Diamond sword that can cut through anything?

[Hypercube]

I just recently finished reading the last Eragon book, Inheritance, which I highly recommend everyone read, because it's awesome. Anyway, an interesting thing in the book was a sword made of diamond that was sosharp that it could cut through virtually anything. it was described as being 'the archetype of an inclined plane'. What exactly that means, I'm not sure, but I'm guessing it means that the thinnest point on the edge of the blade is only one carbon atom thick, and gets progressively thicker to form a perfect slant right down to the atomic level.

 

Now, obviously there is no way we could (or would) make such a blade with current technology, but I couldn't help but wonder; if such a blade could be made, and if its edge really was a perfect slant right down to a single row of carbon atoms, whether it could do what it could in the book. I have no doubt that it could cut through skin and flesh like a scalpel through warm butter, but what about stone and metal? Is that just pure fiction or could there be something to this idea, at least in theory?

[CaptainPanic]

Reminds me of a Discworld novel where death himself sharpens his scythe with ever increasingly soft materials to get the edge that much sharper. First a stone, then with a cloth, and finally it sharpens it with the air itself. lol.

 

What I'm wondering is how the bonds of the atoms at an edge of a diamond lattice would look. Normally, atoms in the middle of the structure are surrounded by 4 other atoms in a tetraeder. But at the edge, there are only 2 or 3, as you can see in any picture of a diamond lattice. So, where do the excess electrons go? Surely, it's not a radical with free electrons, is it?

I think it's more likely that a single atom thick edge is possible with a metal, which shares its electrons regardless of the position of the atom in the lattice.

 

Regarding all other practical problems: Humans are able to make 45 nm large features in computer-chip technology. Manufacturers are even looking (or already working with) 22 nm or even 11 nm technology. 11 nm is only about 100 atoms wide.

 

Scaling it to 1 atom would, I believe, be in the realm of possibilities... if it is chemically stable, then I guess we'll eventually be able to make it. But you surely won't achieve that with sharpening it. And I am not sure diamond is the right material.

Edited December 2, 2011 by CaptainPanic

[Phi for All]

The whole concept of sharpening a sword to razor thinness is pure Hollywood. While a thinner blade cuts better, it also is more easily damaged. If the only thing a sword needed to cut was flesh, razor sharp would be best, but if you encounter bone or metal along the way, a thinner edge is going to fold or flatten or nick very easily.

 

Even with diamond, if it's going to take any damage, the thinner the edge is the more easy it will be to damage it. In fact, diamonds themselves are cut by first carving a groove and then placing a steel blade into the groove, which is then struck on the back with a hammer. The same thing would happen to a diamond sword if its edge were so thin that it could easily be grooved by another blade or edge.

 

Steel is best for swords because they need to flex a bit to absorb the shock imparted when you hit something with it. Diamond would actually be pretty rotten at this. The octahedral crystals that form a diamond make them too rigid and firm for use as a sword. Even tougher metals like titanium are no good for swords (busted, Blade!), due to their rigidity. Steel can also be heat-treated which lets it hold its edge longer than other metals.

[StringJunky]

Japanese swords are probably the ultimate in combining the properties of razor sharpness and shock absorption without breaking:

 

http://www.scnf.org/forge.html

[Phi for All]

Japanese swords are probably the ultimate in combining the properties of razor sharpness and shock absorption without breaking:

 

http://www.scnf.org/forge.html

The combination of high and low carbon steels folded multiple times makes a sword that can survive being highly sharpened AND stressed by concussive blows.

[John Cuthber]

Surely the big problem is that diamond is brittle. You could shatter this "sword" with a good thump from a length of scaffolding pole.

[Phi for All]

Surely the big problem is that diamond is brittle. You could shatter this "sword" with a good thump from a length of scaffolding pole.

Exactly, no way to absorb the shock. And bone would probably shatter it even if the person attacking you had no wooden pole.

[imatfaal]

Exactly, no way to absorb the shock. And bone would probably shatter it even if the person attacking you had no wooden pole.

 

hmmm I would still prefer to be the one wielding it than the one using his skull to shatter it.

 

[clear thinking]

in fact I would prefer to be the guy behind - with a decent metal sword - ready to step in whilst the diamond sword geezer looks at his useless hilt

[/clear thinking]

 

[clearer thinking]

Nope I think I will be the guy observing from the sidelines

[/clearer thinking]

[Phi for All]

[clearer thinking]

Nope I think I will be the guy observing from the sidelines... with a crossbow.

[/clearer thinking]

FTFY.

[Appolinaria]

further proof that the forum should have an rpg system along with rep points.

 

 

+500 xp for Phi.

 

imatfaals level 5 elf crossbow has been upgraded.

 

 

BALLER

[Phi for All]

Hmm, I think imatfaal has distinct rogue characteristics. He "prefer(s) to be the guy behind - with a decent metal sword". Can he disable a trap, or pick a lock?

 

 

 

 

I think the OP is mainly talking about how a blade with an almost impossibly thin edge would hold up against metal or stone. Would it fold or would the atom-sized edge slip cleanly between the opposing atoms? Carbon makes steel strong but too much makes it brittle. Would an edge of single iron atoms alone be able to split stone or other metal?

[Hypercube]

Hmm, I think imatfaal has distinct rogue characteristics. He "prefer(s) to be the guy behind - with a decent metal sword". Can he disable a trap, or pick a lock?

 

 

 

 

I think the OP is mainly talking about how a blade with an almost impossibly thin edge would hold up against metal or stone. Would it fold or would the atom-sized edge slip cleanly between the opposing atoms? Carbon makes steel strong but too much makes it brittle. Would an edge of single iron atoms alone be able to split stone or other metal?

 

Exactly. The thing that most interested me about this sword (which incidentally was named Albitr, or 'Tinkledeath') was that it was implied that it did not need any sort of magical protection (yes, I do know that magic is fiction, but for the purposes of this post it basically means that there is little chance of it being damaged) because the blade was literally so sharp that it would almost never encounter any substantial resistance. Its wielder was able to literally slice through several feet of solid stone as if it were no harder than butter.

 

Now I know how absurd this sounds, but I still can't help but wonder whether there is ANY kind of truth to this idea even in principle, whether it is made of diamond or not is immaterial, as it is never actually confirmed to be made of diamond in the book.

[Fish 40]

I'm pretty sure this would only work with a material that was way stronger than anything else. The materials would let you down and the edge would be more likely to break the thinner it is, so it would seem as though you would need a material vastly stronger than any known to make this work as described.

[imatfaal]

Back to sensible mode - perhaps one of the practising biologists/histologists could advise how long microtome blades last? I seem to remember from histology labs in the distant past that microtome blades break up fairly regularly especially if the angle of attack was steep or operation was poor.. I know that high-end blades use gem quality diamond - but back at med school labs glass was the best they could afford.

 

 

Hmm, I think imatfaal has distinct rogue characteristics. He "prefer(s) to be the guy behind - with a decent metal sword". Can he disable a trap, or pick a lock?

 

I am definitely not the sort with the shiny armour and the loud voice in the foreground - especially with my newly upgraded bow

[Moontanman]

Exactly. The thing that most interested me about this sword (which incidentally was named Albitr, or 'Tinkledeath') was that it was implied that it did not need any sort of magical protection (yes, I do know that magic is fiction, but for the purposes of this post it basically means that there is little chance of it being damaged) because the blade was literally so sharp that it would almost never encounter any substantial resistance. Its wielder was able to literally slice through several feet of solid stone as if it were no harder than butter.

 

Now I know how absurd this sounds, but I still can't help but wonder whether there is ANY kind of truth to this idea even in principle, whether it is made of diamond or not is immaterial, as it is never actually confirmed to be made of diamond in the book.

 

 

have you ever read the Complete Book of Swords"? by Fred Saberhagen? great universe he created in that series....

 

http://en.wikipedia.org/wiki/Books_of_the_Swords

[Hypercube]

I'm pretty sure this would only work with a material that was way stronger than anything else. The materials would let you down and the edge would be more likely to break the thinner it is, so it would seem as though you would need a material vastly stronger than any known to make this work as described.

 

Why? If the blade of the sword really did taper down to an edge of atomic or possibly even sub-atomic thickness, it should be able to pass cleanly between the atoms of most any substance, shouldn't it? As I can't think of any natural material that is one atom thick.

[StringJunky]

Don't know anything about it but this seems to match the criteria for an awesome cutting edge that might cleave at molecular level:

 

* Graphene is one atom thick, which makes it the thinnest material ever discovered. It is a sheet of bonded carbon atoms densely packed in a honeycomb crystal lattice.

 

* At an atomic scale, it looks a bit like chicken wire made of carbon atoms and their bonds. It is almost completely transparent and yet also extremely dense.

 

* Graphene is highly conductive, conducting both heat and electricity better than any other material, including copper, and it is also stronger than diamond.

http://uk.reuters.com/article/2010/10/05/us-nobel-physics-graphene-factbox-idUSTRE6941ZP20101005

[CaptainPanic]

Why? If the blade of the sword really did taper down to an edge of atomic or possibly even sub-atomic thickness, it should be able to pass cleanly between the atoms of most any substance, shouldn't it? As I can't think of any natural material that is one atom thick.

In any solid material, the atoms of the material are still bonded to each other, and if you want to cut through this, you need to separate those bonds. The only advantage of a very sharp edge is that you don't need to physically move atoms right under the edge.

 

You still need to sever countless ionic or covalent bonds. And it would be a competition between the bond strength of the carbon atoms at the edge of the sword, or the silicon, oxygen, iron, carbon or whatever atoms of the material you try to cut through. And as I said, I expect the atoms of a diamond sword at the 1-atom wide edge to be bonded weaker than those in the middle of the lattice. But perhaps someone else would like to comment on that?

 

The theoretical minimum energy required to cut something is the enthalpy of reaction of the breakage of all those bonds in the lattice. But I don't know exactly what happens at the atomic scale of a fraacture when you break a rock...

Edited December 5, 2011 by CaptainPanic

[Tres Juicy]

Surely Graphene is your best bet?

 

Do you need to take precausions while handling graphene?

 

I would imagine you could give yourself one hell of a papercut with it...

 

Has any one here actually seen/used/played with some graphene?

 

I'd love you know

[CaptainPanic]

Surely Graphene is your best bet?

The big question, as has in different words been said a couple of times is: what makes you think that the graphene survives against a rock or a steel plate? Sure, it's thin, but it's just atoms against atoms. Why wouldn't the graphene atoms break off instead of splitting the rock or steel plate?

[Tres Juicy]

The big question, as has in different words been said a couple of times is: what makes you think that the graphene survives against a rock or a steel plate? Sure, it's thin, but it's just atoms against atoms. Why wouldn't the graphene atoms break off instead of splitting the rock or steel plate?

 

 

This is true,

 

but at least with graphene there is a way to test this out though...

 

Does anybody have any graphene I could borrow?

[Fish 40]

This might be going way out into the speculative, but if you REALLY wanted a super sword instead of just using guns like a sensible person, then what about a meta-material used in an electrically operated sword that is able to channel energy to the edge, like a more advanced version of a hot knife?

 

There already are in existence various kinds of meta-materials which can bend light in interesting ways. Is it possible to make one which can generate a focused laser like effect at the very edge of the material when provided enough energy?

[PerpetuallyConfused]

Now thats an interesting idea, but as far as capturing that energy and holding it on the outside edge of the single atom edge, and ONLY on the outside edge to ensure that that edge doesn't dull with use, now that's going to be tricky.

 

Imagine a situation where you are swiping the sword in front of you - light, with no especial container being on the OUTSIDE of the atomic structure - thereby negating any physical structure that could possibly be made - would therefore be subject to normal light behaviours.

 

This means that, if the lased light was emitted towards the hilt, and was propogated along one side to the tip, any time you changed its position, orientation or anything, the wavicles propogating to their initial vector would have no rule set up to guide them to the new vector caused by the change in the sword's position.

 

As far as I am aware, beyond focusing mirrors, there is no way of trapping photon wavicles in a magnetic field or similar construct. If it was possible to do that, and create and impossibly small thin tube along the edge of the sword, then yes - this could propogate a certain amount of energy to break the covalent and ionic bonds, but thats too close to a lightsaber not to just do it that way, IMHO.

[Hypercube]

This might be going way out into the speculative, but if you REALLY wanted a super sword instead of just using guns like a sensible person, then what about a meta-material used in an electrically operated sword that is able to channel energy to the edge, like a more advanced version of a hot knife?

 

There already are in existence various kinds of meta-materials which can bend light in interesting ways. Is it possible to make one which can generate a focused laser like effect at the very edge of the material when provided enough energy?

 

Actually I think Larry Niven utilized a similar concept in some of his Sci-Fi novels; I've never actually read them, but from what I've been told, an advanced alien race known as the 'Puppeteers' use some sort of material to build the hulls of their starships that they are able to remotely send energy to in order to prevent them from being damaged. If I'm not mistaken, the concept was referred to as 'powered structures'.

[khaled]

just a simple question: what if the sword blade is padded by a substance that keep the steel temperature really down, will that make the bindings in the structure stronger ?