Strange streak discussion: 2004 Dec 7 APOD

[smith-at-canada-com]

Secondly, the 'trail' looks to be very straight, but slightly widening farther from the 'flash' end, suggesting perhaps a shadow rather than a trail of some sort - although perspective might account for this....

I have a nice image, which I have no place to post (darn!). It was generated by subtracting 52:37 from 52:52, with a bias of 128, and then using a histogram spread to make the resulting (almost totally) grey image show up the differences between the two images. Incidentally, when I try this same analysis on the proposed 'bogus' image, the beam looks like grey line drawn with a ruler. Waaay too perfect.

The shadow definitely spreads along its length away from the light, as you note.

Incidentally, I discounted any striking of the lamp by energy or matter, since the light was described an undamaged. Anything fast enough to generate that straight a trail would have left a mark!

If you look closely at the dock itself, the flash does appear to generate some extra highlights on the railings.

The odd structure of the flash could be one of several things. Given that we can even see the beam, there must be some mist/fog/moisture in the air, and it could be illuminated by the flash. The odd pattern may be due to one of the protective glass covers outside the bulb, which often contain lenses to focus the light in a preferred way.

Based on the return address, this was taken near Darwin.

If I had to guess, I'd say it was across the street from the Crowne Plaza Darwin hotel, just up from Darwin Government House - which is what the pier connects to. We're looking mostly south, down Middle Arm, with the load cranes just past Wickham Point (which is behind the leftmost tree, so we can't see it). Around the point to the left is Frances Bay, back up the street and around the point to the right is Fannie Bay. It's about 5 minutes before sunset.

Of course, I am just guessing.

[Jaroslaw]

Can anybody see quite big loop on the upper left part of a trace (like after plane aerobatics, behind and right from a bright cloud)?

[rabbit]

I'm with the folks who think it's ice from an airplane, coming down and then splashing to make the reflection in the water, which is only coincidentally near the light pole.

[googlemeier]

maybe some digital works will bring more light into darkness...
[img]http://www.googlemeier.de/temp/strange_pryde_big[1].jpg[/img]

[MonkeyLoverB]

Darwin harbour dock is in the background.

[DOM]

I'm not a specialist then here's my idea on this picture.

When I saw it for the first time , I remembered immediately this picture

http://antwrp.gsfc.nasa.gov/apod/ap010219.html

then the fire visible in the image that we talk become the light source , with the smoke passing in front , that create the streak.

Do I have the right answer ?

then how do you explain that in our pic the 'shadow' doesn't change shape, like the one in your photo converging towards the moon?

I let the experts answer to this I have no idea

[tazko_kong]

The flash is the light, you can see the shape of the box that contains the bulb. As for the condensation trail shadow, nice.

[Guest]

As far as the light reflection on the water illuminating trees on the other side of the water, I can see some increase in light in alternate rows of pixels going 8 pixels up from the edge of the water, but this is within an 8x8 square which I think is related to JPG compression, so I don't think the increase in light is coming from anything on the opposite shore.

It would be interesting to see how the person in Canada did his image processing. I made some amater efforts at image subtraction, with no results.

[Jim]

I notice 1) there appears to be smoke from something at the bottom of the lamp pole. 2)the flash at the top of the lamp pole could be from a bulb burning out or maybe a small sun beam of light hitting the lamp shield and reflecting or some type fire work "ball". 3) the streak.. I notice numerous cloud streaks at the top of the picture. If I were to pick one, I would say the lamp post flash was a fire work because of the smoke from the ground and the streak is a something else... like a bug flying by. Using Photoshop 3x on the large file the streak's image is hard to see.

[Boldra]

Arguments about the light coming on are unsatisfying as the after photos don't show any other lights of the same apparent group being lit.

Perhaps not from the same group, but if you look in the background far to the right, you will see a light coming on across the three pictures. Curiously, the pictures are in the wrong order for this (the light is going out), although the clouds are also shrinking, so the pictures must be the wrong way around (the "before" picture is the last)

As fillip pointed out, the image info from the digital camera supports not only the mis-naming of the pictures, but also that the pictures were taken in evening.

I'd be very interested to hear why meteor experts say it's not a meteor. To me this seems like the simplest explanation (although I can't see any shockwaves). The arguments about the diffusion and direction of the "shadow" seem to indicate that the bulb theory is wrong. It would also be interesting to know if the base of the pole was inspected for electrical damage.

Boldra

[smith-at-canada-com]

I'm convinced it's a bug!

maybe that sounds too simplistic, but i think it is quite realistic.

1. right coloring for a small gnat or mosquito.
2. that is about the distance a bug could fly in about 1/20th of a second (i think, it kinda depends on the distance from the lense that the bug was flying)
3. that clearly explains why it wasnt in the picture before or after.
4. its easy! and obvious!

There is one additional condition for this to be true. Because the shadow goes 'up and to the left', the flash would have to be down and to the right.

The Canon G3 would need to be upside down.

Photographer??? Was the camera upside down?

Incidentally, the 'spot and flares' do resemble a flying insect a little. If the camera was upside down on the tripod, then this is quite possible. If the camera was right side up, I'm sticking to my bulb burning out theory.

[TSL]

Let's look at what we know and don't know. The photo was taken in the evening with one taken 15 s before and another 15 s after the photo in question. The camera was set to 1/20 s and F5.6. Experts in meteors and the atmosphere say it's neither a meteor or lightning. Most meteors would leave a smoke plume a bit longer than observed and lighting doesn't travel in such straight lines. From my observations of contrails the sun is at the wrong angle to produce the shadow.

I would go with the lamp burnout. From the discussion everyone assumes that the lamp is facing us, what if the lamp is on our side of the pier and the pole is closer to us than the lamp? I say this because the pole to the left in the picture appears to be on the other side of the pier and the two poles are too close together to be on the same side. This then allows the pole to be a shadow for the lamp blowout. The shadow would fade in front of lighter objects such as the cloud. The only reason this shadow could be seen is the dark clouds behind it.

As to the question on whether the odds of capturing a lamp blowout is too high for one to be observed - how many pictures are taken a day? It's the same as lotteries - your chance of winning one is very small but the odds of someone winning is good.

[Guest]

I don't understand how people are posting images. I tried but I can't make it work.[/img]

[Wm X Rock]

It it possible that dolphins have laser weapons now?

[Rich]

Static discharge between the focal plane shutter and the film pressure plate.
The dischage was caused as the shutter passed over the film, arcing through the film to the pressure plate.
Sometimes this can happen as the film is being advanced to the next frame, but it us usually straight across the imabe area lft to right.

[Akihiro]

It is impossible that the dark trail is a shadow resulting from the light of bulb. We must first analyse the proportion of the distance between the bulb and the probable location of the object blocking the light. From where the supposed shadow began, the object must be very near to the bulb. And therefore, the 'spreading angle' of the light must be very very great. BUT it apparently isn't so.

However if the 'light theory' proves to be true, then it must be because the light source isn't a point but of a greater surface area. In this case, i think this could be true - look at the size of the glow. And the possible smoke on the left side aren't visible, because that particular object had blocked out light emanating to the left. (Note that the arc of smoke is nearly opposite to the shadow)

[Akihiro]

It is impossible that the dark trail is a shadow resulting from the light of bulb. We must first analyse the proportion of the distance between the bulb and the probable location of the object blocking the light. From where the supposed shadow began, the object must be very near to the bulb. And therefore, the 'spreading angle' of the light must be very very great. BUT it apparently isn't so.

However if the 'light theory' proves to be true, then it must be because the light source isn't a point but of a greater surface area. In this case, i think this could be true - look at the size of the glow. And the possible smoke on the left side aren't visible, because that particular object had blocked out light emanating to the left. (Note that the arc of smoke is nearly opposite to the shadow)

[Guest]

'Casual observer 'worte (and I like what he says):

Has anyone else noticed that the flash has a bowed arc at about a 90 degree angle to the dark streak? this is just a what-if, but if it were a meteor could the shot have caught the object as it was just passing close to the light pole, but not actually hitting it? At the speed it would have been traveling there would have been a pretty good shock wave thrown out right? - what are the chances that it could have taken out the bulb without doing any damage to the pole itself?

I believe its a meteroite, I don't believe it hits the pole (examine more closely), perhaps it past close with its iron core generating enough eddy currents to blow the globe as it passes, It definately seems to have a pressure wave preceeding it....oh yeah, and its not a fake.

And to Smith-at-Canada-com: Its great you've been Darwin, but please don't come back - knobs like you we don't need.

[Guest]

Static discharge between the focal plane shutter and the film pressure plate.
The dischage was caused as the shutter passed over the film, arcing through the film to the pressure plate.
Sometimes this can happen as the film is being advanced to the next frame, but it us usually straight across the imabe area lft to right.

No such luck, this is a Digital image...

[atin@real.com]

i agree with pauld@exploratorium.edu, it is a shadow of a contrail. i just didn't know the right words for vapor/gas trails behind airplanes. a phenomenon i have seen similar to this is the shadow of a mountain onto clouds far into the distance.

[damienhandslip]

Could it be a very subdued rainbow, muted by the clouds in some way?

[sprog]

I don't think the flash has anything to do with the dark streak in the sky.
I too have seen an identical streak as a contrail shadow. I would put my money on that as an explanation.

bruce_bjc@yahoo.co.nz

[Guest]

I don't think the flash has anything to do with the dark streak in the sky.
I too have seen an identical streak as a contrail shadow. I would put my money on that as an explanation.

bruce_bjc@yahoo.co.nz

Contrails last longer than 15 seconds, it should have been in all the frames?

[ukuleledre]

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.

[Yet Another Guest]

It's far too uniform and straight (relative to the horizon) to be either a meteorite trail or contrail shadow.

I haven't read through all eight pages of responses, but if anyone has suggested it might simply be a reflection artifact, from an unknown source, I'd say that's the most likely probability.