Does anybody know more about this "electric honeycomb" phenomenon? All google search results on the first two pages lead to articles about Niazi and I find it difficult to understand the underlying physics from the article. Especially this quote, out of context, is difficult to parse for me:
> "The amount of energy that goes in equals the energy that comes out and thus the flow of electricity is efficient. This way equilibrium is restored,"
Sounds like he's the guy starting the research / work on it if you cannot find anything else on the matter. Not sure if anyone else is, though others might further inspect his claims by independent tests.
The line is just awkwardly worded English, which is understandable because its his second language. What it means is that there is little loss in the "honey comb circuit" which then implies that it is the path of least resistance between the electrodes.
I really hope ArsTechnica covers this, because I didn't get anything of value from this BBC article, but I'd like to know more about the phenomenon and whatever "shadowgraphy" is!
Shadowgraphy is a method of measuring distortion or flow in a fluid by shining a light through it and photographing the shadow. Very useful in studying heat, shockwaves, and turbulence.
In this case it looks like he puts objects in the way of the electric field, creating and measuring the resulting "ion shadows" through thermal and Schlieren photography:
To further strengthen the role of surface charges as the key ingredient responsible for the RWI, we shield part of the oil surface from charge accumulation by creating an ion shadow. An ion shadow forms when an object blocks the path of the charged ions towards the surface of the oil. Even thin objects, like paper, are sufficient to produce a sharp shadow that inhibits charge accumulation on the oil surface. In the absence of surface charges the instability is locally inhibited, as evident from figure 11. Even metal objects produce the same effect when placed in the path of the charged ions. Using Schlieren photography (figure 12), we imaged the corona streamer which shows that the streamer and gas flow stay roughly the same size as the needle diameter, while the instability continues to occur at a larger radius.
As you note, Schlieren photography "uses light from a single collimated source shining on, or from behind, a target object. Variations in refractive index caused by density gradients in the fluid distort the collimated light beam. This distortion creates a spatial variation in the intensity of the light, which can be visualised directly with a shadowgraph system."
Basically the point charge is like the sun emitting light (ions) and if you put something in the way of the grounding plate, you get a shadow (local inhibition of the instability pattern).
Both articles says they've know about it for decades, but both articles also explain what is new: That's he appears to have obtained photographic evidence of the ion movements that forms the honeycomb and recorded the heat generated.
There are all sorts of striking phenomena out there that haven't been looked at. I will never forget the first time i looked down a microscope and saw a polygonal actin network in a cell. Like this stuff on the left, with the cells on the right being more normal:
They aren't in any textbook. My supervisor, a cytoskeleton biologist of many years' experience, had never seen them before. Nobody seemed to know what they were, or why they had decided to form in my cells that day. I tracked down a few mentions of them in the literature, stretching back decades, but this is the only paper i've found that really looks at them with modern tools:
Perhaps the most interesting thing was that nobody seemed very interested in investigating them. They weren't related to anyone's existing research programmes, so they weren't worth it!
Being of Pakistani origin, I'm actually glad that the fact that this is a Pakistani kid has been mostly not remarked on and the focus has been on the science.
It goes some way to normalising the existence of Pakistan as a place where people can make scientific achievements and where it's not always bad news. Well done kid.
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[ 2.4 ms ] story [ 48.3 ms ] thread> "The amount of energy that goes in equals the energy that comes out and thus the flow of electricity is efficient. This way equilibrium is restored,"
EDIT: his paper: http://rsos.royalsocietypublishing.org/content/4/10/170503
https://news.ycombinator.com/item?id=15413731
https://en.wikipedia.org/w/index.php?title=Draft:Electric_ho...
See: https://en.wikipedia.org/wiki/Shadowgraph
Penn State did a lot of pioneering work in and with this technique.
To further strengthen the role of surface charges as the key ingredient responsible for the RWI, we shield part of the oil surface from charge accumulation by creating an ion shadow. An ion shadow forms when an object blocks the path of the charged ions towards the surface of the oil. Even thin objects, like paper, are sufficient to produce a sharp shadow that inhibits charge accumulation on the oil surface. In the absence of surface charges the instability is locally inhibited, as evident from figure 11. Even metal objects produce the same effect when placed in the path of the charged ions. Using Schlieren photography (figure 12), we imaged the corona streamer which shows that the streamer and gas flow stay roughly the same size as the needle diameter, while the instability continues to occur at a larger radius.
As you note, Schlieren photography "uses light from a single collimated source shining on, or from behind, a target object. Variations in refractive index caused by density gradients in the fluid distort the collimated light beam. This distortion creates a spatial variation in the intensity of the light, which can be visualised directly with a shadowgraph system."
Basically the point charge is like the sun emitting light (ions) and if you put something in the way of the grounding plate, you get a shadow (local inhibition of the instability pattern).
Check out the pics on the Schlieren photography page, they're cool: https://en.wikipedia.org/wiki/Schlieren_photography
http://iovs.arvojournals.org/data/Journals/IOVS/933248/m_z7g...
They aren't in any textbook. My supervisor, a cytoskeleton biologist of many years' experience, had never seen them before. Nobody seemed to know what they were, or why they had decided to form in my cells that day. I tracked down a few mentions of them in the literature, stretching back decades, but this is the only paper i've found that really looks at them with modern tools:
http://pubs.rsc.org/en/Content/ArticleHtml/2009/IB/b818874b
Perhaps the most interesting thing was that nobody seemed very interested in investigating them. They weren't related to anyone's existing research programmes, so they weren't worth it!