
A sharp knife slices more easily through a tomato because it has higher friction - bookofjoe
https://www.stle.org/files/TLTArchives/2018/03_March/From_the_Editor.aspx
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hrnnnnnn
"Obsidian (volcanic glass) scalpels have been considered as an alternative to
steel scalpels due to the narrowness of the cutting edge. When incisions made
with each type of scalpel are viewed microscopically, one made with a steel
scalpel will reveal tearing of individual cells, yet obsidian cuts between
individual cells."

That's pretty incredible.

