Tempered Glass Breakage

I'm always impressed with the surprising strength of tempered glass - and the willingness of people on YouTube to do stupid things without gloves.

When we discuss the strength of tempered glass in our summer workshops, occasionally a camper will ask why we would use such glass as a cutting board. If a nick on the edge (or especially the corner) leads to spectacular failure, why would be take a knife and go at the surface of the glass?

Because this video. That's why.