Knots: they attach us to ropes, connect slings to trees, substitute for dropped gear, secure tents, create belay anchors. Like the Force, knots surround us, protect us, and bind our galaxy together. Even a sport climber whose shoes close with Velcro knows a few knots. But here are a few things you might not know.

1 The word “knot” is related to knob, knoll, and knuckle, but not to knowledge. It is knoten in German, knot in Dutch, knut in Swedish, nudo in Spanish, and noeud in French.

2 The Inca’s only “written” language was a system of knots tied into necklace-like “documents” called quipus, or “talking knots.” Some scholars think quipus recorded only numbers, but others believe that they also told stories and encoded historical events. A select class of Incas apparently interpreted the knots, and the code has never been definitively deciphered. Knots were also used for record keeping in ancient China, and the Chinese Book of Changes, almost 2,500 years old, associates knots with contract and agreement.

3 The “bitter end” of a rope refers to its working end, intended to be tied off to a bitt, a cleat-like fastening point found on docks. If a longshoreman bobbled a thrown line or missed his tie-in move as a ship came in to dock, he might be left “hanging on to the bitter end” as the untethered ship drifted perilously past its mark.

4 The “feel” of a rope is called its hand. A hank is a looped bundle of rope, e.g., a lead line done up in a mountaineer’s coil. A bend is a knot that ties the ends of two ropes together. A hitch attaches a rope to a fixed object, such as a tree or carabiner. A short section of slack rope that does not cross itself is called a bight. If it crosses itself, it’s a loop. Twist a loop and you form an elbow.

5 A “climbing rope” is a misnomer. “Rope” properly refers to the raw material—a spool of accessory cord, for example. Once cut to length and given a designated purpose, a rope should be called a line.

6 The square knot—the first knot many people learn besides tying their shoes—may be the single greatest hazard in rope-related activities, due to its default use in sketchy rigging scenarios by reckless amateurs. To see some of the square knot’s antics, tie a firm square knot, then pull on one tail until the knot flips (or capsizes in knotting language). One strand will turn into a lark’s head knot, or girth hitch, feebly grasping the perfectly straightened second strand. Off belay!

7 Anytime you tie a knot in a rope, you weaken it; in drop tests and pull tests, a rope typically breaks at the knot. The strongest tie-in knot you can use is the figure-eight follow-through, which, when pull-tested, breaks at 75 to 80 percent of the rope’s full strength. The bowline is a slightly weaker knot, at 70 to 75 percent, followed by the double fisherman’s at 65 to 70 percent. The clove hitch is the weakest of the common climbing knots, at 60 to 65 percent. Note, however, that modern climbing ropes have a tensile strength of upwards of 6,000 pounds, so even a clove hitch would fail at something like 3,600 pounds. The elasticity of climbing ropes makes that amount of force virtually impossible to generate in reallife scenarios.

8 Although the bowline has been in use for thousands of years, the name first appeared in written English in 1627, when one John Smith called it the Boling Knot. French alpinist Gaston Rebuffat favored the bowline for his tie-in, as did El Cap pioneer Warren Harding. If you make a pre-dawn hike miles into the backcountry only to find you’ve forgotten your harness, you’ll be wrapping the rope around your waist to tie the bowline on a coil, or Space Cadet’s Hitch.

9 To help loosen a stubborn knot, roll it with your palm against a rock. For really stuck knots, such as those found in manky tied slings, soak the knot in water. Conversely, to create a more secure knot, soak it before tying, cinch it tight (bounce test–style), and let it dry.

10 Gorillas and weaver birds are both known to tie knots. Neither is known to wear a climbing harness.