The Sharpest Object Ever Made

ultracool writes "Forget the phrase 'sharp as a tack.' Now, thanks to new University of Alberta research, the popular expression might become, 'sharp as a single atom tip formed by chemically assisted spatially controlled field evaporation.' Maybe it doesn't roll off the tongue as easily, but considering the researchers have created the sharpest object ever made, it would be accurate."

Get dull?

[imboboage0]

Well over time knives get dull from use. unless I'm mistaken, this one atom could easily break off, right? Wouldn't it be instantly dull?

Aleut harpooner

[LiquidCoooled]

It sounds like science is catching up with the glass blades Raven carries in Neal Stephenson's book Snow Crash [wikipedia.org].

Dmitri "Raven" Ravinoff -- An Aleut native who works as a mercenary. His preferred weapons are glass knives - undetectable by security systems and reputed to be molecule-thin at the edges - and throwing spears. He travels on a motorcycle whose sidecar has been replaced with a hydrogen bomb that will automatically detonate if his heart stops beating.

On another technicality, isn't pencil lead actually made up of sheets a single molecule thick?

We could arm minjas [askaninja.com] (midget ninjas) with these molecular spears and graphite shurikens to make the real ultimate killing power even more ultimaterer.

Re:Nitrogen?

[Anonymous Coward]

At first I thought you were on acid. Then I took a sip of coffee and saw the genius in your statements. Well done.
 

Re:Get dull?

[MrSquirrel]

I don't think it would be very easy to just "break off" (you're talking about powerful electron-proton bonds). You could try and get the atom to bond with another atom... but it already has a pretty cozy home. A knife made of this would probably be pretty bendy at the blade... but it would still have a mean cut!

Re:Get dull?

[nacturation]

Well over time knives get dull from use. unless I'm mistaken, this one atom could easily break off, right? Wouldn't it be instantly dull?

"Such a pointy pyramid of metal atoms would normally just smudge away spontaneously..." I'll let you actually RTFA for the hilarious, biting conclusion.
 

Re:Aleut harpooner

[tinkerghost]

Microtome [wikipedia.org] blades for Transmition Electron Microscopy are either made from cracked glass (cheap & disposable, but I used to do 2 or 3 at a pop to get one with a clean break) or gemstone (emerald, saphire, and diamond) cleaves (longer lasting but fragile and pricy).
Oh and for nigh-trivial - check out National Geographic segments on this - it's a bitch & a half to get a consistant & usable blade (something sharp to accidently cut yourself with appears much easier).

One-atom tips are routinely made

[Animats]

The business end of a scanning tunneling microscope is often a one-atom tip. Those are made by cutting a wire of some suitable metal (tungsten, or platinum/iridium), hoping to get a sharp tip. Such tips look like this [purdue.edu]. As you can see, sometimes the break gives you a very sharp one-atom point, but the area around it is ragged.

The technology for making these tips is embarassingly simple. [nanoscience.com]

Electrochemical etching is used to make better-formed STM tips. [unt.edu] Electrochemical etching with STM feedback to determine when the best form has been reached does even better.

Re:Aleut harpooner

[Elvis Parsley]

I suspect we're talking about different things. It's fairly easy to get the sort of blade useful for the kinds of things Raven did. I never got past flakes and hand-axes myself, but I knew a number of people who got the hang of pressure-flaked blades pretty quickly. I'm entirely willing to believe that getting a useful blade for a microtome (I can see how consistency would be a very large problem) is an entirely different kettle of rocks.

How close does a katana come to this?

[Beryllium Sphere(tm)]

When a master sharpens a katana to the best standards of the art, the last step involves a polishing compound so fine that it has to be kept in water so it doesn't fall apart, and the edge is so thin you can see through the metal. (Yes, this process costs as much as a computer).

Googlespace, on my first few searches, didn't turn up any numbers for the edge of a katana. It's bound to be a long way from a single atom, but it would be fun to know just how close or far it is.

Re:Not really

[RedBear]

In other words, imagine two cones, both ending up in a bit of a section of a sphere. Except one is a 0.01 inch radius and the other is a 1 inch radius. What makes the first one sharp and the other one blunt? Pressure. Pressure equals force divided by surface. The surface rises with the square of that radius. So the first one needs 10,000 times less force to produce the same pressure. You can create enough pressure with your thumb to push a tack's small tip through wood, but you'd need an industrial press if you wanted to push a 1 inch steel ball into wood.


There should be a special moderation category for this kind of comment: "Score: 5, Excellent example of why Slashdot kicks Digg's ass and gets read religiously every day by hundreds of thousands of geeks even though the actual articles often suck".

I am less and less impressed every time some twit actually compares sites like Digg to Slashdot, as if they have anything in common besides posting links to geeky articles. I come to Slashdot every day to get insights from commenters who are more intelligent or more well informed than myself. I can pretty much be assured that, no matter what the subject of the article, if I read enough posts I will come away with a well-rounded understanding of it based on seeing several different well-written viewpoints.

Thank you for a very interesting post.