This adds some fundamental physical constants: - Velocity of Light "c₀", 299,792,458 m/s - Magnetic constant, "μ₀", 1.2566370614×10⁻ N/A² - Electric constant, "ε₀", 8.85418782×10⁻¹² s⁴A²/m³kg - Newtonian constant of gravitation, "G", 6.67408×10⁻¹¹ m³/(s²kg) - Planck constant, "h", 6.62607004×10⁻³⁴ m²kg/s - Elementary charge, "ｅ", 1.6021766208(98)×10⁻¹⁹ C - Electron mass, "mₑ", 9.10938356×10⁻³¹ kg - Proton mass, "mₚ", 1.672621898(21)×10⁻²⁷ kg - Avogrado constant, "Nₐ", 6.02214086×10²³ mol⁻¹ They are taken from https://en.wikipedia.org/wiki/Physical_constant#Universal_constants To insert them one would enter the corresponding symbol or use the gui. They are set to a MPNumber from string.