Scifi eyes

[DDE]

8 hours ago, Dragon01 said:

Actually, it is possible (though of questionable utility) for a living creature to "see" radio waves. It just needs a biological antenna. This is not implausible, and the wavelength would be limited mostly by the creature's size.

Apparently some detection ability has apparently been shown in humans.

And it's at energy levels lower than those that, uh, permanently destroy your eyes and fry most of your internal organs.

[Guest]

It's no surprise, really. There's a lot of electrochemical stuff going on in human body, some of that can be susceptible to being messed with by RF radiation. That said, with no natural sources of radio waves (besides incidental stuff like lighting strikes), there's no point evolving dedicated organs for that on Earth. Well, there wasn't, anyway. Assuming we keep our VOR stations running for the next few million years or so (hey, you never know what might happen, right?), we might find some bird that had figured out how to use them for air navigation. Or, if the birds are extinct by that point, maybe a great big insect (nature abhors a vacuum. If we let birds go extinct, we'd only have ourselves to blame for having to live with bugs big enough to evolve VHF antennas...).   

1 hour ago, Spacescifi said:

Don't get me wrong, she's a beauty. but beauty ain't winning this. Science will. So.. what would or should infrared antenna look like?

Like a peculiar sort of eye. Far infrared spectrum acts more like light than radio waves (I assume we're talking thermal vision, because near IR is pretty much the same as normal light). However, the lens will be opaque and probably made of a relatively exotic biomaterial.

Keeping a thermal vision organ on a stalk of that sort actually makes a lot of sense, BTW. If you want it to see other living things (that's what they'd be most useful for, in most situations), you need to cool it to a lower temperature than that of a typical living being in an ecosystem (otherwise, it'll interfere with itself). This likely means it will have to be kept at a lower temperature than the rest of the owner's body. Additionally, it may have a skin flap attached to the stalk, to act as a radiator in order to further cool the organ (as often the case in biology, the flap is likely to have additional uses).

Edited July 14, 2019 by Guest

[Spacescifi]

36 minutes ago, Dragon01 said:

It's no surprise, really. There's a lot of electrochemical stuff going on in human body, some of that can be susceptible to being messed with by RF radiation. That said, with no natural sources of radio waves (besides incidental stuff like lighting strikes), there's no point evolving dedicated organs for that on Earth. Well, there wasn't, anyway. Assuming we keep our VOR stations running for the next few million years or so (hey, you never know what might happen, right?), we might find some bird that had figured out how to use them for air navigation. Or, if the birds are extinct by that point, maybe a great big insect (nature abhors a vacuum. If we let birds go extinct, we'd only have ourselves to blame for having to live with bugs big enough to evolve VHF antennas...).   

Like a peculiar sort of eye. Far infrared spectrum acts more like light than radio waves (I assume we're talking thermal vision, because near IR is pretty much the same as normal light). However, the lens will be opaque and probably made of a relatively exotic biomaterial.

Keeping a thermal vision organ on a stalk of that sort actually makes a lot of sense, BTW. If you want it to see other living things (that's what they'd be most useful for, in most situations), you need to cool it to a lower temperature than that of a typical living being in an ecosystem (otherwise, it'll interfere with itself). This likely means it will have to be kept at a lower temperature than the rest of the owner's body. Additionally, it may have a skin flap attached to the stalk, to act as a radiator in order to further cool the organ (as often the case in biology, the flap is likely to have additional uses).

 

Interesting. So... her stalks should have eyeballs on them?

Eww! Well it could work. Close your normal eyes and open the other ones. Funny eh?

Solid black eyes perhaps? I know black absorbs heat more, but if we can keep the stalks cool enough it won't even matter. Guessing the vision could be all red or green like infrared goggles. Or perhaps something more useful like this:

As this shows the warmer and colder regions of anything. Useful for disease diagnosis, probably even a good lie detector. Plus it just looks awesome!

Perhaps some sort of weird body coolant is siphoned to the stalks to cool them off.

I also think these aliens would sweat more profusely to keep the stalks cool at all times. I doubt they would like the heat unless they could make plant or other unique clothing that absorbed their sweat so they still stayed dry. Otherwise they would be drenched walking around in the heat. I would expect them to be prolific water drinkers too.

Don't cool enough and your infrared stalk vision starts going dim. Eventually it will go black. But it can recover whenever a person cools their stalks and body down enough.

Edited July 14, 2019 by Spacescifi

[Guest]

5 minutes ago, Spacescifi said:

Solid black eyes perhaps? I know black absorbs heat more, but if we can keep the stalks cool enough it won't even matter. Guessing the vision could be all red or green like infrared goggles. Or perhaps something more useful like this:

The eyes will likely be some shade of gray or white. That's how modern IR lenses look, and they'll need something of that sort. As for the vision, it won't "look" like anything a human can experience, nor would it interfere with a normal vision. Rather, it would appear to us as the alien "just knowing" how hot something is. Aliens will be alien, and it will be difficult for a human to comprehend a fundamentally different method of perception. Likewise, we'd be hard to understand for them. There are some sensations simply unavailable to humans, and there will be sensations that we have and they do not.

Quote

I also think these aliens would sweat more profusely to keep the stalks cool at all times. I doubt they would like the heat unless they could make plant or other unique clothing that absorbed their sweat so they still stayed dry. Otherwise they would be drenched walking around in the heat. I would expect them to be prolific water drinkers too.

This is unlikely. Sweating is a mechanism to provide a temporary boost in heat rejection. You lose a lot of water that way, and to keep doing it all the time you'd have to spend way too much time drinking water. This might be viable for an alien organism (for example, perspire only from the biological radiator like the one I mentioned), but if so, then there will be no discomfort (sweat doesn't have to cause foul odors, it's a peculiarity in Earth's mammals). Do note that to make full use of this method they would have to live in an environment with low humidity, so that sweat can dry out quickly, but where water is nonetheless available, so it doesn't have to be conserved. Also note, every heat rejection system has a cold end and a hot end, so if your IR vision organ is the cold end, you also have a body part that is very visible to the same organs. Of course, that fact might somehow be exploited in mating behaviors.

They may not like high ambient temperatures, if only because it'd mess with their heat vision. Indeed, they may be furry, and hail from a comparably cold environment. Of course, sweating requires exposed skin, but they could just have a patch, or a flap (kind of like an elephant's ear) to that end. It should be possible to temporarily conceal it, too, should it get so cold that it loses too much heat. Also, for thermal vision to be worth bothering with, normal vision should be impeded somehow. It's much more complicated than just seeing in visual spectrum, so for it to appear, it needs to have a serious advantages over that, at least in the species' natural environment. 

[Spacescifi]

29 minutes ago, Dragon01 said:

The eyes will likely be some shade of gray or white. That's how modern IR lenses look, and they'll need something of that sort. As for the vision, it won't "look" like anything a human can experience, nor would it interfere with a normal vision. Rather, it would appear to us as the alien "just knowing" how hot something is. Aliens will be alien, and it will be difficult for a human to comprehend a fundamentally different method of perception. Likewise, we'd be hard to understand for them. There are some sensations simply unavailable to humans, and there will be sensations that we have and they do not.

This is unlikely. Sweating is a mechanism to provide a temporary boost in heat rejection. You lose a lot of water that way, and to keep doing it all the time you'd have to spend way too much time drinking water. This might be viable for an alien organism (for example, perspire only from the biological radiator like the one I mentioned), but if so, then there will be no discomfort (sweat doesn't have to cause foul odors, it's a peculiarity in Earth's mammals). Do note that to make full use of this method they would have to live in an environment with low humidity, so that sweat can dry out quickly, but where water is nonetheless available, so it doesn't have to be conserved. Also note, every heat rejection system has a cold end and a hot end, so if your IR vision organ is the cold end, you also have a body part that is very visible to the same organs. Of course, that fact might somehow be exploited in mating behaviors.

They may not like high ambient temperatures, if only because it'd mess with their heat vision. Indeed, they may be furry, and hail from a comparably cold environment. Of course, sweating requires exposed skin, but they could just have a patch, or a flap (kind of like an elephant's ear) to that end. It should be possible to temporarily conceal it, too, should it get so cold that it loses too much heat. Also, for thermal vision to be worth bothering with, normal vision should be impeded somehow. It's much more complicated than just seeing in visual spectrum, so for it to appear, it needs to have a serious advantages over that, at least in the species' natural environment. 

 

1. Actually their vision is required to be perceptible to the reader, as they could be a main character. Nonetheleless, I really like the rainbow infrared vision.

2. Sure I could use flaps but I think that is a bit much when all I wanted was eye stalks. Yet I could recycle an old Idea I once had that to me is far more interesting.

Insectoid wings mounted on the sides of the shoulder about as long as the arm. They  sweat to cool the extra heat the body rejects from the eye stalks.

Almost useless except for waving off flying insects and sweating. Since they cannot fly. Live on an Earth world with 1g.

In space inside a their spaceships though... oh yes they can fly!

Shoulder mounted wings would enable flight there, and given their humanoid size, they won't buzz or whir while flapping.

Just make a soft flapping noise, noyhing more. Nearly silent.

 

3. Serious advantage of infrared vision?  Easy. 48 hours long of daylight. 48 hours long of night. 96 hour days.

Sleeping hours? Normal 8 hours roughly.

So seeing at night is kinda needed now.

Edited July 14, 2019 by Spacescifi
Infrared advantage

[kerbiloid]

When ears get red, they get hot.

When a frozen ear feels a source of warmth, it gets soft and you feel it in the nose.

A ready-to-use signal system.

[KSK]

On 7/13/2019 at 7:34 AM, natsirt721 said:

Wavelength and pupil shape are not related. Both are determined by need, but affected by different factors. 

For xenobio coloration, there are two important factors. Primarily, the star of the homeworld. The human vision spectrum is attuned to center on the 380-740 nm band, from violet to red, with yellow-green (555 nm) in the middle and black on the edges. Why this wavelength? The sun's peak energy output, per wavelength, is somewhere between 500 and 600 nm. The human eye is attuned to detect green(ish - we'll say its green although its a little closer to yellow-green) light because there are more energetic photons hitting the retina at those wavelengths.  This is also why plants (chlorophyll) is green - peak power absorption.

Umm, isn't that the other way around - chlorophyll appears green because it absorbs more strongly in the red and blue wavelengths and only absorbs green weakly? Unless I'm misreading your post.

On the topic of infrared vision, I thought this paper might be of interest. https://www.sciencedirect.com/science/article/pii/S0960982215012464 Very quick summary - various species on Earth can fine tune their visual spectrum on-the-fly by dynamically modifying the photopigments in their retina. This can include shifting their vision into the infrared. One example of where this is useful - living in salt vs freshwater:

Quote

This switch is believed to result in a better match between the sensitivity of the visual system and the spectral distribution of light in fresh water, which is often red-shifted relative to marine and terrestrial environments [12, 14, 15]. 3,4-didehydroretinoids have been identified in the eyes of the vast majority of freshwater fish and amphibian species that have been examined [15, 16]. This observation suggests that thousands of vertebrate species may use chromophore switching to tune the spectral sensitivity of their visual systems.

As an aside - if the purpose for having your aliens come with infrared vision is to equip them for long nights, you could read up on what makes for good night vision instead? Or have your aliens use multispectral vision - low resolution infrared for tracking warm things in motion (to run away from or hunt) and low-light vision for detail work (is this fruit the right shape to eat?)

As another aside - I reckon an interest in biology is extremely useful for aspiring science fiction writers. Expertise not required so much as a willingness to look stuff up on the internet You'd be really hard pressed to make your imaginary aliens any more weird or far-fetched than anything you'd find on Earth!

Personal example - a significant part of my KSP fiction involves the Kerm, which are essentially sentient networks of trees that can deliberately manipulate their local soil ecology. Originally this was a mechanism for fighting other Kerm but the kerbals have long since learned to co-opt it to massively enhance their agriculture. I thought that was something suitably alien for my story and then, several years later, I find this article: https://www.bbc.co.uk/news/science-environment-48257315 

 

Edited July 14, 2019 by KSK

[Guest]

2 hours ago, KSK said:

On the topic of infrared vision, I thought this paper might be of interest. https://www.sciencedirect.com/science/article/pii/S0960982215012464 Very quick summary - various species on Earth can fine tune their visual spectrum on-the-fly by dynamically modifying the photopigments in their retina. This can include shifting their vision into the infrared. One example of where this is useful - living in salt vs freshwater:

This is near IR, same kind as in NVGs. What we're discussing is far IR, aka. FLIR vision. This is significantly harder to do in a biological system, and there are no examples on Earth I know of. Near IR is basically visible light, just "redder" than we can see.

7 hours ago, Spacescifi said:

1. Actually their vision is required to be perceptible to the reader, as they could be a main character. Nonetheleless, I really like the rainbow infrared vision.

They might certainly explain in that way to a human. However, far infrared "colors" will be unrelated and visible "on top" of the normal vision (but it won't impede it in any way). As a rule, xenofiction is hard. Though if you can pull it off, it might be interesting.

Quote

2. Sure I could use flaps but I think that is a bit much when all I wanted was eye stalks. Yet I could recycle an old Idea I once had that to me is far more interesting.

Insectoid wings mounted on the sides of the shoulder about as long as the arm. They  sweat to cool the extra heat the body rejects from the eye stalks.

Almost useless except for waving off flying insects and sweating. Since they cannot fly. Live on an Earth world with 1g.

In space inside a their spaceships though... oh yes they can fly!

Shoulder mounted wings would enable flight there, and given their humanoid size, they won't buzz or whir while flapping.

Just make a soft flapping noise, noyhing more. Nearly silent.

That's a cool idea (pun intended).  Yes, I can see something like that working. A membrane that looks insectoid, but actually has "blood" (or whatever working fluid they use for this) running through it, used for thermal control. In microgravity, they could be, with some practice, used for propulsion. Probably first discovered by an astronaut on a Skylab-sized station, who ended up drifting out of reach of handholds and began to experiment with alternate propulsion methods.

Quote

3. Serious advantage of infrared vision?  Easy. 48 hours long of daylight. 48 hours long of night. 96 hour days.

Sleeping hours? Normal 8 hours roughly.

So seeing at night is kinda needed now.

Do note that sleeping hours would tend to derive from the length of the day. However, it might be that a shorter sleep period evolved after thermal vision. That would certainly give them an evolutionary advantage. If atmosphere is not the best for seeing in visible light wavelengths, so that visible/near IR night vision is not feasible, . They could rely on visible spectrum (with thermal vision mostly for spotting other creatures) in daylight, while during night (which is typically cooler), they'd rely primarily on IR. 

Indeed, in this light, I could see them originally occupying an ecological niche in the middle of the food chain, with their main predator active during day, and particularly hard to hide from, but relatively easy to evade on the move. Their "normal" vision would be optimized for avoiding those predators, and might be panoramic, as well as highly sensitive to movement. Meanwhile, IR would be optimized for nocturnal hunting, and largely forward looking (though the stalks may offer some flexibility in that regard), and work well for detecting static objects such as a sleeping prey animal. They would sleep during night (with nights so long, maybe for more than 8 hours), but mostly after catching their prey, and unlike for humans, they would sleep best after having a large meal. Indeed, the sleep cycle might depend on the size of the meal, so you could have them deliberately synchronize their sleeping with human characters, by adjusting the size of their supper.  It's also fairly plausible that a creature with a behavior this complex would develop intelligence. 

[Spacescifi]

5 hours ago, Dragon01 said:

This is near IR, same kind as in NVGs. What we're discussing is far IR, aka. FLIR vision. This is significantly harder to do in a biological system, and there are no examples on Earth I know of. Near IR is basically visible light, just "redder" than we can see.

They might certainly explain in that way to a human. However, far infrared "colors" will be unrelated and visible "on top" of the normal vision (but it won't impede it in any way). As a rule, xenofiction is hard. Though if you can pull it off, it might be interesting.

That's a cool idea (pun intended).  Yes, I can see something like that working. A membrane that looks insectoid, but actually has "blood" (or whatever working fluid they use for this) running through it, used for thermal control. In microgravity, they could be, with some practice, used for propulsion. Probably first discovered by an astronaut on a Skylab-sized station, who ended up drifting out of reach of handholds and began to experiment with alternate propulsion methods.

Do note that sleeping hours would tend to derive from the length of the day. However, it might be that a shorter sleep period evolved after thermal vision. That would certainly give them an evolutionary advantage. If atmosphere is not the best for seeing in visible light wavelengths, so that visible/near IR night vision is not feasible, . They could rely on visible spectrum (with thermal vision mostly for spotting other creatures) in daylight, while during night (which is typically cooler), they'd rely primarily on IR. 

Indeed, in this light, I could see them originally occupying an ecological niche in the middle of the food chain, with their main predator active during day, and particularly hard to hide from, but relatively easy to evade on the move. Their "normal" vision would be optimized for avoiding those predators, and might be panoramic, as well as highly sensitive to movement. Meanwhile, IR would be optimized for nocturnal hunting, and largely forward looking (though the stalks may offer some flexibility in that regard), and work well for detecting static objects such as a sleeping prey animal. They would sleep during night (with nights so long, maybe for more than 8 hours), but mostly after catching their prey, and unlike for humans, they would sleep best after having a large meal. Indeed, the sleep cycle might depend on the size of the meal, so you could have them deliberately synchronize their sleeping with human characters, by adjusting the size of their supper.  It's also fairly plausible that a creature with a behavior this complex would develop intelligence. 

I have had second thoughts on the wings.

The alternative to wings is constantly sweaty eye stalks, unless in cold weather. Since wings can and do get in the way, and all I really wanted was eye-stalks.   Gross perhaps, the sweaty eyestalks.

I guess one could always wrap them with ice pack sleeves. That would work, since in the story they already have tech more advanced than modern tech. Ice pack sleeves is simple and even we can do that. The 'eyes' will be simple hard green lenses, just like IR goggles, but they can retract within the elephant trunk-like stalks when not in use.

Goat eyes I do not like the look of, and I also think human eyes superior. Color I may change for alien effect, which has little effect on vision anyway.

Longer days/nights mean hotter/colder periods.

My guess is that AC will be a big deal there, and animals will likely burriow underground to endure the heat, perhaps a lot of subterranean tunnels and caves? Which the aliens used in ancient times but no longer need to with their air conditioners.

 

 

Edited July 14, 2019 by Spacescifi
Elephant-like

[KerikBalm]

On 7/14/2019 at 2:29 AM, Spacescifi said:

Solid black eyes perhaps? I know black absorbs heat more, but if we can keep the stalks cool enough it won't even matter. Guessing the vision could be all red or green like infrared goggles. Or perhaps something more useful like this:

Perhaps some sort of weird body coolant is siphoned to the stalks to cool them off.

I also think these aliens would sweat more profusely to keep the stalks cool at all times.

Sweating would not be effective to cool the amoutn required for such vision. Also the vision would not be "red or green", it would be an entirely different sense. Infrared goggles sense one wavelength, and then display a wavelength that we can see. Trying to explain what other wavelength inputs would be like, is liek trying to explain what tetrachromatic vision would be like (it is possible to make take 2 objects that look the same color to us, but birds will see them as two different colors- how would you describe what the birds are seeing?). How yould you explain red and green to a colorblind (red-green colorblindness) person? you just say they are different wavelengths, and give each a name, but that tells the colorblind person nothing about the experience. You'd be better off just inventing new words for colors, than telling people in your book that their heat sense is perceived as "green"- That would make me want to just throw down the book and never pick it up again.

We do know of animals that have an infra-redsense/something likee heat vision:

https://en.wikipedia.org/wiki/Infrared_sensing_in_snakes

https://www.nature.com/news/2010/100314/full/news.2010.122.html

Now... its not great, only a range of several meters in the best case scenarios, down to 1 meter in other cases... but its something. The animals are also cold blooded and hunt prey much warmer than themselves.

It lacks any form of lens, and thus would be similar to the earliest stages of eye evolution, which would be a recessed pit with light sensitive cells inside the pit (a pinhole camera if you will).

Now... I suppose if you want to make them warm blooded (more active/can be active at any time), stalks aren't a bad idea, as that could help in bringing their temperature down relative to the body core, but blood (or whatever they use instead) flow would have to be limited in this case. Perhaps they could be high surface area/volume structures so that diffusion is sufficient, and they don't need blood flow. Its possible to evolve from warm blooded to cold blooded (crocodiles did it), so maybe these heat sensing organs could be in a "cold blooded" part of the alien that is relatively isolated from the rest of the alien, except for some sensory connections and a small amount of nutrient/waste exchange.

Still, I'd limit the range to just several meters, and only let them see very high temperature contrasts.

Good thermal vision requires very good cooling. Military grade FLIR uses cryogenic liquid cooling (like liquid nitrogen), and smaller portable goggles use electricity and the peltier effect, but that's really inefficient, and drains batteries qutie fast (nor does it approach the capabilities of FLIR imagers on larger vehicles). I don't see that practical for an alien given the still relatively poor result, the high energy consumption, and an extremely convoluted pathway that would be required for such a thing to evolve naturally

https://en.wikipedia.org/wiki/Thermoelectric_cooling#Materials

Heat sensing pits on a cold blooded (part of an) alien seems the best you could realistically do, unless the aliens are cyborgs or have done very extensive genetic engineering.

[Scotius]

Why not something like this? Big, extremely light-sensitive eyes to see in nearly total darkness. And a bioluminescent organ to serve as a flashlight when you are working and actually need to see what you are doing Heck, there might even be a second pair of eyes for work - less sensitive, but with much better resolution. And yes, eyestalks are still an option.

[kerbiloid]

13 minutes ago, Scotius said:

And a bioluminescent organ to serve as a flashlight

Is it enough bright to light something, not just to be visible itself?
Unlikely even a silly fish would be glad to see this face next to the light bulb.

Edited July 15, 2019 by kerbiloid

[KSK]

3 hours ago, KerikBalm said:

Sweating would not be effective to cool the amoutn required for such vision. Also the vision would not be "red or green", it would be an entirely different sense. Infrared goggles sense one wavelength, and then display a wavelength that we can see. Trying to explain what other wavelength inputs would be like, is liek trying to explain what tetrachromatic vision would be like (it is possible to make take 2 objects that look the same color to us, but birds will see them as two different colors- how would you describe what the birds are seeing?). How yould you explain red and green to a colorblind (red-green colorblindness) person? you just say they are different wavelengths, and give each a name, but that tells the colorblind person nothing about the experience. You'd be better off just inventing new words for colors, than telling people in your book that their heat sense is perceived as "green"- That would make me want to just throw down the book and never pick it up again.

It’s an interesting problem though - how does a writer convey the sensation of relying on a completely (to humans) unknown sense input?

I found a couple of solutions. One was the analogy ‘how do you move your arm’ You can get into as much biochemical detail as you like but there’s no good way (that I could think of) to describe the gap between a conscious decision of wanting to touch something and the subconscious process of physically reaching out to touch that thing.

In the end the only answer my character could think of was ‘I don’t know, I just do’, which made the point well enough.

The other solution was to cheat and rely on synaesthesia. A first character experienced the alien worldview of a second character via an interface that translated the alien sense data (which was heavily based on molecular recognition - basically a hyper-real sense of smell) into a visual equivalent that the first character could engage with and, more importantly, that I could describe in a meaningful way.

I’m not saying they’re the best solutions though, or whether they’d be enough to keep @KerikBalm reading.

[KerikBalm]

I would say just described that the character "sensed" the heat. One way we look at FLIR today is not with the blue= cold and re= hot spectrum, but just in blakc and white where white is hot, and black is cold (or vice versa)... play arma 2 or 3 and use thermal imaging  to see what I'm talking about.

With those displays, you describe the intensity of the input, not the color. Your character could describe seeing something glowing brightly in infrared (like the engine of a jet, exposed body parts, whatever)

 

Or... there's nothing standing out, you can say that the character didn't see anything, even in the infrared wavelengths, everything seemed to blend together with nothing standing out.

But if you tell me that everything looked green in infrared, I'm going to know that the author has no idea what he's writing about, and I can just expect garbage the rest of the book.

Now if you tell me the "display" of "thermal goggles" or a FLIR camera was green, fine... whatever, that's fine with me, its a device that registers one wavelength, and displays the data in another wavelength.

warning, graphic:

Not here for the political discussion, just that these are the best TI imaging videos I can find on youtube.

[kerbiloid]

57 minutes ago, KSK said:

One was the analogy ‘how do you move your arm’ You can get into as much biochemical detail as you like but there’s no good way (that I could think of) to describe the gap between a conscious decision of wanting to touch something and the subconscious process of physically reaching out to touch that thing.

And as the arms and other body parts are just clouds of elementary particles, a tiny astronomer living there will be watching in horror how a galactic arm suddenly  starts moving in a random direction without absolutely any reason.
"But gravity doesn't works this way?!..", will be his last words before they take him into an asylum.

So we live...

[magnemoe]

46 minutes ago, KerikBalm said:

I would say just described that the character "sensed" the heat. One way we look at FLIR today is not with the blue= cold and re= hot spectrum, but just in blakc and white where white is hot, and black is cold (or vice versa)... play arma 2 or 3 and use thermal imaging  to see what I'm talking about.

With those displays, you describe the intensity of the input, not the color. Your character could describe seeing something glowing brightly in infrared (like the engine of a jet, exposed body parts, whatever)

 

Or... there's nothing standing out, you can say that the character didn't see anything, even in the infrared wavelengths, everything seemed to blend together with nothing standing out.

But if you tell me that everything looked green in infrared, I'm going to know that the author has no idea what he's writing about, and I can just expect garbage the rest of the book.

Now if you tell me the "display" of "thermal goggles" or a FLIR camera was green, fine... whatever, that's fine with me, its a device that registers one wavelength, and displays the data in another wavelength.

IR cameras used for detecting heat output or leaks tend to show color but tactical IR tend to be black and white. Wonder if that is that the B/W image looks more like how things will look at night. 
As hot things tend to also be bright in IR adding an color we would see as artificial would just make the input less visible. 

Don't IR cameras has to be cooled to spot items colder than them-self? 

[Guest]

We really have some insane sensory abilities when you think about it.

-The ability to smell compounds and gasses around us and determine roughly what they come from and from what direction.

-The ability to hear vibrations in the atmosphere to a high degree of sophistication and sensitivity. Even to the extent of detecting vibrations of tiny things moving or a leaf falling to the ground etc...

-We can see many wavelengths of light allowing us to have an impression of everything it touches and determine complex information about the world around us. And even see stars unimaginably far away.

We can detect changes in temperature, we can feel the world around us, taste it...

The extent to which we’re equipped to receive information about the world around us is quite amazing. 

Edited July 15, 2019 by Guest

[Guest]

8 hours ago, magnemoe said:

IR cameras used for detecting heat output or leaks tend to show color but tactical IR tend to be black and white. Wonder if that is that the B/W image looks more like how things will look at night. 
As hot things tend to also be bright in IR adding an color we would see as artificial would just make the input less visible. 

It might have to do with the fact the military doesn't really care how hot something is, just above/below human body temperature. Heat leak inspectors do, because those are rather more subtle. Commercial FLIRs often have a scale somewhere on the screen, showing which color corresponds to what temperature. No need for that in military. Omitting this makes the display easier to read, allows usage of a cheaper monochromatic display and may simplify electronics, as well.

[KerikBalm]

18 hours ago, magnemoe said:

IR cameras used for detecting heat output or leaks tend to show color but tactical IR tend to be black and white. Wonder if that is that the B/W image looks more like how things will look at night. 
As hot things tend to also be bright in IR adding an color we would see as artificial would just make the input less visible. 

Don't IR cameras has to be cooled to spot items colder than them-self? 

The military often uses FLIR in the day time as well.

And yes, my understanding is that the IR camera has to be colder than the objects it wants to see, in order to have a sufficient signal to noise ratio

10 hours ago, Dragon01 said:

It might have to do with the fact the military doesn't really care how hot something is, just above/below human body temperature.

I don't think that's exactly true. I think many displays have adaptive contrast. Its not human body temperature only, its vehicle engines, weapon muzzles (if they've been firing recently), etc.

Its just about contrast. The military wants to spot "active" things, and "active" things tend to emit IR. Its just trying to find anything that stands out from the background. Modern warfare is all about being the first to detect the enemy, since modern weapons are pretty lethal and you can pretty much kill anything you can see

[Guest]

Oh btw, I’m sure a lot of you would be familiar with IsaacArthur on YouTube. His upcoming vids will be a series exploring life in space, what that might look like and also the distinction between technology and biology. He’s a good source of futurism and sci fi info. He ventures into really far out topics while still being securely anchored in the laws of physics. 

Might be helpful to go check out his vids if anyone hasn’t already. I sometimes listen to them while doing my grocery shopping XD

[Guest]

4 hours ago, KerikBalm said:

I don't think that's exactly true. I think many displays have adaptive contrast. Its not human body temperature only, its vehicle engines, weapon muzzles (if they've been firing recently), etc.

Its just about contrast. The military wants to spot "active" things, and "active" things tend to emit IR. Its just trying to find anything that stands out from the background. Modern warfare is all about being the first to detect the enemy, since modern weapons are pretty lethal and you can pretty much kill anything you can see

It is exactly true. A weapon's muzzle or a running engine tends to be much hotter than a human body, so obviously it will also stand out. The general rule is, if something's below ambient temperature, it's probably not of interest. Determining the exact temperature is not important.

You are going to have trouble with FLIR if operating in ambient temperatures close to human body temperature. Daytime FLIR use has it limits for that reason. Abandoned vehicles left out in the sun, metal shacks and other such things can and will clutter up a FLIR picture.

[KerikBalm]

40 minutes ago, Dragon01 said:

It is exactly true. A weapon's muzzle or a running engine tends to be much hotter than a human body, so obviously it will also stand out. The general rule is, if something's below ambient temperature, it's probably not of interest. Determining the exact temperature is not important.

Ambient temperature != human body temperature.

Something can be between human body temp and ambient temp, and still be of interest. That's my point.

I agree that "determining the exact temperature is not important", I was just taking issue with the part " just above/below human body temperature "

I would replace human body temp with ambient temp

[kerbiloid]

Spoiler

1 hour ago, Dragon01 said:

The general rule is, if something's below ambient temperature, it's probably not of interest.

+1

Spoiler

Season 8 has proven that.

 

 

Spoiler

26 minutes ago, KerikBalm said:

Ambient temperature != human body temperature.

Depends on how long the body is lying there.

 

26 minutes ago, KerikBalm said:

I would replace human body temp with ambient temp

Everything to be shot is either cold or warm as / warmer than an alive human.

Edited July 16, 2019 by kerbiloid

[Guest]

1 hour ago, KerikBalm said:

Something can be between human body temp and ambient temp, and still be of interest. That's my point.

Not really. There aren't many things in that category, seeing as we're talking a 10-30 degree range in most circumstances (that is, not a winter in Ukraine). In practice, human body is the coldest thing the military cares about (not counting buildings and such, which tend to be at ambient temperature, anyway). Indeed, you may want to set your cutoff higher than ambient so that localized warm spots are better filtered out. 

An alien's thermal sense would probably work in a similar way, giving a vague outline of image and enough of an idea about temperature to know whether something is prey or not. Range would not be long, depending heavily on cooling. Sure, it'd take a convoluted sequence of events for such a sense to evolve in a warm blooded creature, but it's not like we don't have similarly complex evolutionary pathways in Earth animals (creationists just love to latch onto those, ignoring the fact that with such a complex and diverse biosphere, a few such "contrivances" are more or less guaranteed).

Edited July 16, 2019 by Guest

[kerbiloid]

Spoiler

But sometimes they are cheating...