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"Ahad radius" - does it change with direction of travel ?



 
 
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  #1  
Old December 13th 04, 04:48 PM
Robert
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Default "Ahad radius" - does it change with direction of travel ?

(Apologies if this thread goes diverted, this google retriveable
errors driving me up the wall.)

Ian Beardsley wrote on my glowing phosphorescence screen:

Wouldn't such a radius depend on the direction you go, like towards

the
center of the galaxy would be brighter than going in the opposite
direction, or am I looking at this the wrong way?--Ian


Well no because the Milky Way's centre is so far away from the sun, it
will be negligible in how bright it looks from going _inwards_ toward
it compared to going _outward_ away from it. Besides Ahad's flux
constant is a derivative of the milky way + nearby stars. So the
radius ought to be fixed, I think.

Then suppose saying that, does the sun radiate equally in all
directions? If the sun has more power equatorial;ly, (because it is
_flat_) then Ahad's _vanity sphere_ may actually be no sphere at all,
but a _spereoid_ instead! Who knows...

Rob
  #2  
Old December 13th 04, 05:14 PM
Greg Neill
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"Robert" wrote in message
om...
(Apologies if this thread goes diverted, this google retriveable
errors driving me up the wall.)

Ian Beardsley wrote on my glowing phosphorescence screen:

Wouldn't such a radius depend on the direction you go, like towards

the
center of the galaxy would be brighter than going in the opposite
direction, or am I looking at this the wrong way?--Ian


Well no because the Milky Way's centre is so far away from the sun, it
will be negligible in how bright it looks from going _inwards_ toward
it compared to going _outward_ away from it. Besides Ahad's flux
constant is a derivative of the milky way + nearby stars. So the
radius ought to be fixed, I think.


You only have to stand outside on a clear night under
non light-polluted skies to know that the average light
flux differs from place to place in the sky. The Milky
Way has a much higher average illumination per square
degree than, say, directions galactic-poleward.


  #3  
Old December 14th 04, 11:15 PM
George Dishman
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"Greg Neill" wrote in message
.. .
"Robert" wrote in message
om...
(Apologies if this thread goes diverted, this google retriveable
errors driving me up the wall.)

Ian Beardsley wrote on my glowing phosphorescence screen:

Wouldn't such a radius depend on the direction you go, like towards

the
center of the galaxy would be brighter than going in the opposite
direction, or am I looking at this the wrong way?--Ian


Well no because the Milky Way's centre is so far away from the sun, it
will be negligible in how bright it looks from going _inwards_ toward
it compared to going _outward_ away from it. Besides Ahad's flux
constant is a derivative of the milky way + nearby stars. So the
radius ought to be fixed, I think.


You only have to stand outside on a clear night under
non light-polluted skies to know that the average light
flux differs from place to place in the sky. The Milky
Way has a much higher average illumination per square
degree than, say, directions galactic-poleward.


True but he is finding the surface where the solar
flux is equal to the total flux from the rest of the
sky. That will be close to a sphere centered on the
Sun, though the nearby stars may dimple it a bit, so
defining a mean radius seems reasonable.

George


  #4  
Old December 15th 04, 04:32 PM
robert
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Didn't Greg Neill write on my glowing screen in such colourful
language:

You only have to stand outside on a clear night under
non light-polluted skies to know that the average light
flux differs from place to place in the sky. The Milky
Way has a much higher average illumination per square
degree than, say, directions galactic-poleward.


Ahhaa, but the sphere is a conceptual one, and based on _total_ flux
of the night sky. Its radius is only 0.18 - light year compared to a
30,000 light year distance to the centre of our galaxy. So whether you
are 0.18 light-year out from the sun in a direction _opposite_ to the
galactic core or _toward_ the galactic core, the point of flux
equivalence will be the same.

Check his vanity art--
http://uk.geocities.com/aa_spaceagen...erstellar.html

My other Q, is does the sun radiate _equally_ equatorially as polar?
That could change the dimensions of this sphere of light.

Rob

  #5  
Old December 16th 04, 05:00 PM
Alfred A. Aburto Jr.
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robert wrote:
Didn't Greg Neill write on my glowing screen in such colourful
language:


You only have to stand outside on a clear night under
non light-polluted skies to know that the average light
flux differs from place to place in the sky. The Milky
Way has a much higher average illumination per square
degree than, say, directions galactic-poleward.



Ahhaa, but the sphere is a conceptual one, and based on _total_ flux
of the night sky. Its radius is only 0.18 - light year compared to a
30,000 light year distance to the centre of our galaxy. So whether you
are 0.18 light-year out from the sun in a direction _opposite_ to the
galactic core or _toward_ the galactic core, the point of flux
equivalence will be the same.

Check his vanity art--
http://uk.geocities.com/aa_spaceagen...erstellar.html

My other Q, is does the sun radiate _equally_ equatorially as polar?
That could change the dimensions of this sphere of light.


Good question! I don't know the answer :-)
However, I suspect there might be a slight bias toward the equatorial
regions because of sunspots during the peak in the solar cycle.
But there are also strong solar flares that occur during this time near
the equatorial regions.

Also, I understand that the solar wind from the polar regions of the Sun
is almost twice as fast as from the equatorial regions during the
solar cycle minimums (not sure how this affects the radiated flux though).


Rob

  #6  
Old December 18th 04, 08:37 AM
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Alfred A. Aburto Jr. wrote:

My other Q, is does the sun radiate _equally_ equatorially as

polar?
That could change the dimensions of this sphere of light.


Good question! I don't know the answer :-)
However, I suspect there might be a slight bias toward the equatorial


regions because of sunspots during the peak in the solar cycle.
But there are also strong solar flares that occur during this time

near
the equatorial regions.

Also, I understand that the solar wind from the polar regions of the

Sun
is almost twice as fast as from the equatorial regions during the
solar cycle minimums (not sure how this affects the radiated flux

though).

Doesn't a pulsar flash mainly equatorially, and this is similar to the
sun. So the sun has a definite _flatenning profile_ on its sphere
because of faster rotation. So I am thinking sun radiates more energy
equatorially than polar? Was there some findings on Ulyssis that flew
over the sun few years back..

Jav

 




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