Physical Constants

Physical Constants represent a quantity believed to be the same throughout the Universe in both space and time. The behavior of the Universe is governed by these physical constants.

An example of a physical constant is the speed of light c.

C = 2.99792458 x 10^8 meters / sec * note that 10^8 means 10 to the power of 8 or 100,000,000 (100 million)

Physical Constants have dimensions ( e.g. meters per second) unless they represent ratios and they typically represent some universal property of the universe. For example, the speed of light represents the speed of propagation of an electromagnetic wave in vacuum, independent of your frame of reference. C also represents an upper limit of the speed on anything. The speed of light finds it's way into many different aspects of physics.

Below is a list of some of the major physical constants.



Summary of important physical constants

Fundamental Physical Constants
Speed of Light in a Vacuum c 2.99792458 x 10^8 meters / sec
Gravitational Constant G 6.67428 x 10^-11 meters^3 / (Kg Sec^2)
Plancks constant h 6.626068 x 10^-34 Joule sec
Elementary Charge e 1.602176 x 10^-19 C ( Coulombs)
Electron Mass me 9.109382 x 10^-31 Kg
Proton Mass mp 1.672 621 637 × 10^−27 Kg
Magnetic Permeability u0

Fundamental Physical Chemistry Constants
Atomic Mass Unit mu 1.660 538 86 × 10^−27 kg
Avogadro's Number Na 6.022 1415 × 10^23 mol^−1 ( Mole)
Boltzmann Constant k 1.380 650 × 10^−23 Joule·K^−1
Gas Constant R 8.314 472(15) Joule·K^−1·mol^−1