spin

Syllable breakdown

Dictionary meaning

an intrinsic form of angular momentum possessed by subatomic particles that has no classical analogue and cannot be explained as the result of actual physical rotation; electrons, protons, neutrons, and quarks have spin-1/2, meaning they can exist in two states (spin-up and spin-down) that are the physical basis of the Pauli exclusion principle, which prevents two fermions from occupying the same quantum state; spin is measured in units of ℏ (reduced Planck constant) and is the property exploited in nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI), where the alignment of nuclear spins in a magnetic field produces measurable signals