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Groups > sci.physics.relativity > #454414
| From | Thomas 'PointedEars' Lahn <PointedEars@web.de> |
|---|---|
| Newsgroups | sci.physics.relativity |
| Subject | The Doppler effect (was: The incoming speed of light is variable) |
| Date | 2018-04-01 05:26 +0200 |
| Organization | PointedEars Software (PES) |
| Message-ID | <1888246.bB369e8A3T@PointedEars.de> (permalink) |
| References | (4 earlier) <aIGdnSRt57MgBybHnZ2dnUU7_8zNnZ2d@giganews.com> <b5313a17-c132-4881-8fe8-f37dc215e894@googlegroups.com> <XNydnacFGJ29CCLHnZ2dnUU7_83NnZ2d@giganews.com> <b4246bf2-bc50-480f-9472-bc5947fee33a@googlegroups.com> <iK6dnSA1v7jfvl3HnZ2dnUU7_83NnZ2d@giganews.com> |
Tom Roberts wrote:
> The phase speed for such light, wavelength*frequency, is c in the frame
> of the observatory (at any time of year, moving toward or away from the
> star).
>
> Listen to a train whistle as it goes by. You'll hear
> Doppler shifts, but the speed of sound in the air is
> COMPLETELY UNAFFECTED. (The underlying physics is
> quite different from that of light, but it does show
> conclusively that Doppler shifts do NOT imply a
> change in the speed of the wave.)
Yes, of course.
Often pictures will say more than a thousand words. Since the Doppler
effect issue has been raised here, I have been thinking about coming up with
a *graphical* demonstration that would be more simple, thus more easily
convincing, than (only) an equation. So perhaps the following will help
(finally I can use the library of my experiments in ASCII art :))
[Nobody who knows the basics of wave mechanics will be educated by
the following. However, I would appreciate constructive comments
by those people as to my didactic approach.]
The following is a snapshot in time of a sinusoidal (sinus-like) wave
traveling through space (x), emitted by a wave source (S, on the left) that
is a rest relative to an observer (O, on the right). We take the snapshot
at a time when the wave has just reached the observer:
^ :<----------- λ ----------->:
: : :
: _.-'''-._ _.-'''-._
:.'_________`._______________.'_________`._______________._\ x
:S `._ _.' `._ _.' O /
: `-...-' `-...-'
:
[To see this, use a monospace font for display; see also:
<https://github.com/PointedEars/userscripts#ggformatteruserjs>]
λ (Lambda) is called the *wavelength* of the wave. It can be defined as the
distance in space between neighboring wave crests (here) or troughs.
One (crude) way to define the *frequency* f of a wave is to take our
snapshot and count the number of crests or troughs that fit into a unit of
space (volume). The greater the number of crests/troughs, the greater the
frequency of the wave (as we will see later, because the wave is moving
through space, this is equivalent to the usual, more precise definition of
frequency which is based on time instead.)
When some people think of a wave being emitted by a source moving to the
right, they think that it happens this:
^
: _.-'''-._ _.-'''-._
:____.'_________`._______________.'_________`._____________\ x
: ---S--> `._ _.' `._ O /
: `-...-' `-...-'
:
(The source would be moving to the right and the wave would stay the same,
only shifted to the right, thus reaching the observer earlier than before.
From this they conclude a faster wave speed.)
But what actually happens is this:
^ :<-- λ -->:
: : :
: .''. .''. .''. .''. .''. .'
:____.____.____.____.____.____.____.____.____.____.____.___\ x
: ---S--> . . . . . . . . . . O /
: '' '' '' '' ''
If the source moves towards the observer and keeps producing oscillations
for the wave in the same rhythm (no change of *source* frequency), the
waveform is *squeezed* in the direction of motion. As a result, the
*observed* frequency of the wave increases, *and* its *observed* wavelength
decreases, compared to what the source emits.
This is only so for *that* observer. Thus, we must now tell apart the
*source* frequency f_s and the *observed* frequency f_o, and the *source*
wavelength λ_s and the *observed* wavelength λ_o.
We can see that the waveform is squeezed the *more* – the observed
wavelength becomes the shorter, and the observed frequency becomes the
higher – the *faster* source and observer are moving towards each other
(the greater their relative speeds are).
And if the source that moves *away* from the observer (on the right-hand
side) keeps producing oscillations for the wave in the same rhythm (no
change of *source* frequency), the waveform is *stretched* *against* the
direction of that motion (so *towards *the observer). As a result, the
wave’s *observed* frequency f_o decreases, and its *observed* wavelength λ_o
increases:
^ :<- λ_s ->:
: : :
: .''. .''. .''. .''. .''. .''
:____.____.____.____.____.____.____.____.____.____.____.___\ x
: S . . . . :. . . . . . O /
: '' '' : '' '' ''
:
changes to :
:
^ :<---------- λ_o ---------->:
: : : :
: _.-'''-._ _.-'''-._
:.'_________`._______________.'_________`._______________._\ x
:S <--- `._ _.' `._ _.' O /
: `-...-' `-...-'
:
(Decrease of frequency: Note that now there is only one wave crest instead
of three in the same volume.
If we imagine the wave being emitted to the left-hand side as well, we see
that the waveform is simultaneously *stretched*, and *squeezed*, for an
observer on the *left* of the source when the source is moving to the right,
and to the left, respectively.)
The same picture can also be viewed as several snapshots in time (t) of the
values of a wave as it is passing through the same point in space – say, at
the observer’s:
:<---------- T_o ---------->:
: :
^ P₁ P₂
: _.-'''-._ _.-'''-._
:.'_________`._______________.'_________`._______________._\ t
: `._ _.' `._ _.' /
: `-...-' `-...-'
:
The time that it takes for a full cycle of the wave to be emitted or to pass
through a point in space, here for P₁ to return as P₂, is called the
*period* T of the wave. Because at our observer’s that is only what our
observer measures, we label it T_o, to tell it apart from the T_s that we
would measure at the source.
The change in observed wavelength and frequency due to a *continuous* change
of the distance between wave source and observer – due to their relative
*motion* – is called the *Doppler effect* (after Christian Doppler).
Let us now look at the *phase* of the wave – “the position of a point in
time on the waveform cycle” (Wikipedia), here P₁ and P₂. The *phase speed*
c is a measure of how fast those points are moving (through space).
We (now) know that the observed frequency also increases with regard to
*time* (more crests/troughs travel through a point in space per unit time),
and the observed wavelength decreases, when the source is moving towards the
observer (or vice-versa). So the observer’s picture of the wave, as they
observe/measure it *in time*, changes from
:<---------- T_s ---------->:
: :
^ P₁ P₂
: _.-'''-._ _.-'''-._
:.'_________`._______________.'_________`._______________._\ t
: `._ _.' : `._ _.' /
: `-...-' : `-...-'
: :
:
to :
:
:<- T_o ->: :
: : :
^ P₁ P₂ :
: .''. .''. .''. : .''. .''. .''.
:.____.____.____.____.____.__:_.____.____.____.____.____.__\ t
: . . . . . . . . . . . /
: '' '' '' '' ''
We can see: There are about three times as many crests/troughs passing the
observer in the same time interval as before – the observed frequency f_o
has increased by about a factor of 3. And it takes considerably less time
for P₁ to return as P₂ – the observed period T_o has decreased by about a
factor of 3.
But in that less *time*, P₁ has also traveled proportionally less *distance*
through space, because the observed wavelength is shorter (by about a factor
of 3)!
Likewise, if the source is moving away from the observer (or vice-versa), it
takes *more* time for P₁ to return as P₂; but in that more *time*, P₁ has
also travelled proportionally more *distance* through space because the
wavelength is greater!
(Average) speed is defined as the distance traveled per unit time.
This means that the (average) speed of P₁, the (observed, average) *phase
speed* c of the wave, which is often simply called the (wave) *speed*, is
*unaffected* by the source’s motion relative to the observer (and vice-
versa).
Mathematically:
c = λ_o∕T_o (remember that λ is a *distance*, and T is a *time*,
so this *does* give a *speed*)
f_o = 1∕T_o (the number of wave crests/troughs *per* unit *time*)
c = λ × 1∕T_o
= λ_o f_o
≈ 1∕3 λ_s × 3 f_s
= λ_s × f_s = const.
PointedEars
--
A neutron walks into a bar and inquires how much a drink costs.
The bartender replies, "For you? No charge."
(From: WolframAlpha)
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The incoming speed of light is variable kenseto <setoken@att.net> - 2018-03-26 08:37 -0700
Re:The incoming speed of light is variable Libor Striz <poutnik4REMOVEnntp@CAPITALSgmail.com> - 2018-03-26 17:42 +0200
Re: The incoming speed of light is variable kenseto <setoken@att.net> - 2018-03-26 10:56 -0700
Re: The incoming speed of light is variable Gary Harnagel <hitlong@yahoo.com> - 2018-03-26 12:54 -0700
Re: The incoming speed of light is variable mlwozniak@wp.pl - 2018-03-26 20:01 -0700
Re: The incoming speed of light is variable SolomonW <SolomonW@citi.com> - 2018-03-27 19:52 +1100
Re: The incoming speed of light is variable kenseto <setoken@att.net> - 2018-03-27 06:58 -0700
Re: The incoming speed of light is variable SolomonW <SolomonW@citi.com> - 2018-03-28 16:56 +1100
Re: The incoming speed of light is variable kenseto <setoken@att.net> - 2018-03-27 06:10 -0700
Re: The incoming speed of light is variable Gary Harnagel <hitlong@yahoo.com> - 2018-03-27 08:50 -0700
Re: The incoming speed of light is variable Micah Strobl <aui@cwwi.cu> - 2018-03-27 18:11 +0000
Re: The incoming speed of light is variable Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-03-27 20:53 +0200
Re: The incoming speed of light is variable Micah Strobl <aui@cwwi.cu> - 2018-03-27 20:08 +0000
Re: The incoming speed of light is variable Gary Harnagel <hitlong@yahoo.com> - 2018-03-27 11:55 -0700
Re: The incoming speed of light is variable Micah Strobl <aui@cwwi.cu> - 2018-03-27 19:05 +0000
Re: The incoming speed of light is variable Gary Harnagel <hitlong@yahoo.com> - 2018-03-27 14:45 -0700
Re: The incoming speed of light is variable kenseto <setoken@att.net> - 2018-03-28 07:10 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-28 07:29 -0700
Re: The incoming speed of light is variable Gary Harnagel <hitlong@yahoo.com> - 2018-03-28 15:24 -0700
Re: The incoming speed of light is variable rotchm <rotchm@gmail.com> - 2018-03-26 15:44 -0700
Re: The incoming speed of light is variable kenseto <setoken@att.net> - 2018-03-27 06:05 -0700
Re: The incoming speed of light is variable SolomonW <SoloomonW@citi.com.au> - 2018-03-27 12:37 +1100
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-26 18:45 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-26 18:56 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-26 19:22 -0700
Re: The incoming speed of light is variable kenseto <setoken@att.net> - 2018-03-27 06:41 -0700
Re: The incoming speed of light is variable SolomonW <SolomonW@citi.com> - 2018-03-28 16:58 +1100
Re: The incoming speed of light is variable kenseto <setoken@att.net> - 2018-03-28 15:11 -0700
Re: The incoming speed of light is variable SolomonW <SolomonW@citi.com> - 2018-03-29 19:31 +1100
Re: The incoming speed of light is variable Steve BH <sbharris@gmail.com> - 2018-03-26 18:48 -0700
Re: The incoming speed of light is variable kenseto <setoken@att.net> - 2018-03-27 06:55 -0700
Re: The incoming speed of light is variable Odd Bodkin <bodkinodd@gmail.com> - 2018-03-27 11:25 +0000
Re: The incoming speed of light is variable mlwozniak@wp.pl - 2018-03-27 04:36 -0700
Re: The incoming speed of light is variable Odd Bodkin <bodkinodd@gmail.com> - 2018-03-27 18:12 +0000
Re: The incoming speed of light is variable mlwozniak@wp.pl - 2018-03-28 00:16 -0700
Re: The incoming speed of light is variable Odd Bodkin <bodkinodd@gmail.com> - 2018-03-28 12:30 +0000
Re: The incoming speed of light is variable mlwozniak@wp.pl - 2018-03-28 23:23 -0700
Re: The incoming speed of light is variable Odd Bodkin <bodkinodd@gmail.com> - 2018-03-29 11:39 +0000
Re: The incoming speed of light is variable mlwozniak@wp.pl - 2018-03-29 09:50 -0700
Re: The incoming speed of light is variable kenseto <setoken@att.net> - 2018-03-27 07:05 -0700
Re: The incoming speed of light is variable Odd Bodkin <bodkinodd@gmail.com> - 2018-03-27 18:12 +0000
Re: The incoming speed of light is variable rotchm <rotchm@gmail.com> - 2018-03-27 12:58 -0700
Re: The incoming speed of light is variable kenseto <setoken@att.net> - 2018-03-28 06:50 -0700
Re: The incoming speed of light is variable rotchm <rotchm@gmail.com> - 2018-03-28 07:44 -0700
Re: The incoming speed of light is variable Ed Lake <detect@newsguy.com> - 2018-03-27 09:08 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-27 09:22 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-27 09:31 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-27 09:45 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-27 09:54 -0700
Re: The incoming speed of light is variable Tom Roberts <tjroberts137@sbcglobal.net> - 2018-03-27 13:26 -0400
Re: The incoming speed of light is variable Ed Lake <detect@newsguy.com> - 2018-03-27 13:23 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-27 14:10 -0700
Re: The incoming speed of light is variable Tom Roberts <tjroberts137@sbcglobal.net> - 2018-03-28 09:37 -0400
Re: The incoming speed of light is variable Ed Lake <detect@newsguy.com> - 2018-03-28 07:25 -0700
Re: The incoming speed of light is variable rotchm <rotchm@gmail.com> - 2018-03-28 08:06 -0700
Re: The incoming speed of light is variable Ed Lake <detect@newsguy.com> - 2018-03-28 09:01 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-28 09:10 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-28 09:18 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-28 09:31 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-28 09:43 -0700
Re: The incoming speed of light is variable rotchm <rotchm@gmail.com> - 2018-03-28 13:48 -0700
Re: The incoming speed of light is variable Ed Lake <detect@newsguy.com> - 2018-03-29 08:48 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-29 09:00 -0700
Re: The incoming speed of light is variable rotchm <rotchm@gmail.com> - 2018-03-29 10:33 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-29 11:10 -0700
Re: The incoming speed of light is variable Ed Lake <detect@newsguy.com> - 2018-03-29 14:59 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-29 15:06 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-29 15:17 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-29 16:07 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-29 16:09 -0700
Re: The incoming speed of light is variable rotchm <rotchm@gmail.com> - 2018-03-29 18:05 -0700
Re: The incoming speed of light is variable Ed Lake <detect@newsguy.com> - 2018-03-30 13:56 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-30 14:01 -0700
Re: The incoming speed of light is variable Gary Harnagel <hitlong@yahoo.com> - 2018-03-30 14:41 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-30 15:26 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-30 15:40 -0700
Re: The incoming speed of light is variable mlwozniak@wp.pl - 2018-03-30 21:44 -0700
Re: The incoming speed of light is variable rotchm <rotchm@gmail.com> - 2018-03-30 16:37 -0700
Re: The incoming speed of light is variable Ed Lake <detect@newsguy.com> - 2018-03-31 10:26 -0700
Re: The incoming speed of light is variable Paparios <mrios@ing.puc.cl> - 2018-03-31 10:38 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-31 10:45 -0700
Re: The incoming speed of light is variable rotchm <rotchm@gmail.com> - 2018-04-01 11:25 -0700
Re: The incoming speed of light is variable Odd Bodkin <bodkinodd@gmail.com> - 2018-04-01 20:54 +0000
Re: The incoming speed of light is variable mlwozniak@wp.pl - 2018-04-01 22:49 -0700
Re: The incoming speed of light is variable rotchm <rotchm@gmail.com> - 2018-04-02 07:06 -0700
Re: The incoming speed of light is variable mlwozniak@wp.pl - 2018-04-02 09:12 -0700
Re: The incoming speed of light is variable rotchm <rotchm@gmail.com> - 2018-04-02 13:45 -0700
Re: The incoming speed of light is variable RichD <r_delaney2001@yahoo.com> - 2018-04-02 15:30 -0700
Re: The incoming speed of light is variable Dirk Van de moortel <dirkvandemoortel@notmail.com> - 2018-04-03 12:24 +0200
Re: The incoming speed of light is variable mlwozniak@wp.pl - 2018-04-03 03:38 -0700
Re: The incoming speed of light is variable RichD <r_delaney2001@yahoo.com> - 2018-03-31 14:18 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-31 14:49 -0700
Re: The incoming speed of light is variable "Paul B. Andersen" <relativity@paulba.no> - 2018-04-01 19:05 +0200
Re: The incoming speed of light is variable Gary Harnagel <hitlong@yahoo.com> - 2018-03-28 16:07 -0700
Re: The incoming speed of light is variable Tom Roberts <tjroberts137@sbcglobal.net> - 2018-03-31 09:03 -0500
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-31 08:20 -0700
Re: The incoming speed of light is variable kenseto <setoken@att.net> - 2018-03-31 08:26 -0700
Re: The incoming speed of light is variable Emory Walpole <aibw@wrtwgt.lr> - 2018-03-31 16:13 +0000
Re: The incoming speed of light is variable Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-03-31 20:05 +0200
Re: The incoming speed of light is variable Emory Walpole <aibw@wrtwgt.lr> - 2018-03-31 19:02 +0000
Re: The incoming speed of light is variable Ed Lake <detect@newsguy.com> - 2018-03-31 13:52 -0700
Re: The incoming speed of light is variable HGW <HW@home.net> - 2018-04-01 08:15 +1000
Re: The incoming speed of light is variable Ed Lake <detect@newsguy.com> - 2018-04-01 10:12 -0700
Re: The incoming speed of light is variable HGW <HW@home.net> - 2018-04-02 10:51 +1000
Re: The incoming speed of light is variable Ed Lake <detect@newsguy.com> - 2018-04-02 07:34 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-02 08:13 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-02 08:17 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-02 09:08 -0700
Re: The incoming speed of light is variable Tom Roberts <tjroberts137@sbcglobal.net> - 2018-03-31 19:09 -0500
The Doppler effect (was: The incoming speed of light is variable) Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-04-01 05:26 +0200
Re: The Doppler effect HGW <HW@home.net> - 2018-04-02 10:59 +1000
Re: The incoming speed of light is variable Ed Lake <detect@newsguy.com> - 2018-04-01 10:06 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-01 11:45 -0700
Re: The incoming speed of light is variable Tom Roberts <tjroberts137@sbcglobal.net> - 2018-04-01 15:55 -0500
Re: The incoming speed of light is variable mlwozniak@wp.pl - 2018-04-01 22:50 -0700
Re: The incoming speed of light is variable kenseto <setoken@att.net> - 2018-04-02 09:17 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-02 10:00 -0700
Re: The incoming speed of light is variable kenseto <setoken@att.net> - 2018-04-02 11:44 -0700
Re: The incoming speed of light is variable Tom Roberts <tjroberts137@sbcglobal.net> - 2018-04-02 16:29 -0500
Re: The incoming speed of light is variable Emory Walpole <aibw@wrtwsgt.lr> - 2018-04-02 23:21 +0000
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-02 16:33 -0700
Re: The incoming speed of light is variable Tom Roberts <tjroberts137@sbcglobal.net> - 2018-04-02 22:38 -0500
Re: The incoming speed of light is variable HGW <HW@home.net> - 2018-04-03 20:02 +1000
Re: The incoming speed of light is variable Emory Walpole <aibw@wrtwsgt.lr> - 2018-04-03 11:37 +0000
Re: The incoming speed of light is variable Tom Roberts <tjroberts137@sbcglobal.net> - 2018-04-03 12:39 -0500
Re: The incoming speed of light is variable Tom Roberts <tjroberts137@sbcglobal.net> - 2018-04-03 12:36 -0500
Re: The incoming speed of light is variable HGW <HW@home.net> - 2018-04-04 08:40 +1000
Re: The incoming speed of light is variable Gary Harnagel <hitlong@yahoo.com> - 2018-04-03 20:20 -0700
Re: The incoming speed of light is variable HGW <HW@home.net> - 2018-04-04 16:27 +1000
Re: The incoming speed of light is variable Gary Harnagel <hitlong@yahoo.com> - 2018-04-04 12:31 -0700
Re: The incoming speed of light is variable HGW <HW@home.net> - 2018-04-05 08:23 +1000
Re: The incoming speed of light is variable Python <python@python.invalid> - 2018-04-05 01:35 +0200
Re: The incoming speed of light is variable HGW <HW@home.net> - 2018-04-05 10:56 +1000
Re: The incoming speed of light is variable mitchrae3323@gmail.com - 2018-04-04 18:14 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-04 18:17 -0700
Re: The incoming speed of light is variable Odd Bodkin <bodkinodd@gmail.com> - 2018-04-05 02:15 +0000
Re: The incoming speed of light is variable HGW <HW@home.net> - 2018-04-05 15:32 +1000
Re: The incoming speed of light is variable Odd Bodkin <bodkinodd@gmail.com> - 2018-04-05 10:43 +0000
Re: The incoming speed of light is variable HGW <HW@home.net> - 2018-04-06 09:55 +1000
Re: The incoming speed of light is variable Odd Bodkin <bodkinodd@gmail.com> - 2018-04-06 12:42 +0000
Re: The incoming speed of light is variable HGW <HW@home.net> - 2018-04-07 10:00 +1000
Re: The incoming speed of light is variable Gary Harnagel <hitlong@yahoo.com> - 2018-04-06 17:43 -0700
Re: The incoming speed of light is variable HGW <HW@home.net> - 2018-04-08 08:58 +1000
Re: The incoming speed of light is variable Gary Harnagel <hitlong@yahoo.com> - 2018-04-08 05:08 -0700
Re: The incoming speed of light is variable Odd Bodkin <bodkinodd@gmail.com> - 2018-04-07 02:26 +0000
Re: The incoming speed of light is variable Gary Harnagel <hitlong@yahoo.com> - 2018-04-05 04:47 -0700
Re: The incoming speed of light is variable Gary Harnagel <hitlong@yahoo.com> - 2018-04-04 19:22 -0700
Re: The incoming speed of light is variable HGW <HW@home.net> - 2018-04-05 15:11 +1000
Re: The incoming speed of light is variable Gary Harnagel <hitlong@yahoo.com> - 2018-04-05 04:42 -0700
Re: The incoming speed of light is variable mlwozniak@wp.pl - 2018-04-05 06:04 -0700
Re: The incoming speed of light is variable HGW <HW@home.net> - 2018-04-06 13:50 +1000
Re: The incoming speed of light is variable Gary Harnagel <hitlong@yahoo.com> - 2018-04-06 08:10 -0700
Re: The incoming speed of light is variable HGW <HW@home.net> - 2018-04-07 09:43 +1000
Re: The incoming speed of light is variable Gary Harnagel <hitlong@yahoo.com> - 2018-04-06 17:25 -0700
Re: The incoming speed of light is variable kenseto <setoken@att.net> - 2018-04-07 07:27 -0700
Re: The incoming speed of light is variable moroney@world.std.spaamtrap.com (Michael Moroney) - 2018-04-08 04:10 +0000
Re: The incoming speed of light is variable kenseto <setoken@att.net> - 2018-04-08 04:09 -0700
Re: The incoming speed of light is variable Gaston Levell <jno@itwjwg.tn> - 2018-04-08 11:25 +0000
Re: The incoming speed of light is variable Odd Bodkin <bodkinodd@gmail.com> - 2018-04-08 12:09 +0000
Re: The incoming speed of light is variable kenseto <setoken@att.net> - 2018-04-08 05:29 -0700
Re: The incoming speed of light is variable Odd Bodkin <bodkinodd@gmail.com> - 2018-04-08 12:32 +0000
Re: The incoming speed of light is variable Libor 'Poutnik' Stříž <poutnik@privacy.net> - 2018-04-08 15:20 +0200
Re: The incoming speed of light is variable moroney@world.std.spaamtrap.com (Michael Moroney) - 2018-04-08 16:35 +0000
Re: The incoming speed of light is variable moroney@world.std.spaamtrap.com (Michael Moroney) - 2018-04-08 16:30 +0000
Re: The incoming speed of light is variable Gary Harnagel <hitlong@yahoo.com> - 2018-04-08 05:01 -0700
Re: The incoming speed of light is variable kenseto <setoken@att.net> - 2018-04-08 05:18 -0700
Re: The incoming speed of light is variable Gary Harnagel <hitlong@yahoo.com> - 2018-04-08 07:27 -0700
Re: The incoming speed of light is variable HGW <HW@home.net> - 2018-04-10 19:11 +1000
Re: The incoming speed of light is variable HGW <HW@home.net> - 2018-04-10 19:14 +1000
Re: The incoming speed of light is variable Gary Harnagel <hitlong@yahoo.com> - 2018-04-10 07:12 -0700
Re: The incoming speed of light is variable mlwozniak@wp.pl - 2018-04-04 21:27 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-04 13:02 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-04 13:05 -0700
Re: The incoming speed of light is variable Tom Roberts <tjroberts137@sbcglobal.net> - 2018-04-04 15:08 -0500
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-04 13:19 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-04 13:31 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-04 13:39 -0700
Re: The incoming speed of light is variable HGW <HW@home.net> - 2018-04-05 09:24 +1000
Re: The incoming speed of light is variable Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-04-05 06:15 +0200
Re: The incoming speed of light is variable Tom Roberts <tjroberts137@sbcglobal.net> - 2018-04-09 09:35 -0500
Re: The incoming speed of light is variable Gaston Levell <jno@itwjwg.tn> - 2018-04-09 16:13 +0000
Re: The incoming speed of light is variable kenseto <setoken@att.net> - 2018-04-03 08:39 -0700
Re: The incoming speed of light is variable HGW <HW@home.net> - 2018-04-02 11:06 +1000
Re: The incoming speed of light is variable Keith Stein <keithstein111@gmail.com> - 2018-04-02 18:21 +0100
Re: The incoming speed of light is variable Gary Harnagel <hitlong@yahoo.com> - 2018-04-02 11:21 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-02 11:30 -0700
Re: The incoming speed of light is variable Keith Stein <keithstein111@gmail.com> - 2018-04-03 00:41 +0100
Re: The incoming speed of light is variable Gary Harnagel <hitlong@yahoo.com> - 2018-04-02 19:22 -0700
Re: The incoming speed of light is variable Odd Bodkin <bodkinodd@gmail.com> - 2018-04-03 02:26 +0000
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-02 20:11 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-02 20:15 -0700
Re: The incoming speed of light is variable Keith Stein <keithstein111@gmail.com> - 2018-04-03 09:45 +0100
Re: The incoming speed of light is variable Gary Harnagel <hitlong@yahoo.com> - 2018-04-03 05:15 -0700
Re: The incoming speed of light is variable Keith Stein <keithstein111@gmail.com> - 2018-04-03 14:50 +0100
Re: The incoming speed of light is variable Gary Harnagel <hitlong@yahoo.com> - 2018-04-03 07:06 -0700
Re: The incoming speed of light is variable Keith Stein <keithstein111@gmail.com> - 2018-04-03 18:53 +0100
Re: The incoming speed of light is variable Gary Harnagel <hitlong@yahoo.com> - 2018-04-03 11:46 -0700
Re: The incoming speed of light is variable Odd Bodkin <bodkinodd@gmail.com> - 2018-04-03 17:31 +0000
Re: The incoming speed of light is variable Tom Roberts <tjroberts137@sbcglobal.net> - 2018-04-08 11:19 -0500
Re: The incoming speed of light is variable Keith Stein <keithstein111@gmail.com> - 2018-04-08 19:21 +0100
Re: The incoming speed of light is variable Libor 'Poutnik' Stříž <poutnik@privacy.net> - 2018-04-08 21:11 +0200
Re: The incoming speed of light is variable Keith Stein <keithstein111@gmail.com> - 2018-04-09 08:50 +0100
Re: The incoming speed of light is variable Gary Harnagel <hitlong@yahoo.com> - 2018-04-09 04:49 -0700
Re: The incoming speed of light is variable Keith Stein <keithstein111@gmail.com> - 2018-04-12 18:35 +0100
Re: The incoming speed of light is variable Tom Roberts <tjroberts137@sbcglobal.net> - 2018-04-12 17:06 -0500
Re: The incoming speed of light is variable HGW <HW@home.net> - 2018-04-13 09:32 +1000
Re: The incoming speed of light is variable Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2018-04-13 04:46 +0200
Re: The incoming speed of light is variable Keith Stein <keithstein111@gmail.com> - 2018-04-13 07:42 +0100
Re: The incoming speed of light is variable Libor P Striz <poutnik@privacy.net> - 2018-04-13 08:57 +0200
Re: The incoming speed of light is variable Keith Stein <keithstein111@gmail.com> - 2018-04-13 10:18 +0100
Re: The incoming speed of light is variable Libor P Striz <poutnik@privacy.net> - 2018-04-14 08:52 +0200
Re: The incoming speed of light is variable mlwozniak@wp.pl - 2018-04-14 00:11 -0700
Re: The incoming speed of light is variable Gary Harnagel <hitlong@yahoo.com> - 2018-04-13 06:31 -0700
Speed of light in space near earth Tom Roberts <tjroberts137@sbcglobal.net> - 2018-04-08 17:11 -0500
Re: Speed of light in space near earth SolomonW <SoloomonW@citi.com.au> - 2018-04-09 13:00 +1000
Re: Speed of light in space near earth Tom Roberts <tjroberts137@sbcglobal.net> - 2018-04-09 09:29 -0500
Re: Speed of light in space near earth SolomonW <SoloomonW@citi.com.au> - 2018-04-10 14:55 +1000
Re: Speed of light in space near earth Libor P Striz <poutnik@privacy.net> - 2018-04-10 22:26 +0200
Re: Speed of light in space near earth SolomonW <SoloomonW@citi.com.au> - 2018-04-11 13:26 +1000
Re: Speed of light in space near earth Tom Roberts <tjroberts137@sbcglobal.net> - 2018-04-11 18:46 -0500
Re: Speed of light in space near earth SolomonW <SolomonW@citi.com> - 2018-04-12 10:44 +1000
Re: Speed of light in space near earth "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-08 20:50 -0700
Re: Speed of light in space near earth "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-04-08 20:55 -0700
Re: The incoming speed of light is variable mlwozniak@wp.pl - 2018-04-01 00:02 -0700
Re: The incoming speed of light is variable kenseto <setoken@att.net> - 2018-03-28 15:04 -0700
Re: The incoming speed of light is variable rotchm <rotchm@gmail.com> - 2018-03-28 16:38 -0700
Re: The incoming speed of light is variable Ed Lake <detect@newsguy.com> - 2018-03-29 08:55 -0700
Re: The incoming speed of light is variable kenseto <setoken@att.net> - 2018-03-28 07:40 -0700
Re: The incoming speed of light is variable Ed Lake <detect@newsguy.com> - 2018-03-28 08:28 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-28 08:43 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-28 08:53 -0700
Re: The incoming speed of light is variable kenseto <setoken@att.net> - 2018-03-28 15:32 -0700
Re: The incoming speed of light is variable Ed Lake <detect@newsguy.com> - 2018-03-29 09:23 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-29 09:27 -0700
Re: The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-29 09:36 -0700
The incoming speed of light is variable "David (Kronos Prime) Fuller" <fuller.david@hotmail.com> - 2018-03-28 07:36 -0700
Re: The incoming speed of light is variable rotchm <rotchm@gmail.com> - 2018-03-28 08:06 -0700
csiph-web