There is a JuliaPhysics organization that hosts a number of physics related packages.
This includes:
Measurements.jl. Error propagation calculator and library for physical measurements.
PhysicalConstants.jl. Collection of fundamental physical constants with uncertainties.
PeriodicTable.jl. Periodic Table for Julians! 🔥
PhysicsTutorials.jl. A collection of physics tutorials for the Julia programming language.