Скачать или смотреть Most Knives Are Dull. Why?

All knives start out sharp, even the cheap ones, but they quickly lose cutting power. Why?

It’s because a knife’s sharpness comes from the tiny amount of material that makes up the cutting edge, shown here under a scanning electron microscope. This edge blunts, folds, and chips from normal wear and tear, and while you may not be able to see the damage with your eyes, you can certainly feel it: cutting with a dull knife takes more effort, your cuts aren’t as clean, and making dinner just isn’t as fun.

So my eyes got wide when I stumbled across these videos in a quiet little corner of YouTube. You’re looking at ultrasonic food cutting machines. They work by passing high-amplitude ultrasonic energy through the cutting head, allowing  the machine to make clean, seemingly impossible cuts that look like magic.

Now these cutters don’t rely on a razor-sharp edge, but the knives in your kitchen *do*. And this leads us to the problem: most knives, in home kitchens around the world, are dull.