What is conceivably sharpest?

My rapier wit.

But if you are looking for something a bit more tangible, this might fit the bill.

I propose that sharpness must be a function of cutting utility. In that case your wit might be sharper than that pointy nudger.

A Diamond

Conceivably sharpest? Then I nominate the edge of a plane section (or the intersection of two planes at an infinitesimal angle) for sharpest edge and the end of a line segment for sharpest point.

Also Cabot makes some cheese that is wicked sharp.

Btw, in what way is nuclear fission conceptually sharp?

My tongue when I am perturbed!

@koanhead what is nuclear fission?

anyway BECAUSE it is the forcible DIVISION of a nuculi.

My tool in the shed.

^^^ is sharp as a tack.

My bluntness because it always gets my point across and cuts deep.

The shapest blades from from the hardest metals. The answer for that question will constantly change with science and pratice. The sharpest pains come from the heart, they can leave wonds that will never heal. Much outside of that, I am afriad I don’t know.

@Coloma Diamond makes terrible blades. The are brittle and cannot take the impact required.

Obsidian is said to make a sharper cut, according to Wikipedia: Current use:

Though not approved by the US Food and Drug Administration (FDA) for use on humans, obsidian is used by some surgeons for scalpel blades, as well-crafted obsidian blades have a cutting edge many times sharper than high-quality steel surgical scalpels, the cutting edge of the blade being only about 3 nanometers thick.[34] Even the sharpest metal knife has a jagged, irregular blade when viewed under a strong enough microscope; when examined even under an electron microscope an obsidian blade is still smooth and even.[35] One study found that obsidian incisions produced narrower scars, fewer inflammatory cells, and less granulation tissue in a group of rats.[36]...
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Also a site here.
Then there’s PhysicsForums: What’s the sharpest knife on earth? where somebody says:
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Synthetic diamond scalpel blades are commercially available and well liked by surgeons. Contrary to what you might think they stay sharp much better than steel and chipping doesnt seem to be a problem. Quoted sharpness is 3 nm and achieved with plasma polishing. This is like 30 atoms wide at 1 angstrom per atom.

Outside diamond, cracked glass edges have been used for years as ultramicrotome blades for cutting sections as thin as 200angstroms for electronmicroscopy. These would be similar sharpness to the obsidian blades quoted above by Danger. However the glass blades can cut less than 100 sections before geting blunt even on soft tissue. cutting bone is not possible. 40 yrs ago there were expensive diamond blades available that lasted well and would cut bone ok, but the glass ones were sharper and would cut the thinnest sections. The latest diamond blades are obviously sharper than glass if the 3 nm is correct…
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This agrees with my own personal experience that some of my worst – and most unexpected – skin lacerations have come from sharp edges of glass and ceramic more than sharpened metal. I’m pretty sure, though, that stainless steel is still the predominant scalpel blade material used in operating rooms today. Sharpest is not necessarily strongest (tensile strength) or toughest (shear strength). Ceramics and glasses are notoriously brittle compared to metal, which might or might no be a problem, depending on the specific cutting job.

@Ltryptophan: It’s true that an atomic nucleus splits into two parts during nuclear fission. Not sure that qualifies as “cutting” in the sense of cleaving apart bulk material along an intended straight line. Shooting high-energy neutrons at big, barely-stable-to-begin-with nuclei to cause them to break into two smaller nuclei, is called “splitting the atom,” a euphemism for inducing exotic materials to do exotic things. Everyday materials – atoms of iron, calcium, carbon, etc. – cannot be “split” like plutonium, and even if they could the remaining metal atoms surrounding the fissile zone would remain as solid as ever, too stable to sustain a chain reaction. Some sort of “fission scalpel” might make good sci-fi, however…

[ edit Just realized this is an old thread, re-activated by a recent posting. I must have missed it first time around, lol]