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Physics in the Movies

nucal writes "Here's a site rating Insultingly Stupid Movie Physics. A really thorough site with a rating system which ranges from GP (Good Physics) to XP (Obviously physics from an unknown universe)." My vote goes to the helix of M&M's.

17 of 480 comments (clear)

  1. Crikey, yet another meaning for "XP" by IvyMike · · Score: 4, Funny

    Windows XP, eXtreme Programming, XPCOM, eXperience Points, "Cross Platform", and now this. It's got to be one of the most overloaded acronyms of all time.

  2. Hey! No fair! by philovivero · · Score: 5, Funny

    They give the coveted GP == Good Physics award to Seven Years in Tibet...?!?! Like... okay? How about we give other coveted Good Physics awards to Lolita, Joy Luck Club, Pi, True Stories, and Office Space since they were so full of projectile cars, falling, laser beams, and other physical effects that could be modelled poorly???

    Then they go and say the Matrix had questionable physics, despite the fact that a key element of the plot is that the physics of the world are simply rules in a computer which Morpheus so eloquently describes: "some can be bent, others broken."

    I'm gonna just have to go ahead and disagree with you there.

    1. Re:Hey! No fair! by Lemmy+Caution · · Score: 5, Interesting
      You didn't actually click on the specific film reviews, did you?

      7 Years In Tibet had a very accurate representation of the physics of a pendulum, as well as bullets that didn't spark. His complaint with the Matrix wasn't about the physics within the Matrix, it was primarily about the humans-as-batteries nonsense.

  3. Sniper Rifles by lommer · · Score: 5, Interesting

    I liked the comment about the sniper rifles and laser sights, mostly because they're wrong. They were correct in stating that the army doesn't use LASER sights for sniper rifles, however, as an army friend was recently telling me, they now use a form of IASER for sights.

    The IASER basically paints an infrared dot as opposed to a visible light dot, thus it can't be seen with human eyes. But, If one is looking through the infrared sight of a sniper rifle, it is clear as day. Thus, one gets all the advantages of a laser sight without letting the victim know of his impending death ahead of time.

    One thing to note though, is that these sights are only really practical on sniper rifles, as one would have to be wearing infrared goggles for them to work on normal guns.

    1. Re:Sniper Rifles by Eol1 · · Score: 5, Informative

      No. Not at least for US spec ops.

      IASER is only used in regular infantry units from what I have seen and then only for night fighting. Prob is they show up bright as day in with PLAIN OLD NOD's. Has the same problem as tracers, they draw line back to the shooter. From what I have seen they are using these to replace tracers to solve the tracer visible line issue. Works great -v- 99% of our lowtec opponents though (who don't have NOD's). Sux just as bad as tracer -v- high tech opponents. Needless to say, this is A BAD THING(tm) if you an actual sniper where concealment is vital.

      Snipers I have spotted with all use good old plain scoped crosshair sites, though some like the dotted reflex sites. Key thing with both these is they ARE PASSIVE. This is a key requirement for snipers, you don't need to give you position away. Active snipers are reg. infantry sharpshooters...THEY ARE NOT ACTUAL SNIPERS. (Though they think they are). Giving a guy a rifle and a scope doesn't make you a sniper.

      --
      De Oppresso Liber
    2. Re:Sniper Rifles by Ryan+Amos · · Score: 4, Informative

      This is sort of right. Laser sights are pretty much only useful for close range fighting, where a soldier would need to "shoot from the hip" while maintaining some semblance of accuracy. Snipers often do use IR lasers, however, they don't use them as laser sights. That's what they have a scope for. The lasers are used as rangefinders, so the sniper can tell how far away his target is and adjust his scope accordingly.

      The problem with lasers is that they basically say "Look! Here I am!" And with infrared nightvision available for under $1000, it's not a stretch to assume the enemy has it as well. IR scopes are also not as common as you would assume. Their range is limited compared to a conventional scope, plus they're a lot heavier.

      One other thing to note is that extreme distance, a laser would be utterly useless for aim on a rifle anyway. Keep in mind the bullet travels on independent axes, both forward (inertia of the bullet) and DOWN (force of gravity.) At longer ranges, the bullet's path is going to look more like an arc than a straight line. Last I checked, lasers don't arc. This brings me back to the rangefinder. If your target is 1500m away (not inconcievable with say, a .50 cal rifle) the arc of the bullet is significant. You have to adjust your scope to compensate for the range (thus why you need to know how far away the target is.)

      Another use of IASER sights is to have special forces operatives "paint" targets with the laser for use in bomb targeting systems. This is much more effective than painting the target from the plane itself, as the forces on the ground can keep a better hold on the target and there's minimal risk to them, as they're not actually firing any rounds (and thus the enemy isn't looking for them.)

      So, essentially, the detriments of using a laser sight on a sniper rifle far outweigh the benefits. The main problem is that it compromises the snipers location (his best weapon) while not being very effective. Rangefinders are only in use for a fraction of a second, and aren't likely to be spotted. Lasers, even IR lasers, are stupid as sights at long range. The only ops who actually use laser sights do so at very close range (say, less than 20 feet.) At that range, your presence is already compromised, the bullets won't arc, and you can get a split-second faster target acquisition. But on sniper rifles they really have no point.

  4. Episode II, seismic missles in space? by Fastball · · Score: 4, Interesting
    While I liked the sound effects of those seismic missles used in Episode II: Attack of the Clones in the asteroid belt, I immediately began to wonder if that would actually be possible since space is a vacuum. There's nothing for a seismic or concussive blast to move through, right? No air, water, or anything with mass.

    If you set off some sort of explosion outside the space shuttle for example, would the force of the explosion move through the shuttle?

  5. Explosions in space by SVDave · · Score: 5, Insightful
    I am reminded of what J. Michael Straczynski, creator of Babylon 5, said about the sounds of explosions in space in B5. He said to think of it as music. In the real world, there's no music in the blackness of space, playing dramatically as ships go by, but even physicists don't get upset when they hear music in space in the movies. So think of the sounds of the explosions as music, added for effect.

    BTW, I was mildly amused by the ego on display in their review of The Matrix:

    The Matrix had real potential as a cerebral thriller. ... We would have preferred less oracle mumbo jumbo. ... The Matrix fails to meet its potential because it just can't leave the artificial science in the computer simulation along with the artificial intelligence.

    Somehow, I don't think the creators were aiming to make it a "cerebral thriller". If the maintainers of intuitor.com didn't like The Matrix, that's fine, but they should review the difference between "fails to meet its potential" and "fails to meet your expectations."

  6. Ahem. by Doktor+Memory · · Score: 4, Informative

    God forbid that I attempt to defend Trek physics, but I'm not sure why you believe that the orbital velocity of any spaceship has much of anything to do with the mechanics of doing an EVA or a hull excursion.

    Yes, a ship in orbit around a planet is moving at several thousand miles an hour, with the associated inertia. But guess what? As a fringe benefit of being inside the ship during liftoff and orbital insertion, so are you. Your own body's velocity relative to the planet does not suddenly change as a result of stepping out of an airlock. You'll stay close to the ship until you apply some force to push yourself away from it -- hence the little backpack-mounted gas jets that Shuttle astronauts use for EVAs.

    As far as the boots are concerned, they didn't strike me as terribly unrealistic. Put an electromagnet in the sole, and a pressure switch inside the top of the boot that switches the magnet off when you apply enough upward pressure on it with your foot. Et voila.

    Orbital EVAs are incredibly tricky things; just not for any of the reasons you describe here.

    --

    News for Nerds. Stuff that Matters? Like hell.

  7. This page is great! by Procrasturbator · · Score: 5, Funny

    Nitpicking makes a movie better! Every time I'm watching TV with my friends, and I see a physical error, I pause it with Tivo, and draw out a diagram of how it cannot happen. My friend threatened to shoot me with an Uzi for doing this, but I reminded him that a Mac 10 is what the REAL action heroes use.

  8. Worst movie error by Alsee · · Score: 4, Interesting

    In my oppinion about the worst movie error was in "Voyage to the bottom of the sea".

    In this movie the Van Allen radiation belt above the earth catches fire, slowly roasting the planet. Pretty silly, but that's not the mistake I mean. In a rush to save the planet the nuclear sub Seaview races under the polar ice cap. The Icecap begins to break up from the intense heat and we get to see huge chunks of ice come crashing down on the sub...

    Think about that scene a moment. Submarine a hundred or so feet under water. Blocks of ice raining down and hitting the hull. What's wrong with this picture?

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    ICE FLOATS!

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    - - You can't take something off the Internet! That's like trying to take pee out of a swimming pool.
  9. Star Wars Death Star Physics by vile7707 · · Score: 4, Interesting

    Quoted directly from this page "Lawrence Krauss, in the book Beyond Star Trek, points out that an object with a quarter of the moon's mass, parked in geostationary orbit would create a tide producing gravity force 25 times higher than the one caused by the moon. This would flood coastal areas and disrupt geological formations resulting in earthquakes and volcanic eruptions, not to mention extreme weather changes.

    According to Krauss' calculations these disasters of biblical proportions would only be the beginning. If it took the mother RV an hour to slow down, the energy released by its engines would be about 10 times greater than the entire luminosity of the sun. We'd be fried before the aliens even arrived. In the movie, however, we are somehow miraculously spared from these inconveniences"

    So I guess the Death Star needs no giant laser cannon to destroy planets just grab a handicapped spot in front of any planet and watch it rip to shreds.

  10. Re:Outrunning the sun by Spock+the+Baptist · · Score: 5, Insightful

    Arrrrrgh! No! no! no!

    Mr. Ebert confused the speed of the shadow of an object on Earth with the speed of the Earths Terminator.

    Here's my e-mail to Mr. Ebert...

    Mr. Ebert recently wrote in his review of THE MUMMY RETURNS:

    "4. I have written before of the ability of movie characters to outrun fireballs. In "The Mummy Returns," there is a more amazing feat. If the rising sun touches little Alex while he is wearing the magical bracelet, he will die (it is written). But Rick, carrying Alex in his arms, is able to outrace the sunrise; we see the line of sunlight moving on the ground right behind them. It is written by Eratosthenes that the Earth is about 25,000 miles around, and since there are 24 hours in a day, Rick was running approximately 1,041 miles an hour."

    Mr. Ebert is in error.

    Mr. Ebert has over-simplified the geometry, and physics of the velocity of shadows generated by the Sun.

    While it is true that the Earth's rotates with an angular velocity of ~7.29e-5, and thus has a tangental rotational velocity of ~1041 mph, it is manifestly untrue that a shadow cast by mountains, canyon walls, etc. also travel at 1041 mph.

    The velocity of the shadow is a function of not only the Earth's angular velocity, but also of the hight of the object, the time of day, as well as the time of year.

    Consider the shadow cast by a flag pole. The length of the shadow is infinite at sunrise, but at local noon it will be at minimum at local noon. If the pole is located along the equator, and it's an equinox the the shadow will have a length of zero. Thus in six hours the shadow will have gone from infinitely long to infinitely short, thus having an average velocity that is infinite. (It is written by Zeno of Elea) A second example may serve to make my point a bit better. Consider the same day, and the same flag pole, but this time let us stipulate that the flag pole is 100 feet tall. As 09:00 local time the Sun will be 45 degrees above the horizon therefore the shadow will be 100 feet long as the oppsite, and adjacent sides of a 45 degree right triangle are equal. Thus, in the three hours between 09:00, and 12:00 local time the shadow of the flag pole will have moved 100 feet. Thus, the average speed at which the shadow will move in this period will be 100 feet / 3hours = 33.33... feet per hour, or ~0.0063131313... mph. Manifestly, this is very much less that 1041 mph.

    --
    "Oh drat these computers, they're so naughty and so complex, I could pinch them." --Marvin the Martian
  11. Re:What timing by mfago · · Score: 4, Insightful

    "Crouching Tiger Hidden Dragon" was a Chinese fable.
    i.e. not meant to be taken literally.

    It is a great movie once you keep that fact in mind.

  12. How does they know these things are unphysical? by rsidd · · Score: 5, Insightful
    I'm not at all impressed by their movie reviews. Take AI, which gets their worst rating: they're not impressed that the robots are self-sustaining, "what about energy, refuelling, rebuilding?" They claim it violates the laws of thermodynamics. Well, first law -- how do they know it's being violated? Maybe the things run on solar energy, or geothermal energy, or some such thing which is not inexhaustible but is "forever" on the timescales we're concerned with. Second law -- the earth is not a closed system, it constantly gets energy from the sun. Second law doesn't apply. Maybe they have automatic robot factories which run on solar power, it's not impossible.

    That wasn't the only example. He can't conceive of a machine which can act as a helicopter and a submarine at the same time -- but a hundred years ago people couldn't have conceived of helicopters in the first place. Why should he evaluate everything by present-day technology?

    The Phantom Menace review was even worse. There was no real "physics" being objected to, only stuff like "if the force field can stop water, why doesn't it stop humans who are 80% water?" If we don't know how it works, how can we pass judgements on such things? Perhaps it actively detects the presence of humans or biological objects. Perhaps it only stops liquids and not solids. Perhaps any number of other explanations.

    Remember Clarke's third law: "Any sufficiently advanced technology is indistinguishable from magic." Conversely, in the movies, anything which looks like magic could be the product of sufficiently advanced technology.

    Overall, I'm not impressed.

  13. Anime physics by Megane · · Score: 4, Funny
    And then there's anime physics.

    Like how you can jump on missiles in the air, and then they keep going in the same direction without deflection. All attacks must be called out by name, even if they're as simple as pushing a button on a control panel. The best pilots have hair that completely covers one eye. And of course, all the usual Hollywood ones like the guns that never run out of ammo (unless it's a plot point to run out of ammo), and the Stormtrooper Effect (best parodied by the Rambo scene in UHF.)

    Don't even get me started on the Laws of Anime Cooking.

    --
    #naabhaprzrag, #sverubfr-000, #agi-fcbafberq, negvpyr[pynff*=' negvpyr-ary-'] { qvfcynl: abar !vzcbegnag; }
  14. Re:26 Facts Movies teach you by God!+Awful · · Score: 5, Interesting

    That's great, but I think we've all seen this list before.

    When NASA first started sending up astronauts, they quickly discovered that ball-point pens would not work in 0 gravity. To combat this problem, NASA scientists spent a decade and $12 billion developing a pen that writes in zero gravity, upside down, underwater, on almost any surface including glass and at temperatures ranging from below freezing to over 300C.

    This is another moldy oldy, and what's more, it's wrong:

    NASA never asked Paul C. Fisher to produce a pen. When the astronauts began to fly, like the Russians, they used pencils, but the leads sometimes broke and became a hazard by floating in the [capsule's] atmosphere where there was no gravity. They could float into an eye or nose or cause a short in an electrical device. In addition, both the lead and the wood of the pencil could burn rapidly in the pure oxygen atmosphere. Paul Fisher realized the astronauts needed a safer and more dependable writing instrument, so in July 1965 he developed the pressurized ball pen, with its ink enclosed in a sealed, pressurized ink cartridge. Fisher sent the first samples to Dr. Robert Gilruth, Director of the Houston Space Center. The pens were all metal except for the ink, which had a flash point above 200C. The sample Space Pens were thoroughly tested by NASA. They passed all the tests and have been used ever since on all manned space flights, American and Russian. All research and developement costs were paid by Paul Fisher. No development costs have ever been charged to the government.

    -a