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Flat Earth General / The Green Flash Phenomenon
« on: May 12, 2020, 05:14:36 PM »
In a discussion about an unrelated topic, a rather bizarre (IMO) explanation for the green flash phenomenon was offered, along with challenge to explain what would cause this rare but still repeatedly-seen phenomenon if the earth were a globe. This was an apparent attempt to deflect the conversation away from the topic under discussion, which was going badly for the poster who brought this red herring up, and didn't create enough of a distraction to adequately derail the discussion.
Still, it's an interesting topic on its own, and the visuals and explanations offered in this post and others were not really very good, so let's continue that discussion here.
Below is a quote of the opening salvo, in full. As is often in the case of these topic-changing moves tend to be, it's quite long, and much of the post, including the second image, is simply a copy and paste from the linked paper by an art instructor, in addition to other text gleaned from elsewhere.
I'll address the major points and deficiencies of this post, as well as some of the points that followed, in separate posts that will follow.
Still, it's an interesting topic on its own, and the visuals and explanations offered in this post and others were not really very good, so let's continue that discussion here.
Below is a quote of the opening salvo, in full. As is often in the case of these topic-changing moves tend to be, it's quite long, and much of the post, including the second image, is simply a copy and paste from the linked paper by an art instructor, in addition to other text gleaned from elsewhere.
I'll address the major points and deficiencies of this post, as well as some of the points that followed, in separate posts that will follow.
White is green:
https://web.archive.org/web/20160312043114/http://web.csulb.edu/~percept/kyotocolor.html
The green flash phenomenon can only be caused by the Sun's rays which pass through the aether prism (Dome).
"Newton surmised that when we see a colour spectrum emerge from a prism,
it is due to 'the splitting of light into its component colours'.
If this were the case, then in the photograph below, there should be
a spectrum with GREEN in the middle. Yet, since the aperature through which
the light is shining is large, we get no such spectrum, we only get colour
at the edges. In an attempt to isolate the phenomena, Newton decided to
narrow the aperature which results in the spectrum we are now familiar with,
and which he used as a basis for his Optiks.
What Newton failed to do, was to take a look through the prism.
If you actually do this, the white areas do not split into a rainbow of
colour as might be expected -- you only see colour at the edges of objects.
When light shines through a prism, we are simply projecting a picture
whose aperature has edges -- there is darkness outside this circular patch,
and relatively light within it. We notice that it is at the edges between
the light and dark areas where Colours first make their appearance.
When the aperature is sufficiently small so that the edges meet in
the middle to form the green -- only then can you see a continous spectrum.
A wider aperature brings us to the primal phenomenon -- a reddish/yellow
on some edges, and a bluish/cyan on the others.
The continuous spectrum with green in the middle arises only where
the (blue-cyan and yellow-red) edges come close enough to overlap.
We no longer see the original phenomenon when we make so small a circle
that the colours extend inward from the edges to overlap in the middle
to form what is called a 'continuous spectrum', while with the larger
circle, the colours formed at the edges stay as they are.
Thus, this is the primal phenomenon -- that Colours arise at the borders
where Light and Dark work together, and the Spectrum is a secondary,
compound phenomenon.
In the 1780's a number of statements as to the way colours arise came to
Goethe's notice. Of the prismatic phenomena, it was commonly held by
physicists that when you let colourless light go through a prism the
colourless light is split up. For in some such way the phenomena were
interpreted.
If we let a cylinder of colourless light impinge on the screen, it shows a
colourless picture. Putting a prism in the way of the cylinder of light,
we get the sequence of colours: red, orange, yellow, green, blue - light
blue and dark blue, - violet.
The physicists explain it thus - the colourless light already contains the
seven colours within itself - and when we make the light go through the
prism, the prism really does no more than to fan out and separate what is
already there in the light, - the seven colours, into which it is thus
analyzed.
A look through the prism shows that we do not see the light in seven
colours. The only place you can see any colour is at some edge or
border-line.
If we let light pass through the space of the room, we get a white circle
on a screen. Put a prism in the way, and the cylinder of light is
diverted, (Figure I), but what appears is not the series of seven
colours at all, only a reddish colour at the lower edge, passing over into
yellow, and at the upper edge a blue passing over into greenish shades. In
the middle it stays white.
Goethe now said to himself: It is not that the light is split up or that
anything is separated out of the light as such. In point of fact, I am
projecting a picture, - simply an image of this circular aperture. The
aperture has edges, and where the colours occur the reason is not that
they are drawn out of the light, as though the light had been split up
into them. It is because this picture which I am projecting - the picture
as such - has edges. Here too the fact is that where light adjoins dark,
colours appear at the edges. It is none other than that. For there is
darkness outside this circular patch of light, while it is relatively
light within it.
The colours therefore, to begin with, make their appearance purely and
simply as phenomena at the border between light and dark. This is the
original, the primary phenomenon. We are no longer seeing the original
phenomenon when by reducing the circle in size we get a continuous
sequence of colours. The latter phenomenon only arises when we take so
small a circle that the colours extend inward from the edges to the
middle. They then overlap in the middle and form what we call a continuous
spectrum, while with the larger circle the colours formed at the edges
stay as they are. This is the primal phenomenon. Colours arise at the
borders, where light and dark flow together.
Subsequent to this, Goethe's went on to make more exact observations
which further call this 'splitting up of the light' by a prism into question:
- Begin with a circular slit from which Light shines through a PRISM.
- Light is deflected upwards.
- The projection is not an exact circle, but rather elongated.
- The upper portion is edged with Blue.
- The lower portion is edged with Red.
- Taking into account the observation that Light passing through
any medium is dimmed. In this case, there is a dimming of light
within the prism.
- Therefore, we have to do not only with the cone of light that is here
bent and deflected, but also with this new factor - the dimming
of the light brought about by matter.
- Into the space beyond the prism not only the light is shining,
but there shines in, there rays into the light the quality of dimness
that is in the prism.
- This dimming is deflected upward in the same direction as the light.
- Here then we are dealing with the interaction of two things:
i) the brightly shining light, itself deflected,
ii) then the sending into it of the darkening effect that is poured
into this shining light. Only the dimming and darkening effect is
here deflected in the same direction as the light.
- The Outcome is that in the upward region the bright light is infused
and irradiated with dimness, and by this means the dark or bluish colours
are produced.
- Downwards, the light outdoes and overwhelms the darkness and there arise
the yellow shades of colour.
- Simply through the fact that the prism on the one hand deflects the full
bright cone of light and on the other hand also deflects the dimming of it,
we have the two kinds of entry of the dimming or darkening into the light.
We have an interplay of dark and light, not getting mixed to give a grey but
remaining mutually independent in their activity.
- The material prism plays an essential part in the arising of the
colours. For it is through the prism that it happens, namely that on the
one hand the dimming is deflected in the same direction as the cone of
light, while on the other hand, because the prism lets its darkness ray
there too, this that rays on and the light that is deflected cut across
each other. For that is how the deflection works down here. Downward, the
darkness and the light are interacting in a different way than upward.
Colours therefore arise where dark and light work together."
In the local-ether model, the speed of light is variable.
Here is the green flash being observed in the radiant energy discharged by a capacitor: