Is a Lightsaber a Practical Weapon?

[Rednog]

I don't think it would be practical, too many bad physics involved. For example say you try to cut through something, the molten parts are gonna fly all over, most likely landing on your hand which is holding the saber. Also it is questionable as to the actual physical forces on the blade. Say you try to cut through a moving vehicle, is there and equal and opposite force of blade vs car? If so you probably would break your arm.

1. Well, obviously if you swing fast enough, you miss all the hot moten-ey stuff...
2. No, there is no equal force on the blade. The blade is full of concentrated energy and awesome. It uses kinetic whatsits to tear the object it's slashing to all those tiny bits!

I have no idea. I honestly never thought about the F-ing laws of physics with these blades. Though I would imagine that if the blade is hot enough to melt or completely incinerate the material it hits, the force of impact on the user would be a lot less since the object being hit is disintegrating instead of being forcibly torn apart like with a physical blade. I see it like using a cutting torch on metal.

But no, like everyone else has been saying, without the force, a lightsaber is pretty much useless. Unless you just needed to chop the heads off of zombies, then it'd be perfect!

Something having molten parts fly at you doesn't really matter on swing speed. It is going to melt and splatter. People claim that the lightsaber is insanely hot and thus able to cut through anything with lightning speed, the problem with that however is that an object like that would definitely be radiating heat itself, making it damn near hard to hold, hell I bet the hilt itself would be glowing red or white.
Ok say the blade somehow instantly turns a physical object from solid to gas (despite various scenes from the movies which show items clearly doing more of a melt instead of burn to gas) that is a reaction that is going to leave the air around the person incredibly hot, possibly steam that is hot enough to burn the person.
There has to be forces on the blade, in games and moves if they hit a wall or the ground it doesn't just instantly cut through anything, it clearly has some rebounding effect, further proof is in episode 1, Qui-Gon is cutting through the door, he is physically pushing down on the blade with effort, he isn't just casually holding it there and letting the door melt.
And lightsaber hitting lightsaber, if it was just pure magic energy there is no reason a lightsaber should block another lightsaber, they should pass through each other, hell you see jedi vs sith battles and one or the other bashes the other one down while he or she is blocking, a clear transfer of forces. Also in some of the books discussing jedi training, apparently the blade can have its lethality changed, apparently the low setting turns it into a bashing like weapon.

Things from movies are great, but like anyone who has watched the mythbusters for any amount of time, you come to realize that physics is a huge downer, you just can't wielding amazing forces without huge draw backs.

 

[ad5x5]

Getting the light to stop is theoretically feasible - it would just take the correct manipulation of constructive and destructive interference.

The main problem is power.
Here's some rough numbers -

Energy required to melt/vaporise a 100g bullet made from lead -
specific heat capacity of lead = 0.13kJ/kg
melting pt of lead = 600K
boiling pt of lead = 2013K

assuming the bullet arrives at 373K (100°C)

E = m * c * deltaT

= 0.1 * 0.13 * (600 - 373) = 2.951 kJ to melt
= 0.1 * 0.13 * (2013 - 373) = 21.32 kJ to vaporise


now lets have the bullet coming from a berreta 92G-SD
muzzle velocity is ~380m/s
and assume the lightsabre has a blade width of 5cm

transit time of the bullet through the beam - so time for the bllet to melt/vaporise

t = s / v

= 0.05 / 380
= 1.32*10^-4 s

This means the power output from a lightsabre

P = (E / t )

= ( 2.951 / 1.32*10^-4) = 22356kW = 22.356MW to melt a bullet
= ( 21.32 / 1.32*10^-4) = 161515kW = 161.5MW to vaporise a bullet

To put this in perspective, Sellafield nuclear power station in GB produces 200MW.

So to vaporise a bullet as some people on here claim, each jedi would have to lug around his/her/its own nuclear power plant.

hardly practical.

 

[Captain Blackout]

Go take a few years of kendo, master the art,

While I appreciate that you probably weren't really trying to denigrate Kendo, I can tell you, as a student, that 'a few years' is not adequate to 'master the art' of kendo, any more than you could get a black belt in any of the more common martial arts in a few years.

Sorry, was trying to point out how many people were commenting who had no martial arts training and were talking out of their ass.

 

[Tears of Blood]

I think it could certainly be a practical weapon if you were trained to use it properly. If not, then you're likely seriously injure yourself, however.

 

[Aunel]

A lightsaber in real life would not have a stopping point.

It would just continue on in whichever direction it's pointed at.

Therefore, it would be completely useless, unless you had to take out an entire army.

useless?
are you crazy, you could chop a planet in half, from 6 solar systems away!
that is the most usefull weapon ever made by man.

OT: strings for my bass made out of light would be so awesome...

 

[sephiroth1991]

If you drop it your fucked (Clip from Robot chicken)

 

[Koeryn]

A lightsaber in real life would not have a stopping point.

It would just continue on in whichever direction it's pointed at.

Therefore, it would be completely useless, unless you had to take out an entire army.

It's a plasma jet controlled by future-magnets, not a laser. Actually, almost every 'laser' in star wars is really a plasma based weapon. Well, Sci-Fi Plasma based weapon...

 

[Macgyvercas]

If you have the Force, you are unstoppable with a lightsaber unless you get hit with a sneak attack (or Order 66), but even then there's no certainty. If you didn't have the Force, you could still use it, but it wouldn't be as effective.

Oh, and OP. Jedi would jump over the rocket.

 

[hebdomad]

In the hands of someone who can use it well, it's awesome. Also if they have the force. Seriously, facing a jedi, you can't shoot them with a rocket launcher (they force push it back), you can't snipe them (they dodge), and you can't shoot them with conventional guns (they deflect).

Well you could drop a large object on them... like a small moon. Edit ( wait thats no moon! )

 

[The_Blue_Rider]

A lightsaber in real life would not have a stopping point.

It would just continue on in whichever direction it's pointed at.

Therefore, it would be completely useless, unless you had to take out an entire army.

Well lightsabers arent actually made out of light, they are made out of some sort of plasma, i was confused about that too

 

[KyleThePirate]

lightsaber has no heft and would be insanely hard to handle, now you take into consideration that if it touches you your gonna get fucked up. I would say a lazer gun would be much preferable to a lightsaber unless you had the force and could wield it properly. oh and the light part of the light saber folds back onto itself at the point and returns to the hilt. that is why it doesn't continue going.

 

[Mozza444]

Lightsabers are just stupid.. i'm sorry. Give me a gun anyday.

 

[I Resurection I]

No light sabers are not practical, a beam of light would never be able to controled into a heat light that could cut off your arm. All it can do is get in you eyes.

 

[Robert632]

Pratical, yes(I'd imagine the only wieght would be the handle, making it quite light weight.
Feasible, no. ignoring the whole laser just stopping, its momentum might be a bit hampered, as momentum is mass times velocity.

 

[WestMountain]

Lightsaber + The Force + Incredible Jedi reaction times = Useful because Jedis can deflect bullets and rockets and do things with The Force, just for example its like a guy with Riot Shield on MW2 but he dont have to expose himself when throwing a knife and he have unlimited super knifes that make things go flying when they hit

 

[Joe Deadman]

I guess you could just use it to intimidate people I mean they don't know that you don't know how to use it properly it might also come in handy for welding and cutting through doors etc. But as an actual usefull weapon? Not unless your plan is to kill yourself before the enemy get a chance.

 

[Onyx Oblivion]

Not in the least. When you have telekinesis (The Force) WHAT THE FUCK IS THE POINT OF A LIGHTSABER? Jedi and Sith shouldn't get into CQC in the first place.

 

[MMMowman]

It has no limit on ammo and it looks bad-ass

 

[Imat]

A lightsaber in real life would not have a stopping point.

It would just continue on in whichever direction it's pointed at.

Therefore, it would be completely useless, unless you had to take out an entire army.

There are ways to make it stop. None of these are even hinted at in the movies or any of the books as far as I know, but there are ways.

Then again, suspending disbelief is fairly prominent here, considering men and women of every race get together and move things with their minds on a regular basis.

And being a Jedi is what makes the lightsaber practical. If you don't have the force and training you have no way of deflecting lasers or throwing it long distances only to have it pull a boomerang (Or get stuck in a wall...) and fly back to you (Or not...). Therefore the lightsaber is only truly practical, excessively so, with the caveat that the wielder is, in fact, a Jedi (Or other force sensitive individual).

 

[Double A]

If I can avoid hitting myself with a claymore, swinging it around like an insane beserker, I can probably avoid cutting my arm off at the shoulder with a lightsaber. And if I practice fending off Nerf guns for a few years I'm sure I can do it with real bullets!