These two pieces of nonmagnetic metal mysteriously stick together when pushed together in a special way. This video will demonstrate that and explain why this happens.
Image Sources:
https://upload.wikimedia.org/wikipedia/commons/e/ed/Gauge_block_adhesion.jpg
https://upload.wikimedia.org/wikipedia/commons/thumb/2/26/Gauge_block_wringing.svg/500px-Gauge_block_wringing.svg.png
