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On 13 Apr 2006 05:24:32 -0700, "George Dishman" <george@xxxxxxxxxxxxxxxxx>
wrote:
>
>Henri Wilson wrote:
>> On 12 Apr 2006 04:40:50 -0700, "George Dishman" <george@xxxxxxxxxxxxxxxxx>
>> wrote:
>>
>> >
>> >Henri Wilson wrote:
>> >> On 11 Apr 2006 04:38:17 -0700, "George Dishman" <george@xxxxxxxxxxxxxxxxx>
>> >> wrote:
>> >>
>> >> >
>>
>> >> >> I would want to know more about it.
>> >> >>
>> >> >> It brings us to the psychology of colour mixing
>> >> >
>> >> >Not really. The sensors in the eye react to
>> >> >the energy in separate bands and the brain
>> >> >then interprets the ratio of the responses,
>> >> >a bit like a crude spectrum plot.
>> >>
>> >> That's my point. In this case the mixed wavelengths remain sparately
>> >> detectable.
>> >
>> >Individual photons are detected by the receptors.
>> >Processing that into the perception of colour is
>> >done mostly in the brain.
>>
>> Yes George I know that.
>>
>> >
>> >> In the laser heterodyne thing, they supposedly form another frequency
>> >> altogether.
>> >
>> >As I explained, that only happens because of the
>> >non-linear property of the HgCdTe material.
>>
>> That's not the impression I have of the 'frequency comb' idea.
>
>The frequency comb is an entirely separate idea
>which Jerry happened to mention, it is not related
>in any way to what I am discussing here.
The harmonics are involved somehow. I cannot get a clear picture of this.
>> >
>> >If a << b we call it modulation, if a ~ b and we use
>> >the a-b you get a beat frequency and if a=b and you
>> >use the a+b term it is a frequency doubler. They are
>> >all the same maths and the same principle and they
>> >all rely on producing the product of the two instantaneous
>> >field strengths.
>>
>> What I am getting at George is this. Why don't the lines in line spectra
>> interact in this way.
>
>Because there is no material in space that has a
>non-linear characteristic. Think of a simple amplifier.
>You put in music which has a mix of frequencies and
>you expect to get the same thing out but louder. The
>amp has to have a transfer function of Vout = A * Vin
>and A is the gain. Then a sum of sines in gives the
>same sum of sines out but bigger.
>
>For a mixer, it has to be Vout = A * Vin + B * Vin^2
>The B term is what produces the product of the
>sines and creates new frequencies. Look up
>"intermodulation products" on Google and see what
>you get. An FET is a good mixer because the drain
>current depends on the square of the gate voltage.
>Stuff in space doesn't have a B term so there is no
>natural mixing.
George, AM modulation is just a.sinx.siny...where x is the modulated frequency
and y the carrier...or vice versa. As you know that is = a[cos(x-y)-cos(x+y)]
>> >And the time between those arrival is what is measured.
>> >If you want to measure wavelength you need a different
>> >method such as a grating.
>>
>> That is what is usually detected.... I'm not convinced the above device
>> detects
>> frequecy at all.
>
>Well I've explained why it can do nothing else
>but it's not important for our other discussion.
no
>
>> >> It is not intrinsic to the
>> >> signal. The distance between crests IS.
>> >
>> >Nonsense, when light meets a change in
>> >refractive index, the frequency stays the
>> >same, the wavelength changes. Wavelength
>> >is just how far the last crest has gone when
>> >the next arrives.
>>
>> Why introduce this red herring George. It is obvious that the speed change
>> causes this to happen.
>
>Of course, but if wavelenggth was fundamental and
>frequency the derived quantity as you claimed then
>the light entering the material would keep the same
>wavelength and would would measure a different
>frequency.
I think photons ARE affected by the electrical properties of the medium. So
they DO shrink when entering a medium. That is not in conflict with my other
claim that photons do not change length due to their ends traveling at
different speeds.
>
>> >> I've now forgoten what it is that I should have done.
>> >
>> >Not what you "should have done", what you claimed
>> >you had already done. Look back at the previous posts
>> >if you can't remember the question, it should take less
>> >than two minutes of mental arithmetic but after several
>> >weeks of excuses I am getting the impression it is
>> >beyond you.
>>
>> I've forgotten what it is.
>
>Calculate the amplitude of the frequency modulation of
>the 339Hz pulse repetition rate (of the order of tens of
>mHz) so that we can match the amplitude of your red
>curve to it and thus infer what ballistic theory predicts
>is the orbital speed of J1909-3744.
Just use 1+v/c
>
>> >> >> Read my answer to Paul and you will see where you are both going wrong.
>> >> >
>> >> >Your reply to Paul has no relevant content, it is
>> >> >mostly pointless.
>> >>
>> >> Oh? I thought I was being polite considering his massive error.
>> >
>> >No, you are just being slow to realise he is right.
>>
>> Both you and he are on the wrong track entirely.
>
>I think you have finally realised what everyone else has
>been saying now. I'll address the details in response to
>your other reply.
>
>George
HW.
www.users.bigpond.com/hewn/index.htm
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