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| 2013: Why I Study Physics | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| 2011: Some Rocketry and Some Spaceflight Young's Double Slit The Industrial Revolution A Haiku Proof That Time is Relative Paradichlorodiphenyltrichloroethane A Brief History of Orbital Mechanics PAIN Physics Poetry Night is This Friday 2007, 2008, 2010: Poetry from previous years. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
2013 Physics Poetry | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Why I Study Physics by Ben Duffus ... Studying physics is so much fun, Solving equations is number one! And even if it takes me a while, Getting the answer makes me smile! Oh, who am I kidding?!? I never expected it to be like this, Now I can see ignorance is bliss! I study all day and I study all night, And I still can’t get these problems right! Sleep deprivation becomes a way of life, With no time to spare, I won’t be finding a wife! Don’t get me started on lab reports, They mess with my head, stuffing up my thoughts! Then I have to face the terror, That is the task of estimating error! If I was an engineer, I’d get three times the pay, Don’t need third year maths, to know it’s that way! Still, let’s consider the options: One: Theoretical. Pondering the universe: when, where, why and how. Pffft, forget it! You’re a just mathematician now! Missing factors of pi, i and root two, These are the things that will consume you! Two: Computational. I hope you like counting parentheses, And know five languages, including C. Constantly waiting for code to compile, If you call that fun then you’re in denial! Three: Cosmology. Or should that be statistician? Does it make you incredibly mad, That you sample all night, And your data’s still bad? Look at this graph it’s just a bunch of random dots! But look! I just fitted Hubble’s constant right on the spot! Four: Experimental. Your supervisor asks, “Why aren’t you working?” “Oh geez, I can’t possibly start, I’m still waiting for a crucial part. I ordered it 8 weeks ago, But it’s still stuck inside Moscow.” Great! And then there’s the pressure to publish, And risk getting told all your work is rubbish. No one likes writing 100 pages to apply for grant, So everybody nod your heads as I go on my rant: Frustrated lattices, I can relate, Trying to comprehend a cat in a dead and alive state, Or the universe expanding at an increasing rate, And what is causing it to eternally inflate? And is the grand canonical ensemble really that great? Although I try hard not to procrastinate, I’ll be in the tea-room stuck in a philosophical debate, About whether the universe has a deterministic trait, Or is it just probability that decides on my fate? Trying to form an ultimate theory that will encapsulate, Quantum mechanics and gravity and fields that permeate. But it’s just too hard for me to formulate, And that is why we must collaborate. My mind gets blow when I contemplate, Is the universe eternal or have a use by date? I simply can’t help it! My curiosity’s innate! But I still have these deadlines that simply can’t wait! And although not understanding is something I hate, I am still so sick of staying up late! It’s on that final BSc that I fixate, And towards that critical point I propagate, Along an unstable path from which I cannot deviate, But I’m at light speed and can’t accelerate, So it feels like I am never going to graduate! I wish my life was equation I could simply translate, Into a coordinate system in which it is straight, Or if it’s all imaginary, I need the conjugate! Must have divided by zero since things don’t equate! And I simply cannot help but to speculate, I need a new future with which I commutate. And then I might have a life of simplicity, But until then I’m here, getting a physics degree.... Back to Menu 2011 Physics Poetry
| Some Rocketry and Some Spaceflight by David Barry There's a great lot of detail in rocket design, But tonight, for our purposes, it'll be fine To consider a model discovered by Moore (Who thought not about space but of rockets in war). Assuming the mass of a rocket decreases Consistently during the time it releases Exhaust that's created from burning its fuel, Conserving momentum then gives us a rule: Δv = ve * ln(m0 / m1) The change in the rocket speed, called delta-v, Will be the effective exhaust speed v_e Times the natural log of m-nought on m-one, That's the mass at the start on the mass when it's done. The log in that formula's quite consequential: The growth in the fuel that you need's exponential For larger desired delta-v's. And in spite Of its seeming quite similar, orbital flight Requires much greater speeds than the ones that were true Of the spaceflight achieved by the German V-2. The V-2 was a single-stage rocket designed By one Wernher von Braun. They inflicted a kind Of emotional fear in the Second World War As they headed to London at speeds of Mach 4. These rockets were fueled by a mixture of three Quarters ethanol, one quarter water, to be Quickly burnt with near five tonnes of LOX. At their high Point V-2's would be moving in freefall and fly Almost ninety kilometres up. Once the war Had been ended, America tried to ensure That the brightest of Germany's scientists went To the West, which would crucially also prevent Them from working for Russia. Recruits from this mission Included von Braun, who was given permission To join the American Army in spite Of his work with the Nazis, a sizeable blight That was wiped from his record. In American hands, The V-2's and equipment were moved to White Sands In New Mexico, ready for firing in June '46. With their vertical launches, they soon Had the first ever spaceflight photography, Followed soon after by UV spectrography. But for orbital flight, the V-2's were too slow, As some simple Newtonian physics will show. GM/r2 = v2/r Since GM on r-squared must be v-squared on r, Then as long as we have an idea of how far Above Earth it will finish, it's easy to see What the necessary speed while in orbit will be. If you plug in the numbers, you'll see it works out That for typical altitudes, speeds of about Eight thousand metres per second are needed -- That's several times more than V-2's had succeeded In reaching. That log you'll remember implies A great need for fuel. So it's not a surprise That it wasn't till almost a dozen years later That Sputnik was launched. It was one of the greater Successes the Soviets had; consternation In Washington soon led to NASA's creation. The satellite Sputnik itself was quite small: Less than two feet across, in the shape of a ball. Attached were a pair of antennas which each Had two parts, and were set so that signals would reach The Earth's surface regardless of orientation. The rocket which launched it, a modification Of Russia's first ICBM, employed four Strap-on boosters for launch, which together held more Than forty-two tonnes of its fuel, a refined Kerosene with no linear alkanes, designed To be burnt in exactly two minutes with two Times its volume in LOX. While the second stage drew On the same two propellants, the rocket this stage Would burn for five minutes and then disengage. The orbit of Sputnik began to decay A little bit into its ninety-third day. Its orbital period measured a touch Over 96 minutes, and therefore as such, It lasted a thousand four hundred complete Revolutions, burned up, and became obsolete. When the cosmonaut Yuri Gagarin became The first man in space, one could credibly claim That the Russians had further established their power In the Space Race. In circling the world in an hour And a half, the Lieutenant Gagarin compelled The Americans into response. It propelled Their space programme: Kennedy started a plan That would see the Americans "landing a man On the moon and returning him safely to ... Earth." With a president thinking the programme was worth The expenditure, all of the years that would follow Were hectic for people who worked on Apollo. The rest of the decade was not all smooth sailing. The worst was the crew of Apollo 1 failing To put out a fire in the cabin which led To the astronauts trapped in there ending up dead. Remarkably, though, the direction of Wernher Von Braun kept Apollo on schedule, the sterner Procedures on safety not stopping his staunch Commitment to seeing the moon mission launch By the end of the 60's. It came to fruition On 16 July '69. The ignition Occurred just a couple of seconds before The clock ticked to nine thirty-two. Then the roar Of the Saturn V rocket was heard as it burned Its refined kerosene with its LOX. As we learned From the rocket equation, the fuel that is needed Scales with the payload; Apollo's exceeded All previous payloads. All up more than two Thousand tonnes of propellant were used as it flew To sixty kilometres altitude. Nearly Some five hundred more got the spacecraft to merely An orbit round Earth. Then it came time to start The Trans-Lunar Injection, which made it depart The Earth's orbit and head to the moon. By the end Of this burn, the spacecraft would have to contend For propulsion with rockets on board The command/service module. Despite being ignored Early on, the designers all chose the outstanding Idea of employing a module for landing, Which saw the command/service module remaining In orbit. The Eagle detached, while containing The astronauts Armstrong and Aldrin, descended, Then after some moonwalks and sleep time, ascended Back up and re-docked with the orbiter. Choosing This setup perhaps might have saved them from losing The Space Race -- the fuel savings meant that the mission Fulfilled the late Kennedy's early ambition. No longer useful, the Eagle was sent To an orbit they didn't keep track of. It spent Its last days by decaying in orbit until, In an unknown location, it crashed, and lies still. The last major burn was the Trans-Earth Injection, Followed by only the odd course correction, The astronauts finishing this most terrific Of stories by splashing down in the Pacific. Subsequent spaceflight just doesn't compare To Apollo. The missions, though, didn't end there -- Voyager, Skylab, the shuttles, and Mir -- But to rhyme all of that? Well I'll wait till next year. Back to Menu
| Young's Double Slit by David Barry Near the middle of London in eighteen-oh-one, An experiment studying light had begun. Before then the model most thought to be right Was Newton's corpuscular theory of light. Newton had seemingly put to the grave The notion from Huygens that light is a wave. But one Thomas Young caused a massive retraction, With light rays that underwent two-slit diffraction. When waves pass through slits that are suitably narrow, Their motion's no longer as straight as an arrow. Some minor diffractive effects notwithstanding, They move out in arcs that all keep on expanding. In a double-slit system, from each little gap, The arcs all expand, so they soon overlap. And when waves come together, they must interfere - They might both add up or they might disappear. It's not hard to determine (assuming coherence) The pattern that's made by the waves' interference. If the waves can all hit and then light up a screen, A series of light and dark fringes is seen. In Thomas Young's lab back in eighteen-oh-one, Young tried this diffraction with light from the sun. He saw all the fringes, and this observation Persuaded him that the correct explanation Of light is it's simply, entirely composed Of waves, not the particles Newton supposed. None could then argue: the pattern appears, And the wave theory ruled for some one hundred years. But the theory that light is just wave-like was wrecked When we first saw the photoelectric effect. As well as being wave-like, it's thought to be true Now that light comes in small massless particles too. It was therefore conjectured that matter could act As a wave and might therefore refract or diffract. And indeed the diffraction works not just with photons But also electrons (or neutrons or protons). And making this further bizarrely sublime, It works if they only go one at a time! Each single electron just makes a small dot, But after a while you'll end up with a lot. And if you can wait with enough perseverance, The dots will add up to show wave interference - With single electrons we see the same sight Of the fringes we'd normally make using light. This should befuddle you out of your wits, For it means the electrons all passed through both slits. It's not just not knowing which one they go through - To self-interfere they must go through the two. A particle in such an oddball condition Is said to exist in a superposition. You might think a detector could give us a clue, And tell us the slit each one really went through. But such an addition would come at a price: The forced interaction with such a device Will make the electron state start decohering, And quickly prevent it from self-interfering. The screen now will only show two brighter bits - One corresponding to each of the slits. Whether or not we can get all the fringes Displayed on the screen is a question that hinges On letting the "particle" act as a wave. If we find its location, we make it behave As a classical particle, thereby ensuring That all the results will be normal and boring. These experiments all with particular clarity Show us the concept of complementarity. We can only see one of the path information And wave-like results in the fringes' creation: We're given this choice and it's sad but it's true That the universe doesn't allow us the two. So from Young's demonstration in eighteen-oh-one, To all of the later experiments done, There's nothing so constant and no bigger hit In laboratory physics than Young's double-slit. Back to Menu
| The Industrial Revolution by Murray Baker Let's dig in the ground a really big hole, And extract fossil fuel called black coal, Crush it in a ball mill, grind it to dust, Maximise surface area we must, Furnace burns coal, Carbon reacts with air, Exothermic, makes megajoules to spare, For ΔHVAP, turn water to steam, Power all industry, that is the dream, Steam pushes piston, James Watt did decree, The power of horses, nearly for free, Waste goes up the chimney, no one will see, What happens next, what harm could there be, Watt's engine moves with an up down motion, Parson's turbine, the better solution, Smoothly rotates, an advance that he, Found was ideal to make electricity, In magnetic fields copper windings spin, Voltage and current in wires begin, Investing in infrastructure it pays, To exploit Nicola Tesla's 3 phase. The transmission grid throughout the nation, Distributes 50 Hertz alternation, At potentials to hundreds of kV, So you and I can... watch a DVD... play a PS3... make a cup of tea. Back to Menu
| A Haiku by Annette Spierings Galaxies collide A thousand particles dance Ripped from space and time Back to Menu
| Proof That Time is Relative by Lucy Waldron I've got proof that time is relative, I found it when I was eight. My own personal reference frame Where time does things I hate. It speeds up when I am sleeping, Goes even faster when I'm late, But slows almost to a standstill When I do things I hate Like standing up and speaking In front of you this way But nothing makes time go slower than that Awkward silence, When I have nothing left to say. Back to Menu
| Paradichlorodiphenyltrichloroethane first synthesised by Othmar Zeidler A mosquito screamed out in PAIN, A Chemist has poisoned my brain, I'll be dead tomorrow, The cause of my sorrow, Is Paradichlorodiphenyltrichloroethane. Back to Menu
| A Brief History of Orbital Mechanics by N Copernicus, J Kepler, I Newton and A Einstein I'm might burn in hell, the church is irate, I say 'round the Sun the planets rotate. Copernicus thought his orbits were round, Ellipse fits the data better I found. Explaining Kepler no effort was spared, Force goes with the inverse of distance squared. 'Bout Newtons gravity I've had a think, It is when space time develops a kink. Back to Menu
| PAIN Physics Poetry Night is This Friday by Murray Baker Only *FOUR* more sleeps to Physics Poetry night, If you haven't yet seen the light, Learn some optics nice and bright, Or the aerodynamics required for flight. Explain that Physics is really fun, How nuclear fusion in the sun, Which consumes Hydrogen by the ton, Is Earth's energy source number one, Write that poem and find a rhyme, For names of elements which sublime, Or standing wave patterns when bells chime, Start now, 'cause Friday night's the time! Back to Menu | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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