Tuesday, March 11, 2014

Aerial Omily: A Frictional Relationship

It's why I can have this awesome chill moment! Also enjoy the amazing Floating Feet of Brooklyn, Ladies and Gentlemen! And avoid matte black like the plague when costume designing for the MuseIam...
Friction: it's your best friend! It's your worst enemy! It's crucial to the aerial moves you love! It's responsibly for those nasty burns you got last week! It's, you know, like everything else in the world.

Knowing just how crucial friction is can actually be disconcerting in your early days on the silks, because you want to feel SAFE: locked in, with no possibility of falling out. Ok, if you've done silks long enough, you've found a way out of at least one move that a teacher said was 'impossible to fall out of'. You can never be careless in the air. But yes, some moves are just really solid. A lot of them though? They're on a continuum. On a cold, dry day, you might find yourself sliding right out of a move that felt 100% locked on a hot, humid day, or you may find your teacher recommending an extra wrap in a familiar move because she or he just washed the silks.

The weather, and the cleanliness (or lack thereof...) of the silks in question are two important factors when you're choosing what to work on. We like to think of some tricks as falling into one of two categories: winter tricks, and summer tricks. Bicycle climb in July just makes you want to take the rest of the day off with a snow cone. On the other hand, taking half monty as a drop in January? Uh...maybe break out the spray rosin for that one. Another factor that comes into play is what you're wearing. Your bare skin is the best gripper you've got, and if you don't believe me, just try doing your basic climb with socks on. You just did your conditioning for the day! You're welcome.

Want another (maybe not so) fun way to experiment with friction? Climb up just one or two climbs, hold onto the silks overhead, and start slowly sliding down. If you don't feel anything, start to go a little faster. Oh yeah. The heat gets turned up really fast. That flare of fire in your palms is friction: the reason why you can start a fire by rubbing two sticks together (for real, you can; it's just pretty inefficient compared to other options). When you rub two things against each other (minds out of the gutter, guys), the resistance each provides to the other build energy, which is released as heat. Which is how you end up with what we call a burn when your skin slides along the fabric too fast. It's not just a good word choice for what it feels like. It literally is a burn. Your skin isn't being rubbed off (usually); it's being burned off. Fun, right?

There's actually a couple different kinds of friction, divided up based on the nature of the two things rubbing up against each other (No, there is no porn friction. What did I say earlier?). In the case of aerial, we're talking about dry friction (No, that's ok; I winced, too.) Dry friction is subdivided further into two categories, both of which are relavant to us: static friction (or stiction) is the force between two things that aren't moving (this force is why it's safe to do your 360 drop without holding the tails if you wrap the tails around your legs a few times), and kinetic friction, which yes, you guessed it, is when one or both surfaces are moving, and that's the friction that causes burns, but also slows you down when you're descending with the silks pinched between your feet, or in your knee pit.

So why does putting fabric between your skin and the silks keep those burns at bay? The friction is still there, but now the friction is in between the fabric you're wearing, and the fabric of the silks, and fabric is not a great conductor: heat does not travel through it very well. You slide fast enough, with those silks clamped tight enough, and you will burn through your leggings. You may have already noticed that some of your thinner tights don't provide as much protection as the thicker ones. Different materials will be more efficient or less efficient conductors of heat as well.

If you're trying to avoid burns, you may think the answer is to try to cut down on the friction by choosing leggings and tights that slide easily down the silks. It should be pretty obvious why that's a bad idea. You need friction, remember? Try climbing with socks on, again. It's not just because you're making your job a ton harder, though. If you're dealing with stiction (that's static friction, friction between two surfaces that aren't moving), there's no energy being generated and released as heat. The friction is just holding everything in place. It's only when you start moving that the heat starts building, and even with slick tights, there's going to be some friction. Since you're sliding more, you're going to end up burning more, not less, because you're exposing yourself to more of the potentially burning type of friction.

Aren't physics fun? Happy flying!

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