"The problem with the Lightsaber is that it's physics aren't properly understood according to how it functions. Theoretically, it creates a blade of hard light that can cut through anything. Physicists say it's anything from a blade of plasma to a blade of energy. The result: you actually have a weapon that all of it's weight is in the hilt. It is possible to have "hard" Energy. For this you need to understand the physics of Energy and Matter. If Matter is energy spent, then a Lightsaber is in-between energy spent and energy yet to be spent. Since we don't understand the Lightsaber, it's physics are beyond our understanding."
Sigh. There are 30 angels that dance on the head of a pin. No, there are 31. Wait, I've just realized, there are 29.
I've written an answer to the above:
"The lightsaber possesses what we would think of as an impossible density of energy, similar (but not as much as) the mass/energy ratio of a neutron star, except in this case the "weight" of the sword's energy/mass is exactly what the wielder needs it to be - it can never be too heavy or too light because the wielder's mind is the master of this energy. Thus the sword is always the PERFECT weight, perfect in a manner that manufacture cannot equal, as the sword is not made it is conceived. This conception, in turn, causes the energy to distribute itself along the weight of the weapon so as to create a perfect balance of action, so that the weight is not carried in the handle, it is carried at some point along the "blade" that exactly fits the requirement of the Jedi. As such, no weapon in existence can match the lightsaber as a potential extension of the user's arm and body. It only fails to seem as such in the films because films are inadequate to properly represent exactly how the movement of the lightsaber would appear in reality."
I so hate, hate, hate star wars.