A tomato is mainly water, but a sharp knife is needed to cut through it. A knife works by concentrating the force you apply downwards into the very narrow region of the blade tip. A knife blade is between 1 and 3 millimeters thick, but its sharp edge is much thinner, one thousand times thinner (1 to 3 microns) on a well sharpened knife. When we first press a knife against food, the knife does not cut it, but instead squishes the food.…

I still have all my fingers. But that is thanks to the Demiurge and not my smarts. Three hours in the emergency room and five stitches later I was back to the kitchen. How a knife cuts so well is one of the wonders of material science. Steel is not a neat arrangement of atoms, but a complicated structure. The strength of the steel is what allows the atoms of one material to tear through another (like a block of cheese or an unfortunate finger).…

Temptation. Sometimes it’s fine to yield. I stumbled on a math problem while writing the entry for TGRWT #5 and I can’t solve it. What is the most efficient way to cut diamond shapes from a square? Making the cut Baklava and kibbeh are usually cut into diamond shapes, which is a little harder to do than squares or rectangles. My mom eyeballs her way through a zig-zag patterns. The perfectionist in me wants to get some edible inks to print a guide for the knife to follow.…