Quote:
Originally Posted by Anthony
Infravision sufficient to detect a person is probably not possible for an exotherm, though there are endotherms (pit vipers) with a primitive version, and there's certainly no easy evolutionary path that leads to it. Night vision adaptations are more possible but won't do a lot of good underground, as they only work in conditions of low light, not no light. Echolocation (in GURPS, probably a low res air sonar) is an option but again there's no easy evolutionary path.
|
You've got those terms reversed. An endotherm is an organism that generates heat internally ("endo"); an ectotherm is one that takes in heat from its external environment ("ecto"). Pit vipers are ectotherms.
Realistically, infrared vision that responds to human body temperature has poor resolution; the wavelength of peak emission at human body temperature is about 16x that of monochromatic green light at peak human visual sensitivity, and for an eye of a given size, resolution is limited by wavelength. So you'd get around 20:320 visual acuity at best. You can do a lot better with near infrared, which could get you to around 20:40, but NIR emission from a human body is nearly zero; you'd need a temperature of around 4000°F to get peak emission in the NIR, if I'm figuring Wien's law right.