the force that doesn't break things by pulling — it breaks them by sliding past themselves
means To cut, clip, or slice through something (as with shears or blades), or — in physics and engineering — the kind of stress where one part of a material slides parallel to another rather than being pulled apart.
from From Old English 'sceran,' to cut or cleave, rooted in a Proto-Germanic verb that also gave German 'scheren' and is a cousin of words across the family meaning to divide. The same source branches everywhere: 'shears' for the cutting tool, 'share' as in a piece cut off, and even 'sheer' fabric so thin it seems cut to nothing. The physics sense — that sideways sliding stress — is a much later borrowing of the old cutting word, fittingly named for a force that parts things by making them slide rather than snap.