10 July 2011

Itsy Bitsy Spider

One morning, I placed great measure against a spider’s web and found my mind up to the task. A single strand of spider silk needs to be over eighty kilometres long before it will break under its own weight. It can be streched close to one third before it will snap.

This picture taken in Jindera surrounds on 26 June 2011 is not a great photograph, but it would be impossible for the human eye to plan anything so elegant in symmetry or form. From my reading, I can not determine what type of spider made this, but it is probably not an orb weaver. Certainly this web does not appear spiral throughout, but they are often not. The web is definitely damaged and spiders often eat damaged webs depending on their predeliction, even overnight, but webs can last for months.

Consider the letter D, balancing on its belly. Well, the orb-weaver spins the horizontal stroke of our supine D between two branches, jumping or relying on the grace of the wind for it to reach its second anchor point. It crosses this line to dangle a slack line 'neath it, creating the belly of the D. Reaching the other side, it anchors it still loose and then travels downward to the midpoint of the belly of our acrobat D and from there drops to spin the third of three initial anchor points.

For support, probably many spiders spin a central spiral of some description at the core of their completed radial spokes; this is separate to the greater spiral. A lot of spiders, including the orb weaver, use dry and sticky silk. The latter as a means of entrapment. Once the radial spokes are complete and the supporting core spun, an orb weaver travels out from the centre, creating a dry spiral shape. Once satisfied, it travels in reverse, creating another spiral with sticky silk and eating the dry silk as it goes.

To preserve the triangular nature of the space between the radial strands at their end points and maybe keep the radial spokes roughly equidistant, thus maintaining overall vibratory harmonics in the structure, so important to hunting, large or small supporting lines are established between the ends of some radial spokes, but not two adjacent in general. Intervening radial spokes are joined to these supporting lines maintaining the parallel nature of the lines of the spiral between radial spokes travelling outward. An example of this cuts across the bottom left corner of the picture below.

Let us suppose it to be correct that the patterns able to be woven in such a fashion are endless. Two spiders given the same frame of wood and identical conditions are ever unlikely to produce the same web. Indeed, producing an ideally shaped set of branches for web production would perhaps produce a tree that looked like a web. Visions of Escher and a million uniform webs within webs within branches within branches. Knowing the principles of patterns in nature allows the discovery of harmony between shapes.

I would really need to watch the spider that spun the pictured web to learn more about it, for even supposing some generallities between the manner all spiders spin their webs, it is a difficult process to extrapolate in the abstract given the infinite variety of leaps possible. Direct observation is required. Would an infrared camera be required to film it? Or could I sit chill with a muted head torch keeping lonely vigil, for most spiders only hunt at night. An old aquarium might do for creating an indoor micro-clime, but I suppose catching insects to feed any pet subject would serve as a major distraction first, then a chore. A still camera set to take shots at intervals by some ingenious electronic device may capture the development-sequence of construction, if any flash would not interrupt the arachnid's labour.

I am seized by the brain of science and must soon brew potions to control my manias. Love-potions, a philtre of metre, rhyme for measured sport.

To draw or paint such a thing, surely knowledge of its construction is a necessity to know the necessary stroke order and their directions, for else it would fail to convince the eye and subtle brain of art. The principles of nature teach one to acommodate the random without interruption, seamlessly, perfectly. Any invented web could therefore be valid if its creation obeyed a fixed sequence while still allowing for all external influences. Mr Squiggle on a nature-trip, driving a kombi in search of extant Wollemi Pines in their endemic environs.

My initial conjecture that the pictured web was evidence of the result of repairs, because of the mirror Y or y shapes between the majority of radial spokes is uncertain. I imagine a long-term response to prevailing wind conditions can be seen, but wonder still about the genius of design evident.

Further, let the annals note I for the first time accommodated the thought of turning on the dishwasher, before concluding it was a monument to the death of the serving-class and the manual would be too confusing, as well as lost. It was W. Stubbs, who in 1867 explained, “The difference between chronicles and annals was that the former have a continuity of subject and style, whilst the latter contain the mere jottings down of unconnected events.”

Our word silk ultimately derives from Σῆρες, Greek for oriental people, probably the Chinese who supplied the strong, soft, lustrous fibre produced by the larvæ of certain bombycine moths which feed upon mulberry leaves that in its woven form decorates so many necks.

Illustration below from How Spiders Make Their Webs by Jill Bailey.

This picture is the source of my description of web-construction and as a comparison point how I derived some of the theories above. Ideally, a large wall would be the best surface to learn how to draw webs, but as I have so few walls, it would be an extravagance, unless it is covered with paper first.

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