in tactics and strategy. It wasn't about man power anymore. 1-2 people could hold down dozens of men with just a single machine gun. If you want to reduce the risk, but get more reward, you want to come around now.

Before handheld or portable communications were invented (1950s). Fast communications mean a faster response. If you appear with 100 men and start ransacking a place, it helps a lot of the people have to run all the way to a phone to get help rather than pulling out a hand held radio or mobile phone and dialing for help. Weapons are already pretty dangerous, so the main factor is how long can you go ransacking undisturbed before you need to leave.

The later you go, the more materials you will be able to obtain. Industrialization basically meant that the longer you waited, the more they were producing and the more you can steal. Its like dropping into a mine where its pickaxes and carts, vs dropping into a mine with machines carving mountains into nothing. After portable communications are readily available, you risk being caught, pictured and filmed which you don't want. Knowing something is possible is a very good incentive for investment and the military would certainly see the advantages of such a technology so you don't want them biting you back later on.

If you go too early, then you simply won't have the materials you want in a large enough quantity to be worth it. Think of the Effiel tower. It was essentially a display from France to show off how much iron they had. That much material now-a-days is a joke. Its 7,300 tons, but now we currently produce more than a million tons a day.

In fact... the best way would be to go back and rob yourself. Think about it. If you had a warehouse full of goods already. Go back into the alternative timeline, and steal everything you had. Now back in the original timeline you have doubled your goods. Just rinse and repeat. You only need to start with one big robbery, or investment and then you can safely double your goods with no resistance.

• If you're robbing your dimensional clone, whats the chance of another dimensional clone robbing you? – Thorne Oct 26 '18 at 6:23
• @Thorne I'd say about 100%.... You just need to steal it, after they have stolen yours, so you still get double – Shadowzee Oct 26 '18 at 6:33
• For robbing yourself, a must read is The Seventh Voyage from The Star Diaries by Stanisław Lem (en.wikipedia.org/wiki/The_Star_Diaries) – Ister Oct 26 '18 at 9:22

The ideal era for harvesting resources for an advanced society is the present. Strictly speaking, only ten seconds in the past.

The time travel devices take your harvesters to a point in time identical to your timeline, but in another dimension. So go back ten seconds into the past, or even much, much smaller intervals into the past as required, maybe it only needs to be a microsecond. You will be in an identical version of your own timeline. It will be full of the same resources as your timeline. Grab what you as quickly as you can, before they realize you've arrived.

Now you will have acquired identical versions of the goodies used by your advanced society. It wouldn't be a good idea to go back to a timeline you have visited, because they might know you'll be coming back again.

A word to the wise. Remember they're about to do what you're doing, i.e., pop ten seconds into the past of an alternative timeline and plunder it, so maybe you should back somewhat earlier into the past than ten seconds. That suggests going back before you've got your time travel devices working or perhaps back before the time travel research & development project begins.

In conclusion, the near past will be rich in exactly the sort of golden goodies and resources your advanced society uses. They're there for the taking in the alternative timelines of the recent past. So go for it.

Don't forget the potential value of selective kidnapping. Grab a few Da-Vincis, Einsteins and Hawkings during your travels. Build a think tank full of multiple instances of the greatest minds in history and ask them how to best use your unique time travel opportunity.

• The problem of grabbing people like this what's the point? These people were geniuses for their time but any university student doing a degree studies from their work. You'd have to grab them young, teach them everything you know and hope they can come up with something new and unthought of. Chances are it could be a wasted effort beyond appearing on TV chat shows. – Thorne Oct 26 '18 at 6:21
• There's a reason we teach students rather than encourage them to figure things out for themselves. It takes a very different mental approach to innovate than it does to learn presented information. The innovative approach is a lot rarer. The kidnapped geniuses might have less background in the sciences of your dimension-hopping time-travel equipment, but they should grasp the essentials very easily and be able to come up with good ideas. – Ruadhan Oct 26 '18 at 10:27
• Stealing people worked for Bill & Ted! Maybe you want them for skills other than research. (See “Bill & Ted’s Excellent Adventure”.) – SRM Oct 26 '18 at 12:21
• @Ruadham, the geniuses still needed to learn the most up-to-date information available before they were able to innovate anything. "The essentials" aren't sufficient. – Keith Morrison Nov 1 '18 at 6:57

How much control over -back in time- do you have?

If as fine as you could possibly like do the following:

Stockpile as much oil / iron / Uranium and other valuable resources in a location set to be taken from via time portal.

Once the stockpile is full go back in time 1 minute and start lifting from it. Once empty... Go back in time 1 minute v2 and repeat... etc

The most important part of this is to stockpile enough energy resources to make this loop self powering, dump any waste on the other side of the portal and everything in your stockpile not consumed in making the next is profit.

• OP says energy expensive to break into new timeline. Likely not possible to stockpile enough to make this strategy viable. – SRM Oct 26 '18 at 12:22
• @SRM That is the whole point of stockpiling Uranium or other fuel. The whole process pays for itself in any resource. If it needs a whole nations fuel supply for a decade to just power up, stockpile 2 decades and get going. As you are taking from other dimensions which you can setup to your own requirement, just stockpile to that requirement. – Windlepon Oct 26 '18 at 12:30
• You end up with a lot of spent uranium waste whose only value is acquisition of the same resource resulting in more waste. The gain has to be in something you get alongside the energy resources. ... [hmmmm] but if you could dump your spent fuel into the alternate past, that might make this viable. Ok. I’ll reverse my downvote but please change your answer to note needing to cache MORE than the energy needed to make this viable. (I cannot reverse vote unless answer is edited.) – SRM Oct 26 '18 at 12:40

You can’t rob the future. But if you can swing it, try to rob an Earth already robbed by your future selves. They can leave important research notes for you. It doesn’t help them to help you, but that kind of pay-it-forward-no-wait-I-mean-sideways thinking would benefit them when their own future selves do the same (and so on forward) so everyone benefits (weird proof by induction!). You can pick up the physical leavings not taken by your future selves, but more valuable will be the science... and the winning stock picks/lottery numbers known to your future selves.

You have a pretty bad mathematical collision problem here. If I have an infinite number of parallel universes that all evolve the same way, then there are an infinite number of me that all choose to visit one of these, presumably chosen by cosmic randomness, at the same time, all of us choosing to visit exactly the same time and to plunder exactly the same resources and bring them back.

Off the top of my head I believe the mathematics of that works out, in the infinite limit, as $$\frac{1}{e}=36.79\%$$ chance that I will randomly choose a universe that another "me" also randomly chose. I'm not sure what happens then; but it seems to me both of us appearing in the same place at the same time is not going to be good for our health, or anybody close to us.

With only a 63.21% chance of survival on each trip, I'd probably want to keep the number of trips to a minimum. Like zero!

Alternatively, I would not send myself back, but some sort of robotic AI to accomplish the mission and bring the treasure forward.

As for the best place to visit: I'd research the largest natural gold and precious gem deposits ever found, and pick the easiest to exploit (easiest both physically, and at a time of no resistance to the taking). To me that would be the least morally objectionable; those resources when found are pretty much fantastic luck, and denying somebody fantastic luck is (to me) less objectionable than actively robbing them or harming them or killing them.

• You may like to put a percentage after the first chance statement. Otherwise i dont know if you mean expectation is more than certain and in fact several me appear at the same place. – joojaa Oct 26 '18 at 15:24

Gabon, about 1.7 billion years ago

Uranium 235, the Uranium isotope that is used in nuclear reactors, has a shorter life time than the non-fissile but more common U-238. So in earlier times it's abundance was so high that there were naturally occurring nuclear fission reactors. You could just strip mine the area and fuel nuclear reactors with simple naturally occurring uranium. No need for involved enrichment. For extra safety build the reactors there and transport the energy back one way or another. Also don't worry about the nuclear waste. Just bury it somewhere. Complex life won't show up anyway for another 700 million years or so.

As exposed previously, setup a Rob-myself scenario:

Invest heavily to produce the most valuable object that can be carried (advanced tech, more stored energy that the required to time-travel, etc). Place it within your control, and educate people around that this object is for the time travelers to grab. Keep it here as long as you want to duplicate it.

-After some time (months), travel back 5 seconds, and grab it.

-Return to the same dimensions, but 10 seconds before.

-Keep doing until you reach the timestamp when the object is placed on site for first time.

-Profit: either by taking energy from other dimension or replicating advanced tech.

• OP says energy expensive to break into new timeline. Likely not possible to stockpile enough to make this strategy viable. – SRM Oct 26 '18 at 12:26
• See comments on Windlepon’s answer. – SRM Oct 26 '18 at 12:42

The most valuable thing the alternate dimensions have is living space.

You don't want to import resources, you want to export people.

The best time period to export to would be one with an easily impressed, organised workforce so that your new settlers can move in as a rich upper class rather than having to get their hands dirty themselves.

I would suggest the pre industrial classical period. Say ancient egypt or rome. You can set your settlers up as gods, take over the existing monarchies and use their established power bases to quickly industrialise and uptech your new world.

Phase 2 is large scale modern city building and ramping up colonisation.

With infinite space to work with, the size of your economy is limited only by your birth rate. Your problem is not lack of resources, but physical limitation on the speed you can get people out through the time gateways.

Ideally you would have a kind of conveyor belt of birth, basic training, opening new time portal, take over world, uptech to time portals, repeat.

Of course this assumes that you can only open one time gateway per dimension. If you can open 2, future travel becomes possible and you should use this to get future tech.

The general theme is going to be

Before

For example there was silver in Spain before the Romans mined it, so go back to before the Romans mined it.

All the deposits of anything you might want that have been mined out, just go back to before they were mined. If you want historic artworks, go back to before they were stolen or destroyed. If you want extinct animals, go back to before they were extinct.

• This answer makes an obvious yet important point, but I think other answers do a better job of caveating that point with regard to energy budget and risk-reward trade offs. – SRM Oct 26 '18 at 12:28
• At some point these timelines have to have similarities or they are different worlds. Today we know where resources are. You don't have the expense of exploratory mining or extraction technology development. Go back to pre man and take it all. – Jammin4CO Oct 26 '18 at 14:05

Something I don't feel has really been touched on, but could easily bring in a profit: tourism.

Assuming these devices aren't common or otherwise easy to produce, you have a gateway to the Roman Empire, primordial Earth, Victorian England... all without any risk that whatever mistakes some dumb tourist makes will actually affect your timeline! Even if you could only make one portal to one time, imagine the money that could be made from investors in real estate on a planet where the concept doesn't exist yet! Not to mention the lack of pollution.

I know the question focused on resource harvesting specifically, but I feel this is potentially a more lucrative strategy.

While not directly answering your question about "when" I wanted to provoke some thoughts you might not have considered yet.

We can't really go back in time, literally. Every time we visited the past, we got into a new dimension identical to ours to the point the visitor arrived. Then, it just changes direction chaotically, but nothing really changes on our timeline.

Huge amounts of energy are used to visit this new dimension for the first time, although revisiting it demands a lot less.

Is your "new dimension" something that already existed previously like how Myst linking books work or is this a dimension that is created by the effect of your time traveling?

Consider the ramifications of either. If a new dimension is created by the act of visiting (and revisiting is possible, connecting to the same dimension) then that dimensions timeline continues along with our own after that point.

If the new dimension is "new to us" like I bought a used car that is new to me in that I previously didn't own it but previously existed then that dimensions timeline continues along with our own with the side effect of whatever we do it from there.

If you go back to say yesterday, this new dimension as the exact same technology that we presently do.

In all three cases is there a potential that our own dimension will raided by one of these other dimensions? How do we detect these anomaly and protect our own dimension? By the act of building these defenses, at some point we will attempt to travel to another dimension with these defenses in place. What happens to the travelers then?

With an identical to that point dimension, I guess you don't have to worry about a dimensions technical evolution being faster then our own.

The early 22nd century, shortly after 2100-ish.

They've only just recently discovered time travel, so they don't have any idea how to defend themselves against visitors from the future yet. Their first immediate plan after discovering it was to go back and ransack all of their history for valuable resources. That means that within a few short years -- or less -- they'll have warehouses full of great stuff that's ripe for the looting. And their defenses will be no match for anyone from the 23rd, 24th, etc. centuries. Score!

Take a look at H. Beam Piper's Paratime books.

Nutshell: Some form of the multiverse is real. Under certain circumstances (left vague) the timeline splits. You can't go BACK in time, you can go SIDEWAYS in time. Some of those timelines are 'close' to ours in that they separated recently, and are alternate histories. Some are distant enough that humankind isn't there. Some had nuclear wars.

Piper ignores a bunch of obvious problems -- Conservation of mass is one of them, and multiple copies of a given individual if world splits are common. It's not clear how you create a canonical index of timelines.

Most of the stories concern a Paratime cop, Verkan Val, who deals with the ways that people mis-use their power. (Slave trading, keeping the Paratime secret confined to Val's culture...)

Some of his stories are on LibreVox.

Good adventure stories if you can get past the above flaws.

One solution would be to literally trade with the future. They provide nice technology (in the form of blueprints) in return for the tech they have gotten in their past.

Essentially by cooperating the gains can be immense.