You think you can see the cutting edge of a knife, but you really can’t

Hookai. So I just saw this video by our friend Nikola Slavkovic, and my mind exploded. Because what I thought I was seeing, I actually can’t see. I thought I could see the cutting edge of a knife but, in reality, it is invisible. Our eyes can’t see it because they can’t see something so small—much smaller than a red blood cell.

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