Science Buddies: "Ask an Expert"

I’m doing a Lightsaber project for the science fair (3rd grade). I was wondering:
• Can a laser beam be short like a sword?
• Could a lightsaber have enough power and could it have a cooling system?
Do you have any insight to these questions or any resources for me? Any other suggestions? Thanks!

peztopia,

Welcome to the forum and thank you for the great question. Since the development of the laser, and of course popularised by Star Wars, this has been a question. There are a lot of physics considerations of how to contain the energy required to make a blade of pure energy. The short answer is that laser light cannot be contained in this manner. However that doesn't mean a lightsaber type weapon couldn't be constructed. Dr. Michio Kaku, host of the scifi channel show Sci Fi Science, The Science of the Impossible actually has an episode where he explores that very question. I've included a link to that episode, about 25 min. He comes up with a plasma blade that has many of the characteristics of a lightsaber, but within the bounds of real physics.

http://www.dailymotion.com/video/x1gqyu ... saber_tech

Good luck,