Of all the outdoor activities that attract thousands of participants, and hold many more in a web of fascination, rock climbing is near the top of the list. It looks relatively easy to the onlooker, safe and happy with his two feet firmly on the ground. But to the participant, it is anything but. Just imagine that you are about to descend from an overhang. It does not have to be too high, say 100 feet. Your lifeline to this world is a thin rope, which the manufacturers claim can hold the weight of an elephant. You just hope that they were not exaggerating. You attach one end of this slim nylon cord to a rock, and pull for all that you are worth hoping that it is secure, and will remain so for the foreseeable future. You then thread the rope through a metal pulley which is bolted to a harness around your waist. This pulley is designed with a special feature that, in the event of a sudden release of the rope, will lock the rope, ensuring that the climber cannot suddenly plummet out of control.
This is the moment of truth. The climber feels anything but brave, his mouth turns dry and his head palpitates with fear. He cannot understand why he ever agreed to such a foolhardy and scatter-brained activity. Sick with fear, he places one leg beyond the overhang and turns round. There is no turning back. He leans out, gripping the rope for all he is worth, which at that moment is not very much. He is already defying gravity, and the rope is taut, mirroring his own terrified tension. Slowly, hand over hand; he jerks downwards, his boots kicking against the rock face, feeling the exhilaration of controlled downward motion, coupled with the joy of having conquered his own fear. Jubilantly he reaches the end of his descent, his surging adrenaline making him feel on top of the world.
If the way down fills you with dread, the way up is much worse, for now you are trailing the rope, instead of hanging from it. You are all ready: sensible shoes, a bag of chalk hanging behind you to give your fingers extra grip, and your muscles flexed. The first three feet are easy, because you can jump down, give a nervous little laugh and try again. Beyond that, you can’t. Slowly you go higher, reaching from hand-hold to hand-hold, your feet instinctively feeling for those cracks and little ledges on which your life depends. There comes a point where you cannot go back, and the way forward is unsure, you are stuck like a fly on the side of this great rock, the wind is picking up and you have never felt more alone in your life. At that moment, when one wrong move could… you are experiencing the incomparable joy of climbing, that great outdoor feeling, at one with nature… HELP!! At that point, we take our leave from our intrepid friend, wishing him much success in all his endeavors.
If mountain climbing is such a hazardous occupation even with a rope, imagine what it would be like with no rope at all. In any case, ropes are such costly items. You have to go to a specialist climbing shop, which supply the lightweight yet strong nylon rope which is guaranteed unbreakable, the special footwear, again, strong yet light, the weatherproof clothing – the list is endless. If we want to be practical, what is really needed is a specially designed body for climbers which will allow them to climb any surface in any direction, and enable them to produce nylon rope from a special aperture in the body. Climb as high as you want, whenever you wish, wherever you want, swing from overhang to underpass, sail from peak to peak, your rope smoothly and silently spraying out from its place of manufacture, somewhere within you, keeping you safe and secure as you perform your Tarzan act.
“Come on,” you say, “wake up from your daydreams; you know that these things are impossible!”
Are they? Have you ever heard of the spider?
The Invisible Silk Machine
Everyone has their likes and dislikes, and lots of people dislike spiders. In reality; spiders should be welcome in homes and gardens, because they feed on flies and other insects. Of the numerous species of spiders, some are so small you can hardly see them, and others, the ones which form the chief ingredient of horror stories, are as big as your fist. There is indeed one delightful species that preys on lizards and even small birds. Although there is such a variety, all spiders – big and small – have two things in common: they all have eight legs, (as opposed to insects, which have just six), and they all produce silk from their bodies.
If you can, look at a spider very closely. You will see that at the end of its body are six tiny tubes. These tubes are called spinnerets, and the silk thread comes out of them. Naturally, it does not just come out – the spider uses two of its eight legs to pull out the thread. The thread is so thin that very often you cannot see all of it, unless it is covered in early-morning dew, but it is very strong. It has to carry the weight of its owner, which is sometimes substantial, and it must be able to withstand the impact of a flying insect without shattering into fragments and allowing the potential victim easy escape. This silk is at first a liquid, and is manufactured in specially constructed glands inside the body.
No other creature uses silk in so many different ways as our spiders. They make it into houses, diving bells, cocoons, traps, parachutes and lifelines to save themselves if they fall. Just imagine what specialist machinery is required to produce the precisely specified silk. If it were too thick, it could never leave the spinnerets, and if it were too thin, it would be useless for its multitude of purposes. And, it has to be converted from a liquid to a powerful thread the instant it meets the air. How would you care to manufacture that mind-boggling set of machinery to a size that could comfortably fit into a body so tiny that you can barely see it?
Learning From the Spider
Whenever you see one of the world’s great suspension bridges – such as the Golden Gate or the Humber Estuary – you gaze at the graceful arch spanning the river, suspended by seemingly delicate cables, and you admire the wisdom, design, and technology that made such feats of civil engineering possible. Clever men – they learned it from the spider!
The familiar garden spider spins its thread, and attaches one end to a twig. It allows the other end to flutter in the wind, knowing that it will soon blow onto a leaf. Once a horizontal line has been secured, the spider constructs a frame, resembling a pentagon, within which the web will be spun. Lines are strategically laid from corner to corner, resembling spokes of a wheel. Starting from the center of the web, the spider constructs a spiral, moving ever further from the center. Then, an amazing thing happens. The spider leaves its work, and runs to the outer section of the frame, and begins to build a spiral from the outside working inwards. The difference is that this thread is different from that which has been used thus far: it is now special adhesive thread – all the better to catch you with. Please bear in mind when planning your machinery that you require two distinctive grades of thread, one smooth and one sticky. It is interesting to note that these garden spiders have specially designed oily legs so that they do not become trapped by the sticky strands of their own webs!
Such amazing creatures need specialist equipment. A spider is able to run up a wall and along ceilings thanks to their tiny claws and pads at the end of the eight legs. Some spiders can climb tall buildings, but like a trapeze artist, it always attaches a line of silk behind it, so it will not fall too far if it misses its footing.
That little spider – cunning hunter, master rope maker, mountain climber, and civil engineer; from where did it obtain its training, skills and highly specialized equipment? If you look carefully, you will notice that every creature possesses the tools needed for its individual trade. May we happily acknowledge the Great Intelligence that designed it all.
Tuvia Cohen is a humorist, scientist, and an accomplished author. This article was adapted from an article that appeared in The Jewish World of Wonders.