Ways for Monsters to See in the Dark

[Anthony]

Originally Posted by Farmer

Studies vary on what human tetrachromats can see

It should vary with the tetrochromat, since the way you achieve it is by having two slightly different variants of one of your color receptors, and there's three receptors that can be doubled.

[Farmer]

Originally Posted by Anthony

It should vary with the tetrochromat, since the way you achieve it is by having two slightly different variants of one of your color receptors, and there's three receptors that can be doubled.

it does, but there seems to be (and the studies are limited, but growing) a higher rate of various combinations, with some influence based on gender (which we know impacts things like colour blindness) through hereditary genetic traits.

[whswhs]

Originally Posted by Farmer

it does, but there seems to be (and the studies are limited, but growing) a higher rate of various combinations, with some influence based on gender (which we know impacts things like colour blindness) through hereditary genetic traits.

Technically, it's sex, not gender, that influences color blindness. Gender is assigned to you by your culture or, in our current culture, subjectively decided by the individual; but color blindness depends on how many X chromosomes you have.

[ericthered]

Originally Posted by Daigoro

Spore Vision?

The cave system is filled with a species of fungus that emits clouds of sticky spores when anything moves through. The fungus and the spores emit a particular wavelength or magical aura that the cave-dwellers' eyes are attuned to, allowing them to make out the shape of the terrain as well as see visitors who have been tagged. People tagged by the spores would need to have a thorough soaking or a Sterilise spell to become undetected again.

That's a very gameable idea, and it really fits the feel I'm trying to get. I've got that Mana Bloom Ecology going, so little spores waiting for higher mana zones should be getting on everything. Its exotic, but its also very intuitive to interact with.

Originally Posted by thrash

Something similar could be achieved with vibratory sensors and the Preparation Required limitation -- e.g., spider webs that not only transfer vibrations in the air to a tactile receptor, but provide specific feedback when brushed against.

Originally Posted by Willy

Ha someone in this threat already mentioned trap door spiders and their hunting method? They hav ea system of silk strands around their hiding place, if anything stepping on that strands the spiders gets the info when were and how big, sometimes this system is big enough to have a 1 meter diameter, quite far away from the hiding place. A mostly sessile cave living creature could use such a trick.

I like this idea! It works for an ambush predator with a small home range (It does almost turn them into a trapping predator), but I can also see it working for a community as well. They run threads all around the tunnels they live in and collect food from, and you can tell you're approaching their homes by looking for the filaments. Then you have specialized scouts who go out and lay the new filaments, perhaps given actual site by magic while they're exposed in the outside world. I'm planning an arthropod race this could work well for.

Originally Posted by Fred Brackin

Some birds (along with some insects) can see slightly beyond the upper limit of visible light. I think it's 260 nanometers v.350 for us and most other creatures. Some flowers have pigments in this range.

The required adaptation is a different type of rod/cone. No cooling or other exotica is required. The near UV photons have plenty of energy.

Its not just birds, its also a great number of reptiles and fish... vertabrates ancestrally see four colors, including a UV band and a color of green much more evenly centered between blue and red than ours. Mammals just lost two of those colors at some point, and then some primates picked up green from a mutant red.



Insects I don't know as well, but its my understanding that at least some (bees are often shown as the illustration) have three types of cones, very widely spaced, that pick up some IR on the low end and UV on the high.



I don't think of the UV and IR that other critters see as having the properties we normally associate with those bands: they're so close to visible light that we may as well consider it to be visible light we can't see.

Originally Posted by Farmer

So if you're looking for "science" ways to have dark vision, consider self originating illumination in exotic frequencies that humans don't have but might be able to detect once they figure out what's going on.

that's a nice trick. I suppose even echolocation is a variant on that.

[whswhs]

Originally Posted by ericthered

I don't think of the UV and IR that other critters see as having the properties we normally associate with those bands: they're so close to visible light that we may as well consider it to be visible light we can't see.

That is exactly the case. Chemistry journals regularly mention UV-visible-NIR spectroscopy; that covers all the UV that can get through Earth's atmosphere (vacuum infrared, the higher frequencies, doesn't do that), visible light, and infrared down to 1400 nm (so about an extra octave on that end). Apparently they can all use more or less the same optics.

The first visible red light from metal heated in a fire is at about 900 K, so the first NIR light should be at about 450 K, which is about 350°F.

[whswhs]

If you want to be weird sciencey rather than magicky, you could give the critters para-radar, or make up a precision or targeting variant of para-radar.

On a more mundane level, I believe Enhanced Senses has rules for Targeting Hearing. Owls actually have something like that in the real world.

[Farmer]

Originally Posted by whswhs

Technically, it's sex, not gender, that influences color blindness. Gender is assigned to you by your culture or, in our current culture, subjectively decided by the individual; but color blindness depends on how many X chromosomes you have.

Technically, gender also refers to sex in the genetic sense, but you are correct that sex is the much better term because it doesn't have alternative meanings which are socially based and which are needed to broaden our inclusiveness as a society (globally, locally, any level). So I appreciate the correction.

Colour blindness is influenced by X chromosomes, but females can be colour blind - it's just less likely for them to inherit both genes required for the condition. And for added complexity, I know twins (female), one of whom is colour blind and the other isn't. So there's also gene expression and possibly RNA influences going on.

[Farmer]

Originally Posted by ericthered

that's a nice trick. I suppose even echolocation is a variant on that.

Yup, for sure. As is para-radar that Bill and I referenced (in "psychic wavelengths" which might be much harder for science to detect). If you want longer range "through walls" senses, you can also use general vibrations either from ultra low sonic emissions or other percussive emanations. Again, these might not be detectable by humans or, at least initially, not recognised. Eventually, they might get to "Oh, no, do you feel that? They're coming!".

Either predators or prey might develop such senses for opposing reasons.

[Anthony]

Originally Posted by ericthered

I don't think of the UV and IR that other critters see as having the properties we normally associate with those bands: they're so close to visible light that we may as well consider it to be visible light we can't see.

UV vision is basically extended blue band, it doesn't do anything terribly interesting for any wavelength that is useful in atmosphere. The big advantage near IR would have is seeing by firelight, a 1,500K blackbody is a hundred times brighter in NIR than in visible light.

[ericthered]

Originally Posted by Farmer

Yup, for sure. As is para-radar that Bill and I referenced (in "psychic wavelengths" which might be much harder for science to detect). If you want longer range "through walls" senses, you can also use general vibrations either from ultra low sonic emissions or other percussive emanations. Again, these might not be detectable by humans or, at least initially, not recognised. Eventually, they might get to "Oh, no, do you feel that? They're coming!".

Is there a reference for seeing via ground vibrations rather than air vibrations? That's something else that might end up being ambient

"oh no, they're coming" is a fun thing to play with.

Originally Posted by Anthony

UV vision is basically extended blue band, it doesn't do anything terribly interesting for any wavelength that is useful in atmosphere. The big advantage near IR would have is seeing by firelight, a 1,500K blackbody is a hundred times brighter in NIR than in visible light.

That's really good to know. Perhaps night vision X (firelight only-20%). Any thoughts on the color pallet folks using that band would wear?

Originally Posted by whswhs

On a more mundane level, I believe Enhanced Senses has rules for Targeting Hearing. Owls actually have something like that in the real world.

That's not a bad option, and when echolocators are trying to be stealthy they may have to rely on that.