APOD: A Triple Sunrise Over Gdansk Bay (2009 Aug 04)

[Chris Peterson]

doesn't gdansk face west?

Why ask what you can Google?

Gdansk is on the southwest shore of Gdansk Bay; thus, when you look out over the bay you are facing northeast, precisely into the sunrise in late July. In the first APOD image (this one) you can make out the Hel Peninsula on the left side- a sandbar separating the bay from the Baltic Sea.

[stanman]

doesn't gdansk face west?

Newby here. Enjoying the debate!

I figure that the pictures were taken from apx 54.421901,18.583513 (paste into Google Earth's 'Fly To' box). The Google Earth picture is 4 years old now, but you can see the other blocks of flats, and about 900 metres to the North East is the hotel/casino you can see in the wider angle picture.

The line of sight is facing the late July sunrise slightly North of East.

[ricardelico]

The fact that glass reflections are clear in image 9802 should settle the matter.
Andre Geo's photo study pasted above, and Chris Peterson's expositions further establish the double windowpane explanation.
I would add the window seems to be perpendicular to the direction of the sun, thus diagonal to the vertical planes of the neighboring balcony, and the reflections seem to originate from a similar exterior balcony. If the APOD explanation wasnt so insistent on the photographer's honesty, I would say the window was not fixed but open about 45°.
Thank you all for making this an interesting discussion topic.

[Hangar#8]

The windows on my house are double-pane, with an additional reflective film between the panes. The house in on a hillside some 1400 feet above the city center, and at night the street lights produce similar reflections in the windows. So I agree with the window pane explanation.

[dockwatcher]

There must be something more we are missing. The double pain glass/camera optics vs it a real atmospheric phenomena side is about down to raising hands.
It is a very pretty area. The Google satellite image doesn't do it justice at all. I was looking just because I thought it might be a sunset. If someone left off the UT it changes things. Morning air can add ice, evenings are is good for layers and thermals. I guess at 54 degrees this could almost be noon or midnight. No that would be looking south from the other side of the bay.

The original information said it was a digital camera. It doesn't rule out SLR I guess. I was impressed at the focus on the railing and the boat at the same time. That would have to be a really high f maybe over 100. It also has some impressive magnification between the different shots. I'd feel funny looking at the sun with a hundred mm lens even stopped down to f100. I guess I could add a filter to be safe. Would that be three pains of glass?

I think we have a lot of astronomy buffs out there. and I really liked the post where the guy measured color content from different spots in the photo. What do the photographers have to offer?

[Chris Peterson]

There must be something more we are missing. The double pain glass/camera optics vs it a real atmospheric phenomena side is about down to raising hands.

Actually, it's pretty darn certain. The effect was created by glass. No atmospheric phenomenon exists that could do this, and nothing contradicts the simplest reasoning. This requires voting about as much as deciding if we really went to the Moon <g>.

The original information said it was a digital camera...

All the imaging data is intact in the file headers. It was a Canon PowerShot S51S camera, and the exposures were made from f/2.7 to f/4, 6 mm to 72 mm focal length.

[polymath]

I ran the subject image through routines I use for detecting digital retouching. I found expected compression artifacts but no evidence of localized alterations. I did find retouching evidence (and compression artifacts) in the admitted retouched simulation images contained in this thread. The method is not infallible, but I've yet to miss. In the process, I noticed the distant cloud deck extends well above the superior solar image and the inferior mirages. Actually, there appears to be a higher layer of stratocumulus above or at a greater distance than the one that cuts across the middle of the superior solar image. Also, I found that the clouds in front of the solar images noticeably vary across all three. I found no reason to distrust the claims made of the picture's genuiness. I conclude that the bifringence or trifringence theory has no fatal flaws, and that the reflection theories, while rigorous, lack validity for the simple reason that the images reveal cloud evidence intervening at great distances between the superior solar image and inferior mirages and the camera's observation plane.

[apodman]

This requires voting

Cast my vote for Pluto. I love that planet.

[Hangar#8]

Photos taken at 21:10 PST in Kamloops BC, through double-pane window with reflective foil between the panes. The sodium lights are 200 and 350 feet away.

Street lamp 200 feet away

P1140266.JPG (64.92 KiB) Viewed 3050 times

[Chris Peterson]

I conclude that the bifringence or trifringence theory has no fatal flaws...

You mean other than the fact that there is no physical basis for inducing significant birefringence in a bulk, low density gas? What do you propose?

Really, it is so obvious that this is nothing more than a simple reflection from the window in front of the camera. Why try to turn it into something impossibly exotic?

[Hangar#8]

The easiest way to find the right answer is to get the author of the original photograph in Gdansk to take more photoe of sunrises for a few consecutive mornings, from the exact same location.

[polymath]

The mirror reflection simulations themselves demonstrate the beam splitting principles of birefringence, probably caused by resin coatings and birefringent chemicals added to the glass formulation to control glare, UV light, and themal properties. Other atmospheric mirage phenemonas of bifringence, false dawn and green flash caused by atmospheric conditions. Bifringence, decomposition of a ray into two rays. But for the evidence of intervening clouds of prismatic medium, the picture wouldn't depict a triple sunrise.

[Chris Peterson]

Other atmospheric mirage phenemonas of bifringence, false dawn and green flash caused by atmospheric conditions.

Neither of these things has anything to do with birefringence.

[polymath]

I don't see how they're not. One refraction to decompose the beam and one to return another decomposition refraction along the direction of the original beam's travel. Rainbows and raindogs certainly are single refractions.

[dockwatcher]

A cannon s51, f2.4 is the macro, 72 mm 3.5f I guess that's a one inch lens. It does have image stabilization. The knowledge base I found most interesting follows

Try forcing the lens. More people have reported success with this method than with any of the other methods.
Variations include gently pulling, rotating, and/or twisting the lens barrel while hitting the power button. Attempt to gently straighten or align the barrel if it's crooked or twisted. Another variation includes looking for uneven gaps around the lens barrel, and then pushing on the side of the lens barrel that has the largest gap (note pushing the lens barrel all the way in is NOT recommended as it may become stuck there). While doing any of the above, listen for a click that indicates that the lens barrel guide pins may have reseated in their guide slots. If you hear this click, immediately stop and try the camera

[contributor]

While on the 4th floor balcany of a building atop a dune 70 feet above the surf just north of Myrtle Beech S.C. USA at about 5am in early april of 1998, I witnessed a green flash and then the sun "pop" above the luminescent green ocean's horizon. It had been pitch black, and when I turned to my friend to say "The Sun just rose!": his expression was incredulous. I looked back at the ocean and it was pitch black. My friend literally thought I was seeing things.
I never spoke a word of this until years later when I was visiting my grandfather who was a career Coast Gaurd Captain. He told me it was a bonifide phenomenon that usually only captains or first mates of ocean going freightors see as they are about 100 to 120 feet above the sea. He said it was indeed the sun lensing through the ocean by way of the earth's curvature and extraordinary conditions. I had been lucky to see one of the rare events commonly noted among those few as sun lensing through sea before dawn!
Due to my personal experience, I completely believe the authenticity of these photos.

[StACase]

The easiest way to find the right answer is to get the author of the original photograph in Gdansk to take more photoe of sunrises for a few consecutive mornings, from the exact same location.

(-:

[Naos]

I made some simple calculation about deformation of a window.
The drawing represents the two pieces of a double glazing window. (The glass thickness of each panes is not represented).

bend.GIF (15.33 KiB) Viewed 2914 times

Considering the very large radius of curvature, we can make the approximation of parabolic shape y = x^2/(2R)
The local slope is given by : y’ = dy/dx = x/R
The angle between the two panes is : alpha = 2*atan y', so : alpha ~= 2*y' for small angles (in radians !)

For a deformation 'a' at the center of the window, and total size L of the window, we can calculate the value of R.
R = x^2/(2y) with x = L/2 and y = a
R = L^2/(8a)

1) The slope at the center is zero. The local tilt angle between panes is also zero.

2) if the beam goes through the window at x = L/4 :
y' = L/(4R) = 2a/L => alpha = 4a/L (radians)
L = 1 m, a = 1 mm => alpha = 0.23 deg

3) if the beam goes through the window at x = L/2 (close to the edge) :
y' = L/(2R) = 4a/L => alpha = 8a/L (radians)
same values => alpha = 0.46 deg

All these calculations to say that : 1mm central bending is much easier to produce than a 6.5mm gap variation from one edge to opposite.

If the window is 1m wide, the gap variation is about 6.5mm which is quite big indeed, compared to typical value of gap (16 mm) inside double glazing.

Glass is a very "flexible" material. While taking the pictures I posted yesterday, I tried to push by hand at the center of the window, the effect was to increase the deviation of the ghosts (first ghost was visible with unaided eye) whatever the initial sign of the deviation.
That means I increased the deformation of the surface which was already concave.

[DLTbluefrog]

Hello... I shot this 15 FEB 2008. The sun was visible naked eye AND had already set. This was photographed from Nashua NH. Peace David

http://www.flickr.com/photos/dltbluefro ... 914937728/

[Naos]

Me again !

@ Chris : I tried do make some new simulations, I hope less confusing

Description:
- a collimated beam (set of parallel rays)
- a window : composed of 2 surfaces with air in-between (the glass thickness of each pane is neglected)
The inclination of the incident beam on the window is +45 deg in drawing 1 and 2, -45 deg in drawing 3
There is a wedge of 1 deg between the two panes. (Wedge is orientated to the bottom on drawing 1 and 3)
- a bi-convex lens to simulate the objectif of the camera
- a flat focal surface to represent the CCD/CMOS detector
The ray tracing is limited to the first two ghosts.

We can clearly see that the global inclination of the window does not change the position of the image and its ghosts.
We see also that the orientation of the wedge change the orientation of the ghosts. If we take into account the fact that the images are reverse in the focal plane (juste like in human eye or digital camera : they are "automaticaly" restored to normal orientation by the electronics/brain), the position of the ghosts exactly indicates the direction of the wedge.

EXPORT3.GIF (10.39 KiB) Viewed 2823 times

EXPORT4.GIF (10.67 KiB) Viewed 2825 times

EXPORT5.GIF (10.81 KiB) Viewed 2826 times

[blastoff]

Dang stanman, thats definitely the hotel. [google earth 54.421901,18.583513] if you go back a few years the photos even show the east face of the building, revealing the balconies and certain alcoves where a certain window of questionable panage may be hiding.
So who wants to call the hotel and ask if their panes are straight!?!?

[kamoses]

You mean other than the fact that there is no physical basis for inducing significant birefringence in a bulk, low density gas? What do you propose?

Really, it is so obvious that this is nothing more than a simple reflection from the window in front of the camera. Why try to turn it into something impossibly exotic?

Easy Chris...some of us are slower. Patience. As much as it makes me realize that I'm wrong when you tell me I'm an idiot for believing otherwise (in slightly different words)....well, actually it doesn't.

And lets face it, natural phenomenon (the "real" ones) are often, how shall I describe them...."impossibly exotic" to those who don't fully understand them. I once heard a story of an African man who came to America and thought the bathroom sink was possessed because water just came out from nowhere!

On the other hand, I caught a potential flaw in my arguments against the 2 pained window, as I have been using a finite light source. I'll have to play around with the other option later tonight. Do I switch my vote? Not yet. I still find it hard to believe that the photographer would not catch on to it being the window if the reflected image "danced" back and forth across the real sun. At least, that it what it should have done given the converging panes argument. Any time the viewer would have crossed in front of the window the reflection would have moved from one side to the other.

[GliderPilot]

Problems with the atmospheric phenomenon explanation:
1) An explanation is needed for the horizontal separation.
2) The vase foot on the suns is clearly duplicated. The separation of images is after that optical phenomenon.

Problems with the multiple glass pane explanation:
1) The differential angle between the two window panes is large (6+ mm over 1 meter) relative to typical glass pane separation distance.
2) The differential angle varies and in the latest pictures (over a time duration of about 40 seconds) is reduced by at least 50% as the photos show the suns merging.
3) If the differential angle varies this much over time, what causes this rapid change?
4) If the differential angle variation is a variation in different parts of the window, why didn't the observer notice this variation as the camera was moved?
5) The clouds appear to be between the observer and the multiple suns. (I put this last - my personal impression was that the clouds lie between observer and suns, but this is a close call.)

If I owned this window, I'd be taking similar pictures at 4:30 AM over several days.

[apodman]

Hello... I shot this 15 FEB 2008. The sun was visible naked eye AND had already set. This was photographed from Nashua NH. Peace David

http://www.flickr.com/photos/dltbluefro ... 914937728/

This photo demonstrates that, unlike the APOD being discussed, a mirage caused by an atmospheric phenomenon shows a distorted image with diffuse edges. So much for the atmospheric mystery science some here are trying to peddle.

[polymath]

An absentminded slip of the mind. A false dawn is an atmospheric dispersion effect, unfocused refraction. A false sunrise is a focused double-refraction effect. Poro prism binoculars demonstrate changing the path of a light beam, they correct and erect the image to true orientation and extend the length of the opitical path. Two collimated prisms In each monocular tube. Light follows S and Z paths, respectively, through the binocular tubes.

Green flash, false sunrise, rainbows, and raindogs demonstrate that intervening atmospheric prismatic medium cause majestic phenomena. The distant stratocumulus cloud decks in the picture act as beam splitters and double refractors. Only a portion of available prismatic particles, water droplets and/or ice crystals, in the clouds collimated in ideal axes by vertical convection currents would do all that's needed to create the double mirages.

Nor am I inclined to doubt the straightforward reporting of the conditions under which the picture was taken. I'm convinced by evidence in the picture it's not a hoax nor a guileless aberration of the camera or photographer.