We
all watch movies for many different reasons. Some people want to
escape, some want to be educated and some want to laugh; but no
matter what genre you love, above all we want to be entertained. And
sometimes directors choose to play with the laws of physics in order
to keep up that entertainment value. One principle they love to
experiment with is Newton's Third Law, which states that for every
action there is a equal reaction in the opposite direction. By
playing with this rule, directors can create interesting action
sequences, although maybe not very realistic. The genres such as
sci-fi, action and fantasy tend to do this the most often, but it can
be seen in almost any film. In the films Scott Pilgrim vs the World,
The Matrix and the TV show Firefly, Newton’s Third Law is ignored
in certain cases to enhance the drama of the scene.
The
film Scott Pilgrim vs the World is based on the graphic novel series
Scott Pilgrim by Bryan Lee O'Mally. The story centers on a young
Canadian musician named Scott who falls in love with Ramona Flowers.
However, in order to win her Scott must defeat Ramona's seven evil
exs who are coming after him one by one to try to kill him. The
director of this film stayed true to the story's original graphic
novel roots, so many of the fight scenes are impossible and over the
top to say the least. For example one of the exs burst into coins
upon death, and one grinds his skateboard so intensely he
spontaneously combusts. The fighting style was very much influenced
by video game style fighting, so there were many challenges in
bringing this story to life on the big screen, but most fans agree
that the director was very successful.
The
third evil ex that Scott has to fight is Todd, who posses psychic
powers thanks to his strict vegan diet. Scott and Todd are standing a
few feet apart, facing each other when Todd plays a note on his
guitar. The force of this sound-wave throws Scott backward, and he
crashes through a bench, 3 walls (at least on of them brick) and a
table before finally coming to a halt. As he is destroying all of
this property, the audience can clearly see Todd still standing in
the room, completely unaffected by the force of his music. Now
obviously this miraculous stunt is attributed to his mystic vegan
powers, and apparently vegans are immune to Newton's Third Law,
because this is not how the scene would have happened in real life.
The action force in this case is Todd's sound-wave pushing against
Scott. The reaction force would be Scott/the air between them pushing
back on the guitar and Todd. If the sound-wave was truly that
powerful, it would have blown apart the guitar at the very least, and
probably thrown Todd through a wall as well. However this does not
happen, and Todd doesn't even seem to be bracing himself or feeling
the effects of his music at all. In this case the director obviously
broke Newton's Law on purpose. This extremely unbalanced
action/reaction force fits with the film's comic book style and adds
intensity to the scene. Also, they had to go through quite a bit of
effort to get this shot, with CGI and wire work, so its clear the
director knew this would never happen naturally.
The
television show Firefly was only on air for one season, but it was
incredibly well done and still has a cult following years later. The
show follows a group of smugglers who work together on a spaceship
trying to make ends meet and avoid being tracked down by the
Alliance. The main character Mal and his first mate Zoe fought in
the war against the Alliance so they know their way around weapons,
and with their not-always-legal line of work they often have to use
those skills. The show is set in our universe, just with more
advanced technology, and for the most part it portrays things like
space travel and the fight scenes in a very realistic manner. The
space western theme lends itself very well to this gritty realistic
style of television.
However,
no western (space or otherwise) is complete without a shoot-out
scene, and there happens to be one in the pilot episode of Firefly.
Zoe each other. One enemy on
a horse roughly 10 feet away aims his shotgun at Zoe and hits her
square in the chest. She flys back several feet and lands flat on
her back on the ground. However, the man who fired shows little
reaction to the guns recoil. If the bullet's force was that strong,
according to Newton's Third Law there should have been an equal
reaction in the opposite direction, in this case pushing against the
man with the shotgun. Even if he was very strong and bracing the gun
against his shoulder, he should have been knocked off the horse to
the reaction force of the bullet. Of course, in reality his reaction
is appropriate, but the action force of the bullet on Zoe is
impossibly exaggerated. The forces simply don’t add up.
Now
don’t worry, she doesn't die because she was wearing a
bulletproof vest and she survives to pull of an impressive, yet
scientifically inaccurate, shot a few moments later. While still
lying on the ground, Zoe raises her neck and shoulders enough to
see a enemy trying to escape. She raises her pistol one-handed and
kills the man, all while still lying on the ground. This sequence in
particular caught my eye, because my friend owns that gun and I have
fired it at the range once. The gun is a lever action pistol know as
the “Mare's Leg” because of its impressive kickback. This gun is
meant to be fired from the hip with both hands, but for newbies like
me you can also fire it with both arms fully extended in front of you
at about shoulder level. Its important to keep the arms extended,
because if you hold the gun too close to your face it will hit you
and probably break your nose as you fire. When Zoe fires her arm is
extended, but she only has one hand on the gun. She also has her back
on the ground, with only her head and upper shoulders off the ground.
Her other arm is on the ground, so the only thing supporting her
upper body is her ab muscles. When she fires the gun, her body does
not react at all. Her arm doesn't jump up, and her upper body isn't forced back to the ground at all. The reaction force of the
gun pushing back on her should have had some visible effect, no
matter how strong she is. Now once again, I believe that the director
chose to film the scenes in this way to make Zoe seem like a
stronger and more powerful character. She was in the army for years
and survived when most of her unit did not. For the most part the
show's fight scenes have very realistic physics, so I think they can
get away with smaller inaccuracies like this.
The
Matrix is a film who's very plot is based on breaking and twisting
what we believe to be laws of the “real world”. The film follows
a computer hacked called Neo who learns that what most people
perceive as the real world is actually a simulated reality created by
the machines to subdue the human race so they can be used as an
energy source. Morpheus tells Neo that in the Matrix things like
gravity are simply computer programs, that can be bent or even broken
if you know how. Using this idea, the characters can jump impossible
distances, move extremely fast and even dodge bullets.
In
one scene Morpheus is trying to teach Neo this concept in a “training
program”. They begin to fight each other, with increasingly
impossible moves and actions. At one point Neo leaps forward while
kicking Morpheus several times. As he jumps and kicks his forward
momentum does not slow, and Morpheus does not react to the kicks at
all. He does block the kicks though, and the reaction force from him
blocking should be pushing back on Neo. This reaction force should
slow Neo's leap and alter its trajectory, but it does not and
therefore violates Newton's Third Law. This happens several times
throughout the scene. At one point Morpheus kicks Neo square in the
chest and Neo flys up and backward about 10 feet. Once again this is
a violation of Newton's Third Law, because the reaction force of Neo
flying away is not equal to the action force that was exerted on him.
Morpheus does not put much his body weight into the kick, so it
shouldn’t have been strong enough to send Neo across the room. Of
course, its difficult to call this movie scientifically inaccurate
when the characters themselves state the are purposely breaking the
laws of physics as we know them. The director is very aware of
Newton's Third Law and looks for places to break it, because it helps
strengthen the plot of the film.
The
laws of physics are often bent, and sometimes even broken, in most
action/sci-fi/fantsay films today. While it occasionally may be due
to ignorance, for the majority of these films I believe the directors
purposely go out of their way to exaggerate the natural physics of
fight scenes. They often will have unbalanced action-reaction forces,
with the action being too powerful and the reaction being very under-powered But it takes quite a bit of effort to have these
superhuman actions, and directors often use a mix of CGI, stunt
doubles and wire work to achieve them. Because they have to go
through so much effort, there must be a reason behind it. I believe
that most directors choose this style to make the heroes feel more
heroic or to enhance the drama of a battle scene. The main goal of
films is to be entertaining, and as artists and directors we have to
use every trick in our book to keep the audience engaged. As long as
the effects are well done, I have no problem with directors choosing
to play with the laws of physics from time to time.
