Imagine a world as we know it. People go about their daily business, working to earn money to spend to be happier. Politicians lying about the same things to get votes to get more power. Wars happening for the same reasons and un-reasons. Only with a slight difference:

Each and every man-made mirror works as a viewpoint and portal into a parallel world.

Scientists hypothesize the mirroring having happened due to the LHC going haywire and blowing up on the day of its inauguration-run in September 2008. This event likely having created a strong-link to an alternate timeline and thus bound the two earths1 together, somewhat, physically.

Thus you can imagine it as a tandem of two earths inhabiting physically the same space but then not because space-magic. These earths being inhabited by clones2 of the people and animals and everything on earth up to the specified date.

These mirrors allow people the following things:

  • see the other earth
  • hear sounds from the other earth
  • communicate with people from the other earth
  • pass things through to the other earth

..alas they do not allow:

The mirrors themselves are limited to locations where mirrors have been put on both earths. Though as the parallel earth only has been created relatively recently, the infrastructure development on both worlds are about 99.99% similar to each other.

mirror-linking: The linking between mirrors is based on their absolute position on their relative earth. Thus and in addition the following laws apply:

  • a mirror placed on earth at (100, 10, 10) will only be linked to a mirror placed on htrae at (100, 10, 10)
  • the linked surface of the mirrors will only be the area that overlaps on both mirrors
  • only mirrors that are positioned back-to-back will actually form portals

- Place a mirror A with the dimensions of 10m length x 2m height facing east on earth at the center of the Alexanderplatz
- Place another mirror B with the dimensions of 2m length x 4m height facing west on htrae at the center of their Alexanderplatz3

We now have created a portal on AlexanderplatZ with the dimensions of 2m length x 2m height.
On earth people will see the eastern part of the place
On htrae elpoep will see the western part of the place

Question: What would be the ramifications of such mirrors on the economy of these earths?

1call them Earth and htraE if you feel like it (or maybe Earth and !Earth, which is somewhat easier to read) 2I definitely prefer the term: mirrorlings; but who am I to tell you? 3respectively Ztalprednaxela

  • 1
    $\begingroup$ how many worlds are their (infinity and many are very different) because with infinitely many worlds you can start with 1 item in each world and use a never ending pyramid scheme to get plenty. $\endgroup$ May 19, 2016 at 21:06
  • 1
    $\begingroup$ And then if you move houses and put the same mirror in your new room, it would be bound to the mirror on htraE in that location, if there is one, and not the previous one? Gotcha. $\endgroup$ May 19, 2016 at 21:40
  • 1
    $\begingroup$ @Jonathan there would be clones of people up to the day of the inauguration run in 2008. I'll add it $\endgroup$
    – dot_Sp0T
    May 19, 2016 at 21:47
  • 7
    $\begingroup$ Everyone will have terrible hair $\endgroup$ May 19, 2016 at 22:32
  • 2
    $\begingroup$ @dot_Sp0T What physical forces travel through mirrors? Gravity? Magmatism? If gravity they all the people on both earth will suffer under 2 earth gravities of gravity, if not I Know a way to make an infinite energy machine which is worth infinite $. $\endgroup$ May 19, 2016 at 22:35

8 Answers 8


I can think of several interesting possibilities from this new phenomenon. Now, keeping in mind, this is somewhat of a 'what if' question leaning towards idea generation, but still, I think it's an interesting question.

After the initial shock of this change wears off, people will be looking for ways to exploit or utilize this new dimension. The first thing that comes to mind would be the possibility of linking the respective internet equivalent from both worlds. Depending on how similar the programming language and computer science tech trees are in the parallel world, it could take anywhere from a few weeks to a few years to develop a way for our internet to interface with theirs, effectively doubling the size of the internet.

After the internet infrastructures are connected, I can imagine that trade and the stock markets of the respective dimensions would also be linked up after a short amount of time, this could have a huge impact on the world economy, for better or worse, although I would be inclined to think the change would be for the better. Stocks, and trading in actual physical goods across a mirror dimension may be cheaper than trading to a place that is geographically distant but has a larger profit margin, because the transportation costs of trade over a mirror dimension would be much cheaper.

The next big change would be that companies could set up facilities which use mirrors to have production on one side of a mirror with storage and transportation on the other. This wouldn't happen overnight, as it would require communication, trust and a common currency between dimensions, but this would be one of the long term opportunities for collaboration. I can imagine this and other similar space saving setups being the biggest overall impact from the event once the dust settles.

Another possibility would be for drug cartels and other unsavory types to buy trade and sell drugs and illegal weapons across dimensional barriers where the jurisdiction and active laws may be different. Selling legal over the counter drugs to people in another dimension where their state laws prohibit that kind of sale, probably wouldn't be punishable by your own state/country's laws, as you didn't break any, and their law enforcement cannot reach you. Over time these loopholes would be fixed, but for a while, there would be a lot of money to be made exploiting these differences in legal structure. Gun laws, drug laws, restrictions on over the counter pharmaceuticals, just about any controlled substance or object could be traded with an enormous possibility for profit at a lower risk and expense.


We generate infinite energy.

Gravity does not pass through the mirrors but mass can move through them.

This lets us temporarily violate conservation of mass which lets us build an infinite energy machine. This is simplest and most efficient in space were we don't need to worry about friction or other gravities as much.

We have a movable mass m near a very large empty container with a mirror with a lid on it. We a large reservoir of water or mercury on ~Earth on the other side of the mirror.

We open the mirror and water flows into earths container, then we shut the lid. The gravity of the new mass pulls m forward/Down to the mass's gravity. As the mass falls inward it pulls a turbine and produces energy.

We will have the mirror on the same side of the container as m. So once m reaches the container its gravity will pull the liquid against the closed lid. Once m reaches the edge of the container, we open the mirror to let the water return to ~earth, and we shut the lid.

We then reset the system by pulling m back to its starting point which now takes less energy then it produced falling in since the container no longer contains all of the mass of liquid.

There are other variants but we can generate infinite energy which will have many implications including economic as energy production industries crash. Energy will be abundant and cheep, space travel becomes feasible on a large scale. There will be a growing need for new ways to store and move energy

  • $\begingroup$ I believe gravity is too weak for this method to have a positive energy bilance, let alone to be profitable from an economic standpoint. It could work with magnetism as you also suggested. $\endgroup$
    – emu
    May 20, 2016 at 8:40
  • $\begingroup$ @emu electro-magmatism is a stronger force at these distance scales and would be a better choice. It alos would work on earth where the gravity one sort of has to be in space to avoid the costs of friction and other gravity wells. It is just harder to explain but they both work. $\endgroup$ May 20, 2016 at 15:58
  • 1
    $\begingroup$ Could you explain this process with help of some diagram(s)? $\endgroup$
    – dot_Sp0T
    Oct 6, 2016 at 10:51

"What would happen to the economy" is one of those weird questions that is both incredibly broad and too narrow to work with at the same time. This is because the economy is tied so closely to everything else. That said, here are some of the quick and "easy" answers. TLDR, not a whole lot changes.

The mirror business increases. Kind of a cheap answer, but it would happen. Mirrors can open doors to another world, but only if they happen to be in the same place. There would be a (temporary) uptick in mirror purchases as people try to make portals.

Drugs and other restricted substances become legal. Or at least they become as legal as they are on the version of Earth where they are most legal. Otherwise it would become an effectively unenforceable crime. Suppose heroin is legal on ~Earth, but not on Earth. It would be really easy to get your fix through your mirror. The governments of Earth would therefore want to legalize it so that they could get the taxes from it.

Stores are able to help each other. Imagine something like a Walgreens, only it never has to worry about running out of things, because they can just ask for extra from the other side of the mirror. This is great for smaller stores, assuming that they're a similar store to their mirrored store.

Tech companies have a field day. While everything is the same up until 2008, that's eight years of technological development that took two similar but different paths. Not tons of time to diverge significantly, but there'll be some successful ideas on each world that never made it on the other. Maybe ~Earth's initial version of Uber failed because they started it in a different city where it didn't get as big of a market share as it did on Earth. There won't be tons of new information, but any little bit will be grabbed and expanded upon. HOWEVER, they now effectively have double the number of workers. Apple wouldn't have two teams both independently developing the iPhone 7, they'd have one team work on developing it and one team work on something new.

Cross-world production. In a similar vein to the last sentence above, why have factories in two worlds producing iPhones when you could do it with one? Particularly the larger corporations would divide the work so that Earth produces one set of products and ~Earth produces another set. Depending on what happens, this could lead to spikes in unemployment, but the savings from reduced production would probably free up money to simply move people to different types of jobs (e.g., a car company would re-train people who no longer make Car A to be able to help with the new increased production requirements for Car B).

There honestly won't likely be too much trade outside of that type of production swapping. There hasn't been enough time for one world to get too different from the other, meaning that neither one will really have anything that the other doesn't. Both worlds will have the same reliance on gasoline; both worlds will find it very expensive to get rockets to space; etc etc.

But let's stop and think for a minute. The large corporations are going to be able to take advantage of this in a way that smaller companies won't be able to. Apple can shift around hundreds or thousands of workers to grow even bigger than they already are, while a small company wouldn't be able to do that on nearly as large of a scale. So ultimately I feel that this would slowly lead to the world being controlled by mega-corporations even more than it already is.


A functioning economy is, in its simplest terms, a network of trade among people for things of value.* "Things of value" can be broken into two major classes: goods and services. In your universe we can really only transfer goods between worlds, and not so much services (though that's not 100% true; I'll address that momentarily). Unfortunately, I don't see that happening at all.

Transfer of Goods

We probably need to examine specifically how the mirrors function because that might change things, but your description leads me to believe that a person cannot physically cross the boundary between worlds (maybe like a selective forcefield that only allows inanimate objects but a person would just feel glass?). As a result of this limitation, there is no way a person can guarantee the people on the other side will follow through with their side of the bargain. For example, let's say MozerShmozer A and MozerShmozer B (henceforth A and B) meet at a mirror and agree to trade. A says he will throw a bar of Gold through the mirror if B throws an equivalent amount of Silver. So A throws his Gold. B is smart, and does not throw his Silver. Now B can walk away with the Gold and Silver at no risk to his own person because A can't actually get to him. If both parties were desperate, they might both arrive with a gun, or a grenade, or a nuclear device, which would force the other party to act in good faith, but this could easily result in disaster. The amount of risk involved, both physically and financially, would prevent most people from even seeking the bargain in the first place, much like modern banks will not lend money to a person if they have a poor credit score.

Possible Transfer of Services

Technically, intellectual property is also transferrable through the mirrors. This could be done simply with sound (spoken voice, or something like a dial-up modem) or if light passes through the mirrors then maybe even other electromagnetic waves can make the trip and wifi can be propagated through the mirrors allowing for wirelessly interconnected computers. Internet A and Internet B will have to overcome IP address conflicts, but after this is accomplished people can communicate and transfer ideas between the worlds as easily as we do now. Unfortunately, payment will be difficult to enforce. Small wire transfers might occur, and cryptocurrencies could also function, but with no physical financial transactions upon which to base these online transfers, most banks and other financial institutions likely will not support them.

All told, I feel like the economies of the two mirror worlds will be affected only in small amounts. Most financial institutions will avoid major transactions of wealth between the worlds because the risks involved, and intellectual property is already a fragile commodity.

*Note: all financial transactions, even of electronic and fiat monies, are conducted in good faith. Some level of guarantee is expected, and transactions are enforced by laws which are themselves enforced by the threat of financial penalty or physical violence.

  • 1
    $\begingroup$ What you describe in the Transfer of Goods is a simplified version of the Prisoner's Dilemma, a game theory problem which, in real life, is basically a solved problem. In real life, social effects (which we can capture in drama theory) solve this issue. MozerShmozer B knows that there's more in this transaction than just gold and silver. THere's also a reputation. B can certainly get a free gold bar, but the expense is that he quickly finds nobody will ever trade with him ever again. Thus, it is in his best interests to conform. $\endgroup$
    – Cort Ammon
    May 21, 2016 at 22:40
  • 1
    $\begingroup$ Will cheating happen? Absolutely. However, it will be mitigated by societal factors until the risks are offset by rewards. $\endgroup$
    – Cort Ammon
    May 21, 2016 at 22:40

Changes to transport, manufactures, research, technology - pah, no big deal. Even the prospect of unlimited energy as described by sdrawkcabdear is an idea we are familiar with; its effects are just the effects of cheap energy writ large, and compared to our ancestors we already have nearly unlimited energy.

No the big change is that nearly every person who had reached the age of self- awareness in 2008 now has another self. (There will be some exceptions due to deaths since then.) The psychological shock will be huge. The effects are so big that it is hard to restrict them to "the economy", but here are a few ideas that came to mind:

  • Trusted intermediaries. MozerShmozer's answer suggested that trade would be held back by difficulties in ensuring people on the other side will fulfil contracts. Actually, I think this idea is mistaken, since trade occurs worldwide now between people who have no practical means of enforcement. They just rely on the rule of law and the long-known commercial advantage of having a reputation for honest dealing. But even if that were not so, there is definitely someone on Htrae that I have very good reason to trust: mirror-me. So if I want to make a deal with Company X on the other side, I go through my counterpart, Ecnarfnitsol, who is subject to all the laws of that world.

  • Confidant(e)s / therapists They say that talking to yourself is the first sign of madness. Maybe really being able to do it would be the first sign of sanity. A general increase in mental health would surely have economic benefits. Those widowed or otherwise bereaved would be able to talk to someone very like those they had lost. Their grief would be assuaged by the dead person simply not being dead in the mirror world. Or maybe the above is 100% wrong. Maybe knowing that your dead loved one was still alive on the other side of the mirror, and that you yourself were not unique, that there was a rival "you" who had made different and possibly better decisions for the last few years, would be an agony that would drive half the world mad. That would definitely have economic effects.

  • Backup people. When someone with rare creative skills or talents like Steve Jobs dies in one universe, they may well be still alive in the other. I'm not assuming that the Htrae version would be drafted or anything like that, but surely Apple and Elppa could come to some sort of deal. Which leads me to the next economic sector for which this situation would be a bonanza…

  • Lawyers.


Mirror market crash

The market for small to medium-sized mirrors would take a swandive. Yes, there's this brand new use, but this rather ruins the original use. And do you really want what is essentially a window in your bathroom or bedroom? Existing mirrors would be removed and sold.

The market for large mirrors might see a rush, but it's unclear how long that would last.

Laws would equalize

There would be pressure on both sides for laws to either become laxer or tighter to match the other side. Drugs, guns, porn, etc. would all be easy to smuggle in this system.

There's also a problem with crimes committed across mirrors. How do you prosecute someone who commits a crime from the other side of a mirror? It seems likely that the two sides will agree to prosecute such crimes for each other. Otherwise it would encourage criminals to switch to cross-mirror crimes.


One thing to consider is how are mirrors linked? Are they linked in space, such that if a mirror exists in one location on Earth and the same exact location on the mirror Earth, that's a portal, or is it more complex than that. Once two mirrors have been 'linked', is it possible to move one of the mirrors while the other stays in the same place?

If so, then transporting goods becomes ridiculously easy. Simply have a terminal in each city/town with mirrors linked to other terminals. It would also make putting stuff in space extremely cheap, the only thing you'd need to move manually would be astronauts.


It depends. If the two worlds are same, the changes would not be big. The main thing is a possibility to teleport things.

The cheapest way would be to transfer goods from world 1 to 2 via mirror, and then the same in return, the same goods from world 2 to world 1 (that originated from world 2). Doing that, you use only 2 mirror transportations. To transfer back to the same world, you will need 2 transportations for one package and 4 for 2 packages from both worlds.

Further, worlds could "fuse" according to the routes - for example, for a person who lives in world 1, it would be easier to get to world 2 to work or some travel through the mirror. These routes could become very complicated, as people would use more mirror traveling and less common traveling.

However, some things would be dangerous - for example, criminals from any world (1) can teleport to the defined spot in world 2, commit a crime and quickly retreat. Not mentioning, that one world could nuke another one in an instant.

But it depends on how exactly the mirrors are working. Also, I think there would not be much gain with gravitational energy. Just think how big the mirror must be to have the power of a hydroelectric power station?

  • $\begingroup$ In the question it was specified that people cannot travel through a mirror. Otherwise it's not a bad answer. $\endgroup$
    – Jonathan
    May 22, 2016 at 1:34

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .