Dancing Cloud Phenomenon on YouTube - Bad Astronomy

[DaveC426913]

Caught this on Youtube. At first I thought it was a camera aberration, such as a drop of water on the lens. But the effect is independent of camera movement.

Anyone know what's going on here? Is this effect something between camera and cloud, or is it really something up at the cloud level? If so, what? The text has a hypothesis by a meteorologist.

http://blogs.discovermagazine.com/b...ng-video-of-a-bizarre-twisting-dancing-cloud/

 

[wukunlin]

that was plain weird

 

[zoobyshoe]

Joel had sent the video to Walter Lyons, a meteorologist from WeatherVideoHD, who was able to identify this phenomenon. Here’s his reply:
The answer lies in this: ice crystals, especially long needles, tend to become aligned with the ambient electric field.
So what you are seeing is sunlight reflecting off ice crystal faces that are constantly being oriented by the developing electric field just above the [cumulonimbus] top. Then there is a discharge in the cloud, and the field collapses momentarily, and the crystals begin to realign again. Then this just keeps happening over and over.
Aha! I hadn’t thought of that. The outer surface of ice crystals can hold a static electric charge, similar to what happens when you rub a glass rod with a cloth, or rub a balloon on your hair and stick it to the wall. When placed in an electric field, the charges feel a force on them, and align themselves along the field. So all the ice crystals above that cloud top are aligned one way in the field. Then the field snaps (maybe due to lightning releasing the energy) and then reforms. The ice crystals change their orientation suddenly when that happens.
So why does it look like the entire shape is changing? That’s because ice crystals can act like little prisms, bending light when it passes through them (or they can act like mirrors, with light reflecting off their flat surfaces). When they float in the air you get all sorts of astounding and beautiful formations like sun dogs, halos, sun pillars, and more. These all depend on the angle between you, the Sun, and the orientation of the crystal in between.

I thought this was good.

 

[Simon Bridge]

Yeah - there's also a link to supporting examples.

It does look like water on the lens or some transparent sheet between the camera and the cloud - but the meterologists' suggestion looks good from here.

 

[lostcauses10x]

light is moving not the cloud it is most likely a reflection of some thing from directly around the photographer. Maybe even a watch on their arm..The source of the light of course is not in the camera view it is off to the side were it partaly reflects off the lens.

One of the reason a good lens hood is used.

 

[Gabe21]

it appears the video is being taken through a piece of glass. the moving cloud is just an image behind the camera reflecting off the glass. if a cloud moved that erratically it would also cause movement in the clouds around it because of air flow.

 

[DaveC426913]

light is moving not the cloud it is most likely a reflection of some thing from directly around the photographer. Maybe even a watch on their arm..The source of the light of course is not in the camera view it is off to the side were it partaly reflects off the lens.

One of the reason a good lens hood is used.

No. As I pointed out - and you would have seen if you'd watched the whole video - the phenomenon does not move with the movement of the shot. It stays in the same spot in the sky, regardless of how much the camera moves.

That categorically rules out any phenomenon related to the camera.

 

[DaveC426913]

it appears the video is being taken through a piece of glass. the moving cloud is just an image behind the camera reflecting off the glass.

This is the only non-genuine-phenomenon explanation I can think of. But it would require the assumption that this is a hoax.

if a cloud moved that erratically it would also cause movement in the clouds around it because of air flow.

There is no assumption that any cloud is moving.

What is moving is (ostensibly) just refracted light paths as ice crystals get reoriented.