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Re: APOD: Galaxy in a Crystal Ball (2018 Jun 22)

Posted: Sun Jun 24, 2018 5:22 am
by alter-ego
Cousin Ricky wrote: Sat Jun 23, 2018 4:34 pm
Sa Ji Tario wrote: Fri Jun 22, 2018 1:38 pm If it is crystal ball it is refraction, but as it says it is marble it is reflection
The ground (the dark crescent) is on top in the sphere image, indicating refraction, not reflection. The orientation of the Milky Way is also inverted for Paranal’s location, confirming that this is a refracted image. “Marble” clearly indicates the metaphor for Earth in this context.
The globe image is well centered in the background, blurred FoV. I've inverted the APOD image, scaled it so the background blurred stars match the focused stars inside the original globe image. Distortion limits the accuracy of overlapped stars but it's pretty close.
 
Inverted Globe in Globe.JPG