Is It Possible to Make a Sword So Sharp That It...

OK, there’s a scene in the movie The Bodyguard where Whitney Houston’s character and Kevin Costner’s character are at KC’s house.

WH grabs one of KC’s swords, removes it from its scabbard, and playfully holds its tip to KC’s chest. To demonstrate the sword’s sharpness, KC reaches toward WH’s neck and takes a silk scarf from her neck and tosses it into the air. The scarf lands across the blade of the sword and is gently sliced in half. Wow.

In a word, is this possible? I would think that for an instrument to be sharp enough to slice something as light as silk, with nothing more than gravity to move it against the blade, would require precise laboratory conditions and thus could not be repeated in someone’s basement.

Now, if KC had tossed a piece of ham into the air…

KC is always tossing ham in our general direction.

I wondered this as well. When reading Gullivers Travels I wonder how sharp a sword would become if it was taken for the giant place the sharpened by Europeans then taken to Lilliput for further sharpening.

Do we have the tech to make a blade that is one molecule thick at the cutting end, the two then four etc till we have a blade we can see?

I don’t think the scarf would have been cut in the way it was shown myself because there would not be enough weight in the scarf.

Do you mean in theory or in practice?

In theory, we have some technologies that allow us to make molecular-level creations, which could conceivably make a monofilament sword. Obviously, there are serious practical lmitations on this, not the least of which is actually keeping the edge - it can’t be sharpened back without totally rebuilding the edge, and will be awesomely weak.

ANy way, at that point, it would be really really sharp. If you want to get sharper, get yourself down to the Plank Constant width on the end of the blade. It will cut through air itself.

Do a search. We had the exact same thread with exactly the same question inspired by exactly the same scene only about 2 weeks ago.

Wouldn’t such a sword, cutting down past an atomic level have the nasty side effect of constantly blowing up it’s user in a nuclear explosion?

This is just the dramatization of a very old story about Damascus steel. In that story, a scarf or a pillow is tossed into the air and is sliced in two by the sword. Sounds like bragging to me. And a tall tale. The Damascus smiths must have loved it.

Is this not based on the meeting of Richard the Lionheart and Saladin? Richard broke a steel chain with his sword; Saladin did the silk hankie trick?

And the old Damascus steel story IIRC, in the down-pillow form, was inserted by Walter Scott into The Talisman. In the case of Costner/Houston, again IIRC, they use a Japanese katana, which shorthands to its intended public of 1990s Americans all sorts of samurai-ninja kewlness, as in, surely those mystical masters knew some metalworking technique that “rulez” (heck, even Japanese movies/tv/etc. propagate the icon of the “master” with a katana who can precision-cut your clothes off w/o scratching you, or slice you in half w/o you noticing it until your top half falls off your legs)

SWEET JESUS NO!!
You cannot sharpen a sword so sharp that a piece of silk will just slice in half from falling on it.

You cannot have an edge 1 or even a few molecules thick because it will dull (as every blade does) when you cut something.
Two quotes I am reminded of:

“Doesn’t anything work from the movies!?” - Homer Simpson
“I once sliced a piece of ham so thin you couldn’t even SEE it!” - Kramer
“…how did you know you sliced it?” - Elaine
“I…just naturally assumed.” - Kramer

Asked and answered two weeks ago

Then there is the subtle knife. One edge is sharp enouph to split atoms (IIRC), the other is so sharp that it can cut the fabric of space-time and open up dimensional doors. Now THATs sharp!

(Ok, really a Cafe Society post, but it is the sharpest blade I’ve encountered in fiction. From Pullman’s His Dark Materials trilogy)

Brian

You’re even more right than you know. If a blade gets to be that sharp, it will “go dull” on its own, without being cut, simply by virtue of Brownian motion of the metal molecules/atoms. Yes, very little motion actually happens, but at that level of “sharp”, very little is all that would be needed to disrupt such a perfect edge.

Would it be possible with very slight movement of the blade, causing a sawing action, as the silk touches the blade?
The experiment using cotton has the problem that though starting a cut in cotton is relitively easy, you have to continue generating the cut. By this I mean, with silk when a cut is started it is very easy to then pull the silk appart at the point of the cut, this isn’t true with cotton.
I still strongly expect some weight to be needed in the silk, but that would not be uncommon in a silk worn by a dancer, which would be weighted in order for it to move a flow nicely.