ki_cz
Member
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Strange straight line in the sky [Anticrepuscular ray]
- Thread starter ki_cz
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cloudspotter
Senior Member.
Yes, looks like a crepuscular/anticrepuscular ray (they're essentially the same thing, just depends which whay you are facing!).
Similar photo examples:
In this case it seems to be a single wide shadow, with the edge passing almost directly over the camera position, which makes it look more like a "two-tone" sky rather than an obvious ray.
Similar photo examples:
In this case it seems to be a single wide shadow, with the edge passing almost directly over the camera position, which makes it look more like a "two-tone" sky rather than an obvious ray.
When the camera spins round towards the end of the clip you can see what may be the cloud casting the shadow.
This seems to be the view away from the sunset:
and then the camera turns to face the other way, towards the sunset, and there is a cloud in the right place to be casting the shadow overhead.
This seems to be the view away from the sunset:
and then the camera turns to face the other way, towards the sunset, and there is a cloud in the right place to be casting the shadow overhead.
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Clouds Givemethewillies
Senior Member
The earth's shadow on smoke, near the tropopause, from a forest fire?
ps. I have no idea how I make this stuff up.
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More examples, searching for "anticrepuscular split"
https://www.google.com/search?biw=1920&bih=1076&tbm=isch
https://www.google.com/search?biw=1920&bih=1076&tbm=isch
You don't need anything that complicated. It's just a cloud shadow from a low sun in a hazy atmosphere.
This one looks odd because it's so big, and the edge is overhead, so you can't see any converging.
Clouds Givemethewillies
Senior Member
We need to know where the sun is.
I'm pretty sure it's just a case of following the line. It's either just over the horizon, or behind the camera.
Hard to tell exactly from the video, as the sun appears to have set at ground level so there are no shadows, and ther location doesn't seem to be identifiable. But the shadow line appears to be pretty well aligned with the road, and the camera starts off pointing away from the sun, based on the relative brightness of the sky.
The sun appears to be directly behind the camera at the start of the video. The high clouds are illuminated by the sun and look pink to the right of the shadow line, but they are hardly visible to the left:
Compare with this pic of anticrepuscular rays: the high clouds are again brightly lit and look pink in the light areas, but are almost invisible in the dark areas.
Clouds Givemethewillies
Senior Member
What about the plane?The sun appears to be directly behind the camera at the start of the video. The high clouds are illuminated by the sun and look pink to the right of the shadow line, but they are hardly visible to the left:
View attachment 20907
Compare with this pic of anticrepuscular rays: the high clouds are again brightly lit and look pink in the light areas, but are almost invisible in the dark areas.
Trailspotter
Senior Member.
Good point. As the plane is sunlit, the Sun is certainly behind the camera. On the day, it was setting North of West.
Clouds Givemethewillies
Senior Member
For the sake of argument.. What would it mean if a plane came out of a shadow, just to the _right_ of the line in the sky? (1:17)
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Trailspotter
Senior Member.
Actually, the video does not show its coming 'out of shadow'. When the the plane comes into the frame, its contrail is at some distance from the 'line in the sky'. Before that, the patch of the sky where the plane presumably crossed the line was out of the frame for about 25 seconds. The cameraman filmed the sky overhead and behind and probably just missed the plane while it was crossing the dark side. Just before the camera moved to scan the sky, a bird crossed the line at 0:50, but, given the plane apparent speed, it wouldn't come into the frame by that time yet.
I do not think that the high flying plane would be in the shadow of a low cloud. There are a few higher white clouds spreading across the line at 1:00, when the camera points to the opposite direction (South of East).
Clouds Givemethewillies
Senior Member
Does anyone know how tall alien spacecraft are, I wonder.
ps. here is a nice SH dawn shadow:
Source: https://www.youtube.com/watch?v=28hqMP5Kvbg
Whitebeard
Senior Member
Does anyone know what an alien space craft really looks like, never mind its dimensions?
mind you...
Clouds Givemethewillies
Senior Member
How smalll was the dog?
Whitebeard
Senior Member
Douglas Adams doesn't specify in either book, or the scripts for the radio or TV series (this sequence was omitted from the more recent movie). However the animation shows a dog that looks a bit like a wire haired Jack Russell Terrier. Jack Russells are about 30cm high at the shoulder on average.
A google image search for 'small dog' reveals these results. Now in the clip the dog looks adult, rather than puppy like, so discounting puppies we are left with a selection of toy and miniature breeds. Looking at the average shoulder height of a selection of the small breeds featured on http://www.smalldogplace.com/ we get ...
Bolognese - 27cm
Cairn Terrier - 30cm
Chihuahua - 20cm
Dachschund - 22cm
Lakeland Terrier - 35cm
Pekingese - 20cm
Pug - 30cm
Shetland Collie - 36cm
Tibetan Spaniel - 25cm
Yorkshire Terrier - 20cm
So we can claim the average small dog is 26.5cm at the shoulder. Therefore if such a dog can swallow an entire combined battle fleet, which if we look at the few clues in the clip (the fact that the two fleets were big enough to devastate an entire galaxy) must still have been fairly large - from few hundred ships up to many thousands. We can conclude that the alien space craft in question must be really, really, really small.
Spectrar Ghost
Senior Member
It's never made clear how big the galaxy was, either. Of course, the smallest galaxy ever discovered has a radius of ~100 ly and about 1000 stars, so we still need to assume some impressive energy densities on the weapons.
Trailspotter
Senior Member.
I have identified the location of the OP video on US-119, Weston, West Virginia:
The camera was pointing South of East, that is, in the opposite direction to the sunset on the day. This means that the line in the sky was coincident with the direction of anticrepuscular rays.
Update:
I have used the FR24 playback to estimate the time of the video:
Assuming that the video was taken on the same date it was posted, the two planes captured in it are probably DAL1643 and SWA2285, which passed east of Weston around the sunset time (00:00 UTC = 20:00 EDT).
The camera was pointing South of East, that is, in the opposite direction to the sunset on the day. This means that the line in the sky was coincident with the direction of anticrepuscular rays.
Update:
I have used the FR24 playback to estimate the time of the video:
Assuming that the video was taken on the same date it was posted, the two planes captured in it are probably DAL1643 and SWA2285, which passed east of Weston around the sunset time (00:00 UTC = 20:00 EDT).
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How the heck did you manage that?
Marin B
Senior Member
Good question!
386
Member
For some additional data, there appears to be a third plane at the very end of the video, at about 3:39 travelling in the same direction as the first one. If you slow YouTube to 0.25 speed it's a bit easier to catch.
Clouds Givemethewillies
Senior Member
Very impressive, but I don't see where he could park there...
There's a gravel and grass median with no central barrier at that point. And when the camera pans down to the road briefly it appears that the traffic is stationary. It looks as if he was caught in traffic and pulled over a little way to the centre of the road.
Trailspotter
Senior Member.
Well, finding a location on Google Earth using visual and other clues is a hobby of mine, which provided some entertainment during the long weekend. I have a lot of experience and learned many tricks of trade. The main trick here is to figure out first the viewing direction of a photo or video frame, if unknown. Here the direction came from the assumption of anticrepuscular ray, which I wanted to verify by finding the exact spot where this phenomenon was observed. Other important clues came from the video description and narrative. The cameraman is from the Boston area and traveled to help victims of recent West Virginia floods. He said that his truck was caught in traffic, giving him the opportunity to get out to take the video. Apparently, the traffic is stationary only in the right-hand lane. Presumably, this is an exit lane, one of the three lanes on this side of the road, according to the road sign above. On the other side of the road, there is a set of traffic lights, suggesting this probably is a minor road in a populated place and the traffic congestion probably was at the junction with a major road.
Assuming the time was near sunset, the truck was heading west and probably was not far from its destination somewhere in WV, where I eventually found the right patch of the road.
Clouds Givemethewillies
Senior Member
Now find the thunderstorm.
Marin B
Senior Member
Trailspotter
Senior Member.
No, I haven't. I routinely use Google StreetView to verify my guesses, not to make them. It appears that Geoguesser allows the players to look around and even to wonder away from the spot where they can find informative road and other signs.
cloudspotter
Senior Member.
Just had a few goes with that and got remarkably close with most wild guesses!
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