Art Unwin wrote:
I don't know about waves but my understanding is that all colors come
from the mixing of the three basic colors, or is it four?

Your understanding is in error... at least, if you're referring to
colors in terms of actual photon behavior (energy and wavelength)
rather than to the human *perception* of color.

That's the RGB standard designed for fooling human
eyes into seeing more than just red, green, and blue.

Yup. And, the red/green/blue system is an artifact of the human
visual system... most of us happen to have three different types
of photo-sensitive molecules in the cone cells in our eyes, and these
three types of molecules have their peak receptivities at the
frequencies that we refer to as "red", "green", and "blue."

There seems to be some amount of genetic variation, among humans, in
the exact frequencies at which the peak sensitivies lie. And, some
people have are missing one or more of these types of photoreceptor,
and are referred to as "colorblind".

There are apparently some humans who have four different types of
photopigment, and thus may have an improved ability to perceive
distinctions between colors. Certain species of animal are known to
have four photopigments (one for e.g. UV sensitivity) and I wouldn't
be surprised if some species have five or more variants.

Photons in nature come in *all* EM frequencies.

Yup again. It's an interesting process:

- Light comes in a continuous range of frequencies.

- Our eyes "sample" this continous range, with three types of sensor
having different-but-overlapping sensitivities. Each sensor
generates a variable amplitude (or pulse train) based on the
intensity that it's detecting, within its sensitivity range.

- Our nervous system maps the three amplitudes back into a perception
of a continuous range of colors.

The process is far from perfect... information is lost during the
sampling process, and thus the perception of a continuous spectrum is
necessarily flawed and imperfect.

This is why a mixture of two different pure colors (e.g. red and
green) can look like a single pure color to our eyes (e.g. yellow or
amber)... it happens to excite the red and green photosensors in the
same proportion that a single, pure-yellow light would. Mixed
together, the colors look like one... split them apart with a prism
and you can easily distinguish them and see the trick.

[Almost] All Is Illusion.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

"Dave Platt" wrote
...
Art Unwin wrote:
I don't know about waves but my understanding is that all colors come
from the mixing of the three basic colors, or is it four?

Your understanding is in error... at least, if you're referring to
colors in terms of actual photon behavior (energy and wavelength)
rather than to the human *perception* of color.

That's the RGB standard designed for fooling human
eyes into seeing more than just red, green, and blue.

Yup. And, the red/green/blue system is an artifact of the human
visual system... most of us happen to have three different types
of photo-sensitive molecules in the cone cells in our eyes, and these
three types of molecules have their peak receptivities at the
frequencies that we refer to as "red", "green", and "blue."

There seems to be some amount of genetic variation, among humans, in
the exact frequencies at which the peak sensitivies lie. And, some
people have are missing one or more of these types of photoreceptor,
and are referred to as "colorblind".

There are apparently some humans who have four different types of
photopigment, and thus may have an improved ability to perceive
distinctions between colors. Certain species of animal are known to
have four photopigments (one for e.g. UV sensitivity) and I wouldn't
be surprised if some species have five or more variants.

Photons in nature come in *all* EM frequencies.

Yup again. It's an interesting process:

- Light comes in a continuous range of frequencies.

- Our eyes "sample" this continous range, with three types of sensor
having different-but-overlapping sensitivities. Each sensor
generates a variable amplitude (or pulse train) based on the
intensity that it's detecting, within its sensitivity range.

- Our nervous system maps the three amplitudes back into a perception
of a continuous range of colors.

The process is far from perfect... information is lost during the
sampling process, and thus the perception of a continuous spectrum is
necessarily flawed and imperfect.

This is why a mixture of two different pure colors (e.g. red and
green) can look like a single pure color to our eyes (e.g. yellow or
amber)... it happens to excite the red and green photosensors in the
same proportion that a single, pure-yellow light would. Mixed
together, the colors look like one... split them apart with a prism
and you can easily distinguish them and see the trick.

Sometimes the screen on TV or cinema is perfectly white. This in cinema
reflect. This reflected light splitted with the prism has only three
frequences?

[Almost] All Is Illusion.
S*

In article ,
Szczepan Bia³ek wrote:

Sometimes the screen on TV or cinema is perfectly white. This in cinema
reflect. This reflected light splitted with the prism has only three
frequences?

They're likely to be three bands of frequencies rather than three
narrow single-frequency lines, because the technologies used to create
the frequencies aren't narrow-band. But, yes, what you are seeing as
"perfectly white" under these circumstances is often *not* a smooth,
continuous spectrum.

In the case of a TV screen, you're seeing either:

- The mixed emissions of a set of red, green, and blue phosphors,
individually excited by electron beams [for CRT displays], or

- The emission from the phosphors of a cold-cathode fluorescent
backlighting lamp (a complex spectrum with multiple peaks) filtered
through red, green, and blue pixel-sized filters (for most LCD
tubes).

In traditional film cinema, you're seeing the emissions of an
incandescent or halogen bulb (fairly continuous spectrum) filtered
through three colors of dye in the film print.

The fact that these complex mixtures of overlapping color spectra can
look "pure white" to our eyes, is due in large part to our complex
nervous systems. Our eye/brain systems adapt to the mix of colors
present under differnet lighting conditions, and interpret different
combinations as "pure white" depending on what's available at the time.

This is why, for example, indoor fluorescent lighting can actually
look half-decent to our eyes once we get used to it (we "see" a fairly
complete range of colors there) but what looks "white" to use under
fluorescents will actually have a distinctly greenish cast to a film
or digital camera.

It's also why a rather curious phenomenon can be demonstrated. The
*exact* same mix of color emissions may look very different to us,
under different ambient lighting conditions... what might look
greenish outdoors will look pure white or even slightly pinkish under
indoor fluorescent lighting, because our brains *interpret* that input
differently due to the different surroundings.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

"Dave Platt" wrote ...

In article ,
Szczepan Bia³ek wrote:

Sometimes the screen on TV or cinema is perfectly white. This in cinema
reflect. This reflected light splitted with the prism has only three
frequences?

They're likely to be three bands of frequencies rather than three
narrow single-frequency lines, because the technologies used to create
the frequencies aren't narrow-band. But, yes, what you are seeing as
"perfectly white" under these circumstances is often *not* a smooth,
continuous spectrum.

I was thinking that some transparent and semitransparent substances are
phosphorescent (some time in dark) but ALL are less or more fluorescent
(rework frequency). Rube in laser rewoork into one. But in laser are many
passes. But what happens in one pass?
May be that it rework also but only a little.

Raman discovered that some substances can rework one frequency into many
(also in higher).
May be that a cotton screan also rework.

In the case of a TV screen, you're seeing either:

- The mixed emissions of a set of red, green, and blue phosphors,
individually excited by electron beams [for CRT displays], or

- The emission from the phosphors of a cold-cathode fluorescent
backlighting lamp (a complex spectrum with multiple peaks) filtered
through red, green, and blue pixel-sized filters (for most LCD
tubes).

In traditional film cinema, you're seeing the emissions of an
incandescent or halogen bulb (fairly continuous spectrum) filtered
through three colors of dye in the film print.

The fact that these complex mixtures of overlapping color spectra can
look "pure white" to our eyes, is due in large part to our complex
nervous systems. Our eye/brain systems adapt to the mix of colors
present under differnet lighting conditions, and interpret different
combinations as "pure white" depending on what's available at the time.

Yes. But for me is interesting the phenomenon at reflecting, scatering and
refraction. May be that "polarisation" is an effect of that.

This is why, for example, indoor fluorescent lighting can actually
look half-decent to our eyes once we get used to it (we "see" a fairly
complete range of colors there) but what looks "white" to use under
fluorescents will actually have a distinctly greenish cast to a film
or digital camera.

It's also why a rather curious phenomenon can be demonstrated. The
*exact* same mix of color emissions may look very different to us,
under different ambient lighting conditions... what might look
greenish outdoors will look pure white or even slightly pinkish under
indoor fluorescent lighting, because our brains *interpret* that input
differently due to the different surroundings.

Is the light polarisation the hard prove that light vaves are transversal?
S*



--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

"Szczepan Bialek" wrote in message
...
Raman discovered that some substances can rework one frequency into
many (also in higher).
May be that a cotton screan also rework.


This is a subject I have considerable experience in. My group at Eastman
developed a process Raman spectrometer that used communications grade
fibers to transmit both the excitation wavelength and the anti-Stokes
Raman scattered light. Chalcogenide fibers, at around $1K per foot,
would be needed to transmit the IR wavelengths needed for the analysis we
were doing. The communication grade fibers cost less than one foot of
the expensive fibers for the entire several hundred feet needed to
separate the analyzer from the chemical process. Our patents were
eventually licensed to the Rosemount division of Emerson Electric.

Raman spectroscopy is based on the _non-linear_ (inelastic) scattering of
photons. It is quite weak; more than 100 million photons are reflected
by the linear (elastic) Rayleigh scattering for every photon reflected by
Raman scattering.

I am convinced now that Szczepan Bialek is nothing more than an offensive
troll. It is best to ignore him as the physics newsgroups seem to have
done. May he bask in his own stupidity! Or perhaps he and Art and the
gays and the gay bashers could form their own "alt.troll" newsgroup.

--
73, Dr. Barry L. Ornitz WA4VZQ




--
73, Dr. Barry L. Ornitz WA4VZQ

U¿ytkownik "Szczepan Bia³ek" napisa³ w wiadomo¶ci
...


Raman discovered that some substances can rework one frequency into many
(also in higher).
May be that a cotton screan also rework.

Next Dr. wrote:
" This is a subject I have considerable experience in. My group at Eastman
developed a process Raman spectrometer that used communications grade
fibers to transmit both the excitation wavelength and the anti-Stokes
Raman scattered light. Chalcogenide fibers, at around $1K per foot, would
be needed to transmit the IR wavelengths needed for the analysis we were
doing. The communication grade fibers cost less than one foot of the
expensive fibers for the entire several hundred feet needed to separate
the analyzer from the chemical process. Our patents were eventually
licensed to the Rosemount division of Emerson Electric.

Raman spectroscopy is based on the _non-linear_ (inelastic) scattering of
photons. It is quite weak; more than 100 million photons are reflected by
the linear (elastic) Rayleigh scattering for every photon reflected by
Raman scattering.

For this reason it was observed very late (1928). It is seen on the film
after many hours of continued radiation.

I am convinced now that Szczepan Bialek is nothing more than an offensive
troll. It is best to ignore him as the physics newsgroups seem to have
done. May he bask in his own stupidity! Or perhaps he and Art and the
gays and the gay bashers could form their own "alt.troll" newsgroup.

YOU ALL make me troll. For my simple question, instead of answers, you send
questions. "Why you want to know?", "Why you write here?". I simply try to
be polite and I write.
You was the first who wrote ( in the answer in my topic): "Nowhere in all of
the respected literature will you find frequency
doubling caused by the two ends of a dipole."
Till now nobody answered me why the polarisation of radio waves disappear
after long way.
Only Richard wrote that the term "polarisation" apply to an equipment. To
waves rather "polarity".
Too late for me for study. "Trolling" is more efficient. About the frequency
multiplying now I know eneugh.
About light polarisation not all. The radio waves and the apparatus are
large enough to observe this phenomenon. The Hertz apparatus is the best for
it. Of course the emitter only. To analise the waves is necessary more
sophisticated than the ring.
S*





In the case of a TV screen, you're seeing either:

- The mixed emissions of a set of red, green, and blue phosphors,
individually excited by electron beams [for CRT displays], or

- The emission from the phosphors of a cold-cathode fluorescent
backlighting lamp (a complex spectrum with multiple peaks) filtered
through red, green, and blue pixel-sized filters (for most LCD
tubes).

In traditional film cinema, you're seeing the emissions of an
incandescent or halogen bulb (fairly continuous spectrum) filtered
through three colors of dye in the film print.

The fact that these complex mixtures of overlapping color spectra can
look "pure white" to our eyes, is due in large part to our complex
nervous systems. Our eye/brain systems adapt to the mix of colors
present under differnet lighting conditions, and interpret different
combinations as "pure white" depending on what's available at the time.

Yes. But for me is interesting the phenomenon at reflecting, scatering and
refraction. May be that "polarisation" is an effect of that.

This is why, for example, indoor fluorescent lighting can actually
look half-decent to our eyes once we get used to it (we "see" a fairly
complete range of colors there) but what looks "white" to use under
fluorescents will actually have a distinctly greenish cast to a film
or digital camera.

It's also why a rather curious phenomenon can be demonstrated. The
*exact* same mix of color emissions may look very different to us,
under different ambient lighting conditions... what might look
greenish outdoors will look pure white or even slightly pinkish under
indoor fluorescent lighting, because our brains *interpret* that input
differently due to the different surroundings.

Is the light polarisation the hard prove that light vaves are transversal?
S*



--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

On Tue, 19 May 2009 15:40:04 +0200, Szczepan Bia?ek
wrote:

YOU ALL make me troll.

You must suffer terribly from our imposition, but your form of cure
isn't going to answer the absolutely stupid things that you write.

Only Richard wrote that the term "polarisation" apply to an equipment. To
waves rather "polarity".

Something you still don't understand - even in direct translation.

Too late for me for study.

Too lazy, rather, as evidenced by:

"Trolling" is more efficient.

If you had been sent out of the caves to "efficiently" discover fire,
we would have returned to living in the trees.

73's
Richard Clark, KB7QHC

"Richard Clark" wrote
...
On Tue, 19 May 2009 15:40:04 +0200, Szczepan Bia?ek
wrote:

YOU ALL make me troll.

You must suffer terribly from our imposition, but your form of cure
isn't going to answer the absolutely stupid things that you write.

Only Richard wrote that the term "polarisation" apply to an equipment. To
waves rather "polarity".

Something you still don't understand - even in direct translation.

I do my best. Posting is also a free English lessons. It is a good method
(only the long hair dictionary is better).
So do not discourage. You are doing a good job.

Too late for me for study.

Too lazy, rather, as evidenced by:

"Trolling" is more efficient.

If you had been sent out of the caves to "efficiently" discover fire,
we would have returned to living in the trees.

Laurence Hecht advices return to Ampere. Gauss, Weber. See:
http://21stcenturysciencetech.com/ar...odynamics.html
and:
http://21stcenturysciencetech.com/edit.html

What do you think about such "funny" stories?
S*