>This is why you can’t see things in dark; no light means that there is no way that you can channel the information about the surroundings into the person’s eye.
This is not exactly accurate to my understanding. As carl Sagan once said "we are star stuff", and just like stars wherever there is a human to see - even in the "dark" - there is light.
Take the image of the sun/sun rays, moon and eye from the article, its important to remember all matter is emitting light (that includes the moon and the eye and human attached to the eye) not just the Sun.
Even in the "dark" everything including the person will be emitting light (electromagnetic radiation). Humans mostly emit electromagnetic radiation in the infrared wave length, but humans also emit some electromagnetic light in "visible" wave lengths. The issue is obviously humans have not evolved eyes that see "infrared" light like other animals, and similarly the visible light humans emit is below the intensity human eyes evolved to see. However, if human eyes were sensitive enough all humans would appear as shining stars emitting their own light.
Not sure its a thought experiment, but I always thought to understand human sight look at your hand. Then pretend you saw infrared and imagine what you hand looks like (or google a hand in infrared), then do the same as though you saw x-ray wave length light. Now try to imagine if you could see all 3 spectrum at once...what would that look like?
>> This is why you can’t see things in dark; no light means that there is no way that you can channel the information about the surroundings into the person’s eye.
> The issue is obviously humans have not evolved eyes that see "infrared" light like other animals, and similarly the visible light humans emit is below the intensity human eyes evolved to see. However, if human eyes were sensitive enough all humans would appear as shining stars emitting their own light.
In other words, the quote you pulled is completely accurate. It didn't say there was no way to channel the information about the surroundings into any photosensitive device. It says quite clearly that you can't channel the information into a human eye.
> Not sure its a thought experiment, but I always thought to understand human sight look at your hand. Then pretend you saw infrared and imagine what you hand looks like (or google a hand in infrared), then do the same as though you saw x-ray wave length light. Now try to imagine if you could see all 3 spectrum at once...what would that look like?
Probably much like looking at a solid object embedded in colored but not opaque glass. The ability to see things inside other visible things is not foreign to the visible light spectrum.
> It didn't say there was no way to channel the information about the surroundings into any photosensitive device.
No it specifically said
>"This is why you can’t see things in dark; no light means...".
Not sure how to make the distinction any simpler, maybe you can follow:
If there is no light, then it is dark (true) - thats what you claim is being said, but thats not what is said, what is said is
If it is dark, then there is no light (false) - any time you have been in the dark, there has always been light.
>Probably much like looking at a solid object embedded in colored but not opaque glass. The ability to see things inside other visible things is not foreign to the visible light spectrum.
Sure the non-imaginative approach is to say just superimpose 3 images on top of one another with each image having some transparency. And sure that may make sense for objects like bone inside the persons outer skin...but emitted heat is not a solid object inside another solid object, it neither embedded in the object (its emitted) nor solid.
When did "I pretend otherwise"? My comment(s) have nothing to do with the meaning of light. I'm not sure what you get out of pretending otherwise.
Either way in the dark when you can't see, the author is wrong, that doesn't mean there is no light...there is light, at minimum the person who can't see is emitting it. Many people don't know that and find it interesting.
Now I see the problem and confusion on your end...you don't think humans emit visible light.
Like I said, most people don't know and are fascinated, that is why I shared it...I don't find many who dispute it, but here are some articles about the studies that confirmed it:
This is not exactly accurate to my understanding. As carl Sagan once said "we are star stuff", and just like stars wherever there is a human to see - even in the "dark" - there is light.
Take the image of the sun/sun rays, moon and eye from the article, its important to remember all matter is emitting light (that includes the moon and the eye and human attached to the eye) not just the Sun.
Even in the "dark" everything including the person will be emitting light (electromagnetic radiation). Humans mostly emit electromagnetic radiation in the infrared wave length, but humans also emit some electromagnetic light in "visible" wave lengths. The issue is obviously humans have not evolved eyes that see "infrared" light like other animals, and similarly the visible light humans emit is below the intensity human eyes evolved to see. However, if human eyes were sensitive enough all humans would appear as shining stars emitting their own light.
Not sure its a thought experiment, but I always thought to understand human sight look at your hand. Then pretend you saw infrared and imagine what you hand looks like (or google a hand in infrared), then do the same as though you saw x-ray wave length light. Now try to imagine if you could see all 3 spectrum at once...what would that look like?