the blueshift journal

PHYSICS TEST NO. 3

LILY ZHOU

1. There is a girl (5'2'') and there is a bell tower (146'3''). There is a novel (8 in x 10 in) and there is a clock (50 in x 50 in). The girl walks at constant velocity (2.5 mph); the bell tower is stationary (0 mph). On the other side of the sidewalk, there is a man who likes to cut things up (tangerines, philosophy, virgins). He is walking at constant speed in the opposite direction (-2 mph). What is the girl's acceleration?

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(A) Use the kinematics equation v=v0+at. There are two unknowns: final velocity and time. Final velocity, she finds on the sidewalk, reeling, furling like daisy blue curtains, widening and contracting, hands shuttering mouths. Something spills. Something froths. Something gives way.

(B) Large enough to make her head spin. The splinter of a bone white leaf and she is climbing the bell tower. San Francisco, minimized. Similar figures, scale factor 163:1.

(C) Time, she finds on the clock. 9:10. Then, 9:11. Time, she manipulates, weighs down on the minute hand (force = mass x gravity). Time decreases, therefore acceleration increases. Metaphorically, this works. Mathematically, not so much.

(D) Time = 0. Therefore, acceleration = {-∞,∞}.

 

2. The girl dropped her novel on the way to the tower. Does she retrieve it?

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(A) No. It's a book, for fuck's sake.

(B) Have you ever seen a book decompose? Pus and skin flakes and ink, mixed in with spilled gasoline and the yellowed headlines of yesterday's newspaper. Have you ever seen a book collapse into itself, a bird with honeyed joints and waxen feathers?

(C) No. It's not worth the trouble.

(D) The man picks the book up. Parts it to its first creamy-smooth page. Wonder how many girls he's touched. Wonder what ever happened to them. Wonder if she can recognize them on the streets now: girls more mirror than glass, girls with tongues bitten to a nub, girls with pigeons trapped in their throats. A flicker of a gaze, a brush of a hand. Saying, I know. I know.

 

3. The girl cracks a spider web on her glasses. Pupil the epicenter, spiraling outwards to the whites of her eyes. Like a fist, unfolding the same way the sky does at the coup de grâce of dawn. San Francisco, fractured. Which is to say: San Francisco, shaken. Magnitude 7.6, Richter scale. Calculate the force of this action in newtons.

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(A) She never learned optics in Physics, dropped the class three and a half weeks before they got to it. She's guessing that it's something big, though, triple digits at least, for it to be able to alter sunlight (massless, frictionless).

(B) Newton's third law states that for every action, there is an equal and opposite reaction. The world exists in pairs. The novel and the glasses. The words and the sight. An action and a consequence. Everything works in tandem; nothing is isolated.

(C) The girl puts on the glasses. The splinters intersect at a common point (5, 5) – life, sharpened. Skewed angles, irregular polygons. Starts at the center and curves outwards, a sticky cherry mouth growing, gaping, wider, faster, louder, stronger.

(D) He used to say that people like them (bespectacled, critter-like) saw the world clearer than anyone else. Saw things for what they were, unmuddled by half-truths and white lies. The sight of a thinker, he'd say, and his glasses would catch light, one million pinpricks of white-hot truth splintering, fracturing, shattering.

 

4. The bell tower strikes 9:14. Calculate the centripetal force (Fc) given that radius = 15 in, and that mass of the girl = 50 kg.

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(A) Fc = 0. The girl is still. The clock is still. Everything is still. Everything is still through glass. Everything is glass through mirror. Everything is mirror through rain. Pay attention and you'll realize that this is true.

(B) Alternatively, Fc = ∞. Clocks don't strike, they shudder: into minutes, into seconds, into now. In the now fifteen seconds ago, her glasses are not cracked. In the now five minutes ago, her novel is not soaking up sewage water. Remember eighteen months ago, golden nose ring and silver coins in mouth. That now occurs every eighteen seconds. A twitch and a shudder. All you have to do is watch and wait and listen.

(C) This would be analogous to age seven, curled around the branch of the old oak, if the clock were still and silent and permanent. Nothing is permanent here, at least not for long. Did you know, time is only responsive to gravity in between the minutes? Strange things happen in the jump from one digit to the next.

(D) Time shudders, then stills. Somewhere, dusk suspends over horizon.

 

5. The man who cuts things up decelerates. Looks up at her and waves, face split straight down the middle in merriment. The ring on his finger (14 karat at most) catches light. What is the frictional force ( Ff) between the man's finger and the ring?

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(A) The first time, he spends the entire afternoon sucking on a bowl of cherries, spitting the pits into his hand, mouth red and bloated like a fever. He says would you like some and she says no thank you I just ate even though that was a lie. He says my wife makes them for the kids every morning and they love it, just some casual, offhand remark, and she smiles awkward and nervous and pops one into her mouth. Later, he twists the ring as if loosening a nail, flings it aside. In the absence of sunlight, it's red as a stain, and she doesn't know what that means.

(B) The equation for static friction (Ff=μs FN) is rendered useless in the scenario that the two objects are not touching. Think about the way his ring flits under hallway fluorescence, a band of shadow stretched tight against the skin, slipknot like a promise. Think about the way his mouth twists when he speaks, Catherine my wife Catherine. Think about this: palm to cheek, red, hot, gasping, phantom touches not yet phantom enough.

(C) Remember November. Leaves more bone than vein. He unpeels tangerines with one fluid motion, sets apart eight even slivers in a glass bowl. Places Newton's cradle next to it. Pulls, then releases. He says you're taking Physics this semester, aren't you and she says conservation of momentum because that's what he's really asking and he grins white-teethed and adjusts his glasses and says smart girl, as if he were her teacher or her priest or maybe even her father. Later, he gives her an umbrella, my little girl's, and his hand lingers too long, and she doesn't know what that means, either.

(D) The wind the tree the clock. The book the bell the ring. The man the wife the children. They say that in the absence of matter, Ff=0. There is no him or her or them or us. There is only time there is only gravity there is only tension there is only friction.

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6. The bell tower clock strikes 9:16 and the minute hand dips downwards. The girl has fallen asleep. Her glasses skitter down the arrow, three quick staccato beats to overcome friction and then the falling, the resolution, the decrescendo of stone hitting water. First the glasses and then the girl. 9:16:12. How long does it take for someone to notice?

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(A) An aerial view: two dimensions, radius 5 meters, center (5,5). The girl is at the center of the circle. The bell tower is at the 4 o'clock position, the glasses, 9 o'clock, the novel, 6 o'clock, and the man, nowhere to be found. 1 o'clock, and the teenagers make out by the benches. 5 o'clock, and the old man feeds the ducks, breadcrumbs shriveling like a eulogy. Time spins, compresses, falls. The glasses, a broken compass, floats, swells, deflates.

(B) Define “someone.” For instance, the girl is someone. For instance, the girl is not asleep. There is a strange pleasure in knowing that you will be within time's grasp one second and then out of it the next: time passing to gravity passing to earth, a relay of forces. There is a strange pleasure in knowing that gravity (9.8 m/s2), at least, is constant no matter where you end up.

(C) At the same time the bell tower strikes 9:17, the lenses of the glasses tip their heads to the horizon. 9:18. The teenagers head downtown with bruised lips. 9:19. The old man reads the obituaries. 9:20. Several miles away, a man orders his coffee black.

(D) In the end, it's the jogger who notices, the one with the hot pink halter top and the visor, 972 seconds late for an optometrist appointment, though she doesn't know that. She sees the spider web on the left lens, remembers, and sprints down to the optometrist's office. In the parking lot, she sees a girl with a book, remembers, and calls the police. Two months later, they rebuild the clock. Rewind time. 9:15, two ironbound arms splayed out to sky. Questioning – God? No, just the sky.

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