How would an entity automatically know when someone is directly observing it?

Question

Imagine that you're watching, say, a human (a stand-in for said entity) from a distance, and, the second you physically see them with your own eyes - they do not necessarily have to see or hear you - they immediately know you're there until you break eye contact.

There are caveats to this:

• If your eyes are pointed at it but you can't physically see it - for instance, there's a fogbank in the way, or the environment is too dark for you to see it, or you're blindfolded - this property will not take effect.

• You have to make direct eye contact with a portion of its body in order for it to know you're there. This means that observation via camera or other such means doesn't trigger the effect.

• You have to be able to perceive it in order for it to know you're there. The blind do not trigger this effect.

• It still has normal senses - for the sake of the question, let's say it's essentially a human with this property "grafted on", with the full sensory suite that being a human entails.

• This property works in vacuum.

• When someone breaks eye contact, the effect ends, although the entity still remembers that someone was perceiving it. Think of it as hearing a jackhammer in the distance that suddenly stops - you stopped hearing it, but you still remember that you did hear it.

• If said entity is completely covered in clothing, such that you can't see its body, this property does not take effect.

• Whether or not observing it via mirrors causes it to know you're there is up to the question-answerer to decide, as is whether or not the entity knows the specific location or direction which it's being observed from.

The question: How, exactly, would such a thing be possible? To me, this seems like quantum mechanics insanity of the highest degree, and I have absolutely no idea how it would work, nor what tags I should put on this other than "senses".

I initially figured that giving this entity ultra-sensitive whiskers capable of detecting air current shifts would do the trick, or biological radar, but that didn't fit many of the criteria.

Answer 1

As described? There's nothing I can think of that fits the bill.

The reason why humans know they're being watched: they don't. So what's this 'I feel like someone's watching' thing we have? Other signs.

A vaguely human-ish form, even if it really isn't there. That's why ghillie suites are so effective, we don't associate that shape with humans, thus it isn't a human.

A dip or spike in the ambient sounds. A dip in birds squawking. Deer suddenly hoofing it. Branches snapping. A rhythmic sound that wasn't there before.

Another really good indicator is smell. Bloodhounds are famous for it, of course, but 'there's something in the air' is usually what sets off the other things.

So, how can you pin this directly on unobserved 'sight'? You can't. Not without handwavium, ESP, or game mechanics. By definition, to observe something, you need to see it. It's either you pin it on other senses, or you introduce something new.

Plausible '6th senses'? Brainwave scanning, it would allow for some sort of 'recognition pattern' if sufficiently advanced. Or a simple 'advanced monitoring tech', that allows you to see things around you and alert you.

All beings, that I'm aware of, cannot directly process all stimuli we take in. There's just too much of it and our brains need to keep us alive--busy with other stuff we also don't consciously handle. So, if you introduce some sort of symbiosis between 'beast and machine'? There's a higher chance of picking up details.

Humans and other species already use hairs to sense things, but that's for sounds and/or movement (air pressure differential, subtle shifts in the wind, that sort of thing.)

As I understand Quantum Mechanics, you've got nothing to work with. The scales are far too small to be useful to something as, relatively, large as a human. But I've been wrong about most things quantum.

Answer 2

Emission theory is true

There is an ancient theory called Emission theory, which (attempts to) explain vision by asserting that humans and other animals fire invisible eye beams out of their eyes. As these beams hit an object, we become aware of some of its properties, which our brains interpret as an image.

In a universe where this theory turns out to be true, it isn't inconceivable to imagine some kind of physical process, perhaps some chemical reaction, that could be influenced by being hit by an eye beam. With luck, evolution might even find some way to incorporate this into some kind of sensory neuron covering the skin of this entity. It would be able to sense whenever any given part of its skin was observed by a creature, in the same way that we can sense heat.

As with our own senses, clothing can block or dampen this sense. If no eye beams reach the skin, it cannot feel them.

Stretching the laws of physics even more, if the physical eye beams can have different properties (for lack of a better term: "frequencies") that perhaps vary from creature to creature, the being may be able to tell what or maybe even who is looking at it, in case such a property is desirable for story purposes.

(Seeing as this being itself has eyes, it would also sense itself looking at, say, its hand.)

Though, one particularly difficult thing to justify would be "if Emission theory is true, how on earth do cameras work"? Though that could possibly be handwaved with something along the lines of "They fire artificial eye beams. Since the electronics are more sensitive than eyes, the beams are too low-power to be felt by the entity."

Answer 3

It must be limited mind-reading. The being can read the unique thought patterns that observers have when they see the being's skin. This is then translated into a vague sense of "I'm being observed".

In particular these aspects "...too dark for you to see it..." and "...completely covered in clothing, such that you can't see its body..." require knowledge about the individual observer's perception.

Any normal ("real") sense that can even hope to tell an observer with bad (night) vision apart from another observer with good (night) vision must be extremely detailed. Maybe detect dilation of the pupils or a change in heartbeat - but then the being already sees/hears the observer in great detail.

Answer 4

A virtual world

If this entity is in some way part of a computer simulated world, for example a video game, then being shown on screen would be a distinct thing that can be detected, in theory.

Typically in games, no models are shown (rendered) until a player can see them. Otherwise they take up useless memory and processing. So if you cannot see an enemy it is not rendered. Still exists in the exact location you would encounter them, however, player's vision is what makes the model render on the screen. And this might involve extra steps, like loading the model from the disk in order to render it.

If the entity is somehow aware of that rendering process, even if it does not understand what they are, then it would know of being observed.

This covers all scenarios described as long as

• the observers will require the model being rendered
• the entity can have some way of being notified that its model is being rendered

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Just to clarify some of the scenarios:

You have to make direct eye contact with a portion of its body in order for it to know you're there. This means that observation via camera or other such means doesn't trigger the effect.

There are various tricks to get camera views in games. It is possible that whatever computer engine is doing this takes a copy or projection/transformation of the model to show in camera screens (and similar). And since this would act as a different model for the creature, then it would not be able to be aware.

If said entity is completely covered in clothing, such that you can't see its body, this property does not take effect.

• In some games, the clothing acts as actual clothing and you can put it on in layers over the actual model. Saints Row 2 and onwards is an example of this. In those cases, the model not being visible, means it will not render.
• In other games, the character is "built up" by several parts. One might be the torso part, one the legs part, for example. So, "putting on pants" or "putting a jacket" just replaces that part with a generic "legs with pants" or "torso with jacket". Then the entity might be able to know rendering of the original parts but not the ones replaced with clothed equivalents.
• In other games still, there is just one model with all the gear on it. If you "change clothing" it just loads an entirely different model. In this case, the entity would need to be aware of loading any model other than the ones that show it completely covered. Maybe those models are corrupted somehow. Or vice versa - they are the ones that work correctly, all the other ones somehow alert the entity.

Answer 5

It sounds like the observer is using some sort of radar or sonar to "see" the observed, using an actively emitted beam to scan and observe its surrounding, beam which can be sensed in some way.

This already happens in nature for examples with certain moths which, upon detecting the ultrasounds emitted by bats hunting for them, trick the bats into avoiding them

Some moths use ultrasound to either jam bats’ sonars or to signal to bats that they taste bad. Barber explains that some of these species are Batesian mimics, because they don’t truly taste bad but mimic the ultrasound of other moths that do, tricking the bats into avoiding them as food.

Answer 6

Hyper-specialized gaze detection

Humans have the ability to sense when someone is looking at you, or at least in your direction. It's referred to as 'gaze detection' for the most part, here's a link on it.

Now, this isn't possible unless the pair of eyes are already in your field of view but you're just not focusing on it(peripheral), and this requires a certain kind of sclera-iris ratio to work, so unless your creature has a spherical peripheral vision ability this isn't going to work.

I suggest that it has eyes in strategic positions all over its body. It doesn't necessarily need them to be the focus of their view(seeing everything at the same time with great clarity) but you're going to need this all-round view as at least a peripheral focus if you want the creature to have gaze detection from all directions. A creature specialized to detect eyes might not need a specific range of sclera-iris ratios to detect gazes, but at least as far as humans are concerned that is a requirement

Answer 7

Very easily - according to quantum physics, any observation influences the object being observed. Imagine some good technics, that measure unexpected quantum effects. If you exclude all effects from known influencing objects, all that remains is the result of unknown observation. Notice, it works for absolutely any sort or way of observation.

Answer 8

Sixth Sense

Ever get that prickling feeling in the back of your neck where you get the feeling you're being watched?

Ever find yourself feeling like you're not alone in an empty room?

Yeah.
You probably were alone and shouldn't worry about it.

But in your fictional world, this feeling has meaning and actual cause. Some people have access to a sixth sense which allows them to be able to tell when someone else is watching them.
A "Danger Sense".

For your specific entity, this ability is substantially heightened, and they can consistently and reliably tell when they're being observed, even at a distance.

How does it work?
Maybe they're feeling the psychic mind-pressure given off by the observer.
Maybe they're hearing the echoes of a mind that recognises their visual-profile as a person.

Who knows?
It's not as important as the fact that there's someone behind you.
Right now.
Start running!

Answer 9

Not without having certain knowledge of the (potential) observer.

The only possibility of the entity being able to know they are being observed that I can think of is when extensive research into the recognition of said entity has been conducted, and the brains of potential observers are constantly being monitored for the presence of the established recognition pattern (i.e. the activity in that specific network of neurons).

This entire concept stands and falls with the observer realizing they're watching the entity. And obviously - unless these patterns are similar in all observers of a certain type - with these observers having been monitored beforehand to begin with.

Answer 10

It's not really there.

The Purple Spotted Bronwyn's Lesser Extricopead (PSBLE) is not out there in the universe. It is instead a small Worm (W) that lives in your head, manipulating your sensory organs to make you perceive a large purple animal. You only see the PSBLE when the W decides you should. Hence it is always aware of you looking at it.

Answer 11

I don't think there's any good physics law that can give this to you for free.

You can always invoke magic/telepathy/astral thought fields/etc - aka simple handwavium - but I suspect that you wouldn't be asking this question if this was an option for you.

So that leaves us with... Advanced Handwavium. Still handwavium, but at least scientifish sounding. Let's go with... spins the Wheel of Handwavium... biology!

Now, normal physics laws do not allow you to detect that someone is observing you. Not passively anyway. Thus all observers must be transmitting what they are seeing, and all observees must be receiving this transmission. And, naturally, this can happen entirely subconsciously, so that you just get this vague sense of "being watched".

But how do you know that it's specifically YOU that is being observed? Well, how about vision in a different spectrum? Each individual has their skin covered in a personalized colourful pattern (kinda like fingerprints) - but it only shows up, say, in ultraviolet or infrared spectrum. All creatures have a fifth (or maybe even more) kind of receptor in their eyes which can perceive this light, but it's not accessible for conscious viewing - only the subconscious has access to it.

The transmission and receiving happens through standard radiowaves at a certain frequency or maybe a range of frequencies. So if your species pick up on this, they can actually "jam" this sense by transmitting loud white noise at the right frequency(-ies), but there's a drawback - it causes all who can "see" it feel uneasy or maybe even nauseous (because the light will be too bright), so the use is limited.

So, what might have caused this to happen? Again, more handwavium. Weird evolutionary quirk. Alien bioengineering. Remnants of ancient alien bioengineering. Parasites/symbiotes that are trying not to get each other killed by warning their hosts that someone is observing them. Alien bioengineering virus malfunctioning. I dunno, I'm not an alien bioengineer.

Answer 12

A combination of pattern-based mimetics and esp.

The observed species have esp to a limited extent, but this has evolved along with complexly patterned skin. Seeing the creature's skin sets up a feedback in the mind of the observing creature that is detectable by the creature being observed. This feedback may even have a slight dazing effect, since it evolved to help capture prey. The prey tended to not startle off of a trail and just stand still while the predator approached. This could possibly be defeated by something similar to infrared goggles, or just colored lenses; filter out enough of the right color wavelengths, and the pattern doesn't have the effect. Some prey creatures probably evolve this naturally. And then the constant evolutionary arms race may have different races of your species with different effective color ranges depending on which color ranges the prey species in the region evolved to filter out.

Quantum entangled particles

If you want a quantum method, if the species evolved in some extremely exotic environment, maybe their skin produces paired particles, or their metabolism somehow separates naturally paired particles. One of the pair is emitted and the other remains as a sensor within the skin. When observation changes the state (I believe your eye is supposed to be able to register a single photon, perhaps it actually registers even less?), a corresponding change occurs in the skin of the observed. Perhaps a single change wouldn't be enough to say "not random" but enough particles unconsciously observed by a single observer throws enough of a "statistically not random" effect for the "skin to crawl" and the observation is noticed.

I don't think that's going to work without a lot of handwaving, but quantum stuff all seems like a bunch of handwaving to me anyway. :)

Answer 13

There is a tradition in SF of (wildly) over-interpreting the implications of quantum superposition, and I guess the question is angling for an answer along those lines. But I'd argue quantum physics has suffered enough; besides, this scenario would require the entity to observe itself in a superposition of states, which no interpretation of quantum mechanics has ever suggested. But that's OK, there are plenty of other approaches.

Perhaps the entity's skin is covered in bioluminescent cells that flicker in a random pattern, and it is also somehow sensitive to the activity in human brains. It can't decode that activity to read minds as such – it can't even distinguish human brains from the background noise – but it can detect if some tiny fraction of that noise starts to fluctuate exactly in sync with the random pattern its skin is giving out.

I'm not sure if the entity could plausibly detect "brain waves" in the normal sense, but you could bridge this gap with only minimal handwaving. Whatever medium it uses, the key is that because the entity controls the signal it is looking for, that makes it much easier to detect the returning signal. It's like how if you close your eyes, you can easily hear when you are near a wall, by picking up the reflections of ambient noise; the signal involved is incredibly faint – far below the threshold of what you can consciously hear – but because the "coming" and "going" sound waves are so closely correlated, your brain is able to detect the correspondence.

Answer 14

Third-party overseer

Several fictional universes explain magic by having a being or a system with godlike powers granting the spells. It can be a fine invisible mist of interconnected nano-machines gathering information and passing it on, or it can be a powerful being of a "higher dimension" pulling the strings.

Such an entity, knowing when someone observing it, is already featured in Ward, the sequel to Worm:

A supervillain called Mama Mathers can instantly know if someone observes her, and she can affect the minds of anyone who observed her. If someone has seen her, she can affect the observer with visual hallucinations, if someone heard her she can send debilitating auditory hallucinations, etc.

How is it done?

Superpowers are granted to humans by transdimentional planet-sized entities with immense power, which reside in a parallel universe but are able to observe our universe and form connections with specific humans they have chosen to grant powers to. In this case the character doesn't directly observe someone having observed her, it's the overseer entity which notices this and feeds this information to her via a neural link.

Answer 15

Some time ago Rupert Sheldrake reported experiments about people detecting being looked at. He has a set of explanations for that, look up "morphic resonance". Largely considered pseudoscience and without valid evidence, but it may work for you as an explanation. Although it does not cover all your requirements, I think.

Answer 16

You could use a variation on the "Akashic records" principle. That there exist somewhere (A quantum plain, or some magical dimension, or whatever fits best with your story) where knowledge is stored that people can tune into and access to gain access to it.

You could say that when someone observes something the observer and the object being observed are connected through the Akashic records, and that the person in the story is tapping into their own personal portion of the record and can see this connection.

Answer 17

They get flashes of precognition.

They're particularly sensitive about being observed, it makes their hackles rise and provokes a fear-response. They can't by any means predict the future, but anything that turns up in the future for them and registered as "they're watching me" gets shot back in time to that moment.

Answer 18

If I can see your eyes, then you can see me

In the real world, it is not true that people automatically know when they are being watched. However, it is true that if I can see your eyes, then you can see me. Because light goes both ways.

If you can extend that "light goes both ways" idea with something else instead of light, you might achieve what you want.

When I see you in the real world, I touch you in the Astral plane.

Maybe there exists an Astral Plane, or a Magic Plane, or Star Wars' "the Force". This Plane exists in parallel to our universe, and most people aren't very aware of it. Objects and living beings can be connected through the Astral Plane, and the connection always works both ways. There are different kinds of possible connections, with different degrees of strength. One possible connection is through observation. If I watch you in the real world, then my Astral form will inevitably "touch" your Astral form on the Astral Plane. Unless you're a proficient magician, you probably won't be able to exploit that connection; but you'll still feel it and it will give you a feeling of being watched.

You can adapt the vocabulary depending on your setting. Magic plane, astral plane, mind plane, quantum realm, astral forms, souls, chi, etc.

Answer 19

electromagnetic resonance

Nerves use electricity. Electricity creates magnetic fields. Field presence and shape can be detected, sometimes at significant distances, with a variety of sensors. Some of these sensors are biologically feasible.

Postulate a human with a higher-than-average level of these sensors (cryptochrome, one of the eye's photon detectors, can react to magnetic fields as well for instance, and it is present in many places besides just the eyes).

It may be possible for such a creature to learn to sense the shape of the fields around it and determine when it is being observed. This may be easily confused with someone nearby merely thinking about observing them. It may also be easily fooled by someone focusing loudly on a subset or superset which contains the creature but does not match the normal pattern of how people casually observe it.

The range of this would probably be fairly limited under normal circumstances, but humans are incorrigible tool users and somebody might come up with some sort of antenna.

edit: apparently this is something people are studying... https://web.archive.org/web/20220115070017/https://www.sciencedirect.com/science/article/pii/S2405844021004680

Answer 20

Induced Phreaking

Since you didn't ask for science-based, I'm going for "it sounds vaguely plausible as long as you don't think about it". It's well known that you can recreate (poorly) the image on a monitor by inductively sensing the RF emissions produced by the signal cable. The cable acts like a very poor transmitting antenna, and the emissions have a regular pattern due to the monitor's refresh cycle.

So, let's say your person's skin produces a rapidly changing but consistently patterned color sequence at all times, and that furthermore they have a ridiculously sensitive RF pickup. You could even say that the light emitted by the skin is physically coupled to the RF pickup as a sort of lock-in amplifier or even a not-too-distant variation on quantum radar. When their skin is observed, the signals produced in the observer's eyes weakly radiate RF with the same timing pattern as the skin's color changes, and it's this RF that's detected. It's quite a bit more believable if your setting is such that everyone has at least one cybernetic eye, since then you'd have actual electronics and wires producing the RF signals rather than optic nerves. Or you could have the pattern induce some very specific activity in the brain itself, and the "sense" would be like doing a remote MRI scan. If you don't want the effect to be noticeable to a casual observer, you could make the visual effect subliminal but still detectable a the mechanical/subconscious level. That also opens up some potential plot points, where the effect can perhaps be easily seen with a special camera, etc.

The sensitivity that you'd need here are well beyond believable, but it nicely explains several of the points you've asked for: clothing fully covering the skin would prevent its functionality, and it explicitly relies on observation, not some kind of radar that wouldn't care whether the target is actually looking or not. A regular camera would not trigger the effect because the shutter speed would be too slow, although you could imagine a high-speed camera might trigger it. And you don't have to rely on any half-baked hand-wavy appeal to quantum observer effect!

Answer 21

Anthropics and acausal trade

Use anthropic reasoning to deduce that there's atleast one lifeform existing in the universe observing you at any given point in time.

Use acausal trade to deduce what they might be doing in real time, assuming their source code is similar to your own.

Answer 22

Any sort of persuasive and intrusive sort of surveillance system will do

I think the Orion's Arm Worldbuilding project has a great article on these kinds of systems.

An angelnet is any all-pervasive distributed processing supervision and safety infrastructure. Angelnets are found on many developed worlds and megastructures, and in many smaller habs of all kinds in polities throughout Terragen space. They protect sapient populations or important local subsystems and other valued beings or objects by eliminating both accidents and deliberate attacks. The archetypical angelnet is designed and operated by a transapient intellect, and consists of ubiquitous smart matter (including rapidly deployable utility fog) plus the region's machines and bots. Less pervasive or less sophisticated angelnets are also widely used.

Within its own sphere of influence, such an angelnet has seemingly supernatural powers to observe, predict and intervene in pursuit of its designer's goals. While this is the most powerful application, any dense and highly networked system of technology, even one employing only middletech and designed by ordinary sophonts, can have a similar though lesser effect. Angelnetting is more a concept than any one particular implementation. Secondary functionality of angelnets varies widely, but includes distributed processing capabilities, networking, weather control, paraterraforming, conservation and recycling, autotopia infrastructure, mechosystems, Known Net relaying, virchworlds and virch-rl interfacing, cliology, environmental protocols, and scanning of underground and above ground features and structures. All of the major modern archailect-ruled worlds and capitals are heavily angelnetted.

See: Angelnet - Encyclopaedia Galactica

Basically the controlling artilect only allows the entity to receive a signal of gaze detection. All the specifics... these are just peculiarities of the systems implementation. It might have been designed for some meaningful purpose, probably a political one, once. However as the memetic ecosystem/social situation/politics changed, it stayed behind. Such systems are quite common in genetic evolution.

Why does it appear to be a an intrinsic ability? There are several options. The system might be detection resistant and disassembles itself in sections where someone looks. It might be sticky and hijack it's subjects biochemistry to reproduce (think viruses, mitrocondria, symbiosis), it might be extremely penetration and as soon as you get into its sphere of influence it can simply hijack your perception and memory. Reality is whatever the system manipulates your mind into believing.