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I'm developing a silkworm that spins webs of a particular kind of "silk" and weaves thin, fragile webs. The magic part of this is that it also spins wind. The following addresses how this works and my question.

Info

The silkworms "fold" breezes into the silk, basically funelling the wind into a handwaved sheath that surrounds the silk. The wind rushes freely through the unobtanium sheath, causing it to accelerate rapidly until it's really, really violent. Think a very strong dust devil/mini tornado.

The webs are about 30 cm in diameter.

To make matters worse, the worms fold hot and cold air into opposing ends of the single, closed loop of the web. As the winds move through the web, they dance past each other. But when the web is broken--it's fragile, remember--the sheath of wind also snaps. Then the winds, now moving very very fast, rush into a mini "tornado," encircling their helpless prey. Let us say a strong gale-force wind at 47–54 mph.

The spinning wind sucks the air out of the vortex, which sucks the air out of the lungs of the prey. The prey falls unconcious and is slammed back and forth by the wind until the wind spins away. Then the creatures, summoned by the sound of the wind, come up to their prey and poison it before eating it.

My Question

What's the best material that satisfies the following critera?

  • Fragile but tensile enough
  • Can be looped into a single, nonending piece
  • Economical for a creature to expend energy producing
  • Ensures that, e.g, the tree it's stuck against survives
  • Can be made hollow (tubes for support/strength and to make the webs easier to produce)

Keeping in mind the winds released are

  • like a very strong dust devil/mini tornado.
  • strong gale-force winds at 47–54 mph.
  • and move in "mini-tornado" form.

and the material needs to withstand the force of this wind across its surface


Thank you to all in the Sandbox who helped me develop this question.


Note:

In accordance with this meta post, please do not use magic as an answer (handwavium is reserved for the purposes of wind-weaving, and the magic sheath, not for the purposes of the material used. That's why this is tagged , not

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  • $\begingroup$ Note to VTCers and Downvoters: Please leave a detailed comment outlining why you are downvoting/VTCing this question and leave a suggestion showing how you think this issue can be fixed. Thank you for being considerate. $\endgroup$ – FoxElemental Jun 5 '18 at 13:59
  • $\begingroup$ a magical sheath (...) please do not use magic as an answer. Don't you mean a "handwaved sheath", then? $\endgroup$ – Renan Jun 5 '18 at 14:22
  • $\begingroup$ It's good, you had my +1 even before the edit. $\endgroup$ – Renan Jun 5 '18 at 14:25
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If you do want a vortex, then I think you need two layers of regular silk, opposite to each other and connected through their hubs by a perpendicular thread. The webs disconnect from the surroundings and spin (no pun intended) violently and in opposite directions when the axis string is broken. This will cause them to release the handwaved air contained in them, and when both masses mix, you will have your vortex. Most kinds of trees should be able to survive it with just a few leaves lost, maybe a branch gone, even if you do reach the gale force figure in the question.


If you want to be realistic, though... A gale force wind is hardly obtainable biologically. The Mythbusters guys have managed to sneeze at up to 39 mph. Real scientists, on the other hand, have measured average speeds of 10 mph.

If you wish for a truly reallistic scenario without the vortex, a regular mix of silk and some mucus may do the trick.

What the worm needs to do: dig a tunnel with two opposite openings. On one end, make a membrane of silk + mucus. The silk must be tense as a guitar string, and the mucus should make it airtight. This membrane will act as a drumhead.

The other end of the hole should have an opening just small enough for the prey or the worm, whichever is largest, and the wall should be hard. Perhaps the worm is digging through a tree, for example. Or it may furnish the wall of this opening with rocks, sticks, and mucus.

Next step, the worm pulls connects many thin threads to the drumhead wall and to random points inside of the tunnel. This can be done in a black widow web pattern. The important thing is that the threads should pull the drumhead towards the insde of the tunnel, with some force, but in a very delicate equilibrium. You will soon learn why.

Last step, which is optional, is setting some bait along the tunnel.

When unsuspecting prey comes inside and unwittingly cuts one thread, the drumhead wall will vibrate. With every few cycles of vibration, it will cut more and more threads, vibrating ever strongly, untill all threads are cut. It should then keep vibrating for some time and then stop, which is when the worm enters and does what it needs to do.

Now for some science. Such vibrations will form a note, and the tunnel will act as a resonating chamber. If the wavelength of the note matches the length of the tunnel, you will have a stationary wave. Long story short, these are sound waves that do not move around, but rather just stay there. These things have nasty effects. Certain materials will vibrates without apparent cause. On humans, even a considerably weak standing wave can have the following effects:

  • Severe middle ear pain
  • Persistent eye watering
  • Respiratory difficulties
  • Sensations of fear including excessive perspiration and shivering

From the same link:

‘Vibration of the body mostly affects the principal input ports, the eyes, and principal output means, hands and mouth.'(p. 287).

‘Exposure to vibration often results in short-lived changes in various physiological parameters such as heart rate…At the onset of vibration exposure, increased muscle tension and initial hyperventilation have been observed.’ (p. 280).

If such effects can happen to humans in a very wide environment, imagine what a standing wave will do to a small insect. The vibration of their carapace would be extreme, and could mess up with their trachea and keep them from breathing for a moment, causing momentary stun.

If you want to tune your silk/mucus drumhead... For a 10cm (~4 inches) long tunnel, you are looking for what would be approximately the A7 on a piano. I have calculated this using this formula and this table.


All threads in both ideas can be made of regular silk like that of a spider. The threads which are supposed to break first will just be thinner. The threads that do not break first can be made as thick as human hair, or even all the way to the thickness of a couple sheets of regular printer paper. Even then, I expect that a gale force wind will break all the threads a little after the release of the air.

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  • 2
    $\begingroup$ These would be like tiny tuneful ant lions. One could imagine a ‘dusk concerto’ when flies settle en masse into a field full of these things. $\endgroup$ – Joe Bloggs Jun 6 '18 at 7:38
  • $\begingroup$ @FoxElemental done. $\endgroup$ – Renan Jun 8 '18 at 11:37

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