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Re: APOD: Return at Sunrise (2015 Mar 14)

Posted: Sun Mar 15, 2015 11:04 am
by BDanielMayfield
geckzilla wrote:Thanks, Bill. That's excellent. Knowing there was no window (hey, my original assumption was right!) and then this image settles it. There's not much more to say except you've got something unique going on with your optics causing that streak.
:clap: :thumb_up: :yes:

The debate was fun while it lasted Art. Better to have debated and lost than never to have debated at all...

Re: APOD: Return at Sunrise (2015 Mar 14)

Posted: Sun Mar 15, 2015 2:19 pm
by owlice
All we know for sure is that sleeks did not cause the effect. If there were a bit of a lower pillar, isn't it likely the image would show... well, what it shows? Yes, there is some camera/optical effect going on, too, as is shown by the blown-out sun in other images, but I don't see anything in the other images that absolutely rules out a pillar.

Re: APOD: Return at Sunrise (2015 Mar 14)

Posted: Sun Mar 15, 2015 2:47 pm
by neufer
owlice wrote:
All we know for sure is that sleeks did not cause the effect. If there were a bit of a lower pillar, isn't it likely the image would show... well, what it shows? Yes, there is some camera/optical effect going on, too, as is shown by the blown-out sun in other images, but I don't see anything in the other images that absolutely rules out a pillar.
As geckzilla points out: this vertical image shows similar horizontal sun streaks in precisely the same picture location as the APOD's vertical sun streaks effectively pointing to a camera problem. (How geckzilla could have been so confident of this simply based upon the APOD image alone still mystifies me, however. :? )

Re: APOD: Return at Sunrise (2015 Mar 14)

Posted: Sun Mar 15, 2015 2:51 pm
by Cousin Ricky
I believe this is the first time in 15 years that I've seen verification that Chris is wrong. :mrgreen: Not bad. Shall we shoot for another 15?

Re: APOD: Return at Sunrise (2015 Mar 14)

Posted: Sun Mar 15, 2015 2:55 pm
by Chris Peterson
owlice wrote:All we know for sure is that sleeks did not cause the effect. If there were a bit of a lower pillar, isn't it likely the image would show... well, what it shows? Yes, there is some camera/optical effect going on, too, as is shown by the blown-out sun in other images, but I don't see anything in the other images that absolutely rules out a pillar.
As I suggested earlier, a pillar is a possibility. But in fact, this simply doesn't look very much like one. It is too short, and doesn't show the variation in width that we normally see with pillars, both visually and in images.

Eliminating effects from a window, my next choice would be some combination of diffraction and scatter associated with the iris in the camera lens. It appears to be an eight-vane iris, and we can see light rays aligned with each. Indeed, except for the higher intensity of the lower rays, they all appear virtually identical in terms of width, length, and shape.

Re: APOD: Return at Sunrise (2015 Mar 14)

Posted: Sun Mar 15, 2015 3:01 pm
by Chris Peterson
Cousin Ricky wrote:I believe this is the first time in 15 years that I've seen verification that Chris is wrong. :mrgreen: Not bad. Shall we shoot for another 15?
We can try.

That said, I wouldn't say my comments were "wrong". The main point was that this doesn't look like a sun pillar. It still doesn't, and the evidence points away from it being one. Beyond that, effects from a window was just a guess, and a not unreasonable one given the information available at the time.

Re: APOD: Return at Sunrise (2015 Mar 14)

Posted: Sun Mar 15, 2015 7:50 pm
by geckzilla
neufer wrote:As geckzilla points out: this vertical image shows similar horizontal sun streaks in precisely the same picture location as the APOD's vertical sun streaks effectively pointing to a camera problem. (How geckzilla could have been so confident of this simply based upon the APOD image alone still mystifies me, however. :? )
I'm a wizard. Duh.

Re: APOD: Return at Sunrise (2015 Mar 14)

Posted: Sun Mar 15, 2015 7:53 pm
by Ron-Astro Pharmacist
I was going to post this question yesterday when Microsoft took over my computer then I had to leave. Then conversation revolved around its content in one way or another so I’ll try again-

I was curious about how this photo was taken? When I clicked on the NASA link I saw the commemoration of pi day.

“If you like numbers, you will love March 14, 2015. When written as a numerical date, it’s 3/14/15, corresponding to the first five digits of pi (3.1415) -- a once-in-a-century coincidence! Pi is useful for all kinds of calculations involving the volume and surface area of spheres, as well as for determining the rotations of circular objects such as wheels. That’s why pi is important for scientists who work with planetary bodies and the spacecraft that visit them. At NASA's Jet Propulsion Laboratory, pi makes a frequent appearance.

I wonder if all the pastry chefs 'round the world also celebrate the day too as they don’t have to make “pies” square. Especially back on the date : 3/14/1592. They most likely were marking a hundred years since “sailing the ocean blue.” Columbus was probably happier that the Earth turned out to be:
Sphere.jpg
Sphere.jpg (2.85 KiB) Viewed 2677 times
rather than:
Flat Surface.jpg
Flat Surface.jpg (5.02 KiB) Viewed 2677 times
Many aspects of this APOD show the importance of those who, over history, strove to understand and use pi’s relevance.

Re: APOD: Return at Sunrise (2015 Mar 14)

Posted: Sun Mar 15, 2015 10:12 pm
by Cousin Ricky
Ron-Astro Pharmacist wrote:They most likely were marking a hundred years since “sailing the ocean blue.” Columbus was probably happier that the Earth turned out to be:
Sphere.jpg
rather than:
Flat Surface.jpg
No, Columbus was probably happier that America happened to exist. By 1492, all educated people knew that the Earth is (roughly) spherical. (The story you were taught in school was actually fan fiction by Washington Irving. :shock: Seriously.) The reason the venture capitalists of the day were skittish about Columbus’ plan was that they also knew the correct answer to 2πr, and determined that Columbus and his crew would starve long before they reached Asia. Columbus thought the distance was shorter.

Columbus was still alive when Amerigo Vespucci started to suspect that Columbus’ “Asia” was another continent previously unknown to Europeans—although I still don’t know what navigators of the day thought of the lands explored by the Vikings almost 500 years earlier.

Re: APOD: Return at Sunrise (2015 Mar 14)

Posted: Mon Mar 16, 2015 4:01 pm
by Ron-Astro Pharmacist
Cousin Ricky wrote:
Ron-Astro Pharmacist wrote:They most likely were marking a hundred years since “sailing the ocean blue.” Columbus was probably happier that the Earth turned out to be:
Sphere.jpg
rather than:
Flat Surface.jpg
No, Columbus was probably happier that America happened to exist. By 1492, all educated people knew that the Earth is (roughly) spherical. (The story you were taught in school was actually fan fiction by Washington Irving. :shock: Seriously.) The reason the venture capitalists of the day were skittish about Columbus’ plan was that they also knew the correct answer to 2πr, and determined that Columbus and his crew would starve long before they reached Asia. Columbus thought the distance was shorter.

Columbus was still alive when Amerigo Vespucci started to suspect that Columbus’ “Asia” was another continent previously unknown to Europeans—although I still don’t know what navigators of the day thought of the lands explored by the Vikings almost 500 years earlier.
You're kidding. :wink: What did him and his crew have to worry about then? Now I'm kidding. Actually I just finished listening to Flatland: A Romance of Many Dimensions an 1884 satirical novella by Edwin Abbott Abbott. http://en.wikipedia.org/wiki/Flatland I am curious about how this book influenced the thinking of Albert Einstein (if it did?) Who's birthday, per chance, we could have celebrated on pi day. Born 3/14/1879
http://www.geom.uiuc.edu/~banchoff/Flatland/
Can't wait to watch the movie.
Click to play embedded YouTube video.