9 Laws of Physics That Don't Apply in Hollywood 807
Ant writes "Neatorama lists nine laws of physics that don't apply in Hollywood (movies and television/TV shows). In general, Hollywood filmmakers follow the laws of physics because they have no other choice. It's just when they cheat with special effects that people seem to forget how the world really works..."
Been there, done that. (Score:5, Informative)
The "Hollywood special" from a few moths back.
Intuitor (Score:5, Informative)
http://www.intuitor.com/moviephysics/ [intuitor.com]
Re:Outerspace is Cold (Score:5, Informative)
That one bugged me about a recent Battlestar Galactica, as well. Inside the room, the characters were freezing because the air was leaking away. (Thus cooling the room.) I can accept that. But once they're blasted into space? Not a chance of freezing. No air for cooling == no loss of heat. (Actually, you can still lose it slowly through black-body radiation, but that's another topic.) Human skin is pretty good at holding pressure, so the big things are:
- Don't hold your breath (unnecessary internal pressure)
- Close your eyes (they're more susceptable to decompression)
See the research into the Space Activity Suit [wikipedia.org] for more info.
also partially incorrect (Score:5, Informative)
until they burned out. old WWII radio dial markings from military gear have a lot of brown markings. they are radium paint with the phosphors all burnt out atomically, like a ghost image on a burned-in computer screen or monitor screen on an ATM. still radioactive and dangerous if ingested.
radium, polonium, radiocobalt, and other strong alpha emitters will emit a Czerinkon glow of blue when in the presence of hydrogen or water, which may be what you are thinking of. the blue glow is that of ionized hydrogen from the alpha hits, however, and should be thought of as a form of phosphorescence.
Re:Been there, done that. (Score:1, Informative)
Re:Outerspace is Cold (Score:4, Informative)
When you sweat, the fluids come from inside your body. Since they're already heated, they will carry away some of the heat when they vaporize. So you'd probably die of other causes long before you overheated.
In the Space Shuttle, however, the bay doors are opened for heat rejection when in flight. Unlike the "cold" problem we see in Star Trek whenever they lose power (e.g. TNG: Booby Trap), they're far more likely to overheat due to the heat rejection systems being inoperable. (Presumably, a ship like the Enterprise would have a circulatory system that would pump heat from the inside of the ship to the outer skin, where it would be rejected as black body radiation.)
Copper doesn't spark (Score:5, Informative)
silencers (Score:3, Informative)
Don't forget that you want to use a lower grain count in your rounds, to reduce muzzle velocity. The last thing you need is the "pop" of a supersonic bullet giving you away. To compensate for the reduced muzzle velocity, use a bigger caliber to get the same stopping power.
So: large caliber, reduced power round, flash/sound suppressor on the barrel.
Pet Gun Peeve (Score:5, Informative)
Re:Vacuums and Muzzle Flash (Score:3, Informative)
Mind you, the weapons master also told me that they often add other things (corn starch, non-dairy creamer, etc.) to enhance the flash when they're shooting movies, because most directors like the effect so much.
In fact, most of the explosions that you see don't use gasoline any more either. Apparently non-dairy creamer produces a much better (and less dangerous to store) explosion. In fact, if you put a one gallon jug of non-dairy (powdered) creamer around a flash powder charge, you can get a 30 foot fireball. (My dad worked in pyrotechnics shows.)
Mirror here (Score:2, Informative)
MIRROR [mirrordot.org]
Re:also partially incorrect (Score:3, Informative)
Re:Outerspace is Cold (Score:4, Informative)
Re:#4 and #5 (Score:3, Informative)
Without resistance, the vertical component eventually might dwarf the horizontal.
However, if you look at a movie like Pearl Harbor you'll see planes dropping bombs straight down without any horizontal component at all. There's no initial velocity with is dwarved or diminshed. There is simply a straight drop.
Re:Outerspace is Cold (Score:5, Informative)
The part you are referring to is heat transfer mechanism (1), conduction, as your body heats cooler air molecules around you. Mechanism (2), as occurs when those heated air molecules rise toward the top of the room making room for cooler ones, also requires air.
However, mechanism (3), the most effective of the three, does not require any medium at all. You, like all baryonic matter, emit electromagnetic radiation with frequencies and intensities as described by blackbody radiation, dependent on temperature. An object twice as hot gives of 16 times as much heat in radiation per unit time.
Normally, when sitting in front of your computer, you are radiating like mad, and so losing heat. However, so are the walls of your apartment. Those walls, being nearly the same temperature as you are, heat you to a large degree, making up for the heat that you are losing to radiation. Hence if, on a cold night, you are walking down a hallway in which one wall has a fireplace behind it, you immediately notice how warm the wall is without coming anywhere near it.
Considering that the "walls" in space are the 2.73K cosmic microwave background radiation, and that a person's temperature is more like 300K, you would radiate 10^8 times more energy than your receive. You'd freeze in a hurry.
Now, if there's a star heating you from one side, this can partially make up the difference. You still get the one-side-super-hot and one-side-super-cold problem, then, like the surface of Earth's moon writ small.
Re:What bugs me (Score:2, Informative)
Explosions are actually rather easy, and the software somewhat cheap (see Particle Illusion [wondertouch.com] for one such solution). One of the best showreels I have seen is Autodesk's [autodesk.com]. It goes to show that almost every work whose post-production goes further than clip rearranging and editing has effects of some sort; most of which you won't even notice.
Not really 'sparks' in technical sense. (Score:4, Informative)
The muzzle flash that comes out of a gun is superheated gas, the product of the powder's rapid combustion; a "spark" would indicate some form of burning / incandescently-hot large particles, and there really shouldn't be anything that big left after combustion. If there are big (enough to be visible) chunks of burning powder coming out the muzzle of your (modern) gun, you have some sort of problem. I'm not sure whether you'd even technically call a real muzzle flash a "flame," since it's not really burning anymore; the majority of the chemical reaction that launched the bullet, ran to completion in the first few fractions of a second after the primer detonated. On weapons with short barrels, the muzzle flash is visible because the exhaust gases exit the muzzle out into the atmosphere before they've had a chance to cool below the point of incandescence. I don't think there's really anything in the way of actual 'combustion' still going on.
Muzzle flash is another thing that Hollywood tends to exaggerate; although it's definitely an issue in real life, it's more difficult to see on a bright, sunny day than you'd expect from watching action flicks. FWIW, I think that they simulate muzzle flashes by using propane or methane, particularly for automatic weapons, in movies.
Re:Outerspace is Cold (Score:3, Informative)
Re:Outerspace is Cold (Score:4, Informative)
I would add that the author of TFA doesn't understand the physics of hand to hand combat very well. It is true that targets will not fly accross the room when kicked. In fact the better targetted the kick the less they will recoil. However, when kicking you are accelerating much of your body (hip, leg, foot) toward the target. The reaction has to overcome this momentum. Furthermore, if you use orthodox technique you have a connection to the ground specifcally designed to transfer the reaction through my musculo-skeletal structure into the earth (the emphasis on this base varies from style to style, but it always exists). In movies people are always jump kicking, but in real life that is of limited utility. You don't want to lose that connection to the ground unless absolutely necessary.
Re:Been there, done that. (Score:5, Informative)
M-14, the rifle from the Basic Training there in the first part is a 7.62mm caliber weapon, the M-16 is a 5.56mm
Steel cases, not steel jackets, IIRC. (Score:5, Informative)
You used to find this stuff under the "Wolf" brand name, and it was mostly made in Russia and some other ex-WP countries. I think Wolf may be trying to move upmarket and has ditched the steel-cased stuff, recently though.
At any rate, the bullets in that stuff were pretty standard at least that I ever saw, but instead of using a brass case, as is used in most Western countries' ammunition, they went with steel cases, covered in some sort of paint and lacquer (assumedly for rust-proofing). There were a number of issues with it, particularly in close-tolerance weapons. First was just the threat of damage to the chamber because it's a harder metal (although I have doubts about this), more significantly was that if you blasted a bunch of it off rapidly, you could get the gun's chamber hot enough to start melting the lacquer off of the cartridges, and over time, build up a layer of lacquer inside the chamber, that would change its dimensions, and lead to feed problems, particularly if you switched back to other types of ammo.
I know a number of people who got burned by the lacquer-buildup problems, because they had AR-15 style rifles with tight-tolerance chambers (the
Re:Pet Gun Peeve (Score:5, Informative)
After firing 800 rounds with one magazine, the actors start talking to each other calmly.
Try this, fire 4 rounds from an AR-15(or M-16 if your lucky) with no earplugs.
Now try to hear ANYTHING.
Your ears will be ringing like churchbells.
The 5.56 is such a high pitch that it rings your ears very easily.
Flying kicks (Score:3, Informative)
Not only that, but it fails to take into effect the masses of the two individuals. Just like I could push, kick, or punch a ball away from me, a person with enough mass can in fact repel a person of smaller mass over a certain distance. Perhaps not across the room and partway through a wall, but most people could already figure that part out.
Still, whether it's a person or any other object, it all comes down to friction, angle, and mass. I semi travelling at decent speed can send a small car flying, especially if it manages to "scoop" it with a certain angle. A mid-sized person braces right can propel another person away, and a larger person (well, more massive) can do so to a greater extent.
As to the shotgun blasts blowing someone across the room, I've never shot anyone or anything at close range with a shotgun, but it might work against a smaller person/animal. With a really big gun held by a really massive person (properly braced) it would possibly stagger the shooter while propelling the shootee...
Re:Steel cases, not steel jackets, IIRC. (Score:3, Informative)
As a matter of fact, almost all the steel cased rifle rounds I've seen have steel bullet jackets too, though there are a number of brass cased rounds with steel jackets too (I've got a few boxes of Sellier & Bellot
If you need proof, pull the bullet and stick a magnet to it
That being said, I've noticed that *most* of the steel cased ammo is rifle ammunition. I don't shoot cheapy stuff in my handguns though (I shoot a lot of oddball loadings so I generally just press my own rounds).
Re:Copper doesn't spark (Score:2, Informative)
Re:Been there, done that. (Score:3, Informative)
Re:Been there, done that. (Score:3, Informative)
Again, mythbusters is TV, do not try to take anything they "prove" as some sort of fact. Half the time, they don't seem to have any real intention of finding out if something can happen, just making a big mess and some explosions. It is entertainment, not science.
I dunno. I think their demonstration with the .50 caliber was pretty conclusive. I don't have a hard time imagining that a supersonic round would disintegrate on impact with water. As you obviously know, a .22 doesn't even compare to that.
The general pattern was that the slower bullets penetrated further. Sure, the "experiment" wasn't exactly scientific but I buy it.
Re:Pet Gun Peeve (Score:3, Informative)
Re:Pet Gun Peeve (Score:3, Informative)
How do you know, you weren't talking lauder after firing?
You missed his/her first paragraph — about talking to each other calmly. Combatants don't do that — not with own side, not with the enemy.
Re:Pet Gun Peeve (Score:4, Informative)
My pet peve with holleywood is mortars, they drop a 81mm down the tube and they put a little ploop on the sound track that sounds like a wine cork being pulled. a 40mm grenade launcher like a M79 or a M203 makes a little ploop but a mortar goes Ker-fucking-Boom loud enough to slap your cheeks against your gums.
Re:Pet Gun Peeve (Score:3, Informative)
That theory fits when the enemy is throwing concussion grenades. Those just make a godawful loud bang and displace a lot of air (hence the loud bang of course). The purpose is that the shockwaves will force the enemy down, either by the force of the blast, or by laying down like you heard.
The other type of grenade, the fragmentation grenade, produces a smaller bang, but if you're in the blast radius, you're screwed, because it showers hot, sharp fragments of casing everywhere. If you're in the blast, you'll be hit, lying down won't save you.
Of course, lying down to avoid the blast effects of a concussion grenade won't help much, as you'll be prone against the inevitable close assault that follows a concussion grenade attack.
Side note: this assumes explosions in more or less open spaces. In enclosed spaces the lethality is reversed, the larger blast making the concussion grenade more lethal.
Mart