Somewhere out in space, we stumble upon an alien device. It is immediately taken back to base or Earth or wherever and given to scientists to investigate. Reverse engineering the device reveals that it's fairly simple to duplicate, and it can be used to greatly simplify some process (in this specific case, FTL transportation), but the scientists are completely baffled as to how the device is able to do what it does (and in fact, all records indicate that the aliens discovered how to build it by accident). The people in charge of the operation aren't phased by this, however, and immediately begin mass production of the device.

How long, depending on the complexity, is it reasonable to assume that the physics behind such a device could go unexplained? With the whole human population—and specifically, all human entrepreneurs—exposed to fully operational replicas, I can't imagine it would stay this way for long. But what if I made tampering with the device to set up scientific tests difficult (e.g. remove or modify any one piece and it won't start) or dangerous (e.g. add another wire for debugging and turn it on and suddenly your insides are your outsides)? How impossible or fatal (or both) would I have to make it to have the device stay unexplained for 50 years? 100 years? Indefinitely? And how would this affect its use or marketability?

  • 15
    $\begingroup$ I think it depends what you mean by "explained". Humans have used arrows for millennia without understanding how it is that they fly. $\endgroup$ Feb 8, 2015 at 23:59
  • 4
    $\begingroup$ You can look at photosynthesis and how we have been trying for decades to recreate it artificially.dailymail.co.uk/sciencetech/article-2733759/… and commondreams.org/news/2010/04/13/… $\endgroup$
    – tls
    Feb 10, 2015 at 10:22
  • 5
    $\begingroup$ Potentially a very long time. Consider that gravity is not well understood, but we've been observing and using it for all of human history. Its effects are pretty well understood, but its cause isn't. See also (make sure to read the mouse-over text.) $\endgroup$
    – reirab
    Mar 24, 2015 at 9:17
  • 7
    $\begingroup$ Compasses were invented and reproduced for almost 2000 years before we understood Magnetism. If the science it is based on is "sufficiently advanced" then it could take us a very long time, even hundreds of years, to understand it, even though it may be simple enough for us to use and even replicate. $\endgroup$ Jun 29, 2015 at 15:46
  • 3
    $\begingroup$ When they finally discover that it works via blood sacrifice of only the cutest animals, will they stop using it? $\endgroup$
    – IchabodE
    Dec 10, 2015 at 19:34

10 Answers 10


I think it's dependent on how we can go about constructing more of the device.

Anything that we can construct, we can reverse engineer and study the parts of. We can trace how our technology produces an unknown effect, modify how we do that, and learn its parameters. In this case, it wouldn't take long after we start mass producing the device that we can figure out how it works.

On the other hand, what if the alien technology that we found allows us to create more of the alien technology? We start with a device that contains some warped chunk of space. The warped chunk doesn't fit in at all with our understanding of physics, but with some technology that we do understand, we can pump energy into it and create another warped chunk of space. These chunks, when used in a different way, allow us to travel faster than light by warping space around them, effectively letting us set up an Alcubierre drive.

If this were the case, with the alien technology being required for the full manufacturing loop, there isn't a point in the process where we actually know or understand what's going on. It may be that doing so isn't even understandable based on how we as humans experience the universe. For example, what if the chunks are actually 5-dimensional, and mostly interact with a portion of the universe that doesn't intersect ours? We might not understand how they work, because we only see a tiny cross section of where the chunk intersects our reality. In this case, the answer could be once humans transcend the true nature of the universe, which could be thousands of years later, or never.

  • $\begingroup$ Or on simpler terms, someone hands you an extremely sharp knife. The knife was sharpened with a laser. All you know how to do is mould, cast and sharpen metal with non-laser tools. It's impossible for you to get the same kind of knife because you can't know it was sharpened by laser, nor how it functions. $\endgroup$
    – Oak
    Jan 28, 2016 at 8:53

It could be incredibly simple to make and yet completely unfathomable.


We could be given a lens or antenna that focuses energy from a dimension or stream of particles that we haven't discovered and don't have the technology to detect or produce. For example in our own world it's possible to make a working radio antenna out of damp twigs.

The device acts as a transducer and converts the (undetectable to us) rays into a form of energy we know about - heat for example.

What we don't know and can't detect is the nature of the incoming energy. We just know that if we point the antenna in a certain direction, (say a particular star system) it outputs heat (or whatever).

The principle is similar to public-key encryption. Anyone can encrypt a message but only people with the decryption key can decrypt it.


What do you mean by unexplained? This is a serious question. One can pretty much say that the fundamental laws of the universe are those which we cannot explain. Some may later prove to be explicable in terms of more deeply fundamental laws as yet unknown. Others may remain forever inexplicable, bearing much the same relation to physics as axioms do to mathematics.

So far this reductionist approach has resulted in things of technological use being explicable right down to entities so small that just accepting them as given bothers only the physicists trying to find an ultimate theory of everything which may or may not exist. Some hitherto overlooked macroscopic property of matter or energy that does not have an explanation in terms of the underlying entities seems ... unlikely.

The least understood fundamental is gravity. If you have visiting aliens that implies FTL travel which is immediately an inexplicable observation. FTL breaks down into causality-violating and paradox-creating actual motion, and wormholes or jump-drives which suggest strongly that gravity is far more capable of manipulation than we believe.

Speculating further: what they've accidentally left behind is a wormhole-connected interstellar access thingy. We don't understand it because it's the most accessible tip of a huge gravItic-tech pyramid like a mobile phone is the accessible tip of a global network. The bit that does the real work is ... elsewhere. Soon, we're using that tech like swallows use the telephone network. The aliens were using it like arts graduates use mobiles. The types who set their passwords to 1234.

And somewhere out there, a bill will soon become payable.

  • $\begingroup$ +1 for your first para on the nature of explanation, and +1 again for an entire SF story in the last 2 paras! $\endgroup$
    – peterG
    Jan 2, 2016 at 17:10
  • $\begingroup$ That'll be 19.99 (tons of antimatter) :-) Indeed, most people don't understand much of the tech around us, and just trust that it works because it was made by a company with a good name (that manufactures in China). $\endgroup$ Dec 11, 2016 at 12:20

In your universe, you could be talking about some device that exploits as-yet-not-known physical law, or even a device that exploits a flaw in the universe's operating system, so to speak.

In the first case, it would probably be a matter of time before the operation of the device may inspire a line of research that led to a discovery that explains its operation, though whatever time would be up to you as the author.

In the second case, there may not be a reasonable explanation why the device works as it does. In such a case, it may not ever be explained, and researchers could waste a lot of time and resources in futile efforts to understand it.

  • 1
    $\begingroup$ Wouldn't the difference between a quirk of our universe's laws and a "flaw in the Yehova OS" be apparent only from the OS user's perspective, since a flaw is "not working as designed"... $\endgroup$ Feb 8, 2015 at 23:50
  • $\begingroup$ @SerbanTanasa, quite possibly, though not necessarily. If we consider the universe to be like a sort of multi-dimensional cellular automaton, a bug that allows a certain configuration of cells to propagate a change to cells that would not ordinarily be affected (i.e. nonadjacent), that's FTL, and I think we'd notice that if it happened. From within, we could verify its existence but explain it? I'm not so sure. $\endgroup$
    – Monty Wild
    Feb 9, 2015 at 0:01

A misconception can hide the real working principle for millennia.

The sundial was misunderstood for at least 3000 years, if you count from egyptian shadow clocks (1500 BC) to heliocentrism (1543), but it is likely that people have been sticking sticks and stones in the ground for timekeeping purposes much longer (consider Stonehenge), presumably without grasping the mindnumbing thought that the Sun's apparent motion is just apparent and it is the ground that is rotating.

  • 2
    $\begingroup$ Ships worked in the old world on the basis of the fact that wood contains a lot of "air element", therefore it floats. $\endgroup$ Dec 11, 2016 at 12:16

Consider that most of society will not be trying to figure it out. If it is so easy to reproduce, most of society will be busy trying to make money selling them.

Honestly, it could be a very long time. "Any sufficiently advanced technology is indistinguishable from magic," if I may quote Arthur C. Clarke. It would not be unreasonable to compare such a magically complicated device to organics. We've been trying to figure out what the human form can do for centuries with limited success, even though we know how to pop one out with as little as 9 months lead time.


from the example that we know for sure (humanity), the answer for how long could a technology go unexplained physics-wise (rather than a device) is hundreds of thousands of years.

the primary example is fire. cro-magnon, neaderthal, heidelbergensis and even erectus used fire for a long, long, long time. according to the wikipedia article on fire, and i checked a couple of the sources, evidence for cooked meat goes back like 2 million years, and controlled fire is at least as old as cro-magnon (who is, biologically, us).

fire is a technology, and although its use, and even its creation has been known and practiced for a long, long while, the underlying physics, what with the atoms and the frantic motion and the thermal dynamism produced therefrom have only been known for what, a few hundred years. and that's being generous.

so it's possible the underlying physical reality of a technology could go unknown or misunderstood for millions of years. and that's, like, a historical fact.

  • $\begingroup$ You are right that humans and proto-humans did successfully use fire without understanding it for aeons but there are such big differences between the societies then and now that I don't think it is a good parallel. Prehistoric people probably didn't have the concept of technological progress, let alone that of analysing physical phenomena as a means to it. Contrast that to a space-travelling society such as in the OP in which the obvious thing to be done with an unknown object is that it is "given to scientists to investigate" specifically so that it can be duplicated and put to use. $\endgroup$ Dec 11, 2015 at 10:14
  • $\begingroup$ @Lostinfrance I've thought about your comment, and I think it's a fair criticism of the example with one caveat. You've written that '[the technology] "is given to scientists to investigate" specifically so that it can be duplicated and put to use'. However, the questioner mentioned the technology is readily reproducible and easy to use. The fact that the eggheads and the whitecoats can't write a glossy Wikipedia article on how the thing works doesn't affect its popularity, and as such there might not be much incentive, and therefore not too many brilliant minds, studying the thing. $\endgroup$ Dec 11, 2015 at 12:33

Quite a long time.

But, you would have to make it both interdependent on every part (thwarting learning things / reverse engineering by building partial copies / removing portions of full machines, substituting parts/materials), and probably powerfully dangerous. Simple danger to individual humans probably won't cut it. There are plenty of disposable (as well as insane and/or suicidal) people around: criminals, political prisoners, etc. to throw at simply dangerous machines. Things which blow up significant portions of the planet, or make the space-lanes less habitable, will not get blown up as often.

And that's if the alien device is not part of the manufacturing process. I personally think the 'warped space' solution is the best - if you want it to always be a conundrum. If you eventually want someone to solve it, you just need to make it a matter of supreme luck to decipher it, and it can last a damn long time.

But, to be believable, it should use something other than just simple arrangements of masses of atoms, as we can examine those quite well remotely. Something that's small enough that Heisenberg applies, or some other type of force-field / multidimensional access point.

Heisenberg would be interesting, especially if we didn't know how we were manufacturing stuff: an X percentage of the production run wouldn't chance to be correct, and would come off as duds. Which would keep the price of the items way up, since you have to produce a lot of them in order to get one which happens to work. You can't look at it to see if things are in the correct state, you have to put it together blindly, and hope for the best.


It could well be impossible to understand.

Consider the possibility that we are in a Matrix-like computer simulation. This is a well debated philosophical problem and the thing is, we cannot prove that we are not in such a simulated world.

Now, imagine that in the simulation machinery there are some admin-codes hardwired into the system. Maybe they are accessed by drawing certain symbols, arranging certain objects or whatever - and when detected they somehow change the simulation.

Scientist discovering such a code, in the form of a set of simple rings that when electrified opens a gateway to somewhere far away, will be able to reproduce and mass produce the item. The explanation on why and how it works however can literally not be found in our universe.

Now this is just a thought experiment - this applies equally well if our layer of physical access to reality is in some other way separated from a higher physical access to reality, The Matrix is just one example.

The point of this is that it is entirely possible to find a technology we could never understand.


We already have devices like that and we are unable to explain the idea behind them. For instance, we don't know how exactly quantum teleportation works but we have microscopes that exploits it. We have no idea about how quantum entanglement works but we build quantum computers (search D-Wave) that relies on them.


You must log in to answer this question.

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