APOD: Return at Sunrise (2015 Mar 14)

Post a reply


This question is a means of preventing automated form submissions by spambots.
Smilies
:D :) :ssmile: :( :o :shock: :? 8-) :lol2: :x :P :oops: :cry: :evil: :roll: :wink: :!: :?: :idea: :arrow: :| :mrgreen:
View more smilies
BBCode is ON
[img] is ON
[url] is ON
Smilies are ON
Topic review
   

Expand view Topic review: APOD: Return at Sunrise (2015 Mar 14)

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

by Ron-Astro Pharmacist » Mon Mar 16, 2015 4:01 pm

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.

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

by Cousin Ricky » Sun Mar 15, 2015 10:12 pm

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)

by Ron-Astro Pharmacist » Sun Mar 15, 2015 7:53 pm

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 2824 times
rather than:
Flat Surface.jpg
Flat Surface.jpg (5.02 KiB) Viewed 2824 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)

by geckzilla » Sun Mar 15, 2015 7:50 pm

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)

by Chris Peterson » Sun Mar 15, 2015 3:01 pm

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)

by Chris Peterson » Sun Mar 15, 2015 2:55 pm

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)

by Cousin Ricky » Sun Mar 15, 2015 2:51 pm

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)

by neufer » Sun Mar 15, 2015 2:47 pm

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)

by owlice » Sun Mar 15, 2015 2:19 pm

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)

by BDanielMayfield » Sun Mar 15, 2015 11:04 am

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)

by geckzilla » Sun Mar 15, 2015 9:32 am

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.

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

by bingalls » Sun Mar 15, 2015 9:27 am

Sorry - mean to include full exposure:

ISO 800
Shutter 1/4000
f-Stop = f11

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

by bingalls » Sun Mar 15, 2015 8:27 am

I'm the photographer that made this image - I was asked if I could stop by this discussion and share some more about how it was made...

This was shot out of an open helicopter door at approximately 6-7,000 feet. No windows between my lens and the subject, just some pretty cold air. :)

Here is my camera EXIF data:
Nikon D4
ISO Speed - 800
Date and Time (Original) - 2015:03:12 08:05:51
Metering Mode - Multi-segment
Focal Plane X-Resolution - 1368.888885
Focal Plane Y-Resolution - 1368.888885
Focal Plane Resolution Unit - cm
White Balance - Manual
Focal Length (35mm format) - 98 mm
Subject Distance Range - Unknown
Lens Info - 80-400mm f4.5-5.6

As you will see in this set of images there are others with this effect from the Sun and at various directions. I could not tell you if it was introduced by the camera/lens or not, but I think it may be. You can see all images from this event here:
https://www.flickr.com/photos/nasahqpho ... 0846481517

Hope this helps or at least helps to narrow down the possibilities.

Cheers - Bill Ingalls

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

by geckzilla » Sun Mar 15, 2015 5:44 am

neufer wrote:
geckzilla wrote:
Can you not see the differences between the sun pillars you've posted and the effect present photo?
Todays APOD sun pillar is:
  • 1) not quite so overexposed

    2) using a telephoto lens so that one can't see the sun dogs.
Ok, so if you think the Soyuz picture is overexposed, how is it that there really isn't much of a sun pillar there at all? It's not like a longer exposure makes the sun pillar go away. It should appear longer and more obvious. It's just right next to the sun which is exactly where one might expect some kind of smearing from the window to be.

I know you think it can't possibly be scratches on the window or otherwise you wouldn't be so sure about it being a sun pillar, because you think that random scratches all over will result in rays evenly in more than one direction. But if you search for images of the sun through a car window you can find a few examples of the sun doing this. I have also thought that the presence of gravity and the constant blowing of wind could cause water droplets or other substances on the window to become aligned. Anyway, I'm not convinced it's a sundog.

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

by Mactavish » Sun Mar 15, 2015 3:13 am

I’m relieved that the guy who packed the parachute was paying close attention to what he was doing!

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

by neufer » Sun Mar 15, 2015 12:46 am

geckzilla wrote:
Can you not see the differences between the sun pillars you've posted and the effect present photo?
Todays APOD sun pillar is:
  • 1) not quite so overexposed

    2) using a telephoto lens so that one can't see the sun dogs.

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

by geckzilla » Sat Mar 14, 2015 8:53 pm

Chris Peterson wrote:I agree, it's not an atmospheric effect. Not in the camera, either, I think. I'd say it's scatter off the sleeks which are always present on the surface of aircraft windows.
Ah, yeah, for some reason I was imagining he was shooting through an open side in the helicopter. Probably not, on further thought!
neufer wrote:Sleeks in all different directions perhaps.

It's a sun pillar: http://www.glorie.de/sonstiges/subsun.jpg

http://blog.newscom.com/wp-content/uplo ... nomena.jpg
Can you not see the differences between the sun pillars you've posted and the effect present photo?

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

by Chris Peterson » Sat Mar 14, 2015 5:46 pm

neufer wrote:It's a sun pillar
Maybe. But I don't think so. It doesn't really look like one to me. I'm going with scratches on the window based on what I see. I've taken images out of windows that produce exactly this same artifact. And I've shot quite a few sun and moon pillars, as well, which don't look quite like this.

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

by neufer » Sat Mar 14, 2015 5:39 pm

Chris Peterson wrote:
Jim Armstrong wrote:
I came over from the APOD to see if the sun as lightbulb question had been asked and answered.
Of course it had.
Unfortunately I can't find out what a sleek is.
Is it inside or outside? Does it come with the window or develop later? Are they friendly?
Sleeks are very fine, long scratches on plastic or glass- typically with widths on the same order or just a bit longer than light wavelengths. They create interesting optical artifacts (and are the bane of amateur astronomers trying to clean telescope mirrors). They are created by wiping the surface when it has abrasive dust particles on it. Depending on how the wiping is performed, you can have circular sleeks or straight ones, which tend to be aligned. In addition to scattering light, they can also diffract it, acting like a grating.

Airplane windows usually have a plastic film on the inside surface, which is much softer than glass and acquires sleeks very easily.
Sleeks in all different directions perhaps.

It's a sun pillar: http://www.glorie.de/sonstiges/subsun.jpg

http://blog.newscom.com/wp-content/uplo ... nomena.jpg

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

by Chris Peterson » Sat Mar 14, 2015 4:10 pm

Jim Armstrong wrote:I came over from the APOD to see if the sun as lightbulb question had been asked and answered.
Of course it had.
Unfortunately I can't find out what a sleek is.
Is it inside or outside? Does it come with the window or develop later? Are they friendly?
Sleeks are very fine, long scratches on plastic or glass- typically with widths on the same order or just a bit longer than light wavelengths. They create interesting optical artifacts (and are the bane of amateur astronomers trying to clean telescope mirrors). They are created by wiping the surface when it has abrasive dust particles on it. Depending on how the wiping is performed, you can have circular sleeks or straight ones, which tend to be aligned. In addition to scattering light, they can also diffract it, acting like a grating.

Airplane windows usually have a plastic film on the inside surface, which is much softer than glass and acquires sleeks very easily.

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

by Jim Armstrong » Sat Mar 14, 2015 3:59 pm

I came over from the APOD to see if the sun as lightbulb question had been asked and answered.
Of course it had.
Unfortunately I can't find out what a sleek is.
Is it inside or outside? Does it come with the window or develop later? Are they friendly?

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

by Chris Peterson » Sat Mar 14, 2015 3:03 pm

geckzilla wrote:I think it's just a camera optics artifact. Just does not look like an ice pillar or anything like that.
I agree, it's not an atmospheric effect. Not in the camera, either, I think. I'd say it's scatter off the sleeks which are always present on the surface of aircraft windows.

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

by neufer » Sat Mar 14, 2015 2:46 pm

geckzilla wrote:
BDanielMayfield wrote:
M.A. wrote:
Why does the sun look like a great big lightbulb in the sky in this picture?
I was going to ask the same thing. Sol also looks like a hot air balloon.
Does this have something to do with observing the Sun from high altitude?
I think it's just a camera optics artifact. Just does not look like an ice pillar or anything like that.
It sorta looks like an ice pillar or something like that:
http://www.sundogcoaching.com/uploads/1 ... 0_orig.jpg

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

by BDanielMayfield » Sat Mar 14, 2015 12:53 pm

geckzilla wrote:
BDanielMayfield wrote:
M.A. wrote:Why does the sun look like a great big lightbulb in the sky in this picture?
I was going to ask the same thing. Sol also looks like a hot air balloon. Does this have something to do with observing the Sun from high altitude?
I think it's just a camera optics artifact. Just does not look like an ice pillar or anything like that.
Thanks. It would have had to have been a very fast exposure too ...

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

by Dad is watching » Sat Mar 14, 2015 12:50 pm

The clouds look just like a lake with ripples or waves on it. Any ideas as to the scale, wind velocity, 'wave height' and the peak-to-peak distance? Is the 'ridge' going from lower right to upper left caused by ground-effects or some sort of wind sheer? I would have thought that they would have picked a really big, really flat area for the target 'crash-down' sight. Also, I hope there is a backup for that one parachute...

Top