How would you design a sci-fi sword?

[NecronLord]

Inspired by some of the discussion on swords in off-topic, what factors do people think would be best emphasised in a sci-fi sword?

Assume you have to make this to kill a wide variety of things, be worn for prolonged periods of time and therefore be somewhat comfortable, and so on. Likely opponents range from small robots to other humans to big alien acid bleeding bugs, or whatever else you fancy; your objective is to make a general, rather than specialised blade. You've say, Star Wars/Warhammer level of portable lightweight energy sources and materials technology.

This is not a discussion about the feisability of sci-fi swords: assume for whatever crazy reason you have to use one, or want one because it's fashionable, not for real use (though it should still be usable, in order for their to be a discussion) and so on.

To avoid the obvious: no lightsabers.

[adam_grif]

I'll mention the whole monomolecular edge thing to get it out of the way. Starts out with several layers of 1 molecule behind each other, then a few atoms of two, then three, then four.... until it reaches macroscopic size. Main questions are "can it be built", "would it really be as effective as monomolecular whips/what have you are presented as in fiction", "how durable is it" and "how do you stop it from cutting through it's sheath?"

As for the last question, perhaps the edge can retract back and be housed on the inside of the blade. That of course means the inside is not entirely solid, reducing strength.

[NecronLord]

I imagine if you were doing a 'monomolecular' blade, you'd probably need to have the scabbard 'sharpen it' to maintain such a level of thinness or something, given that it would begin to erode immediately on being drawn. This assumes you don't have some kind of stasis field or whatever protecting it. Of course, even blunted somewhat, that is surely likely to remain a very, very, sharp object.

I'm honestly not sure how monowire is meant to work; I'd think if a single molecule line cut through someone's arm, the disruption would actually be minimal without some other damage mechanism.

[adam_grif]

Well, the idea is that it's only 1 molecule wide for a few layers back on the edge of the blade, then it starts spreading out to 2,3,4,5... etc molecules thick, so driving it into somebody would work exactly like it does with a normal blade, only it would be the "sharpest possible blade", since sharpness is based on the thickness of the blade's edge.

Otherwise it's very conventional.

[Ghost Rider]

Saddest particular is lightsabers are the finest option. No need to sharpen, no fancy breaking of the material involved. Small package, and has other funtions then simply being a blade.

If anything, you shape the said sword to being more like an axe or knife that modern militaries use. Have the function be for a more conventional use with the addition of being a last resort melee weapon. Simply use whatever super alloy/metal/superium.

[adam_grif]

Having recently played No More Heroes, the Beam Katanas there are at least a little more plausible than lightsabers (barely), by having actual metal framework with 2 generator things at either end, so at least the beam has a reason to be limited length-ways.

[NecronLord]

Saddest particular is lightsabers are the finest option.

Well, yes, but the point is rather to see how people would make something more in the warhammer 40,000 style, and what particular historical designs they would adopt, rather than to just say 'energy beam' and call it a day. It is of course, a wasteful idea, but you can be certain writers and filmmakers will continue putting bladed weapons in their sci-fi for some time, regardless.

Hence the question about how people would implment actual swords in a sci-fi setting. Not knives - because I don't imagine the knife going out of use for a very, very long time; any future will doubtless have future-daggers of one flavour or another. They make perfect sense; swords are rather more exotic, and I'm wondering how practical they could possibly be made, without resorting to precognition or energy shields a la Dune, etc.

[Ghost Rider]

Saddest particular is lightsabers are the finest option.

Well, yes, but the point is rather to see how people would make something more in the warhammer 40,000 style, and what particular historical designs they would adopt, rather than to just say 'energy beam' and call it a day. It is of course, a wasteful idea, but you can be certain writers and filmmakers will continue putting bladed weapons in their sci-fi for some time, regardless.

I understand the point which is why I recommend if people want, look toward how militaries do it. Make a utilitarian object then build from there. It at least gives a reason not to go leap at what fancy whatever metal but first it's logical uses then use said attributes to form a better whole rather then having an bauble that hangs on the belt.

The lightsaber point is that it is a small object with melee purposes, because even with the fanciest abilities, running around with a weapon that is over a meter or two long in ranged arena is damned silly. Much better have something that is concealed with the ability to become said 1.5 meter object.

[NecronLord]

Mmm? So the point is size in general then? I suppose that certainly something retractable would be ideal, but obviously short of actually making a lightsaber, you might end up with something that either compresses, along the lines of the fighting pikes in B5, or something that telescopes, like Sulu's sword in the new Star Trek film. At least, I think that telescoped, maybe it unfolded...

[Ghost Rider]

Mmm? So the point is size in general then? I suppose that certainly something retractable would be ideal, but obviously short of actually making a lightsaber, you might end up with something that either compresses, along the lines of the fighting pikes in B5, or something that telescopes, like Sulu's sword in the new Star Trek film. At least, I think that telescoped, maybe it unfolded...

Size is the biggest problem after usage. If anything a world that has melee combat, you want something that won't mark you as Ninjedu fighter off the bat.

B5's telescoping staff filled it pretty nicely when I think about it, given they gave them suprising endurance and the fact they could have other purposes, as well general concealment. Sadly, I don't remember what Sulu's sword was....I am hoping it did something of unfolding or something.

[Ford Prefect]

Having recently played No More Heroes, the Beam Katanas there are at least a little more plausible than lightsabers (barely), by having actual metal framework with 2 generator things at either end, so at least the beam has a reason to be limited length-ways.

You know, until Travis gets the five bladed beam bird cage. Something quite similar to that appears in Mobile Suit Gundm SEED in the form of the anti-ship swords that a few people are packing. It's a fairly cool and unique visual motif for a series that otherwise has no positive visual motifs, but in practice they weren't much different to generic beam sabers.

Of course, if we are prohibited from just saying lightsaber/beam saber then you can't go past your usual vibrating sword.

[NecronLord]

It is very strange I think it's the same thing as the helmets in 'Stargate' - which is to say, inexplicable in how they get all that stuff in there. It appears to unfold, but also parts seem to disappear. On screen, of course, it was fast enough that you just got the impression that it snapped out from somewhere.

[NecronLord]

Of course, if we are prohibited from just saying lightsaber/beam saber then you can't go past your usual vibrating sword.

I'm never actually sure how vibroblades and so on are meant to work, are they meant to have little teeth or something that tear flesh? The original(?) Heinlein appearances seem pretty uninstructive in what the actual mechanism is, too.

[adam_grif]

As I understood it, it's supposed to have the blade vibrate super fast, and this somehow means it can cut through anything?

Nope, no idea.

[Shroom Man 777]

Like a turkey carving knife?

Personally, I'd use a T-1000 for a sword. Super-advanced intelligent metal that can make itself as sharp as a mono-edged blade, and can configure itself to all sorts of shapes and forms. I can make it look like a katana, a broadsword, a tiny knife, a big meathook, a butcher's knife, a screwdriver, anything!

[adam_grif]

I was always amused that the T1000 couldn't make "complex machines", but had no problem forming a human body complete with moving eyes, mouth, voice synthesizing and musculature. Obviously it isn't the same internally, but it's still a bit odd.

[Blayne]

I understand the speculative nature of the discussion and that swords being practical weapons in non rule of cool settings being extremely unlikely and implausible is probably obvious to us but I think that we must consider scenarios why would you need to rely on a sword and when would you rely on a sword when gun type weaponry is probably superior assuming equal technological progress in materials? Technology capable of making a monocular or vibrosword would also probably be capable of projectile monocular bullets which might be infinitely more practical assuming our potential enemies are armoured to the point it is required.

However I do recall a plausible scifi usage that seemed realistic at the time. Side arms on a spaceship.

Using both the Babylon 5 justification for not having projectile weapons and the Turtledove World War series justification for why the Race had swords in space is understandable, when in a space ship it might be possible that spraying around closed sealed cabins might do something that goes boom.

I could see swords capable of easily cutting through space suits and mobile power armor as being feasilbe in a situation where its tactically preferable to board and capture enemy ships, in this case it will probably be something reasonable in size and hopefully easily controlled so you don't hurt your comrades.

So as a kind of assault weapons for in spaceships or maybe even in HEV walks outside a station or ship?

Another possibility though assuming we allow soft science scenarios is that assume we have either advanced projectile weapons or laser weaponry we could probably justify swords if the technology existed to A) Jam lasers and B) jam bullets in some way over a suffiently large area.

Assuming average prevelence then a rifle type standard weapon might still be the backbone weapon but a sword equipped to front line soldiers just in case.

So not too big or over the top, probably averaged sized or tailored to individual soldiers.

[adam_grif]

If you can rig a pulsed laser weapon so that it spectrally analyses the cloud after a pulse is fired to determine optimal firing frequency or wavelength (say, some kind of dial-a-wavelength laser), then you can paint the interior of your space ship a specific, proprietary color, and set your guns to "stop firing + give a warning" when it detects that.

A far simpler solution is just to use low penetration weapons like shotguns.

[Ryan Thunder]

I was always amused that the T1000 couldn't make "complex machines", but had no problem forming a human body complete with moving eyes, mouth, voice synthesizing and musculature. Obviously it isn't the same internally, but it's still a bit odd.

I always assumed it was just a specialist program.

[Guardsman Bass]

I'd probably go for something reasonably strong with an edge that doesn't dull easily and a blade that doesn't rust. Some type of reasonably lightweight and strong metal with a diamond-coated edge (or something of equal hardness), possibly in segments so that the blade has some "give" to bend. Couple that with some type of rust-resistant coating.

[adam_grif]

Is diamond even very sharp? I know it's used in drills, but that's got more to do with it being hard than sharp. Any thoughts?

[Lord of the Abyss]

A few ideas:

One idea I saw used in a Robert Silverberg novel ( for a knife not a sword ) had a blade edge that was actually a double edge on the microscopic level. When activated each microedge had an extremely powerful electrical charge of opposite polarity, so anything the blade edge touched got ripped apart on a molecular scale by the opposite charges bridging the microscopic gap.

Laser edge. The sword edge is made of some very strong transparent substance; when you hit something a flat laser ( 2-d lasers do exist ) fires from the edge into whatever you're hitting.

Laser sword. When active, a powerful laser shines between the hilt and a small reflective device that levitates at a specified distance from it, to keep the "blade" from just keeping going. This assumes the Star Wars style technology to make a fast little flier like the training drone Luke had to deal with in A New Hope. Obviously this has the limitation that you can't stab or parry with it, just cut. You can also run a charge though the ionized path though the air created by the laser for a "lightning blade".

Powered sword: As above, also assumes you have the Star Wars level tech to make a small fast flier. This is essentially such a flier that you hold in your hand. The "sword" is actually literally flying in response to the guidance of your hand, feeling essentially weightless and striking much harder than human muscle power could. Note that you could design this with a "dancing sword" mode where it fights on its own. Or where you throw it and it flies true, hits much harder than you could with a normal sword, then flies back to your hand.

Buzzsaw blade: The blade edge consists of many very small spinning saws, counter-rotating to each other to prevent some of the problems of a 40k chainsword.

[open_sketchbook]

I would recommend a good old-fashioned heavy sea saber or cutlass as a base design for a more traditional sword design; it's stylish, designed for fights with limited room, has a curved blade to take full advantage of a monomolecular design, it's got a thick, tough blade and some oomph behind it, and they are practical single-edged weapons for ease of handling and maintainance. Every officer in a space navy should have one.

[Coyote]

Some sort of liquimetal design, like Shroom said, similar to the T-1000. It would also transfer more mass to the tip of the blade as you swung it, adding heft to the chop, so you'd slice right through shit easier. The blade could transform into a machete style (broad, stubby, and tough) or a kukri, or an axe, broadsword, even an epee, etc. And the blade would be eversharp, being able to reform itself even after each chop.

[Oni Koneko Damien]

I was always amused that the T1000 couldn't make "complex machines", but had no problem forming a human body complete with moving eyes, mouth, voice synthesizing and musculature. Obviously it isn't the same internally, but it's still a bit odd.

There's a world of difference between mimicking the three-dimensional shape of something and having a wide range of vocal abilities, and being able to mimic the chemical reactions needed to fire bullets and power explosions. I'm pretty certain the T-1000 could easily make a part of its body into something that looked, sounded and moved exactly like a rocket launcher, it just couldn't actually fire rockets with it as that involved a chemical reaction its body wasn't capable of producing.

As for the OP, I'd actually concentrate on something that looks more like a shield than a sword. Assuming reasonably unlimited access to magi-wank technology, an arm-mounted energy shield that could easily alter its size and dimensions to provide necessary coverage from small arms fire to explosives, 'anchoring' itself to the entire body in general to mitigate the kinetic force of small arms fire, or the nearest sturdy surface for anything larger. And if you were close enough, you could still easily bash someone over the head with it.