How does wood shatter?

Answer 1

Mirrors shatter. Wood splinters. Any force strong enough can create a shearing force that can make wood or timber splinter.

As examples:

1. Driving past a stretch of woods, I saw several trees that had splintered about 3-feet up from the ground. The top half, still attached to the bottom of the tree, lay bent over onto the ground. The splintered section showed ragged pieces of varying heights (splintered). Tracks leading to the trees led me to conclude that a semi-tractor trailer had run off the road at a high rate of speed and ran into the young trees, splintering them from the force.
2. When I was a child, my mother used a wooden spoon or wood yardstick to paddle me or scare me. One day, she smacked the wooden spoon on the edge of the cabinet as she yelled at me. The spoon's long wooden handle splintered. I did not get paddled. Another time, she smacked the edge of a doorway with the yardstick as she moved toward me to smack me with it. The yardstick broke into two main pieces and many small sections. She couldn't paddle me because the stick was broken. The uneven splintering of the wood fascinated me because it made long jagged pieces, and tiny splintered off pieces. Touching the broken part, I got a wood splinter in my finger.