Mageth

Color has a spiritual existence, color has no physical dimension.

Sure it does. It's called the visible light portion of the EM spectrum. It's trivial to measure the wavelengths of light, a quite physical phenomenon.

It is only to perceive by the spiritual consciousness of a creature.

Actually, the wavelengths are detected by the rods and cones in the eye, which then transmits a physical signal to the visual cortex via the optic nerve, which then maps the signal to what we perceive as "color". A physical process, from end to end.

Volker.Doormann

AFAIK electromagnetic energy is not equal to a color. An electromagnetic energy of a specific wavelength may create a spiritual perception of a color in the consciousness of living creature, as a kick of a hammer creates an impression of pain. but pain as well a color is not a physical dimension in any SI units. A color like white has no physical dimension in any SI system units.

I think, to assert only meaningless statements is worthless; physical science must show , that color - p.e. white - has a physical dimension in any SI system as units.

Sorry. No. Who is we? A belief community? What is color? A spiritual perception? If color by it's value could be proved by physical science without the spiritual perception of color by a creature, I would like to listen to a proof. I never have heard, that it is possible to prove color by physical dimensions in any SI system. There is no physical dimension of color. No one can express white without any doubt by physical units without the spiritual perception of it from a creature. There is no physical base for brown or magenta. I think this is standard knowledge of physicist of optics.

A moderator may split this discussion with a new subject to a matching place.

Volker

Mageth

AFAIK electromagnetic energy is not equal to a color. An electromagnetic energy of a specific wavelength may create a spiritual perception of a color in the consciousness of living creature, as a kick of a hammer creates an impression of pain. but pain as well a color is not a physical dimension in any SI units. A color like white has no physical dimension in any SI system units.

What is "SI", BTW?

Visible light may be defined as ectromagnetic radiation at wavelengths which the (human) eye can see. We perceive this radiation as colors ranging from red (longer wavelengths; ~ 700 nanometers) to violet (shorter wavelengths; ~400 nanometers.) A combination of (all) wavelengths generates "white."

EM radiation at particular wavelengths generates perception of particular colors.

Sorry. No. Who is we? A belief community?

Any creature with color vision, I suppose. And, in a similar fashion, some of our machines are quite adept at detecting and distinguishing the colors of visible light.

What is color? A spiritual perception? If color by it's value could be proved by physical science without the spiritual perception of color by a creature, I would like to listen to a proof.

Look at a digitial image generated by subjecting a CCD to light and "reading" and digitizing the CCD's reaction to the different wavelengths of light it detects. Software can be written (I know, because I wrote some) that can accurately identify and differentiate the various colors in the image. AFAIK, there's no spirit in my computer. This software could be written by a blind person just using their knowledge of the EM spectrum and the way it's digitized by the CCD.

Another point this brings up: it is simple to conceive of a machine which would identify colors for a blind person. Without doing the research, my guess that such a machine has been developed, as it would be almost trivial.

Another note: totally colorblind people can and do distinguish between at least some "colors" even though they see the colors in "grayscale".

You don't need "spirit" to detect color. Good thing, too, since, unlike color, spirit's never been detected. We'd all be colorblind.

I never have heard, that it is possible to prove color by physical dimensions in any SI system. There is no physical dimension of color. No one can express white without any doubt by physical units without the spiritual perception of it from a creature. There is no physical base for brown or magenta.

Brown and magenta, like all other colors, are physically detectable and distinguishable - by our eyes and our machines.

I think this is standard knowledge of physicist of optics.

"Brown", "magenta", etc. are merely labels we ascribe to various detected wavelenghts and combination of wavelengths of light. "Spiritual perception" of a creature is not necessary to distinguish between them; indeed, the physical perception of a creature is not necessary to distinguish between them. We can, and do, do it with machines. That is standard knowledge in physics.

alek0

Excuse me, colour can be measured. Since most sources are not monochromatic, central wavelength is not a good measure, but light sources and surfaces of material illuminated by a standard illuminant are characterized by chromaticity coordinates. If anyone wants to know more, search for "CIE coordinates" and you will be able to find the chromaticity diagrams and instructions how to determine CIE coordinates.

Another physical quuantity for characterizing colour (typically used for near-white light sources) is correlated colour temperature, which gives you a temperature of the black body which would radiate similar radiation. It is used to distinguish "warm white" from "cold white", because it matters for some applications.

Pure white has CIE coordinates (1/3,1/3). Different shades of white have coordinates close to this value, and can be more precisely described with color temperature.

If you have any questions concerning standrad knowledge in optics, feel free to ask

Resident physicist

Volker.Doormann

http://physics.nist.gov/cuu/Units/
http://www.chemie.fu-berlin.de/chemi...ral/si_en.html

Quote:

Visible light may be defined as electromagnetic radiation at wavelengths which the (human) eye can see. We perceive this radiation as colors ranging from red (longer wavelengths; ~ 700 nanometers) to violet (shorter wavelengths; ~400 nanometers.) A combination of (all) wavelengths generates "white."

Irrelevant. It must be shown, by proof that color has a physical dimension in SI units.

There also other units in this world like $ or Pesetas, but it is to be shown that color is no money, but has a physical dimension in SI units.

Quote:

Volker."Sorry. No. Who is we? A belief community?" Any creature with color vision, I suppose.

Yes, but if there are creatures needed to receive color, then poetry must also have a physical dimension in SI units.

Is poetry a relevant physical dimension?

Quote:

.. some of our machines are quite adept at detecting and distinguishing the colors of visible light.

No.

Quote:

Volker:"What is color? A spiritual perception? If color by it's value could be proved by physical science without the spiritual perception of color by a creature, I would like to listen to a proof." Look at a digitial image generated by subjecting a CCD to light and "reading" and digitizing the CCD's reaction to the different wavelengths of light it detects.

You need a looking Person with a spiritual consciousness to receive color. Show, that color has a physical dimension in SI units.

Quote:

Software can be written (I know, because I wrote some) that can accurately identify and differentiate the various colors in the image. AFAIK, there's no spirit in my computer.

Correct, but this proofs, that a creature with the ability to perceive colors with your spiritual consciousness is needed, to act on this spiritual phenomena color.

Quote:

... indeed, the physical perception of a creature is not necessary to distinguish between them. We can, and do, do it with machines. That is standard knowledge in physics.

You have not shown, that color has any physical dimension in SI units. All, what you have mentioned is irrelevant to the spiritual phaenomena of color which only can perceived by creatures.

EOD

Volker

alek0

Volker, again, color can be measured and precisely defined with CIE coordinates. Pure white has CIE coordinates (1/3,1/3). For white light sources for illumination applications, correlated color temperature is also taken into account to distinguish between "shades" of white. Another parameter of interest for light sources is colour rendering index.

A number of instruments for characterization of light sources and displays are capable of displaying CIE coordinates in addition to the measured spectrum. In other words, color can be measured and is measured. How do you think people test displays and TV screens and light sources? Have volunteers to say "nah, discard one, it is a bit too green"?

Volker.Doormann

The system of CIE is developed from that, what is be seen in middle by a number of creatures as colors .

EOD

Volker

Calzaer

The system of Meters is developed from that, what is be seen in middle by a number of creatures as "length".

What's your point?

You DO realize that color has physical dimensions in SI units, right? It's called a wavelength, and is usually measured in nanometers.

And, once again, in spite of your very convincing argument ("No."), machines can differentiate between colors. Live with it.

alek0

Volker,

I still don't see anything spiritual about the color. What creatures see can be easily characterized and expressed in numbers. Nothing mysterious about it. No spirits involved.

You claimed that color cannot be expressed in units and has no physical dimension. This is wrong.

You claimed that you need a being with spiritual consciousness to perceive colour. This is wrong as well. All you need is either a luminance meter with CIE calculations included, or you need a monochromator and a detector covering visible range and a bit of software. And you will actually get more accurate information on the color characterized than through the eyes of a conscious creature

Color can be identified accurately without any creatures involved in color detection. Photometry is based on electromagnetic spectra and human eye response curve. Nothing spiritual about it.
If earth's atmosphere were different and the "vision" developed in another part of the spectrum, of course definitions would be different. But in any case, they would be based on physical world, not some spiritual perceptions. What you perceive visually is determined by what your eyes can detect. Purely physical phenomenon.

Volker.Doormann

This is wrong. If light is perceived by the consciousness, which is generated in origin of a small bandwidth of the electromagnetic spectrum in the measurable wavelength range of 400nm to about 700nm, the physical wavelength of the electromagnetic energy can be perceived as color of a creature. But a perceived color is not equal to an electromagnetic wave of a specific wavelength.

This can be understood for the case of white color: The perception of white can be created p.e. from three discrete wavlengths, p.e. 700nm, 530nm and 430nm with a bandwidth of less than 1nm, or from a broad continuum of electromagnetic energy containing all wavelengths. In both cases no one ever is able to solve the physical wavelength in nanometers of the perceived color White.

No one ever can measure a wavelength as physical dimension of the color 'White' in nanometers. No one. Same is valid for all non spectral colors (brown, magenta, pink, beige).

A perception of a color also can be created, if one is pressing softy with his fingers for some 10 seconds his closed eyes and remove the soft pressure after that time. The consciousness then perceives ionic energies created internal of the closed eyes from an ionic loaded fluid. This perception of 'light' and colors hardly is created by electromagnetic wavelengths, because the eye is closed.

The impression of color is a psychic function in the brain of transmitted ionic signal. But neither the perception of the color nor in general the consciousness of a creature seeing light is of any physical existence.

No one can explain the ability of a creature to perceive color and/or light as color and light with electromagnetical energies measured in wavelengths in nanometer.

Volker