The Cellar - 8/21/2006: Close-up of the world's sharpest man-made item

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- - 8/21/2006: Close-up of the world's sharpest man-made item (http://cellar.org/showthread.php?t=11533)

8/21/2006: Close-up of the world's sharpest man-made item

http://cellar.org/2006/sharpestthing.jpg

axlrosen finds it here and I think it was boing boingd as well.

Looks huge to us in this image, but this is a tungsten needle: so sharp that the individual round globe-like things you see there are individual tungsten atoms. From the article linked at the source,

Quote:

The Sharpest object yet made is a tungsten needle tapering down to about the thickness of single atom.

The needle, made by postdoc Moh'd Rezeq in the group of Robert Wolkow at the University of Alberta and the National Institute for Nanotechnology, starts out much blunter. Exposed to a pure nitrogen atmosphere, however, a rapid slimming begins. To start with the tungsten is chemically very reactive and the nitrogen roughens the tungsten surface. But at the tip, where the electric field created by applying a voltage to the tungsten is at its maximum, N2 molecules are driven away. This process reaches an equilibrium condition in which the point is very sharp.

I guess. The article also says that the needles will be "superb electron emitters. Being so slender, they would emit electrons in a bright, narrow, stable stream."

It all seems very impressive, but I don't have a good physics background. All I know is, the next time somebody calls me "needle dick", I'll have a really good comeback: tungsten needle dick.

(Oh please, a dick joke is always appropriate. I'm uncouth, or something.)

an electric tungtsen needle dick for that matter

I wonder, you would even feel the needle if it were to penetrate your skin?

Look out - it's Nano-Snakes on a Plane!!

Okay, I'll bite. If atoms are whirling fields of nuclear particles...and they are...then how can we "see" an individual atom?

Quote:

Okay, I'll bite. If atoms are whirling fields of nuclear particles...and they are...then how can we "see" an individual atom?

Could be one of several things- either it's concept art, or the feilds of nuclear particles are dense enough to look solid in this photo.

Think about it this way: Of course we have to be able to see atoms- if you can't see atoms you can't see anything, and obviously there is such a thing as sight, so we must be able to see atoms.

It's all probability. You're seeing where matter probably is, most of the time (it was there at some point, or it wouldn't have been imaged). That's all you *ever* see, it's just that it's easier to grasp the probabilities involved when you're looking at a single atom.

I think it's a jelly monster.

I think the reason we see them as lumps is that this photo was probably taken with a scanning tunneling microscope. It can resolve to the atomic level, each atom appearing as a foggy gray dot (I believe the image is created by measuring the density of electrons, which of course is greater around an atom). I'm guessing that they took the STM image and applied a few Photoshop filters to make it look way more wickeder.

heehee... more wickeder. Catchy!

Ah-ha, so that's what the needles are used for.

According to Bob Wolkow, up in The Great White North(Alberta), quoted in The American Institute of Physics publication, Physics News Update;

Quote:

The probe tips used in scanning tunneling microscopes (STMs), even though they produce atomic-resolution pictures of atoms sitting on the top layer of a solid material, are not themselves atomically thin. Rather their radius of curvature at the bottom is typically 10 nm or more.

Wolkow (rwolkow@ualberta.ca) says that although a narrower tip will be useful in the construction of STM arrays (you can pack more tips into a small area; and a wide array might even permit movies of atomic motions) the spatial resolution won't improve thereby. The real benefit of the sharp tungsten tips, he believes, will be as superb electron emitters. Being so slender, they would emit electrons in a bright, narrow, stable stream.

That's the thingy that pdaoust mentioned. :thumbsup:

"The real benefit of the sharp tungsten tips, he believes, will be as superb electron emitters. Being so slender, they would emit electrons in a bright, narrow, stable stream."
Know nothing about atoms, but any TIG welder will tell ya the Tungsten needs to be sharp. Most times they use a grinder. In the field I've seen a few sharp hands use a torch and blow a nice tip. FWIW

Can you imagine bundling a million of them into a shotgun shell and firing them at a target? As flechettes would they obliterate the target or leave it looking unscathed?

I was thinking how easily you could run a spit (skewer) through a...

So .. if someone says to you .. "you're about as sharp as a tungsten needle under a microscope! .. " .... would that be the ultimate put-down of the 21st century?? :rolleyes: