There is a stone that when broken correctly produces a blade one molecule thick, making it extremly sharp. (I Believe it to be Obsidian) If there were a blade like this made out of diamond, it would effectively cut through most normal cutting substances, but if the blade could be only one atom thick, and as strong as diamond, then it could theoratically cut through anything at a atomic level.-- krigre55, Jan 29 2010 Monomolecular Wire http://en.wikipedia.../Monomolecular_wire"Various Imperial and alien technologies in the Warhammer 40,000 universe use monomolecular blades or wire offensively." [Jinbish, Jan 29 2010] Absurdly Sharp Blade http://tvtropes.org.../AbsurdlySharpBlade"...have edges only a single molecule wide, letting them slice through otherwise impenetrable materials." [Jinbish, Jan 29 2010] It would also dull extremely quickly, possibly from the effects of entropy itself. []-- DrWorm, Jan 29 2010 You have been smoking the ganj, theoretically.-- ShaneSezWhat, Jan 29 2010 Hey, no. He Believes.-- DrWorm, Jan 29 2010 I'm not going to tag it, but I would suggest this for a widely known to exist/bad science. Monomolecular edges are extremely common in science fiction.
The problem with a mon-atomic edge in diamond (or any carbon compound, is that at one atom thick, diamond does not (cannot) have a full orbital. It will bond with just about anything, and oxygen is one of it's favorites.
In general monatomic edges are going to dull as soon as they make contact with anything, including air. Monomolecular are better, but will still dull the moment they cut anything.-- MechE, Jan 29 2010 Yes, widely know to exist in science fiction. I thought the sharpest edge was slate, but often wondered if graphene could be sharper. Stephenson went with correctly broken glass in "Snow Crash" and Wikipedia backs him up, but also mentions diamond blades are even sharper, but as others have mentioned here, also dull quickly. Personally what I used to dream about was an object made from a single atom with a 1 dimensional nucleus made up of strong bonded helium nuclei, which besides being insanely heavy (short lengths could weigh as much as planets), would also cut through ANYTHING except Cosmic Strings and maybe even them as I would think the bonding would be stronger and more stable with the added Neutrons.
I also had a short SciFi story idea about creating a double bonded string of carbon atoms. Further researched showed that others have tried, but the carbon atoms ended up with triple and then single bonds, so never reached the strengths of nanotubes.-- MisterQED, Jan 29 2010 so....hmm... regarding sharpness, what if the edge exuded electrons which did the cutting (okay, separating), leaving the atoms to just sit there.-- FlyingToaster, Jan 29 2010 I have a knife with a blade thinner than a single atom. In fact, you can't even see the blade it's so thin. It can slice through anything (even diamond - I have tried).
It leaves such a clean cut that the interatomic bonds are severed and left dangling but are not disturbed, so that the cut object re-bonds and heals itself after the blade has passed through it.-- MaxwellBuchanan, Jan 29 2010 How crude. Mine doesn't even sever the interatomic bonds as it goes through.-- pocmloc, Jan 29 2010 Lasers are better at cutting through anything.-- Inyuki, Jan 29 2010 //if the blade could be only one atom thick//
If it's just one atom thick, it's not diamond. It's graphite.-- ldischler, Jan 30 2010 No, it's both.-- MaxwellBuchanan, Jan 30 2010 diamond is an Isometric-Hexoctahedral (wiki!) and thus any face presented by a true diamond is at maximum as wide as the face of a c6 hexagon. Hardly wide but certainly more than "one atoms width". If super-sharp blades were useful we should see more of them in nature and yet we do not.-- WcW, Jan 30 2010 //A knife that can cut through anything//
Another atom blade?-- MikeD, Jan 31 2010 //any face presented by a true diamond is at maximum as wide as the face of a c6 hexagon//
This makes me wonder how sharp a Fullerene blade would be.
From Wiki; The van der Waals diameter of a C60 molecule is about 1 nanometer (nm). The nucleus to nucleus diameter of a C60 molecule is about 0.71 nm.
Microscopically serrated.-- 2 fries shy of a happy meal, Jan 31 2010 if you could get it to assemble with only a single facet face then it would have a natural serration. The depth of the serrations would be less than the width of the blade however.-- WcW, Jan 31 2010 //If super-sharp blades were useful we should see more of them in nature//
Do we see lots of wheels in nature? (Only one example I can think of.)-- mouseposture, Feb 01 2010 Are they really that useful?-- WcW, Feb 01 2010 random, halfbakery