system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does plastic turn white when you bend it?
gpt
Plastics contain lots of very tiny holes. When the plastic is bent, the stress inside the plastic makes the holes get bigger. The empty holes in the plastic scatter the light, and so now the polymer reflects all colors of light instead of its original pigment, and so the plastic appears white.