Physics is kinda hobby of mine. A light saber is actualy pretty easy. I was checking on it. The only thing holding it back right now is the powersuply. I wouldn't go with batteries. Even the best would be too heavy for the amounts of power you'd need. Maybe slow-discharge capacitors. They're a ways away though. A better route would be an actual powerplant. We could build a suitable fission reactor right now. Expensive, but the technology is available now. I'd rather go with a diminutive fusion reactor, because they don't have meltdowns. Fusion is probably a century away, conservatively, though.
The blade itself is easy. Plasma in a magnetic field. We can do that right now too. You could even parry another lightsaber. Oh, and you could make precision cuts. You'd probably have a nob to adjust the blade type you wanted. You metalworkers/weldors out there can attest to the precision of plasma cutters.
The technolgy itself is simple. It's just a matter of money. They'd probably cost in the millions right now, mostly because of the nuclear reactor. If you didn't mind an extension cord, I coul build you one that plugs into the wall for a hundred grand, tops. Bear in mind, that's including developement too.
I don't know why people want to pound and pry with knives. That's not what knives are for. I cannot come up with a plausable scenario where a more appropriate tool would not be available/improvisable. That said, you could hammer with the handle, just like with your knife now. But screw hammering and prying! You can get an even better multi-functionality out of a lightsaber that you'd never get out of a steel blade. Firestarting!
I'm all for lightsabers. There's nothing fantasy about it. If I ever get the money, I'm gonna have one. Hell! I'll open a factory. These things are so easy that if everbody in cutlery circles chipped in, would could be mass-producing them now. Like I said, it's just a matter of money.
That said, I'd still see them mostly as a weapon with certain utility aplications. I wouldn't give up my steel blades. The only thing that could get me to give up steel is ceramet. And only ceramet. This ceramic stuff sucks. Ceramet is a developed and workable material we have now, Why people are messing around with ceramic is beyond me.
}, but fine shaving of fragile objects (paper, fingernails, most food, and such) just seems to cry out for a physical manipulable blade. Just look at the Klingons!
