Strange streak discussion: 2004 Dec 7 APOD

[victorengel]

I studied the three images at http://antwrp.gsfc.nasa.gov/apod/ap041207.html, and I have the following things to say about them.

First, the before and after pictures are reversed. One need only inspect the EXIF data to verify this. The EXIF data contains the time the pictures were shot.

The shadow, trail, or whatever you want to call it is curved. That's right, gravity appears to have affected whatever that line is. That rules out a light beam or effect of a light beam of some sort unless the distortion in the lens happens to match the curvature of the line (I don't think so).

If the light burst happened in the vicinity of the lamp post, I would expect to see a glint on the lamp post as well as on other nearby objects. I don't see this.

The puff of smoke or steam or whatever that is is not centered at the same location as the burst of light. I don't have an explanation for this, but I do think it's interesting.

I looked hard for a reflection of the light burst on the pavement of the drive or parking lot just this side of the burst and also on the water surface. Unfortunately, the water is just a bit too rough to reveal anything significant (or else the reflection simply isn't there). There may be just a hint of a reflection on the pavement, but it's insignificant enough that I'd have to do some numerical analysis to tell for sure. If it's not there, then there's nothing to corroborate the distance from the camera as being the same as the distance to the light pole.

I believe that whatever we're seeing here is actually much closer to the camera. If that really is a puff of smoke so far away, that is a pretty significantly sized cloud. The next shot is only 15 seconds later. Could a puff of smoke that size have disbursed in 15 seconds? I think not. Or maybe I simply can't discern the puff of smoke that is, in fact, there. In any case, it would be nice to have wind conditions at the time and location of the lamp post.

If the burst was much closer to the camera, then it could easily have disbursed in 15 seconds. A thought that crossed my mind was a hand-tossed firecracker. The photographer has already dismissed fireworks, so I suppose that is ruled out.

Did the photographer actually see this with his naked eye?

Here's an animation of a crop of the three pictures, in the correct sequence. Remember, these frames are actually 15 seconds apart.
http://the-light.com/Photography/Discussion/meteor.gif

[yuppie eater]

It is nothing atmospheric in nature. It looks to me as possibly 1 of two things. a) either the film negative was folded and the flash is where the emulsion was weakened, and therefore easily over developed.; or b) it's where the film negative was alowed to touch or overlap each other while still having some remnent of developer on its end. The flash is where the developer contiued to etch the emulsion until it was finally rinsed.
just possibilities.

[Guest]

smith @ canada.com.....I think you've got it!!

Would be nice to get photographer to post a closeup of the light from the same angle we are seeing it now...

Randy A
Taiwan

[victorengel]

This discussion reminds me of some Mars Face explanations I've seen.

My vote is for a contrail shadow and coincidental unrelated flash from the lamp.

Fifteen seconds later, and fifteen seconds before, it's not there. Contrails don't move that fast.

[Garry Young]

I've seen shadow lines very similar to the one in the picture.

This gives me an idea.

The light, when inspected, was not working. This time of the evening (just after 6PM) is when automatic lights often come on - we can apparently see other lights on in the picture.

When lights burn out at startup, they often flash, briefly and brightly. I can't make out the design of the light, but, is it possible that the photographer captured a light bulb burning out -- and the line is the shadow of the light housing? Depending on the design of the housing, a burnout flash could illuminate everything around it, except for the column of air/mist shadowed by the housing.

smith @ canada.com

This is the best explanation yet. All light bulbs flash when the burn out.

Have ever heard of "Occam's Razor", where all things being equal, the simplest explanation is probable the correct one.

Garry

[Guest]

This Slashdot comment is my favourite theory:

http://science.slashdot.org/comments.pl ... d=11019427

You can see this dark streak almost every day in southern california, or almost anyplace that has contrails visible in the sky. When the contrail goes between you and the sun, you can see a dark band coming down from it. Watch for it!

Basically, what you are seeing is the equivalent of a sunbeam, except that it's a shadow-beam. A sunbeam occurs when there is a small hole in the cloud, and the light going through the hole illuminates the dust particles and water droples in the air along the path of the light. If the light is strong and the background relatively dark, it is easy to see these sunbeams (or God rays.)

Shadows through the sky are somewhat harder to see, because the contrast is not as great. When they are dramatic, as in this picture, you have to have the fortuitous situation of looking through a long, well defined slab of shadowed air, with well-lit air on either side. Airplane contrails are the perfect shadow source for this.

Imagine a 3D volume of a shadow cast by a contrail. It is a long thin slab of shadowed air. If you are within that slab, and looking along it, all the air in that direction is shadowed, for many miles, so the contrast between the shadowed air and the surrounding air is strong.

A good bit of the light around the shadow beam is not light scattered by dust or water droplets, but is just the same Raliegh-scattered light that makes the sky blue. The dark streak through the sky will be noticably darker and especially less blue than the surrounding air.

As you can tell, this is one of my favorite (of many!) atmospheric optical phenomena. Once you start to look for them, they are quite easy to see. Occasionally you can see them from natual cloud formations or even topographical or architechural features when the conditions are just right.

Thad Beier

[Guest]

Can anyone comfirm that a flash was used? Many comments refer to the camera's flash, but it doesn't make any sense to me to use a flash for timelaps photography of clouds.

The Exif info:

uExif
Canon
Canon PowerShot G3
ACD Systems Digital Imaging
2004:11:25 15:20:49
0220
0100
2004:11:22 18:52:52
2004:11:22 18:52:52
IMG:PowerShot G3 JPEG
Firmware Version 1.02

[Guest]

It is nothing atmospheric in nature. It looks to me as possibly 1 of two things. a) either the film negative was folded and the flash is where the emulsion was weakened, and therefore easily over developed.; or b) it's where the film negative was alowed to touch or overlap each other while still having some remnent of developer on its end. The flash is where the developer contiued to etch the emulsion until it was finally rinsed.
just possibilities.

It's DIGITAL picture, taken by a Canon Powershot G3, per the EXIF data in the JPG file.

[Brad]

Like others in this discussion I have seen contrails cast a striking dark line through clouds below them; however, I don't think that's what we're seeing here, because it doesn't explain the 'flash' on the ground, and anyway the clouds are too heavy and the sun not high enough for such a shadow.

I do think examination of the negative itself (I presume that the shot was taken on film) may reveal a crease, perhaps orignating in the developing process; while I can't say I've seen 'shadows' in prints from creased negatives, I have seen artifacts such as that 'flash' resulting from stressed emulsions.

Nice picture, by the way.

[Ans: the federal reserve]

My guess is that somebody was testing a relatively weak directed-energy weapon/beam and used the light post for target practice. The "shadow" marks the path of the beam, and witnesses might have seen an aircraft at the other end -- or the beam may have come from a high-flyer, or a satellite.

My sentiments also. The 'microwave' beam 'steamed' the pole, blew the circuitry, changed the density of the air as passed from high in the atmosphere down to the lamp (target), thus giving the streak effect.

There is a hypothesis floating around that the big black deltas (4000+ sightings the world over) carry a microwave beam. They supposedly fly at 60,000ft and can lift 10tons and are dirigibles the size of a football field. They test the targeting of the beam by making crop circles and then view their results by looking through their telescope down to the ground (or maybe they have a local observer nearby). Crop circle analysts of the legitimate circles (not the rope and 2x4 guys) find that the crop material in the circles are damaged in exactly the same way 20 seconds in a microwave oven produces. Animals found in the circles are dead, splayed, and completely dehydrated from any water.

See: http://www.nuforc.org/webreports/ndxsTriangle.html
Also: http://www.ovnis.atfreeweb.com/7_habe_crime_weapon.htm
And: http://www.space.com/businesstechnology ... 20805.html

In memory of Paul Wellstone: http://www.alternet.org/story/14399 &
http://www.scoop.co.nz/mason/stories/WO0409/S00143.htm

[Guest]

For the guys wich doesn't agree with Bug "Theory"


This image it's the result of adjusting the Levels of the picture and doing a Smart Blur to remove the noise.

It's still a bug caught on flash light after the long exposure (induced by Auto mode on low-light) "drawed" the trail.

[Martyn]

i think this photo is very interesting, although i dont think it is a meteor of any type or lightning, there will be a logical explination to it but wouldnt it be great if it turned out to be 'outta this world', i will keep checking this to try find out if you come to a closer truth.

[Guest]

It is nothing atmospheric in nature. It looks to me as possibly 1 of two things. a) either the film negative was folded and the flash is where the emulsion was weakened, and therefore easily over developed.; or b) it's where the film negative was alowed to touch or overlap each other while still having some remnent of developer on its end. The flash is where the developer contiued to etch the emulsion until it was finally rinsed.
just possibilities.

It was an image from a digital camera.

[Anonymous Coward]

If it's film: It might just be a wrinkle or chemical inconsistency in the film itself.

If it’s digital: It could be a strange voltage drop across the optical sensor, a JPG compression phenomenon, or (very unlikely) a flaw in the storage card.

Lastly... it could be a hair/bit of debris that was blown into the lens for this one photo, and blew away afterwards.

[Guest]

This Slashdot comment is my favourite theory:

http://science.slashdot.org/comments.pl ... d=11019427

You can see this dark streak almost every day in southern california, or almost anyplace that has contrails visible in the sky. When the contrail goes between you and the sun, you can see a dark band coming down from it. Watch for it!

Basically, what you are seeing is the equivalent of a sunbeam, except that it's a shadow-beam. A sunbeam occurs when there is a small hole in the cloud, and the light going through the hole illuminates the dust particles and water droples in the air along the path of the light. If the light is strong and the background relatively dark, it is easy to see these sunbeams (or God rays.)

Shadows through the sky are somewhat harder to see, because the contrast is not as great. When they are dramatic, as in this picture, you have to have the fortuitous situation of looking through a long, well defined slab of shadowed air, with well-lit air on either side. Airplane contrails are the perfect shadow source for this.

((deletia))

Contrail shadows are true phenomena, as described above, but they ALWAYS "point" back to the sun. Not possible in this case, because the sun is off to the right in the picture, and the "shadow" comes down from the left.

It's NOT A CONTRAIL SHADOW.

[amateur]

Remarkably clever (by and large) folk are thinking about this. It's pretty impressive.

One theory seems to predominate:
~the (street?)light burned out explosively as the shutter opened, casting a shadow of the light housing on the humid or misty air AND creating a shock wave visible from the camera's POV only to the right of the pole

with assorted arguments, often based on apparent problems with that theory, i.e.
~a meteor or lightning bolt hit the light pole (or behind it from the camera's POV), leaving a trail and causing an explosion and flash
~it's the shadow of a contrail, with no discussion of the flash
~the shadow and/or the wave front are artefacts and only exist on the CCD/film/lens
~it's a bug, very close to the lens and moving pretty fast and lit up pretty good

I actually like the bug idea http://www.dvdc.de/fly/ , just because it's so clever and I would never have thought of it, but I don't think so. I think it's two unrelated things that happen to be juxtaposed in the image and that our familiarity with cartoon conventions help us interpret. It's the shadow of a moving aircraft or a contrail cast UP on the sky by the light from the setting sun, which from the camera's POV points at but does not lead to the light pole, coincident with the flash of the bulb burning out.

The bulb burning out as it first turns on is much more likely than any other explanation for the flash at the top of the pole, given that you can see a glimmer of light from at least one other nearby light pole but not from others, while lights on the bridge to the right are already on, indicating that the photosensors are just being triggered at this moment.

I like the idea of the shadow being cast by the lamp's housing, but the apparent distance of the light pole from the camera would make that an awfully long shadow for such a source.

The shadow of a contrail or a moving aircraft, however, could easily be as visible and as long as in this picture. With nothing in the sky for reference, it's easy to see something many miles away that seems to be close, in this instance something that seems to go right down to the light pole. However, I believe the trail or shadow actually goes to the horizon, and our eyes extend the line to the top of the pole. If we were standing there at the moment the light exploded we could have seen exactly the same thing that the camera "saw", but we would also have been able to see the plane or contrail overhead and, depending on where we focused our eyes, we would or wouldn't have seen that the shadow seemed to point to the flash.

If my speculation is correct, it seems unlikely that the bright arc to the right of the flash is a shock wave, simply because of the apparent size compared to the light pole. That looks like the kind of pole that you would see on an Interstate Highway. If so, it has to be 10-15 meters tall. I can believe that the flash of a large high-intensity light burning out would be that intense, but I can't believe it would create a shock wave that size. Passing cars would have been demolished! Perhaps it's another case of forced perspective, although truthfully I can't see how it would work.

Great discussion; good work, all!

[rickard]

Ask George Malley.

[victorengel]

In the after shot, the pole seems to be surrounded by a faint haze like a puff of smoke. Presumably, this is the remains of the flashing explosion which seems to originate from the top of the post. Another observation...

Too bad the before and after pictures are reversed. Just look at the EXIF data in the full sized pictures.

[Guest]

the flash at the end of the streak isn't near a light pole - that's a ship's mast. look close. you will find it is true.

sorry to all the exploding bulb theorists.

Eliminating the "light pole" assumption leads me to enjoy the lightening hypothesis a little more.

If it's not a lightpole, but a mast, then examining the pole for damage is superfluous.

However, apparently, someone _did_ examine "the lightpole."

Could be a lightpole and a mast aligned with each other?

[Luis]

It does look like a shadow, but as of what, I do not know.

I played a bit with the image in matlab. I split it in the RGB channels and use the command imadjust to change the saturation values at both ends to enhance the visibility of the black line.

The shadow seems to disapear in the region where there are no clouds, making me think that whatever is there is a shadow visible in front of the clouds.

There is a region where the original image seems to go behind one of the white bits of cloud. Form the RGB split it is obvius this is not the case especially in the green channel without any contrast andjustment. Further pointing to the shadow hypothesis.

I think that at 1/20 speed on the camera an object travelling at the speed a methorite would land on the earth would not leave a trail on the picture.

The commands I used in matlab are these ones if any one wants to try them. I think you will need the image processing toolbox.

Note: I use 1-image to display the negative. The strike is easier to see this way (At least for me).

im=mat2gray(double(imread('strange_pryde_big.jpg')));
imR=im(:,:,1);
imB=im(:,:,3);
imG=im(:,:,2);
imshow(1-imadjust(imB,[.6,.85]))
figure(2);
imshow(cat(3,histeq(imR),histeq(imG),histeq(imB)))
figure(1);
imshow(1-imadjust(imG,[.6,.85]))
imshow(1-imadjust(imG,[.6,1]))
imshow(1-imadjust(imG,[0,1]))
imshow(1-imadjust(imG,[0,0.5]))
imshow(1-imadjust(imG,[0.5,1]))
imshow(1-imadjust(imG,[0.5,0.9]))
imshow(1-imadjust(imG,[0.5,0.8]))
imshow(1-imadjust(imG,[0.5,0.7]))
imshow(1-imadjust(imG,[0.5,0.85]))
imshow(1-imadjust(imG,[0.55,0.85]))
imshow(1-imadjust(imG,[0.5,0.85]))
imshow(1-imadjust(imR,[0.5,0.85]))

[Britomartis]

This picture reminded me of a science fair project I did when I was a kid with a cloud chamber. Cosmic rays make similar streaks in one. So, of course the first outragous thought that came to mind was that it was a micro-black hole hitting the ocean just behind that light. Of course this a pretty amazing and improbable event, however, the best way to eliminate this possibilty would be to check seismic records. It would be easy since we have the exact time of the event. Else, I tend to favor the photographic artifact theory.

[WI guest]

I go with the contrail theory; that was my first thought - a jet tail in the darkening part of the sky out of direct sunlight. Eerie shot in the lighting around the trail.

[Bill Kuker]

Assuming that EXIF that says its a 1/20th second exposure with a flash is correct...

1) Open shutter
2) Pop flash and illuminate but, Bright bug and wings make "explosion" and "smoke"
3) Leave shutter open.
4) Dark bug on bright background leaves darkened trail as it flies away scared

Or if the flash pops at the end run through this backwards.

This is a photoshop of a bright bug and that same bug unlit and elongated flying to or from the "point of impact"

[h34tsink]

I was playing around with the images, i made a 3 frame animation with them then i noticed that the white smoke(best description) looks to be in front of the pole. The orange globe(explosion?) is not centered with the pole but looks to be also in front of the pole.

SWF animation
Warning...
the file is large to preserve image detail.
http://members.purplehat.net/~anson/Flash/index.html

[Bill Kuker]

Additionally, while the chances of this lining up with the light post are low, the chances of it lining up with "something" in the frame is pretty high, leaving only a single bug event needed with no luck really needed.