How to make a REAL lightsaber (or one close enough)

I dont know what forum to put this in but here goes:

Ive thought about this a lot and there seemes to be no way of making a lightsaber. Obviously. But has anyone had any ideas of how to make something of the sort? Something that would do the same job (ie. a laser that could chop off someones head without damagind the wall behind it). I understand it would be impossible to have one that clashes with other lightsabers, but I thought that you could have a large laser: (a large ruby tube with a flash tube wrapped round it) but with a convex lens on one end so the light traveles in on itself to a specific focal point about 3 foot away, then spreads back out making it weaker and weaker.

Has anyone else had their ides?

 

That still wouldn't work. If it was possible to do the same with heat without burning the absolute heck out of everything in the area, it might have the same effect. Or electricity. An immense static charge, maybe?

 

SWC?

 

Didn't some guys try making their own lightsabers....and you see how that ended....KABLAM!!!!

 

you speak of the two guys that made their own, had a mock battle and the tubes burst and burned them. Smart of them, endangering yourselfs and earning a hospital trip.

Light Sabers are possible, however the physics is long and complicated, I'm not about to write it out.