View Single Post
Old 03-30-2017, 01:22 PM   #19
whswhs
 
Join Date: Jun 2005
Location: Lawrence, KS
Default Re: [Basic] Advantage of the Week (#38): Dark Vision, Night Vision

Quote:
Originally Posted by Kalzazz View Post
Ah. I've found it very common for Infra vision to exist in same categories as low light vision and dark vision. Also very common to see low light vision and infra vision as alternate a b ilities
When I looked into this when writing Enhanced Senses, I found that the category of "infravision," including the standard Basic Set definition, is scientifically incoherent. On one hand there's near infrared, which occupies wavelengths just slightly longer than red light, and can be resolved to nearly as high precision, but you need extremely high temperatures to get NIR emissions; if the sun's below the horizon it will be nearly as dark in the NIR as in the visible. Living organisms don't emit meaningful levels of NIR. On the other hand there's thermal infrared, which homeothermic organisms do emit—but which has much longer wavelengths and thus very low resolution; it's really more of a ranging and targeting sense than a "seeing" one. For one thing, it can't trigger chemical reactions directly; you need arrangements like what pit vipers have.

Since we don't see IR anyway, we tend to lump it all together. But there are real differences in what can emit different EM bands, and what kinds of physiological systems can detect them.
__________________
Bill Stoddard

I don't think we're in Oz any more.
whswhs is online now   Reply With Quote