Just curious. Any humans ever been verified to have this ability?
Depends on what you mean by ability. IIRC the human eye can process ultraviolet, it’s just our lens is opaque to it.
Which is why people who don’t have lenses in their eyes can see ultraviolet. See here:
Infants can see pretty far into the ultraviolet, because the transparent parts of their eyes have done so little yellowing with age.
At both ends of the spectrum, though there are specific wavelength definitions between visible and infra or ultra, our ability to see is trailing off gradually. So, the more powerful the source, the further beyond that defined wavelength you’ll be able to see it.
Some snakes, I think Pit vipers, have IR detectors. They don’t see as such, but can detect the shape an animal to allow then to strike.
A site about infrared goggles.
Basically, if you block the visible portion of the spectrum with appropriate filters, and have a very bright IR source like the sun, your eyes can detect it.
I actually came in here to link the very same page brossa did.
I’ve always wanted to make a pair of those goggles but I’m really paranoid I’ll fry my eyeballs, even though they actually block more light then standing around with no goggles on and should be safe.
As I understand, this is correct, and the detectors are the pits. They’re depressions that are very good at sensing heat flux, which includes the thermal infrared. Having a curved surface means the relative flux in different areas gives a directional sense to the detection, though still pretty vague.
I also read that similar pits with light sensitive cells are thought to represent an early stage of the evolution of eyes. Why couldn’t evolution continue to improve the pit viper’s infrared detection into much sharper and more detailed vision? In fact, why not refer to what pit vipers are already doing as vision? Makes sense to me.
There was a scandal maybe 10 years back that Sony camcorders would let you see through people’s clothes. They had a nightvision mode that sensed IR, and that mode worked in daylight. With a filter that blocked out the visual spectrum, some fabrics turned translucent. A few synthetic materials became downright transparent.
Edit: and hey! they’re still on ebay
Something about this doesn’t sound right.
Like what?
I didn’t think an object’s color had anything to do with said object’s ability to block light. I can understand the IR filtering letting someone see “heat silhouettes”, but I’d expect nothing at all like comic-book-style X-ray vision.
Some cloth is transparent to ultraviolet light. Some isn’t. Just like some glass is transparent to UV light and some isn’t.
If you don’t block the visual spectrum, then visible light overwhelms the CCD sensor (it wasn’t spectrum-specific). The IR sensor did not pick up body heat, it only worked with light reflected from a bright source of IR like sunlight or incandescents (or the built-in camera IR bulb).
I thought the night-vision filter on the camera detected infra-red light?
Some synthetics are in fact transparent in the near IR. The view you’d get wouldn’t be quite the same as looking at a naked person with visible light, but it’d be similar.
Something like a frosted window pane, wouldn’t it be? Unless the fabric was of an ususually tight weave and was panty-hose thin … thinking that the texture of the fabric would cause the IR light to diffuse too much to get a great image.
Yes, that’s exactly it. The fabric has to be skin-tight. Or so I hear…
Is there any confirmation that these are really infrared goggles. The before/after pics look suspiciously… purple… which might be expected since the filters involved are red and blue.