First question! I'm excited to see if anyone can help me. Any missteps are unintentional, but feel free to tell me so that I may learn.

So, I've recently started brainstorming over a possible story, and I was wondering if someone might be able to lend me a hand with a bit of worldbuilding. The world where the story takes place is a classic high-fantasy setting. However, there is a sci-fi element to it that is giving me some trouble.

Imagine an alien spaceship that crashes on the high-fantasy planet. Imagine that the people who live on said high-fantasy planet eventually scavenge the spaceship and find out that the alien metal is great for forging magical items of all kinds.

Now, imagine this metal glows a pale blue when pieces of itself are near each other. I could chalk it up to magic and be done with it, but seeing how this is a plot device wrought from sci-fi elements, I would like to have a more or less science-based answer for why the metal reacts to itself.

The way I thought about it, the starship itself doesn't glow when it's in one piece, but after being dismantled, its largest chunk begins glowing and doesn't stop glowing, sort of like a beacon for all its smaller pieces, which in turn glow brighter the closer they get to a larger chunk. Chunks of roughly the same size have a faint glow that is sort of noticeable in the dark. Larger chunks have a greater reach, making smaller chunks glow from many metres or even kilometres away. I'm willing to edit these details to better accommodate your answers.

I've considered some sort of nanotechnology being responsible rather than the glow being a naturally-occurring phenomenon—it's an alien artefact from a spacefaring species, after all. I've also looked into bioluminescence and incandescence and pyrophoric properties, but nothing quite hits the mark. If what I'm asking is at all possible, please do tell!

EDIT1: The sci-fi explanation will be required further down the line for the plot, which is why I'm trying to figure it out. People from the high-fantasy world will consider the metal's glowing to be magical in nature until then.

EDIT2: It doesn't have to be metal! It can be any material that can be turned into the usual items you see in fantasy worlds—weapons, armours, cooking utensils, amulets, light fixtures, clockwork mechanisms, fancy furniture, and the like.

EDIT3: I would rather not have the metal be sentient.

  • 3
    $\begingroup$ Given that the denziens of the planet have magic, why isn't "magic" an acceptable answer? (or a tag, for that matter) $\endgroup$ Commented Aug 18, 2019 at 6:10
  • 6
    $\begingroup$ It is even more difficult than you think: As soon as the first micrometeorite hits the ship, it will separate tiny specks of dust from the main body, and the entire ship will start to glow. So you need not only a mechanism that increases the glow as the ship parts separate, you also need a mechanism that disables the glow if the separated part is irrelevant, for whatever definition of "irrelevant" you need for your plot. $\endgroup$
    – toolforger
    Commented Aug 19, 2019 at 4:03
  • 4
    $\begingroup$ "this metal glows a pale blue when pieces of itself are near each other" Uh... If your metal gives off Cherenkov radiation, I wouldn't recommend gathering it together. The results could be... "energetic" $\endgroup$ Commented Aug 19, 2019 at 10:03
  • 3
    $\begingroup$ Edit #4: that ISN'T radioactive $\endgroup$
    – Mazura
    Commented Aug 19, 2019 at 23:43
  • 2
    $\begingroup$ @SolomonSlow There can be a logic to it. For instance, if you take a bar magnet and cut it lengthwise (north to south or vice versa), the two pieces repel each other now. Basically, some stronger effect can dominate and eliminate the glowing when the pieces of metal are fused together. Think about how we can have a big electric potential between two plates of conductive metal, but if they come into contact, then the conduction makes it impossible to maintain a potential. $\endgroup$
    – Kaz
    Commented Aug 20, 2019 at 18:36

13 Answers 13


A Programmed Feature:

This idea is inspired by Willk's answer, though there have been other good ideas in the thread.

It's a deliberate design choice by the long ago designers of the craft. Meant to help highlight and locate damaged components - the nanites activate a phosphorescent effect whenever chunks of the ship become separated from each other.

This affect is particularly activated via damage or forcible removal. The actual creators had the use-permissions or password to remove components without triggering the location beacon effect.

The glow could even be a side-effect - the main signal is a low radio pulse or particular radiation signature that is easier to track - However the high-fantasy locals don't have the technology to detect or track it, so the glow is all they see.

For power source - the nanites could be accessing solar power, or any inbuilt power sources of the components themselves. Maybe the nanites are set up to harness multiple different sources of energy, but they'll slowly fade away if there's nothing suitable.

  • 5
    $\begingroup$ I'd go even further and say that it's not just about highlighting but repairing itself. Nanites are usually dormant but have a blue glow when active. When two pieces of ship are close but separated, nanites wake up and try to repair themselves. Fight between two people with alien swords would be weird, though, because both their weapons would fuse together when they touch. $\endgroup$
    – Jemox
    Commented Aug 19, 2019 at 12:52
  • 3
    $\begingroup$ @Echox Weapons would only fuse if the nanotech was fast acting. If it worked more slowly, there would certainly be "accepted wisdom" to not let two pieces of starmetal remain in contact too long, unless bonding was the desired end result. in fact, when the pieces do bond together, the glowing would stop, indicating desired bondings are complete. $\endgroup$
    – T.J.L.
    Commented Aug 19, 2019 at 15:53
  • $\begingroup$ The bonding could require a stationary period before it began - or some kind of technological trigger lost to time. Though I do like the idea of accidental metal welding $\endgroup$
    – Chromane
    Commented Aug 20, 2019 at 1:24

See someone has already answered with nuclear decay...

My answer is not actually based on science, so I know my answer will not be popular. This is more based on junk science and sci-fi concepts that we haven't yet mastered or even come close to.

Quantum entanglement/FTL communication is the best I've come up with, and that's more sci-fi than regular science. There also might be a way to sci-fi the principle of magnetism and magnetic fields.

Unfortunately, actual science doesn't have much that works this way. EXCEPT in ways that can't be seen.

What you're looking for is a way that the same element can "activate" its twin. The best example of that, though it isn't visual, is magnetism.

When something is magnetic it creates an invisible field--two magnets will either be repelled or attracted depending on which side of the magnet is up against the other. Here's a handy link on how it actually works.

My point is that your unknown element might work on some of the same principles--that of attraction and that two chunks of it might create something like or akin to a magnetic field. There will be differences, of course, but in this case, the field created is more dramatic and visual. There might be something within the metal that is "drawn to the surface" when another of its type is there nearby.

This means that it's going to be unlike ANYTHING on earth...

My other, sort of left-field theory is: there was an experiment and large amounts of this metal was created and quantum entangled and/or has quantum non-locality. From wikipedia:

Quantum entanglement is a physical phenomenon that occurs when pairs or groups of particles are generated, interact, or share spatial proximity in ways such that the quantum state of each particle cannot be described independently of the state of the others, even when the particles are separated by a large distance

But this means that one molecule of the stuff next to another would ALREADY be glowing.

I would make this metal a component of Faster-than-light communication. Something impossible that we have not yet done. Here are the three ways that wiki says that this could happen:

Proposed mechanisms Tachyons Tachyonic particles are hypothetical particles that travel faster than light. These would allow superluminal communication, and for this reason are widely believed not to exist.[2] By contrast, tachyonic fields - quantum fields with imaginary mass - certainly do exist, and exhibit superluminal group velocity under some circumstances. However, such fields have luminal signal velocity and do not allow superluminal communication.[3]

Quantum nonlocality Quantum mechanics is non-local in the sense that distant systems can be entangled. Entangled states lead to correlations in the results of otherwise random measurements, even when the measurements are made nearly simultaneously and at far distant points. The impossibility of superluminal communication led Einstein, Podolsky, and Rosen to propose that quantum mechanics must be incomplete (see EPR paradox).

However, it is now well understood that quantum entanglement does not allow any influence or information to propagate superluminally. Technically, the microscopic causality postulate of axiomatic quantum field theory implies the impossibility of superluminal communication using any phenomena whose behavior can be described by orthodox quantum field theory.[4] A special case of this is the no-communication theorem, which prevents communication using the quantum entanglement of a composite system shared between two spacelike-separated observers. Some authors have argued that using the no-communication theorem to deduce the impossibility of superluminal communication is circular, since the no-communication theorem assumes that the system is composite.[5]

Wormholes If wormholes are possible, then ordinary subluminal methods of communication could be sent through them to achieve superluminal transmission speeds. Considering the immense energy that current theories suggest would be required to open a wormhole large enough to pass spacecraft through, it may be that only atomic-scale wormholes would be practical to build, limiting their use solely to information transmission. Some hypotheses of wormhole formation would prevent them from ever becoming "timeholes", allowing superluminal communication without the additional complication of allowing communication with the past.

So basically, as a result of "active tachyons" or smaller than microscopic wormholes or whatever, whenever non-physically linked chunks of the stuff get close to each other, they "communicate." I would think that they glow all the time, but that they glow more when they near each other, which is something that perhaps might have been used as part of the communication system somehow.

  • $\begingroup$ Oh, I actually like this quite a bit! I've always been a fan of speculative science in fiction. Thank you for your answer to my question. $\endgroup$
    – menecio
    Commented Aug 19, 2019 at 1:18


Short answer, the metal/alloy produces a high frequency low current EM field, and the voltage increases with more in proximity. The oxide layer produced by exposure to the atmosphere acts as an inorganic electroluminescent phosphor. The metal would be able to make other electroluminescent items glow as well.

Long answer...

Electroluminescence works when electrons move between energy bands, gaining energy by electricity, losing it by emitting photons. The material properties determine the wavelength of the photon and its color. Typical inorganic metal phosphors are made of zinc sulfide and doped with something such as copper or silver, giving it a green (copper doping) or blue (silver doping) glow (like a Timex watch Indiglo backlight)

enter image description here

The electricity generally comes from an AC source, or from a DC to AC converter, but can also be provided by EM fields in proximity, take a fluorescent lightbulb underneath an electrical pylon for a good example. In this case, we can generate an electrical field by the metal interacting with the EM field of the planet.

The metal alloy is designed to do this, it is part of the deflector system for FTL travel, a super high strength EM field aboard the ship generates an electrical field on the hull, deflecting ionized particles before they impact. In space there is no oxygen, and the outside of the ship does not glow, but the inside does, providing a light source for the crew by having all exposed and oxidized metal glow, with the specific alloy composition providing the desired color (blue-green is easy to see in the dark).

I believe this is the least "handwavy" answer, as the concepts are rooted in real science that is used right now in consumer applications, and it does not involve harmful ionizing radiation. The downside is that it MUST produce electroluminescence in other items containing a similar phosphor, probably more so that the metal itself.

That is because the voltages energies involved in space would be very high, and the glow will be blindingly bright if the oxide phosphor was very efficient, whereas efficient phosphors like zinc sulfide require almost no energy to glow, but high voltage. Since you are only dealing with small metal pieces like amulets, they would not glow by themselves, but could make normal phosphors glow in proximity. When you have a lot of metal gathered, the metal glows, and other phosphors will glow brightly, even at a distance of several feet.

Possible additional property, the metal fragments would glow by themselves during geomagnetic storms and solar flares, like the Aurora Borealis, or in the presence of high strength artificial EM fields.

Image of watch By Andrew J.Kurbiko - Own work, CC BY-SA 4.0

  • 2
    $\begingroup$ Non-organic, non-handwaved, non-unobtainium, and not radioactive +1. $\endgroup$
    – Mazura
    Commented Aug 19, 2019 at 23:45

It is alive. The pieces are calling to each other.

its largest chunk begins glowing and doesn't stop glowing, sort of like a beacon for all its smaller pieces, which in turn glow brighter the closer they get to a larger chunk.

These things want to be together. They are distressed to be apart. They are glowing because they are calling to each other. The big one is like a chicken calling to its chicks - it has the loudest call. The chicks want to be together too but what they really want is to get back to the chicken.

Maybe in their native habitat these things have a way to act on the glow and move closer together. Or maybe they will move, under the right circumstance. They must be capable of perception if a glow can be a beacon. The glow might include radiation wavelengths not visible to humans.

  • $\begingroup$ I'd rather not have the alien matter be sentient. The closest I'm willing to go to giving it the capacity for thought is by having it be imbued with preprogrammed nanotechnology that handles how it responds to outside stimuli. $\endgroup$
    – menecio
    Commented Aug 19, 2019 at 1:25
  • $\begingroup$ Not a scifi answer but a fantasy answer. $\endgroup$
    – Willk
    Commented Aug 19, 2019 at 1:44
  • 2
    $\begingroup$ @menecio the answer doesn't imply sentience, various microbes and algae will "seek" each other out to form colonies where the group is more efficient than the sum of the individuals. The material can be alive but tough, a bio-metal, if you will. Otherwise, you can have a metal that attracts microbes that behave in this way, and simply cover the metal pieces exposed surface. $\endgroup$ Commented Aug 19, 2019 at 13:25
  • 1
    $\begingroup$ @Nahshonpaz That's an interesting point you're making. Some microorganisms are known to survive the vacuum of space, too... This could work, thank you! $\endgroup$
    – menecio
    Commented Aug 19, 2019 at 18:34

My answer is based on a previous answer which is about radiation. In my opinion that's exactly what you need. I thougth of Tritium which is usually used in watches to power the flourescent glow of the device. The problem is Tritium does not glow, it needs additional fluorescent material to do it, nor is it a metal. So I come up with two ideas:

  1. Should your alien matter be metal at all? Maybe a polymer compound could also be good, and since tritium is an isotope of hydrogen it could easily be attached to any organic molecule. And there are also organic glowing compounds, so a combination of the two is more than likely to be possible.

  2. Europium is a type of glowing metal, but it is not very metal-like, it

    can be dented with a finger nail and easily cut with a knife

    Moreover it rapidly oxidizes in air, so I would recommend your metal to be an europium-based alloy with some other metal that could prevent the oxidization (possibly chromium - I do not know whether its viable or not to alloy it with chrome, but a spacefaring race might figure out how to do it). And the magic would be to have hydrogen, or in our case tritium, diffused into the alloy. Hydrogen in metal alloys is not uncommon, read more about it here. This would introduce radiation, so fuel for the glowing, and would make the alloy harder (that is what hydrogen usually does with steel, also makes it brittle though). Assuming this sentence from the answer of Cort Ammon:

    Now its also known that many radioactive materials emit more radiation when brought into larger masses (I think all such materials do, but I'm not positive).

    (which I also cannot prove nor disprove) we have a radiating, glowing metal alloy with the needed characteristics.

You might feel there are loads of ifs and maybes here, but in my opinion these two could be acceptable solutions to your problem. These would work of course only at night, because of the small amount of emitted light.

Oh and the spaceship should not glow - I recommend it to be painted. (Sometimes the easier solution is the better.)

  • $\begingroup$ Europium compounds fluoresce when illuminated by ultraviolet light, but I'm not seeing anything about it spontaneously glowing. $\endgroup$
    – Mark
    Commented Aug 19, 2019 at 1:10
  • $\begingroup$ Ideally, the alien matter would be something that can be used to make swords and such by the denizens of the planet. It being metal is not a requirement. Thank you for your contribution to my question! $\endgroup$
    – menecio
    Commented Aug 19, 2019 at 1:22
  • 1
    $\begingroup$ @Mark Europium is a common component in glow paint, combined with strontium aluminate to absorb radiation and emit it at a slower rate, including UV light, also it tends to glow white or green, rather than the blue desired here, which you get from silver doped zinc sulfide. Tritium would be a poor choice here, due to chemical properties and short life, a better option would be Nickel-63, which decays to copper $\endgroup$ Commented Aug 21, 2019 at 1:20

This sounds like Newtonian gravity, but restricted to this metal ‐ and not all the matter in the universe‐ and with glowing replacing acceleration.

...doesn't glow when it's in one piece

Just like one piece of matter doesn't accelerates itself.

..its smaller pieces, which in turn glow brighter the closer they get to a larger chunk.

Just like force is inversely proportional to distance...

Larger chunks have a greater reach.

...and directly proportional to mass.

  • $\begingroup$ Well that's clever. $\endgroup$ Commented Aug 20, 2019 at 17:57

Just an idea for you to build off, or anyone else with more science knowledge. - A play off magnetic material - as magnets do seem to call to each other, but not visibly.

But suppose you have a special alien space alloy, this alloy is composed with a super rare-earth magnet type material. The stronger this special magnetic field the more the components glow. Dust sized particles don't have any glow-magnetic property as their mass is insufficient to cause the glow-magnet field.

Particles need to be within some exponential/logarithmic range (depending on which way you're calculating) of other particles to glow. For a "large" particle to glow there must be other particles within a certain size category and proximity to create the glow-magnetic field. Likewise for "small" particles to glow, they must be in range of particles sufficiently large or close to glow.

When fused together, there is no glow because the field is self contained. So then your spaceship might glow while whole if "near" other space ships of similar design and size or within a greater distance but still sufficiently near a "mother-ship". Opposing alloys (enemy vessels) would glow a different color when brought within certain proximity to friendly vessels. (Red fleet versus blue fleet.) But when a scout vessel is lost in space, and crash lands on a remote planet, it is outside the "glow-field" of it's allies (and hopefully its enemies). So until it breaks apart it doesn't glow. Once broken apart it creates its own "glow-field" .

So if the ship broke up in atmosphere, then the largest chunk would be sufficiently large to create a glow field that covers "x" portion of the planet. Other large chunks glow because they are in sufficient proximity to the "Alpha" chunk. Smaller chunks may glow because of the proximity to "Beta" chunks. The intensity of the glow would be based on the proximity of the "larger" chunk and the size (or relative size) of the larger chunk. Though, also possible that a chunk of one ounce may respond to a chunk that's one pound, but not to a chunk that's ten thousand tons due to the field of that larger being overwhelming. (For this the glow feature must be a mutual energy field and if the size variance is too great there isn't sufficient energy received from the smaller particle to facilitate glow - or that it's in the great field of the "Alpha" particle - akin to compasses being pulled to a rod of iron when within a few inches, but despite the mass deferential not being impacted beyond a certain range because the earth's iron core mass and relative proximity overrides the local mass at its relative proximity)

For forging into weapons and armor, you make the alloy one that is pliable under heat at regular forging temperatures and pressure (so heat and strike, but heat alone is insufficient cause then re-entry would be problematic ....but you could have special drop ships that were intended for re-entry and these stellar ships were never meant to be in the atmosphere...)

But the alloy itself remains intact despite pliability unless some other criteria is met (higher heat, an electric arc while forging, etc or even a special "un-quenching" process that unlocks the alloy's particles). Thus, the pliable alloy can mold to other metals like steel or gold, but not actually bond with it, thereby fully retaining its specially properties.


Have a look at Metamaterials

Metamaterials are manufactured materials that have properties that natural materials do not have.

Research into Metamaterials has been continuing for some time, and there are discussions that these materials would become more and more common in the near future as they approach viability, with some already in use today.

They are actually combinations of materials, incorporating anything that may be needed for its usefulness and usually based on modular / repeatable elements.

The basic premise in regards to your question is to create a Metamaterial that:

  • detects proximity to other materials
  • retains a form of electrical charge
  • illuminates given certain conditions

It is easily conceivable that a space-faring race would have advanced technology in terms of materials too.

  • 8
    $\begingroup$ Without a specific example, you're simply saying "use unobtanium" in different words. $\endgroup$
    – Mark
    Commented Aug 19, 2019 at 1:11
  • 1
    $\begingroup$ This is useful (thanks for reminding me metamaterials exist) but very broad. I'm not sure how it can help me with my scientific explanation regarding WHY the metal glows, but I'll have a look around. Thank you! $\endgroup$
    – menecio
    Commented Aug 19, 2019 at 1:29
  • 2
    $\begingroup$ This is actually what I was thinking when I saw your Q, have sheets or loops inside the structure that form a closed circuit. When you crack those circuits the material emits light. Maybe make the circuits ductile en-masse but crack the loops on brittle fracture. You could do things like pinch off a portion without activating the light then. As for the configuration of matter and exactly what's in it... That's probably best to hand-wave. While you can always do code->circuit-diagram->structural-analog for a poor-man's meta-material that's an awful lot of work for something barely passable. $\endgroup$
    – Black
    Commented Aug 19, 2019 at 19:31

I don't think there is a true science answer for this. Materials don't behave this way.

If this were in a large field, perhaps separated pieces would behave differently than the pieces merged. Consider metal in a microwave oven. Small pieces will spark and melt because the currents are too high. A large piece, like a metal bowl, will be fine with no sparking.

But, there is no such field that permeates our space.

You could imagine that the ship is built out of billions of independently knowledgable components and that the "glow" is tiny thrusters on each component trying to place it back in the "ship" configuration. The material would be tough to use for other purposes if whenever you forge it into something useful, it turns back into hull plating when you aren't looking.


You can build an effect like this by invoking a sort of augmented magnetism.

Suppose there is some force that pulls on some particles in the material, and pushes on other particles in the materials so that the net effect is that there is not overall force between the two bulks of material, but microscopically, you are getting motion of the molecules.

Now suppose when a molecule moves fast enough, it spontaneously emits some light and then switches from the type of molecule that is repelled to the type that is attracted, and visa versa, keeping the total number of repelled and attracted particles in balance. This whole processes will end with an equilibrium where all the molecules are moving slowly enough in the material so that no light is emitted (which is why you can have one bulk of the material that doesn't glow). However, you can choose how long it takes to reach that equilibrium without breaking the scientific plausibility of the scheme.

If larger chunks are brought together, then there is more force on the particles and thus more light is emitted. Again, you can choose to say it takes 100 years for the material to come to equilibrium, so the glowing can be constant (and breaking a chunk of material off of a bigger chunk will cause the two to glow for a long time). Or you can say it only takes a few seconds so that you have to be moving the chunks around in order to get the glowing effect.

Basically, this scheme is general enough that you can get almost any behavior. The fundamental idea is that you need to have forces on the particles that cancel out, because otherwise the chunks will be forced together. And you need to have some sort of decay that is tied to the strength of the forces between particles in order to create light that grows stronger when the chunks are brought together.

Two more points:

  1. The reason I said let the particles change from the repelled to the attracted type is only so that the material can be "pure", i.e. made of the same molecule that sometimes attracts itself and sometimes repels itself.

  2. In order to conserve energy, you should have the material slowly waste away. The rate this occurs can be so slow that you almost never see it in practice. There are some technical details about energy conservation that an astute observer might have a problem with, but those could be explained with some more leg-work.


What you have here, is a metal with an unstable outer shell of electrons. At the slightest provocation, an electron may jump to a higher orbit, quickly lose energy, and return to its normal orbit.

These fluctuations cause the metal to emit a field, and the effect compounds: The more metal you have, the wider the field around it.

If another piece of this same metal enters that field, it can cause all the electrons in the outer shell to fluctuate at once, emitting photons of visible light, causing it to glow.

The reason that a single large piece of metal doesn't react with itself is due to polarization. When the metal is melted down and reformed, all the atoms align in a mesh, causing the additive field effect.

The bits of metal can even find each other, a bit like a magnet. If you have one, and it begins glowing, you can turn it in all directions until the glow dissipates. This tells you that the two pieces of metal are polarized and therefore lined up.

Last but not least, it is possible for other forms of radiation to cause the sword to glow. Magical objects, or even inherently magical creatures may give off some sort of field causing this metal to glow, though there may be differences in the glow itself, or the shape of the metal may contribute to its reception.


The material 1) needs to either contain a huge amount of energy or somehow continuously harvest energy to glow, and 2) needs to radiate and be sensitive to the same radiation to sense nearby pieces.

My idea is that the material harvests vacuum energy and turns it into microwaves. Further, if the material is externally irradiated with microwaves it produces visible light.

Call it, say, a "(meta)material that taps the Dirac sea using Casimir oscillators and is photoluminescent".

When the ship was whole, the structure of the ship acted as waveguides for the microwaves, funneling them to a surface at the rear of the ship that was irradiated and thus glowed intensely, producing photon thrust. Small structure changes could change which surface on the ship produces thrust for steering and control. When the ship broke apart the radiation no longer had a waveguide and would simply cause any nearby pieces to glow.

Now, if I actually understood the theory behind the casimir effect or microwave engineering I could probably immediately point out flaws in this, but hey, that's what the comments are for.


Kinda coming off other ideas, here. What if, the material constantly outputs a high frequency wave, i.e ultra violet, And that the metal will glow when subjected to the right frequency (materials that do one or the other exist IRL.) Then, when brought near eachother, the air filtering them slightly changes the frequency, and when at the right distance, will be good enough for them to glow? If too far away, it would only glow dimly, but the same would happen if too close.


You must log in to answer this question.

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