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Movie physics
OK, so several of the comments about "what takes you out of a movie" involved really bad physics.
"Iron Man," for example, has several scenes wherein Mr. Iron Man falls or is thrown a tremendous distance, and yet somehow survives. He's thrown against concrete walls really hard and really fast, and survives high falls. Even if his power suit prevented bones from breaking, the internal damage from the sudden g-forces would be lethal - they would shear arteries, rip out organs from the surrounding connective tissue and reduce his innards to lumpy gravy.
And, yet, somehow, I really really liked this movie because everything else worked - the characters, the story, the effects, the action, the humor - it all worked.

Now.

Here's a trailer for a new Angelina Jolie action flick called "Wanted".
http://www.youtube.com/watch?v=7nqOoboHSQo
(Sorry, something wrong with lj settings and I couldn't cut and paste the link as usual.)

1. We see people "curving" a bullet, where you swing the gun around while firing. This curves the trajectory of a bullet so it can go around objects (like your friends) and hit other objects (your enemies). My understanding is that this wouldn't work - an object leaves another, rotating, object (like a shuttle launched from a rotating space station) at a tangent to the (mother) object's curved path. (A baseball, unlike a bullet, can curve because it is much bigger, moves slower and, most importantly, has raised stitches which cause turbulence - it also rotates at a much slower speed. A knuckle-ball, for example, doesn't rotate at all, which causes its random motion.)
At least, this is my understanding.

2. We see a guy in the middle of the street - Angelina's "pick-up." He crouches down as her car (very cool Dodge Viper) comes screaming down the street; the car turns to a stop, its door open and the car "scoops" up the pick-up.
Wouldn't this, in fact, break his legs?

3. In another scene, Angelina's path is blocked by police cars. She whips the wheel over, flipping over the Viper, through the air, over the cop cars, then landing and speeding off. (The last part I reconstruct because we don't actually see this, but we later see the car speeding off - though trailers are not necessarily time-linear in their arrangement of movie elements, I am assuming the car survived this trick to speed off.) My understanding is that this trick would do all sorts of mischief to your undercarriage and suspension system, if it worked at all.

So my questions for the great lj overmind are these:
A. These gimmicks seem to have no basis in reality - as if the movie takes place in a universe where our physical laws do not apply. Is this true? Am I understanding the physics right?
B. Even if this is true, all these scenes are really really really excruciatingly cool and make me want to see this movie very badly. They make me think that this could be one of the coolest movies coming out this summer. Is that bad?
Comments
the_ogre From: [info]the_ogre Date: May 4th, 2008 04:45 am (UTC) (Link)
A) You are in fact, correct. None of that stuff would work. And the blatant use of it might partially spoil my enjoyment of the movie.

B) This is not bad.
frankwu From: [info]frankwu Date: May 4th, 2008 05:53 am (UTC) (Link)
Yup. The bad physics are the only reason this movie exists - it's raison d'etre.
yourbob From: [info]yourbob Date: May 4th, 2008 05:06 am (UTC) (Link)
There is something called the "suspension of disbelief". As a viewer it is part of the contract. Look on these movies as fantasies, or science fantasies, or however you need to. They're meant for entertainment and not for education. :)

Oh - and while normally I'd agree on the Iron Man thing - woodpecker's brains do quite nicely thank you. So it's not impossible.
frankwu From: [info]frankwu Date: May 4th, 2008 05:54 am (UTC) (Link)
Good point about the woodpecker's head - but I suppose there are things (collagenous bands holding it in place?).

I thought the reason Princess Diana died was because her body hit a hard surface in the car, causing a sudden decrease in velocity, and her heart was ripped away from the surrounding blood vessels, and her aorta was all torn apart.

I always wondered if cheetahs, which run and stop very quickly, have something which holds their guts together for such activity?
lapswood From: [info]lapswood Date: May 4th, 2008 10:30 pm (UTC) (Link)
Ahem! You still used the word SCIENCE!
yourbob From: [info]yourbob Date: May 5th, 2008 02:36 am (UTC) (Link)
Since "science fantasy" is the long-established name of a genre, what would you suggest when refering to it while still making myself clear? Gobbleygook makebelieve?
lapswood From: [info]lapswood Date: May 5th, 2008 11:30 am (UTC) (Link)
Point taken. It's just when one has an understanding in Physics and how forces work than it hard to suspend my instincts to guestion what I'm seeing. Remember, Tony Stark is meant to be a gifted Engineer that understands how most things work!
amysisson From: [info]amysisson Date: May 4th, 2008 05:51 am (UTC) (Link)
I could be completely wrong, because it's been so long since the one time I saw a trailer for this Angelina Jolie movie, but I got the vague impression there was something Matrix-like about it, and that it in fact was NOT in our universe with our laws of physics. At least that's the impression I got with the curving bullet thing.

Could be that that was wishful thinking on my part, though. I can't remember much else about it.

frankwu From: [info]frankwu Date: May 4th, 2008 05:55 am (UTC) (Link)
Maybe. Then, again, iirc, it didn't say anything about the alternative-reality aspects of the matrix in the Matrix trailers, either.
howeird From: [info]howeird Date: May 4th, 2008 06:08 am (UTC) (Link)
Totally right about the bullet - also true of shotgun shot - otherwise skeet shooting and duck hunting would be a whole different challenge.

As for Ironman's g-forces, I'll go with the theory that the writers merely neglected to tell us his suit has compression technology built in. G-force suits are standard for high-altitude pilots, I'd use that fact as a "willing suspension of disbelief" starting point.
shaolingrrl From: [info]shaolingrrl Date: May 4th, 2008 06:29 pm (UTC) (Link)
Yeah, you're right, Frank. I don't think this is bad, though, because you know this won't work. What scares me is the kids who *will* try this at home.
frankwu From: [info]frankwu Date: May 4th, 2008 09:55 pm (UTC) (Link)
Hmm... trying this at home. That sounds like a GREAT idea!
lapswood From: [info]lapswood Date: May 4th, 2008 10:29 pm (UTC) (Link)
I was discussing The G-Forces in Iron Man just this afternoon with a good friend that saw it yesterday too. There's no was anyone could have survived that impact into the sand dune at that velocity. If you recall, he ends up buried to his waist. And the Lab test flight impacts. Forget it!
kmarkhoover From: [info]kmarkhoover Date: May 5th, 2008 01:33 pm (UTC) (Link)
Yes, you are understanding the physics correctly. You can't curve bullets and Hollywood ALWAYS gets the g-forces and results of acceleration all wrong. One of my favorites: a bullet fired from a gun that kicks the victim back ten feet. Impossible. The person firing the gun would experience the same result: basic physics.

Road Runner cartoons often have much better physics than anything that comes out of Hollywood.
arcanepackrat From: [info]arcanepackrat Date: May 6th, 2008 01:41 am (UTC) (Link)
If cars flipping around excites you then you're going to have to see speed racer as well. =)

As for #2 it depends on how fast the car was moving when it hit his legs, in theory if the car came to a complete stop just as it hit his legs it should only knock him over (and presumably into the car) but would probably still leave a bruise.

And the whole crushing thing with Iron Man, I haven't seen it yet but this is pretty common especially in super hero movies but also to a lesser extent in any action movie. The "hero" survives things that no normal person would be able to in the same situation.
dcotelessa From: [info]dcotelessa Date: May 6th, 2008 07:51 pm (UTC) (Link)

Ahh more physics..

Considering my hobbies, it always amazes me when people expect REAL physics in their entertainment. The fact that you are thinking about it really a bad commentary about the movie, not because it is more accurate, but that as an illusion, the movie has not convinced you that it is not important; we've lost any interest in the story and gone into the breakdown.

Movies (or Hollywood, as we have been convinced that all media comes from one place since the 30's) constantly and consistantly breaks physics. And I think for good reason, we all desire to break rules, even when those rules govern science. All we need in many cases is a construct and a reason to want to supersede it.

Since we are discussing bullets, it reminds me of the magic trick, the bullet catch. It is physically impossible to stop a bullet with your teeth without injury. Knowing that, magicians have set up an illusion that does just that. Yes, we can all assume a bullet is in their mouth beforehand, and just by knowing that, this should be a dumb trick. But it's not. Why? First off, we have a gun. Depending on who you are, you have a reaction to one, be it fear or lust. Prove that gun is not tampered in any way and that it is real, and logic starts to seem unsexy. Prove nothing is in the magician's mouth beforehand, maybe he's been training in some remote camp where catching arrows, bumblebees with chopsticks is par for the course. Point REAL gun in front of a person in front of a live audience, possibly with paramedics on hand, because something could go wrong; it has before. Maybe add some music, foreboding, a long pause to get ready, be sure to aim a gun that will make a loud noise towards a human being who is obviously nervous that this may not work, or trying to concentrate. Bang.

And you've been duped, and you want to be duped. Because you don't want to be that person in front of a gun, and yet something primal wants to believe he'll survive, that you could survive something like this too. As soon as you make a connection that love, truth, dedication, strength can defeat fear, evil, chaos or disaster, logic may not be important to you. And that's not saying technology or science can't get you close, but there are those with the desire to fly, to get the girl, to conquer death, to reverse aging, to see God, and those desires cloud logic. Throw in some smoke and mirrors and you've got a miracle.

I recall the slogan for the Superman movie: "You will believe a man can fly." No matter how impossible it may be, the belief that you'd see your comic book hero come alive and do it is probably more important than the "how".

Maybe the kid in "Wanted" should be bruised all to hell, if not fatally so. Our brains say it is logical. But if we somehow have a destiny that respects the memory of our father, gives us a power with weaponry than only a few have, be part of a secret society that not only monograms all their toys with cursive design and sayings but that kills off evil in the world, and gets us unscathed next to Angelina Jolie who has the hots for us in stretchy clothing and picks us up in an expensive car, and all I need to is believe I have that destiny..or wait..this kid has that destiny..then I won't get hurt? Ok, I'll bite.