Ever watching a big effects movie when you come across a scene that you know just can't be right. I mean, Physics just doesn't work like that. According to two scientist's from Central Florida University , who wrote a 20 page paper on films ranging from Aeon flux to Xmen Last Stand, you were probably right. Check out this link to the article which was pulished in a German Scientific journal:

http://front.math.ucdavis.edu/0707.1167 it includes copies in pdf format which you can open if you have adobe acrobat reader on your pc. If you don't it can be downloaded quick a free from http://www.adobe.com