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jelliott

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  1. jelliott

    FIFA Physics

    By jelliott,

    FIFA 15 has recently been released, and it claims to have pretty good physics. For that, they can thank last year's edition, FIFA 14.

    Now, I (and another user on this site, whose name I will refrain from mentioning - you know who you are, Dan) have played a good amount of FIFA 14. For some reason or another, though, we haven't really delved into the physics of its engine, the "next-generation" EA Sports Ignite Engine. Whether or not the recent engine is a marketing ploy is irrelevant in this discussion (though it probably is) - here, we're just going to talk about how, according to gaming and scientific blogs alike, FIFA 14 got their physics right.

    My AP-C pals and I are doing dynamics right now, and for those of you who have taken a look at the retarding/drag forces stuff, you'll probably feel a little nauseated when I mention...well, drag forces. Don't worry, don't worry, I'm not going to pull any derivatives out on you or anything like that. But I will mention drag coefficients, because they're vital in FIFA 14's gameplay mechanics. Before this game, balls kicked would travel in a strangely floaty type of way, like they were balloons. They would basically travel in near-perfect parabolas, with no wind or air resistance affecting its path of motion in the slightest. Basically, the ball accelerated at a set rate regardless of its initial velocity.

    So according to EA (voted the worst company in America until Time Warner Cable overshadowed it), some "intense research and auditing" of game mechanics came into play. And guess what? They got the drag forces wrong! Yeah, the drag coefficient of a spherical soccer ball was miscalculated in the engine. Or maybe it was just a typo. Either way, how it slipped testing for over a decade is pretty impressive, especially considering one of these games gets made every year.

    When a soccer player (or footballer, depending on your location) kicks the ball, it often dips and swerves in various directions. Due to this faulty coefficient, though, the ball would swerve inaccurately. By miscalculating the force of air resistance on a swerving ball, the Magnus force (Newton's 3rd Law) was also miscalculated. I say Newton's 3rd Law because the Magnus force, the force of air on the ball, is equal to the force of the ball on the air.

    Anyway, here's hoping that game physics improve with each new edition of FIFA. And maybe we can stop stuff like this from happening.

  2. jelliott
    Because everyone else was doing video game physics, so why not?

    First off, let's address something. What does Super Mario World for the Super Nintendo have to do with quantum/theoretical physics? Not much, right?

    Well, I stumbled across an article on mentalfloss.com, which I'd recommend looking at if you're at all interested. http://mentalfloss.com/article/17994/super-mario-world-quantum-physics-lots-fun

    It describes how some anonymous gamer (with a lot of time on his/her hands) programmed a playthrough of a Mario level where all previous attempts were superimposed upon each other. This level is gruelingly difficult, so the player dies a lot, but eventually one of the Marios survives the level, one out of...a lot. Here's the clip.


    So, it's just a bunch of Marios who die, and one of them survives at the end. What does this have to do with theoretical physics? Let me just define some stuff briefly, and I'll get to the point soon enough.

    The Schrodinger's cat paradox is a theoretical experiment where a cat is locked in a sealed box with a radioactive source, a cat, and some poison. If a monitor in the box detects radioactivity, the bottle of poison breaks, and the cat dies.

    But, a certain interpretation of quantum mechanics (named the Copenhagen interpretation) would state that in this scenario, the cat could be simultaneously dead AND alive. But obviously, if you looked into the box, you wouldn't see some zombie-cat-hybrid thing; you'd see a cat that was either alive or dead. This moment demonstrates the point where quantum superposition (scenarios "stacked" on top of each other) collapses, and one of two courses of reality takes place. Either the cat's alive, or it's dead. It can't be both.

    BUT WAIT...THERE'S MORE

    The many-worlds interpretation of quantum mechanics says, yeah...the cat is alive. It's also dead. But it's alive in one universe, and dead in another, and these two universes have nothing to do with each other.

    So is it true, then, that there can exist infinite universes, one for each possible scenario of every decision or event ever? That's where Mario comes into play. The death of all those Marios represent a bunch of universes where he failed to complete the level. But, if there can be universes for every scenario, he has to survive at least one...right?

    Well yeah, he does! That universe, where he survives, is represented by the final Mario left at the level's end. The programmer stated that this entire program demonstrates the MWI (many-worlds interpretation). And it does, to some extent, even though obviously not every possible outcome of Mario was shown here. But it's enough to prove a point.

    So the next time you get really ticked off when you die in a video game, just remember...somewhere, there's a universe where you succeeded.
  3. jelliott
    One of the most interesting (and most challenging) techniques of playing a guitar is effectively utilizing a pinch harmonic (the aptly named "squeal"). It is typically used in metal music, as the heavy distortion used in amplifiers can greatly increase the sound of the otherwise subtle harmonic. Eddie Van Halen, for example, used this technique often, and well; an overwhelming number of his solos feature it. Take, for example, his iconic solo in Michael Jackson's "Beat It" (this obviously is a cover, but is nearly identical to the original):


    At around 0:24 is that awesome, squealy pinch harmonic that metal guitarists and enthusiasts love. I think it's pretty awesome myself. So what's "physics" about it? More than you'd think, and more than I'd thought. Obviously, guitar strings have a fundamental frequency when they are being played open (no fingers on any frets). They also have overtones when frets are being played (the harmonics higher than the fundamental). The strings even have those fun little nodes, points in the standing wave of the string that have the minimum amplitude. All of these are vital to the pinch harmonic.

    The technique involves lightly touching the thumb to the vibrating string, immediately after the string is picked. By doing this, and essentially "interfering" with the string's vibration, all fundamental frequencies and overtones are muted - unless the frequencies happen to have a node on that particular fret. Something interesting to note is that to make a pinch harmonic exactly an octave higher than the fret you are playing, you must pluck the string directly between that fret, and the bridge of the guitar. Doing it somewhere else will yield a different, yet equally cool, squealing sound.

    Guitarists like Eddie Van Halen and Joe Satriani use the "divebomb" - using a whammy bar to alter the bridge during a pinch harmonic, thus drastically changing the frequency of the harmonic. This can only be done with very heavy distortion. For a textbook example, I'll use Joe Satriani's "Satch Boogie" - check out 0:32 to see what I mean.


    Pretty cool, huh? So next time you listen to a Van Halen solo, or your favorite metal shredder, or even good ol' ZZ Top, keep this in mind - I'm sure you'll notice this technique!
  5. jelliott
    They said senior year would be a breeze. To avoid such a horrifying prospect, I decided to indulge in AP-C Physics, which, as they say, is one of the most challenging classes the school has to offer. But, as the Chinese proverb goes, "The gem cannot be polished without friction, nor man perfected without trials".

    I am not taking AP-C Physics simply because I enjoy torturing myself with hard problems. In actuality, I hope to be able to tackle hard problems step-by-step. There is always a logical process to everything, and that idea alone is why science exists. So, knowing this, I hope to increase my arsenal of processes this year.

    AP-B Physics was my most challenging class thus far, but also my most interesting one. The idea that this sometimes chaotic world can operate in such mathematical order is still pretty incredible to me, and I took this class to further understand the relationships that exist in the world around us. It's quite nifty.

    I'm definitely nervous to solve more complex problems than I ever have before, using calculus. Calculus is still some obscure, evil concept to me. And on that note, I'm excited to be able to utilize it and learn something that I will hopefully use throughout college and beyond. To quote another proverb here: "Just when the caterpillar thought the world was over...it became a butterfly", and I look forward to becoming a beautiful physics butterfly this year.

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