Why Human Eye is most sensitive in green ?????

On Sun, 11 Jan 2004, "Markus Ludes" wrote:
I hope to find here a expertise answere to this questions, asked to me
by our neighbour who just started in astronomy.
we all know that the human eyes are highest senstive at diffrent
wavelenght on day or night time
Now can somebody explain why the human eyes are most sensitive at about
500 to 530 nm and not at 600 to 650 nm or 400 to 450 nanometer ?
Is it just because God made it that way, or is there any biological or
physical reason for that ?
we asked several PHD Physics and Biological People and they all have
been a bit confused because never somebody asked this question before
and they even dont know the answere
so is here somebody who can explain me the reason ?

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Let's see. The night sky is closer to Indigo (between blue
and magenta or violet). While the day sky's closer to cyan
or bluegreen. Green is yellow-cyan and is exactly opposite
magenta or violet on the zodiacal color wheel. Men adapted
to the color of the Sun in the daytime sky to wit yellow &
cyan, respectively. Yellow & Cyan mixing together is Green.
A simple sidereal & synodic chart of the zodiac shows this:

SIDEREAL (Solars)
|------------------29.45------------------|
| |--------------11.86--------------| |
| | |----------1.881----------| | |
84.02 | | |------0.615------| | | |
/Ur | | | |--0.241--| | | | |
| 164.8 | | | 0.075 | | 247.9 | |
| /Ne | | | | 1 | | /Pl | |
| | | | | | | | | | | |
IVi Vio Red ROr Ora OYe Yel Gre GBl Blu BIn Ind
Sat Jup Mar Ven Mer Moo Sun Mer Ven Mar Jup Sat
Aqu Pis Ari Tau Gem Can Leo Vir Lib Sco Sag Cap
11 12 1 2 3 4 5 6 7 8 9 10
Bb B C Db D Eb E F Gb G Ab A
| | | | | | | | | | | |
| */Ne | | | | - | | */Pl | |
| 1.006 | | | 0.081 | | 1.004 | |
*/Ur | | | |--0.317--| | | | |
1.012 | | |------1.599------| | | |
| | |----------2.136----------| | |
| |--------------1.095--------------| |
|------------------1.035------------------|
SYNODIC (Lunars)

*Ura Earth's sidereal year =~ 1.00004
*Nep Earth's tropical year =~ 1.00000
*Plu Earth's own geocenter =~ 0.00000

Daniel Joseph Min

*Min's Planetary Awareness Technique (Min's fourth book):
http://groups.google.com/groups?selm...amesh-frog.org

*Min's Light & Sound (Min's third book):
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*Min's Historical Calendar Of Jesus (Min's first book):
http://groups.google.com/groups?selm...t orebels.net

*Min's Interlinear Translation of the Apocalypse:
http://groups.google.com/groups?selm...amesh-Frog.org

*Min's $10,000 Reward For Astronomers:
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On a sunny day (11 Jan 2004 16:18:07 +0100) it happened Des Moines
wrote in
:

Let's see. The night sky is closer to Indigo (between blue
and magenta or violet). While the day sky's closer to cyan
or bluegreen. Green is yellow-cyan and is exactly opposite
magenta or violet on the zodiacal color wheel. Men adapted
to the color of the Sun in the daytime sky to wit yellow &
cyan, respectively. Yellow & Cyan mixing together is Green.
Have a break Min, you are way out there.
I suggest a neuron re-connect job.

On Sun, 11 Jan 2004 22:19:48 +0100 (CET), George Orwell
wrote:

i dont get it . some body claim the sun isnt yellow ? i never heard
any thing other then like a " yellow sun " .
if it isnt yellow whta is color like the brite sun ?

"Color" is closely related to human perception. The color of the Sun is white.
It is not yellow at all, although it may appear very slightly so in some cases
from the bottom of our atmosphere due to the loss of shorter wavelengths to
scattering.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

"Color" is closely related to human perception. The color of the Sun is
white.
It is not yellow at all, although it may appear very slightly so in some
cases
from the bottom of our atmosphere due to the loss of shorter wavelengths
to
scattering.

If I colored the sun white my art teacher would give me an F.

"Shawn Grant" wrote in message
...

If I colored the sun white my art teacher would give me an F.

Does the F stand for "Funny"?

On Sun, 11 Jan 2004, George Orwell wrote:
i dont get it . some body claim the sun isnt yellow ? i never
heard
any thing other then like a " yellow sun " .
if it isnt yellow whta is color like the brite sun ?

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The light of the Sun itself is different from the color
of sunlight as viewed here from Earth with our own eyes.
The spectral class of the Sun is G2v, with most intense
wavelengths at about 5010 A (5.010 x 10^-7m) because of
the Sun's surface temperature, luminosity, and distance.
NASA's site describes this as a "solar-type spectra..ab-
sorption lines of neutral metallic atoms and ions..grow
in strength". By contrast, the sunlight we see with our
eyes is definitively yellow near southing (12 Noon LAT)
and falls off toward orangish-yellow, then red-orangish
as the sky appears to blend from skyblue down to yellow,
orange-yellow and red as low bandwidths become dominant
as sunlight filters obliquely through Earths atmosphere.
This of course changes with the seasons, latitudes, and
concentration of various particulates in the atmosphere,
and any weather rolling in changes colors significantly,
e.g., thick clouds can appear green above yellow fields!
But most people aren't color blind and have fair vision,
so what one person sees as "green" another sees it also.
You don't hear anyone saying "out of a CLEAR GREEN SKY"
(or if they do, they're probably tripping on mushrooms).

We seldom look directly at the Sun for more than a frac-
tion of a second. So the color of the sunlight is gaged
more by how it appears from the Earth's surface to illu-
minate our daytime sky and all objects that we see down
here where human beings have lived and evolved for many
millions of years with its contrast of light and shadow,
day and night, and everything in between these extremes.
So the sunlight we see is more yellow than any other co-
lor & our daytime sky is more cyan than any other color.
When you mix predominantly yellow with predominantly cy-
an you get predominantly green. It's really very simple.

Enjoy!
Daniel Joseph Min

*Min's Planetary Awareness Technique (Min's fourth book):
http://groups.google.com/groups?selm...amesh-frog.org

*Min's Light & Sound (Min's third book):
http://groups.google.com/groups?selm...amesh-frog.org

*Min's Compleat Tarot Manual (Min's second book):
http://groups.google.com/groups?selm...amesh-frog.org

*Min's Historical Calendar Of Jesus (Min's first book):
http://groups.google.com/groups?selm...t orebels.net

*Min's Interlinear Translation of the Apocalypse:
http://groups.google.com/groups?selm...amesh-Frog.org

*Min's $10,000 Reward For Astronomers:
http://groups.google.com/groups?selm...amesh-frog.org

*Min's Newsgroup-Archived Home Page On The World Wide Web:
http://groups.google.com/groups?selm...amesh-frog.org

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On 11 Jan 2004 23:58:15 +0100, Des Moines wrote:


We seldom look directly at the Sun for more than a frac-
tion of a second. So the color of the sunlight is gaged
more by how it appears from the Earth's surface to illu-
minate our daytime sky and all objects that we see down
here where human beings have lived and evolved for many
millions of years with its contrast of light and shadow,
day and night, and everything in between these extremes.
So the sunlight we see is more yellow than any other co-
lor & our daytime sky is more cyan than any other color.
When you mix predominantly yellow with predominantly cy-
an you get predominantly green. It's really very simple.

No, the color of the light we see is white. Although direct sunlight itself may
be shifted slightly towards longer wavelengths by the removal of shorter
wavelengths (scattering), this scattered blue light is part of what illuminates
objects. Therefore, a good diffuse source like snow appears white in the
sunlight. Snow in shade will appear slightly blue because it is preferentially
illuminated by the scattered light. You could probably construct an experiment
to isolate just the slightly more yellow sunlight- get in a big box sitting
upside down on snow, and poke a hole for a beam of sunlight to come through.
That might appear to show a little color. But you'll never see that effect when
you are outside under typical conditions. You normally only see strongly colored
sunlight when the Sun is very low, so that there is a strong gradient in color
and intensity across the sky, or when you have a non-uniform distribution of
scattering agents: water, ice, dust, smoke, etc.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

Hello, Chris,
I buy your explanation. But how can we explain why ordinary people, who don't
know about the slightly greater emission in the yellow, call the sun yellow?
Suggestions welcome,
Bill Meyers

Chris L Peterson wrote:

On 11 Jan 2004 23:58:15 +0100, Des Moines wrote:

We seldom look directly at the Sun for more than a frac-
tion of a second. So the color of the sunlight is gaged
more by how it appears from the Earth's surface to illu-
minate our daytime sky and all objects that we see down
here where human beings have lived and evolved for many
millions of years with its contrast of light and shadow,
day and night, and everything in between these extremes.
So the sunlight we see is more yellow than any other co-
lor & our daytime sky is more cyan than any other color.
When you mix predominantly yellow with predominantly cy-
an you get predominantly green. It's really very simple.

No, the color of the light we see is white. Although direct sunlight itself may
be shifted slightly towards longer wavelengths by the removal of shorter
wavelengths (scattering), this scattered blue light is part of what illuminates
objects. Therefore, a good diffuse source like snow appears white in the
sunlight. Snow in shade will appear slightly blue because it is preferentially
illuminated by the scattered light. You could probably construct an experiment
to isolate just the slightly more yellow sunlight- get in a big box sitting
upside down on snow, and poke a hole for a beam of sunlight to come through.
That might appear to show a little color. But you'll never see that effect when
you are outside under typical conditions. You normally only see strongly colored
sunlight when the Sun is very low, so that there is a strong gradient in color
and intensity across the sky, or when you have a non-uniform distribution of
scattering agents: water, ice, dust, smoke, etc.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

In article ,
Des Moines wrote:

No, the color of the light we see is white.

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White is not a color...but of course everybody knows that!

White is not a frequency. That doesn't mean it's any less a color than
brown, or "cornflower".

--
"In any case, don't stress too much--cortisol inhibits muscular
hypertrophy. " -- Eric Dodd

On 12 Jan 2004 01:04:24 +0100, Des Moines wrote:

White is not a color...but of course everybody knows that!

Well, that's just semantics. In a very real sense, white is a color in terms of
human perception. It is actually the color of colorlessness!


The broad day sunlight that we see with our eyes is indis-
putably more yellow than any other color--read *color*, &
the sky we see is more cyan than any other *color* period.

I disagree. Broad day sunlight is about as white as anything gets. IMO, if you
see the sky as "cyan" you are either color blind or living somewhere with some
mighty peculiar air. Where I live, there is no hint of green in the sky, and I
would definitely say that "blue" describes it best.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com