Color (North American English), or colour (Commonwealth English), is the characteristic of visual perception described through color categories, with names such as red, orange, yellow, green, blue, or purple. This perception of color derives from the stimulation of photoreceptor cells (in particular cone cells in the human eye and other vertebrate eyes) by electromagnetic radiation (in the visible spectrum in the case of humans). Color categories and physical specifications of color are associated with objects through the wavelengths of the light that is reflected from them and their intensities. This reflection is governed by the object's physical properties such as light absorption, emission spectra, etc.
By defining a color space, colors can be identified numerically by coordinates, which in 1931 were also named in global agreement with internationally agreed color names like mentioned above (red, orange, etc.) by the International Commission on Illumination. The RGB color space for instance is a color space corresponding to human trichromacy and to the three cone cell types that respond to three bands of light: long wavelengths, peaking near 564–580 nm (red); medium-wavelength, peaking near 534–545 nm (green); and short-wavelength light, near 420–440 nm (blue). There may also be more than three color dimensions in other color spaces, such as in the CMYK color model, wherein one of the dimensions relates to a color's colorfulness).
The photo-receptivity of the "eyes" of other species also varies considerably from that of humans and so results in correspondingly different color perceptions that cannot readily be compared to one another. Honey bees and bumblebees have trichromatic color vision sensitive to ultraviolet but insensitive to red. Papilio butterflies possess six types of photoreceptors and may have pentachromatic vision. The most complex color vision system in the animal kingdom has been found in stomatopods (such as the mantis shrimp) with up to 12 spectral receptor types thought to work as multiple dichromatic units.The science of color is sometimes called chromatics, colorimetry, or simply color science. It includes the study of the perception of color by the human eye and brain, the origin of color in materials, color theory in art, and the physics of electromagnetic radiation in the visible range (that is, what is commonly referred to simply as light).
After going on a ghost tour over Halloween, several people were able to take photos of ghosts seen through an old hotel window, a few stories above our position. This got me to wonder if this was a trick that relied on the way that the digital cameras may be able to detect non-visible...
I am trying to design an optimal colormap for display interval data.
I would like to create a scale that is linear in perceived luminance while adding a hue component to help mitigate the simultaneous contrast effect. However, I am confused on what hue to pick.
The longest curved path I...
Hi folks,
I was just reading about symmetries, and why we say that the two spin states of the electron are states of the same particle, while we are free to say that the two strong isospin states define tow different types of particle. According to the book I'm reading, we must attribute two...
Is there someone how could explain me why is color temperature (Tcol) always greater than the effective temperature (Teff) of a star?
I know that Teff is the temperature of the last interaction surface, where photons are emitted.
In the case that the scattering opacity is the dominant one...
Hello everyone,
I recently posted about making a color organ, in which I was going to use a circuit to process analog signals. Since then, I have decided to move in a new direction of a digital color organ.
I would really appreciate if someone with more experience than me could give some...
Hey guys, I'm wondering how come if we're in a completely dark room and shine a laser beam at an object, we see the color of the laser beam (say it's red). How is this consistent with the the theory that objects appear a certain color since that is the frequency of light that they reflect? For...
1. The problem in attachments
Homework Equations
3. RNA destroyed means no proteins (enzymes) formed, however if some areas showed no color, does that mean other areas did? I'm pretty sure the answer is D but making sure
I'm trying to use 2 color functions within one matrix plot in mathematica. Is this possible to do?
For example, using a very simple matrix:
test = Partition[Table[i, {i, 1, 9}], 3]
I would like to make the even numbers vary in color increasing from white to red; and the odd numbers vary...
I have recently started using Kile on Ubuntu and I experimented witht the color settings of kile for quite a long time to get a good sceme but I still am not satisfied. Can someone here suggest me a good color scheme?
I recently changed my bulbs in my car's HVAC dash to LEDs. I wanted a blue color and it looks really good and exactly what I wanted. The only problem is that there are three buttons that are lit separately from the new LEDs by green bulbs, which I want to be blue as well, but I cannot simply...
while it has been extensively proven that any 2D map can be colored with at most 4 colors, has any hypothesized why that is (outside the computer programmed brute force method)?
similar to the rough picture of how BHs radiate if I put a proton next to a BH can one of the quarks be absorbed into the BH and the other two escape?
I don't really understand confinement very well but does the confinement picture change next to BH horizon?
recently i have been thinking about how colors add when you have 2 different light sources of color and put the streams together, such as taking red and green beams and crossing them to make yellow. i was looking at wavelengths to determine if there was a mathematical way to say what color would...
Hello,
I've asked this question on the other forum, but it seems that its rarely visited, so I decided to ask my question here.
I'm wondering what exactly is the black color perceived by the human eye. I've read some explanations on the web, but none of them gives the exact answer.
So, if...
You have a yellow lamp in your spaceship. Now you accelerate your spaceship significantly. Then you stop accelerating. Does the lamp still have the same color? I would think it should, but I reckon differently as follows:
Consider the situation from an outside observers point of view, resting...
Is additive color mixing a linear process (or close to)?
(if this question has already been answered in detail, please forward me)
If the answer to this question is "yes" then:
Considering three hypothetical LEDs:
Red T-1 (650nm λ), 60° viewing angle, 1000mcd luminous intensity...
I remember seeing a liquid that changes color when you shake it and then changes back to it's original color when it settles. Does anyone know what reaction this is? I would like to do it for a school project. Also, does this last forever, or will it eventually stop? If this does not work, does...
Hi,
This question came up after some stainless steel samples were exposed to high temperatures (metal flame holders in a combustion chamber). Some of them had areas with rainbow colors. What exactly happens to the steel that causes these local rainbows? If the colors in point A and B on the...
it's known that for the visible part of EM wave(electromagnetic wave) , black materials absorb more visible light than white materials do . a friend of mine asked me if in general , black materials absorb more EM radiation(whose frequencies do not lie within the visible range) than white...
Homework Statement
The first questions asks to calculate the LFSE of metal complexes. The second part is to explain the difference in color between [Cr(H2O)6]Cl3, [CrCl(H2O)5]Cl2, and [CrCl2(H2O)4]Cl in terms of Δo.
The Attempt at a Solution
I know the formula for finding LFSE, my...
Before nuclear elements had any practical applications, they were used as an orange coloring glaze for pottery and various other objects.
Please correct me if I'm mistaken, but wouldn't this coloring glaze be highly radioactive?
I have heard, quite simplistically, that "CoCl2 goes blue to pink with water" and "the reverse occurs with HCl solution". I have also heard that Co, and CoCl2, are pink in solution with water (in both cases with a different complex ion formed), and in both cases adding HCl again turns the...
Homework Statement
Given: Spherical blackbody with
surface temperature of 30000K
radius of 6.0 x 10^9 m
located 123pc from earth
Homework Equations
Find the absolute and apparent bolometric magnitudes
The Attempt at a Solution
My camera needs batteries so I cannot post my work...
Since with the help of two different wavelength of light we can make every other wavelength of light why do we need three then - like red, green, blue or red, green, yellow? I guess red, blue or red, yellow will suffice.
Homework Statement
What are the color band colors and associated band values for a 1kΩ resistor
The Attempt at a Solution
resistor color codes are read like so:
ab*10^c±tol
1kΩ=10*10^2
a=1, b=0, 10=c
Now I get confused. What should the tol be?
I understand why the sun is red,, due to most of the blue light of shorter wavelength being scattered in other directions because the sunlight has to travel through more atmosphere before it reaches our eyes, but why does the surrounding sky appear red to us?
Hi every one,
here is a question about drawing and filling in Latex (\usepackage{tikz})
I just draw a circle with 5 sectors correctly,
and what I need help on please, how I fill 3 sectors with green color
and the other 2 sectors with red...
please help me with this task...
Hello, I know from UV/VIS spectroscopy that for many solutions a single frequency from the visible spectrum is absorbed. The color of such a solution is the color complementary to the one absorbed.
If red is absorbed, then presumably it is no longer available to mix with its complementary...
http://www.fpl.fs.fed.us/documnts/fplrp/fplrp57.pdf
Wood undergoes changes when exposed to direct sunlight (above reference) or
incidental light. One of the changes is a change in color. Others include decreased
film finish adhesion, and some other probably not so good changes.
Walnut...
Hi, I am currently doing a project in underwater image enhancement. Just now i got this little question that came to my head. I know it sounds silly.
You could notice the red color of sun at sunset, this is due to light scattering and red is least scattered as compared to blue.
On the...
I'm going to display my rock and mineral collection in glass door cabinets in the living room. I've found some LED under-the-counter lights, 21 small LED lights per 2-ft string. I plan to use one of the strings for each shelf. They come in two "colors", warm and cool. Sorry, they don't...
Hi,
Looking at the emission spectra of Mercury, for instance, how do the lines (I count 9 in the visible range: dark red, lighter red, orange, 3 yellows, green, purple, dark purple) superimpose to give light blue glow?
My lab partner said that blue is the average of the wavelengths, such...
Hi Let's stick to the classical limit.
We have 2 monochromatic light waves of same intensity. Let's say one is blue and one is red.
Now this means the individual photons of the blue light have more energy(obviously, higher frequency) and the red light photons have lower energy. But since...
I was thinking today about whether or not mirroring could be altered to reflect only certain wavelengths of the spectrum? I couldn't think of specified way to do such a thing, thought maybe some more adapted minds could lend some advice. Thanks for any help on the topic.
Coupling constant of strong interaction is only finitely greater than coupling constant in QED if the quarks insides hadron not very far apart each other,so I do not understand why there are not exist color multiplet states of hadrons,other hand I do not understand why the singlet states have...
I know fireworks use different chemicals to get different colors. This probably means combustion/oxidation of the various compounds, resulting in vapor phase gases. With fireworks, this might not be a problem, but if I have an indoor fireplace, are there any chemicals I can safely add in order...
Hi,
I have 3D plot used to represent the amount of light that hits a solar panel.
Basically what I would like is a way to have say 10% of the data red, the next 10% of the data yellow etc.
The 3D plot is at a peak in the centre and then goes to zero by some function based on data, so there...
Hydrogen gas is supposed to be colorless, but what causes the murky grey-white color of the hydrogen gas produced in this reaction?
http://www.youtube.com/watch?v=oQz5YEsx7Fo&feature=related
skip to 00:30
Hello,
My question is regarding a reaction with KI with some chemical in tap water.
Today I was working on a lab at school and had a beaker with about 10ml of 100mM KI in it, when I went to clean it and put tap water in the solution it automatically turned clear yellow.
So I was...
I've learned about the Band Theory of metallic bonds and how they produce color, but how does a covalent bond produce color? Normally a metal such as iron absorbs and emits back the full range of colors due to metallic bonds, but when oxygen or sulfur get added it produces a different color. Can...
Hi friends,
I am confuse in Rayleigh scattering formula.
It says that the intensity of the light corresponding to a wavelength in the scatterd light varies inversely as the fourth power of the wavelength.
Hence the blue light scatters more then red light. Hence the sky seems blue. But the...
Emission of light from a solid object
From my textbook (explaining why an apple is red):
We imagine that the red apple in the picture is illuminated by daylight, IE light which contains all the wavelengths of the visible spectrum. The apple is red because the main part of the light it...
Pluto's changes as it makes its closest approach?
I've seen the photos from Hubble showing the seasonal color changes on Pluto.
Just wondering if the addition of the extra atmosphere as it makes its closest approach to sun, has changed the any of the colors on Pluto, in particular the black...
If you look at liquid crystals in things like moodrings and LCthermometers then you will notice that they can change color when heated.
Now I have looked on the internet and found that it has to do with the The cholesteric (or chiral nematic) liquid crystal phase, where they align with each...
Question 1:
http://i.minus.com/iOmQvqhasiXmx.png
My reasoning is curves 3 and 4. These curves have the biggest relative brightness of orange.
Question 2:
Stars are called blackbody radiators because they
a) never appear perfectly black
b) always appear perfectly white
c)...
What's the "color" of Hawking radiation?
If I understand correctly, the Hawking radiation hypothesis predicts that if a pair of virtual particles appears very close to the event horizon of a black hole, it may happen that one of them falls into the black hole and the other escapes, becoming a...
I have photoshop CS5 installed in my computer, but the "White" color for anything in it always appears to be a facial cream like yellowish color. I don't know why, I chose the value (255,255,255) already. Any help please...