> near-infrared So, still red then?
No. "near-infrared" isn't a red color shade, in fact it's not normally visible at all. Near-infrared is what your media remote uses to control your TV and audio system. You really cannot see it.
Biologically extending human vision into the near-infrared: Initial success
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Re: Biologically extending human vision into the near-infrared: Initial success
#22On the other end of the scale: http://science.slashdot.org/story/12/02/14/165202/followup-u...
Re: Biologically extending human vision into the near-infrared: Initial success
#23On the other end of the scale: http://science.slashdot.org/story/12/02/14/165202/followup-u...
It's funny that most of the jokes tend to revolve around becoming some sort of super hero. The stranger thing is that no one has pondered the potential cons having the ability to see beyond the spectrum. Or maybe I don't read enough comic books?
Re: Biologically extending human vision into the near-infrared: Initial success
#24When is the flash on and when is it off in these plot?
What would these plots look like in a control subject?
Does the subject have any other indication of when the flashes are occurring?
I know that this isn't written to be read critically, but I don't know what the take-away is.
Re: Biologically extending human vision into the near-infrared: Initial success
#25This could certainly be possible. Jay Neitz did experiments on monkeys to cure colorblindness using gene therapy and was successful. [1] He has said that perhaps one day humans can have genes for more color receptors added to be able to see more colors as some birds do.
Re: Biologically extending human vision into the near-infrared: Initial success
#26On the other end of the scale: http://science.slashdot.org/story/12/02/14/165202/followup-u...
It's funny that most of the jokes tend to revolve around becoming some sort of super hero. The stranger thing is that no one has pondered the potential cons having the ability to see beyond the spectrum. Or maybe I don't read enough comic books?
I read something on imgur or here some days ago from a guy who could "see" some UV. He had to wear polarizing glasses because of headaches and had developed a fascination for violet objects.
Re: Biologically extending human vision into the near-infrared: Initial success
#27What an interesting experiment. Could there be some basis, after all, to the urban legend that eating carrots improves night vision? Carotenes are "partly metabolized into Vitamin A" [1], but this experiment is skipping the precursors and going straight for what I assume are large and exclusive doses of Vitamin A. Can it really be that no one has tried this before? Related and probably equally silly idea: I've always…
AFAIK vitamin A is poisonous in larger doses. In Finland they were worried at time that people might be getting to much of vitamin A. http://en.m.wikipedia.org/wiki/Hypervitaminosis_A
Everything is poisonous at some dosage.
http://en.wikipedia.org/wiki/Median_lethal_dose
Edit: From this [1] non-scholarly source,
"The median lethal dose (LD50 value) of vitamin A injected intramuscularly
in a water-miscible form in the young monkey is 0.6 mmol (168 mg) retinol/kg
body weight. Extrapolated to a 3-kg child and a 70-kg adult, the total LD50
dose would be 1.8 mmol (500 mg) and 41 mmol (11.8 g) respectively."
[1] http://www.uta.edu/faculty/sawasthi/Lecture%20Notes%20Chem14...
Re: Biologically extending human vision into the near-infrared: Initial success
#28Earlier quoted context omitted.
"Much publicity has been given to the good effects of carrots on night vision and some newspapers have even begun to use the vegetable as a nickname for certain ace pilots. Actually, night-fighter pilots don't eat anymore carrots than day fighters do..." —LIFE June 23, 1941 (Not quite the same, but in a similar vein)
Thanks. Snopes has this: http://www.snopes.com/food/ingredient/carrots.asp "While carrots are a good source of vitamin A (which is important for healthy eyesight, skin, growth, and resisting infection), eating them won't improve vision. The purported link between carrots and markedly acute vision is a matter of lore, not of science. And it's lore of the deliberately manufactured type. "In World War II, Britain's air…
> I've been known to employ somewhat similar tactics myself.
How can we be sure?
Re: Biologically extending human vision into the near-infrared: Initial success
#29What an interesting experiment. Could there be some basis, after all, to the urban legend that eating carrots improves night vision? Carotenes are "partly metabolized into Vitamin A" [1], but this experiment is skipping the precursors and going straight for what I assume are large and exclusive doses of Vitamin A. Can it really be that no one has tried this before? Related and probably equally silly idea: I've always…
Night vision uses the photoelectric effect to translate a few photons from the lens into a picture you can see. It doesn't change the frequency of incoming light - it absorbs it and transmits an electron. Basically you are carrying around something similar to an old style tv on your head.
Photoreceptor proteins, such as rhodopsin (typically the first GPCR [1] you'll study in a biochem undergrad program), each have different characteristic absorption spectra. But it's much more complex than that--each of these proteins exhibit different absorption spectra given different isomerizations and even different conformers [2] .
Here are some absorption spectra [3] of crystals of various rhodopsin isomers. I'm not sure if any of these are biologically relevant isomers, but it's interesting that these were not in solution. (I suppose that since they're membrane-bound GPCRs and might be difficult to study in solution? This isn't my field of study.)
Check out some bacterial absorption spectra [4]. Visual perception isn't limited to organisms with eyes. Or even eukaryotes, for that matter. It's actually pretty ancient [5].
On that note, pigment chemistry is pretty fascinating.
1. http://en.wikipedia.org/wiki/G_protein-coupled_receptor The GPCR family is really cool. A ton of our sensory perception arises from class A GPCRs. Here's a really beautiful diagram of the 7 transmembrane regions of rhodopsin: http://physrev.physiology.org/content/physrev/81/4/1659/F1.l...
2. http://www.sciencedirect.com/science/article/pii/S2210271X13... Just to cite an instance, though this one isn't vision-related.
3. http://www.pnas.org/content/103/44/16123/F1.expansion.html
Re: Biologically extending human vision into the near-infrared: Initial success
#30On the other end of the scale: http://science.slashdot.org/story/12/02/14/165202/followup-u...
It's funny that most of the jokes tend to revolve around becoming some sort of super hero. The stranger thing is that no one has pondered the potential cons having the ability to see beyond the spectrum. Or maybe I don't read enough comic books?
From Slashdot: "Seriously though, as someone who has a hearing range beyond the standard I sympathise with people forced to endure irritating stimuli that noone else notices and hence cares about. I remember having to leave a bar once because the tube was going on their old television; the high pitched screech was like nails down a blackboard. My girlfriend thought I was mad."