Bulk Modulus
A mechanical material property measuring a solid or fluid's resistance to uniform volumetric compression under applied hydrostatic pressure.
Governing formula
K = -V (dP / dV)
SI unit
Pa or GPa (Gigapascals)
In depth
Defined as the ratio of hydrostatic pressure increase dP to relative volume decrease -dV/V. Reciprocal of bulk modulus represents volumetric compressibility (β = 1/K).
Examples in the real world
Diamond possessing an extremely high bulk modulus (~440 GPa), making it nearly incompressible under pressure.