Alan J Fletcher <a...@well.com> wrote:
> I recently collected some obsidian .. and cut my hand while doing so. It's > reportedly still used for ultra-sharp scalpels. > http://en.wikipedia.org/wiki/Obsidian > As much as I hate to admit there is something of value on Wikipedia, that article has a fascinating detail: "Obsidian has been used for blades in surgery, 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 nano meters thick. 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." So here is a stone-age technology with a pronounced advantage over the best modern technology. Wow! - Jed
