Examples for

Physical Constants

Fundamental physical constants are physical quantities that are universal in nature and have constant values in time. Wolfram|Alpha provides definitions, values and other details for a wide range of physical constants, such as the Newtonian gravitational, Boltzmann and magnetic constants.
Constants

Find information about physical constants, including their values, dimensionality and definitions.

Get the value of a physical constant:

speed of light
permeability of vacuum
Planck energy
classical electron radius
Bohr magneton
Stefan-Boltzmann constant
Schwinger field strength
Thomson cross section
Landauer conductance
geopotential of the earth
magnetic flux quantum

Specify a constant by symbol:

hbar
eps_0
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Calculations with Constants

Calculate the value of combinations of physical constants and other quantities.

Do computations involving constants:

0.85c
Planck mass / mass of electron
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