6
$\begingroup$

My planet is frequently set with thick fog. What is the best way to have its residents see accurately?

One species called Hell Fires fall from the sky, landing on top of prey and killing it. How could they actually see through the fog in order to hit the target? We are talking a range of over 100M.

If it works on Earth it works here too (that is, the planet is similar to Earth).

$\endgroup$
1
  • 3
    $\begingroup$ Your species can see radio waves $\endgroup$
    – nzaman
    Commented Sep 28, 2019 at 16:37

4 Answers 4

10
$\begingroup$

Infrared, Sonar, and Other Waves

Some animals use "bio sonar", or echolocation as a form of "sight" (ie, navigating and foraging). It's also possible for your creatures to see infrared radiation.

If fact, your creatures could emit small amounts of waves from just about anywhere on the electromagnetic spectrum, except for visible light, and therefore "see" what is happening.

$\endgroup$
3
  • 1
    $\begingroup$ Longer wavelength light = less scattering. Reds are the longest we can see but wavelengths get longer and longer. A creature which could emit a headlight-type beam of long wavelength radiation would easily be able to scan the ground thru the fog to find prey. $\endgroup$
    – Willk
    Commented Sep 28, 2019 at 17:34
  • $\begingroup$ @Willk you are right, in general. But longer wavelength also brings inability to detect small objects and require bigger emitters. So practical upper border would be microwaves with 1-10 cm wavelength. $\endgroup$
    – ADS
    Commented Sep 30, 2019 at 7:48
  • $\begingroup$ Sonar scatters badly in air with fog or smoke, and it's not very useful beyond 20 m or so because of time delay. $\endgroup$
    – Zeiss Ikon
    Commented Oct 1, 2019 at 12:30
4
$\begingroup$

Not a biologist or physicist, but the simplest answer I can think of is infrared vision.

https://www.youtube.com/watch?v=Y7mROTPAVZM

As seen here, it does penetrate fog to a degree, and at long distance. Yes, infrared isn't as clear as normal vision without fog, but it is probably enough of an advantage in bad conditions to be viable.

I think you can use the excuse of evolution to explain how they see infrared. It isn't naturally visible for humans, but infrared is on the light spectrum. I don't think it is much of a stretch to say the Hell Fires eyes evolved to see that section of the spectrum. It also has the built in advantage (for you) that it is possibly a disadvantage when there is no fog, so they are not too powerful.

$\endgroup$
1
  • $\begingroup$ Lots of animals see fairly far into the infrared -- insects see both IR and UV, to some level. You don't need to see far IR to penetrate fog, either -- you'd only have to extend human sensitivity by 50-70 nanometers to penetrate fog to well over 100 m. $\endgroup$
    – Zeiss Ikon
    Commented Oct 1, 2019 at 12:29
1
$\begingroup$

Ever seen a snake frisk its tongue !!

It doesn't do it do just look cool, It can see it's prey in 3 different modes.

One, with its eyes, can see a broader spectrum than us.

Second, use its tongue to pick up the smell in the environment.

but the really cool one is the third, that is vibrations. A snake can pick up vibrations around it and pinpoint the exact locations of moving things.

In a foggy atmosphere, I hope the vibrations can travel much more effectively than a normal clean atmosphere. So, essentially your hellfires could be just Snakes with wings, they may not need to frisk their tongues every 10 seconds, but you get the idea.

A predator with 3 ways of seeing in its environment.

$\endgroup$
1
  • 1
    $\begingroup$ Vibration only works if your jaw is in contact with the ground, the broader spectrum won't help if anything it will be a hindrance (poorer night vision) and smell is worthless for fine accuracy. $\endgroup$
    – John
    Commented Oct 1, 2019 at 17:23
1
$\begingroup$

Long wavelength EM or sonar are both probably good picks for low-latency feedback. However, both types of wave will be scattered and attenuated to some extent (just, less so than visible light EM).

One thing to note is that "Temperature and humidity affect odor because they increase molecular volatility."

Perhaps your Hell Fires have extremely sensitive olfactory organs, which they use to detect the general presence of their victims. As a result, the fog (and resulting humidity increase), means that danger is drastically increased. For specific targeting they have to switch to some wave, but maybe this occurs around 30 meters.

$\endgroup$

You must log in to answer this question.

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