In our research for our project film on Bad Physics in film, we discovered multiple clips that break some pretty simple physics rules. Here are a few of the clips we found and the data that says the physics is wrong!http://www.youtube.com/watch?v=4bSefSLaPFs
The above clip is from George Lucas’ Star Wars. What’s wrong with it? Well, first off, there are laser beams shooting from those spaceships, and that is not realistic. Even if deathly laser beams were real, they would not be visible because they would travel at the speed of light. These lasers would have to have pulsed waves because they would more energy to destroy a target. Because they are pulsed they are less monochromatic, making them colorless as opposed the reds and greens seen in the clip. (Data from our wonderful LTT class!) Another thing that is wronf with the clip is the explosions. Those can’t happen in space because there is no oxygen available to continue the explosion. You also would not be able to hear the explosion (or the laser beams for that matter) because there is no sound in space. This is because there is no gas in space to transmit the sound waves.
There are a lot of things wrong with this clip, but we’ll start with the man stopping the van 30 seconds into the clip. Not possible. Here are some calculations!
CALCULATION: p = mv; (2,700kg*27m/s) = 72,900 N*s (for typical ~6000lb van going 60 mph) ; (70kg * 4.4 m/s) = 308 N*s ( for typical 154 lb human with a running head start @ 10 mph to stop truck). The human would gain a lot of momentum in the opposite direction and the van would lose a small amount of momentum. Momentum is conserved. Human is crushed.
Of course sometimes, Physics in movies can be correct. The following clip is a ‘how they did it’ scene for the Guiness record-breaking car flip in Casino Royale.
The funny thing is, the car flip is definitely possible if used with the right machinery. At first, the stuntmen could not get the car to flip the way they wanted it to because of what they were using. Then they used some new things, as seen in the clip, and they car flipped a lot more than they thought it would. But if you were to watch the scene straight from the film, you would think it was naturally possible for a car to flip that many times just by swerving your car off the road. But you can not. You would need the proper equipment to do so.
There is more information, calculation, and resources to come later, but we don’t want to give it all away now!