New OOTS products from CafePress
New OOTS t-shirts, ornaments, mugs, bags, and more
Results 1 to 6 of 6
  1. - Top - End - #1
    Bugbear in the Playground
     
    Absol197's Avatar

    Join Date
    Apr 2011
    Location
    Ashes...
    Gender
    Female

    Default A Polarizing Topic! (I'msosorrydon'thurtme)

    Hey there, fellow scientists in the Playground! I'm having some trouble with something, and I was hoping the more informed among you might be able to help!

    Say I were to have a species that was able to perceive the polarization of light. There are real-life examples, such as the cuttlefish and the mantis shrimp, so not too farfetched. This species has eyes that, in addition to detecting the variance in the amount of light across its field of vision (intensity), as well as the frequency of the light across its field of vision (color), can, as a third dimension of visual acuity, also detect the variation in polarity of light. How would this help them?

    Obviously you can't tell me what this would look like, but in general, how would this change their perception of a scene? After doing some research I have a guess: my guess is that the light reflecting off of sharp edges on objects would be highly polarized in a certain direction, and concave and convex surfaces would have recognizable patterns to how they were polarized (depending on the substance).

    So if my guess is right, this ability would help the species to more easily determine the shape and extent of objects in their environment, especially in lower light, and might help a little with determining what something is made from. Is this even remotely close? Is there any obvious benefit I've missed?

    Also, I was thinking that, to achieve this type of vision, the creatures would have basically a ribbed iris, vaguely similar to the ribbing in a polarizing lens, but extending radially from the center to detect the polarization instead of causing it to become polarized. Would this make sense?

    Thanks for all your help!
    Last edited by Absol197; 2017-08-31 at 12:40 AM.
    "It is important to draw wisdom from many different places. If you take it from only one place, it becomes rigid and stale." --Iroh
    LGBTAitP! If you want to talk, learn, or have some fun, stop by!
    Avatar by the lovely Lycunadari!

  2. - Top - End - #2
    Colossus in the Playground
     
    BlackDragon

    Join Date
    Feb 2007
    Location
    Manchester, UK
    Gender
    Male

    Default Re: A Polarizing Topic! (I'msosorrydon'thurtme)

    Bees can see polarised light as well--they use it to determine what direction the sun is in even on overcast days, which allows them to navigate very precisely to and from their hives.

  3. - Top - End - #3
    Bugbear in the Playground
     
    Absol197's Avatar

    Join Date
    Apr 2011
    Location
    Ashes...
    Gender
    Female

    Default Re: A Polarizing Topic! (I'msosorrydon'thurtme)

    Hmm, they do! I'm curious as to why being able to see polarization helps with this. Does the polarization of sunlight line up in a certain orientation across the sky? I would have assumed that random scattering would have made the sky sort of like its own light source, with the light coming from any one place being randomly unpolarized. Apparently I'm wrong, but I'm still confused on the why.
    "It is important to draw wisdom from many different places. If you take it from only one place, it becomes rigid and stale." --Iroh
    LGBTAitP! If you want to talk, learn, or have some fun, stop by!
    Avatar by the lovely Lycunadari!

  4. - Top - End - #4
    Colossus in the Playground
     
    BlackDragon

    Join Date
    Feb 2007
    Location
    Manchester, UK
    Gender
    Male

    Default Re: A Polarizing Topic! (I'msosorrydon'thurtme)

    In fact, it's the scattering that makes the light polarised--the line of the polarisation is at a tangent to concentric circles with the sun at the centre. More info here:

    https://www.polarization.com/sky/sky.html

  5. - Top - End - #5
    Bugbear in the Playground
     
    Absol197's Avatar

    Join Date
    Apr 2011
    Location
    Ashes...
    Gender
    Female

    Default Re: A Polarizing Topic! (I'msosorrydon'thurtme)

    That is very useful, thank you!

    So that explains the sky, and gives my creatures an ability to help them navigate. I am still wondering how this would affect their perception of objects. Intuitively, I would think that light that strikes an object would polarize so the plane of polarization would be parallel to the surface it reflected off of, mostly regardless of what that surface is made of.

    If this is the case, I'm thinking that using the polarization of the reflected light would allow a critter to more easily distinguish the shape of an object, as even if there was very little variance in the intensity or color of light across it's surface, the patterns of polarization would help define its shape. For instance, light bouncing off a convex surface would tend to polarize circularly (i.e. similar to sunlight, with the top of the "bump" being the sun), having a gradient of change with an intensity that increases the more curved the surface is. Comparatively, sharp edges would provide a consistent polarization until you hit the edge and then change to the polarization of the background objects, creating a sharp contrast.

    Is this right? If so, I would imagine that this would help with defining the dimensions and shapes of objects in the environment, especially in low light when color vision is more difficult and there are lower variations in intensity.

    Also, reading more into mantis shrimp and why scientists believe they have this vision, I've found mention that it might help them see transparent objects. Would this track? light passing through a transparent (but not 100% transparent) object would naturally polarize to a degree (not completely, but a little), allowing a distortion to be more easily visible? Or would it depend on the substance of the transparent object? I think it would.

    Regardless! Thanks for your help, Factotum! I'm using this for a writing project, so being able to accurately describe how these beings can perceive the world is super-useful to me.
    "It is important to draw wisdom from many different places. If you take it from only one place, it becomes rigid and stale." --Iroh
    LGBTAitP! If you want to talk, learn, or have some fun, stop by!
    Avatar by the lovely Lycunadari!

  6. - Top - End - #6
    Ogre in the Playground
     
    gomipile's Avatar

    Join Date
    Jul 2010

    Default Re: A Polarizing Topic! (I'msosorrydon'thurtme)

    Quote Originally Posted by Absol197 View Post

    Also, I was thinking that, to achieve this type of vision, the creatures would have basically a ribbed iris, vaguely similar to the ribbing in a polarizing lens, but extending radially from the center to detect the polarization instead of causing it to become polarized. Would this make sense?
    This would cause the light to become polarized, and the way it would do so would allow the detection of the polarization direction. It would do what you want, but not precisely the way you said it.

    In one of my physics classes in the 90s we had a polarizer whose microscopic inscribed lines were concentric circles. It let you see at a glance what angle light was polarized at, and also see what the rough proportion of light polarized in different directions was for mixed or partially polarized light. I've tried a bunch of Google searches, but I can't find one to even see what this type of polarizing filter is called.

    Anyway, these types of measuring filters do polarize the incoming light as it passes through. The important part is that the direction of polarization changes predictably as one moves along the surface of the filter.

    Quote Originally Posted by Absol197 View Post
    Also, reading more into mantis shrimp and why scientists believe they have this vision, I've found mention that it might help them see transparent objects. Would this track? light passing through a transparent (but not 100% transparent) object would naturally polarize to a degree (not completely, but a little), allowing a distortion to be more easily visible? Or would it depend on the substance of the transparent object? I think it would.
    It would depend on the refractive indices of all the parts making up the transparent object, and what angles all those parts are put together at. Those are functions of the substance of the object, so the answer to your question is yes.
    Quote Originally Posted by Harnel View Post
    where is the atropal? and does it have a listed LA?

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •