Every child is afraid of the darkness. For them its not simply the absence of light, its the absence of information. Even if you know that there should be a wall or a doorway right in front of you, how can you be sure without seeing it? What other dangers might lurk there, besides stubbing your toe on a chair, and what was that movement you just saw out of the corner of your eye?
But what if all this wasn't just imagination, What if the darkness itself could take physical shape?

I started exploring this idea, where in a dark space "things" would manifest over time, similar to how fog condenses into dew, except that this dew can move, has some simple instinct-based intelligence and mild hostility towards sources of light an heat. When exposed to light (electromagnetic radiation with wavelengths < 1000 nm) the creatures would quickly disintegrate, but something the size of a wolf - which could materialize during a long cloudy winter night in an open field - would last long enough against a torch or small flashlight to cause some serious harm to the wielder.
To make sure things don't get out of hand, the maximum size of creatures is based on the geometry of the space. A half empty tetrapak of milk would simply spoil faster, a drawer is big enough for a bunch of fruitflies, the space under the bed or in a wardrobe is ideal for bugs or a couple of mice, a cellar with broken lighting could generate something cat- or dog-sized and deep caves can house huge horrors.

I ran into problems with explaining the process behind this natural phenomenon, specifically the conservation of energy. The creatures need to have at least some mass to be dangerous or they could be defeated with a ventilator, but generating mass from nothing is hard. Bonding together surrounding air molecules could work, and with 1 $m^3$ air weighting roughly 1kg, it corresponds well with the creature sizes i listed. But when the creatures are made from highly compressed air, every sunrise would be announced by a devastating wave of explosions, which turns the original design upside down by making light more dangerous than darkness.

Question: By which scienc-y process could the described creatures spawn from dark spaces, while using as little magic and handwaving as possible?

  • $\begingroup$ When exposed to wavelength of light less than 1mm (1000nm) which is heat, every stuff that occupy space emits heat (>0°k) so I think you might wanna use UV instead more credible I think. $\endgroup$
    – user6760
    Commented Sep 26, 2015 at 11:40
  • 1
    $\begingroup$ @user6760 technically everything above 0K radiates some nonzero fraction of visible light, but near-infrared (thats 1 $\mu m$ btw.) should be really scarce without something really hot or bright nearby and would simply slow the creation by a few percent $\endgroup$
    – DenDenDo
    Commented Sep 26, 2015 at 13:51
  • $\begingroup$ What kind of setting are you thinking for them? Similar to modern day Earth, or past times in Earth? $\endgroup$
    – zeta
    Commented Sep 27, 2015 at 7:37

4 Answers 4


The real problem you are facing (if you want to make it science-compatible) is not to create explosion-free dark creatures under the consideration of conservation of energy/mass. The real problem you are facing is how would matter condense into creatures of given shapes and sizes.

As in, can we create dark creatures in a lab under scientific supervision? Can we study their qualities? What force triggers their creation? If these creations are made up of matter, why aren't they produced in light? What about their inner systems (circulatory, nervous, respiratory etc)?

You would notice the more we get into scientific details of mythic creatures, the more uncomfortable it gets. The rule of thumb is, unless you are writing science fiction (which it doesn't appear to me), you have to do a huge amount of hand-waving and nobody would argue back with you about it.

Take for example, the case of Avatar. In this movie, the "soul" of the hero is passed into his avatar by some magic ritual at the end of the movie. Nobody is going to question it, because it simply fits the theme so well.

OK, this was my piece of advice about the introduction of mythic creature in a horror/fantasy based universe. Now back to your basic question.

The process of creation of dark creature involves air and water molecules sticking together. (How you explain it, is your choice). The process occurs very slowly and is endothermic. Similarly, reversal of the process in light also occurs very slowly, but is exothermic. Which means ... when sunlight falls on a large dark creature, its outer body melts away immediately, but the inner body has been condensed so much that it would take lots of time to gradually melt it away. So even if a dark wolf steps in the sunlight, it would not burst with an explosion. Rather, it's mane would immediately evaporate, while it's inner body would appear to slowly sublimate into nothingness (its matter would be dissolving into air alongwith release of energy).

In order to make a dark wolf explode, you would have to place it in a very intense beam of light that pierces it all the way. X-ray machines would probably be their worst nightmares!

  • $\begingroup$ Actually, the event from Avatar you reference is probably more plausible than a whole lot of science fiction. The transfer is basically performed by a huge collective consciousness housed in a planet- spanning computer. Obviously the Na'vi and humans have very similar biology, so a transfer of memories and personality could be done if both neural systems were understood well enough, and some method of interfacing with both were present. $\endgroup$
    – Obie 2.0
    Commented Sep 28, 2015 at 6:02
  • $\begingroup$ The trick is that the planetary biocomputer probably had the necessary knowledge of human neurology from reverse-engineering the avatar connections. To recap: if human and Na'vi neurology is fairly similar, the computer (Eywa) understands both, the computer has a protocol versatile enough to interface with both (something electromagnetic), and the computer can exist, it is scientifically plausible that the computer could transfer consciousness from one organism to the other. Particularly since the Avatar protocol was most likely essentially the same thing. $\endgroup$
    – Obie 2.0
    Commented Sep 28, 2015 at 6:08
  • $\begingroup$ Now compare that to the Force, psychohistory, or time travel. $\endgroup$
    – Obie 2.0
    Commented Sep 28, 2015 at 6:09
  • $\begingroup$ "it is scientifically plausible that the computer could transfer consciousness from one organism to the other". Just explain this statement in the light of known scientific discoveries/experiments. Also notice that the genetic code of the Na'vi is not changed when the soul is transferred. Furthermore, the avatar lays dead and lifeless, but when the soul is transferred to it, he opens his eyes and comes to life. How could you explain that? Also, after the transfer of soul the human body immediately dies. Whats the science in that? $\endgroup$ Commented Sep 28, 2015 at 6:33
  • $\begingroup$ Consciousness is thought by scientists to be merely the result of "programs" running in the brain, a sophisticated biocomputer. If you are asking for a successful experiment doing just that, of course one does not exist. But that is hardly a barrier to plausibility, if the underlying theories are sound. People can simulate brains at a very primitive level on an ordinary computer. There is no compelling reason to believe that, with sufficiently good programming and hardware, the entirety of the brain could not be simulated. $\endgroup$
    – Obie 2.0
    Commented Sep 28, 2015 at 17:36

Well, as scientists have found out, the universe is full of dark matter; indeed there's more than five times as much dark matter than ordinary matter. Now dark matter is called such because we cannot see it, but only see its gravitational effects. It is thought that it consists of particles that don't interact with light, nor with ordinary matter, except through their gravitation.

Well, it turns out scientists are wrong about this last part: Dark matter does interact with light, but not in the same way as ordinary matter. Namely electromagnetic radiation effectively switches off their interaction. So as long as there is sufficiently electromagnetic radiation (such as light), it will behave exactly as describes by physicists. However, in darkness its attractive forces turn back, and its behaviour starts to get very similar to the behaviour of normal matter.

But where does the energy come from? Well, from dark energy! It's everywhere, and we have not the slightest clue what it is, except that there's even more of it than dark matter, and it pushes our universe apart. So let's say that dark matter couples to dark energy in a way that it gains an attractive potential, making it clump similar to how ordinary matter clumps. Now electromagnetic radiation will disturb that process and decouple dark energy and dark matter, giving both the properties the physicists unconditionally ascribe to them. When the electromagnetic radiation vanishes (it gets dark), then the clumping of dark matter sets in.

Now to explain how the condensing dark matter generates life forms, rather than simple clumps/drops of matter (like the condensing fog) needs some more serious pseudoscience (maybe something with morphogenetic fields).


First off, invoke Sanderson's First Law of Magic:

Sanderson’s First Law of Magics: An author’s ability to solve conflict with magic is DIRECTLY PROPORTIONAL to how well the reader understands said magic.

This is key for avoiding writing yourself into a corner in a desperate attempt to over-explain magic.

Personally, I think it would be terrifying if such a creature could play on our fears to make it seem to be more than it actually is. Rather than actually trying to make something which has a mass of a wolf, use people's fear to manipulate them into never actually testing its mass in a scientific sense. If everyone involved believes the creatures of darkness are actually flesh and blood creatures, does it matter if most of it is in their head?

This could play into any number of storylines you would like it to. For example, consider that perhaps a flashlight doesn't actually disperse the fog creatures, but rather makes it easier for us to see what they actually are, and thus be less fearful. This would mean that, if you are truly terrified out of your wits, not even a flashlight will save you.

No humans around? no problem. all you have to do is deal with a light weight creature which is more subject to winds dispersing it. It would have to spend energy to keep its shape in a wind. Interestingly enough, this means that the creatures are more powerful around fearful humans, so would have a completely rational reason to seek them out and scare them more...

Slender Man

... and more, and more.

  • $\begingroup$ Interesting, but in the course of writing this answer you seem to have neglected the OP's actual premise in favor of another one. It doesn't really seem to me like a good answer to the question given. $\endgroup$
    – zeta
    Commented Sep 27, 2015 at 7:39
  • $\begingroup$ @sumelic True, there is some difference. His premise wanted to have the atoms of the air bond together physically. Mine, with proper application of fear, simply sets the stage such that no character in the book can distinguish what is actually happening from atoms of the air bonding together physically, and thus may act on the assumption that the atoms are actually bonding together physically. $\endgroup$
    – Cort Ammon
    Commented Sep 28, 2015 at 17:06


This sounds similar to what you are looking for. Thought Dr. Who does not specify how they evolved.

Rather than say it is a creature made out of darkness, it may be better to just make them creature that evolved naturally. They are absolutely deadly in their shadowy domain, but cannot survive long outside it. They appear to be like a cloud of darkness, but are a hive-minded group of extremely small animals.

As to why they cannot survive in the light, rather than pale like most low-light life forms, these are absolutely black. This way they blend in, making them better predators. But the flip side is that their bodies absorb light too efficiently. When exposed to a certain level of illumination they quickly overheat, eventually self-immolating.


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