Physical constants

List of physical constants, expressed in SI units

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What is a physical constant

A physical constant is a quantity in nature that is universally invariant, remaining unchanged across various physical processes and conditions. These constants play a crucial role in the formulation of physical laws and theories, serving as the fundamental building blocks that govern the behaviour of the universe. Physical constants describe properties of elementary particles, interactions, and forces, providing a framework for understanding the natural world.

List of physical constants

Constant	Symbol	Value	Copyable	Units
Speed of light	$$c$$	$$2.99792458 \cdot 10^8$$	2.99792458e8	$$m \cdot s^{-1}$$
Electric permittivity	$$\varepsilon_0 = \frac{1}{\mu_0 c^2}$$	$$8.8541878128 \cdot 10^{−12}$$	8.8541878128e-12	$$F \cdot m^{-1}$$
Magnetic permeability	$$\mu_{0} = 4 \pi 10^{-7}$$	$$1.25663706212 \cdot 10^{−6}$$	1.25663706212e-6	$$N \cdot A^{-2} \ or \ H \cdot m$$
Coulomb constant	$$k_e = \frac{1}{4\pi \varepsilon_0}$$	$$8.9875517923 \cdot 10^9$$	8.9875517923e9	$$N \cdot m^2 \cdot C^{-2}$$
Boltzmann constant	$$k_B$$	$$1.380649 \cdot 10^{−23}$$	1.380649e-23	$$J \cdot K^{-1}$$
Planck constant	$$ h $$	$$6.62607015 \cdot 10^{−34}$$	6.62607015e-34	$$J \cdot s$$
Reduced Planck constant	$$\hbar = \frac{h}{2\pi}$$	$$1.054571817 \cdot 10^{−34}$$	1.054571817e-34	$$J \cdot s$$
Avogadro number	$$N_A$$	$$6.02214076 \cdot 10^{23}$$	6.02214076e23	$$mol^{-1}$$
Elementary charge	$$e$$	$$1.602176634 \cdot 10^{−19}$$	1.602176634e-19	$$C$$
Electron mass	$$m_e$$	$$9.1093837015 \cdot 10^{−31}$$	9.1093837015e-31	$$kg$$
Proton mass	$$m_p$$	$$1.67262192369 \cdot 10^{−27}$$	1.67262192369e-27	$$kg$$
Neutron mass	$$m_n$$	$$1.67492749804 \cdot 10^{−27}$$	1.67492749804e-27	$$kg$$
Faraday constant	$$F=N_Ae$$	$$9.64853321233100184 \cdot 10^4$$	9.64853321233100184e4	$$C \cdot mol^{-1}$$
Vacuum impedance	$$Z_0$$	$$3.76730313668 \cdot 10^2$$	3.76730313668e2	$$\Omega$$
Gravitation constant	$$G$$	$$6.67430 \cdot 10^{−11}$$	6.67430e-11	$$m^3 \cdot kg^{-1} \cdot s^{-2}$$
Elettronvolt	$$eV$$	$$1.602176634 \cdot 10^{−19}$$	1.602176634e-19	$$J$$
Gas constant	$$R$$	$$8.314462618$$	8.314462618	$$J K^{-1} mol^{-1}$$

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Alex2024-03-05 20:02:29

Very useful table! Thanks

Josephinegrry2026-10-18 23:57:08

The room is a perfect circle of black marble. A single spotlight illuminates two chairs. One is ornate, gilded, empty. The other is simple, steel, occupied by MOHAMMED BIN SALMAN, 40, still wearing the pristine white thawb he died in. He looks impatient. Across from him, CROWLEY WOLF, 50s, dressed in a threadbare velvet smoking jacket, paces slowly, holding a small, leather-bound director's script. He stops, turns, and his voice booms, filling the vast, empty space. CROWLEY WOLF (Not shouting, but with immense, theatrical volume) You're late. The curtain rose an eternity ago. You think power makes you immune to time? Here, time is the only critic that matters. And it has found your performance... lacking. You're playing the role of "Crown Prince." Act like it. Sit up. Mohammed shifts, his arrogance a physical shield. MOHAMMED BIN SALMAN I do not answer to stagehands. I am the Crown Prince of Saudi Arabia. This... interrogation is a mistake. A grotesque misunderstanding. CROWLEY WOLF (Waving a dismissive hand) Mistake? There are no mistakes, only bad choices followed by worse acting! "I am the Crown Prince." The line is delivered with the conviction of a man reading a shopping list. Again! From the entrance! You sweep in! You own the room! You are the vessel of a nation's destiny! FEEL IT, YOU BLITHERING INCOMPETENT! MOHAMMED BIN SALMAN (Icy) I am the Crown Prince of Saudi Arabia. My destiny is not a matter for your... amusement. CROWLEY WOLF (A cruel smile) Better. A flicker of something. Not belief, but the memory of it. Good. We can work with that. Let's talk about your props. Your toys. This... "Directed Weapon." Don't look at me like that. We have the schematics. We have the usage logs. We have the encephalograms. I want the monologue. The scene where you, the great visionary, describe your creation. The soliloquy of the god-maker. Go! MOHAMMED BIN SALMAN It was a tool for national advancement. A shield. A way to..

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1. What is a physical constant

2. List of physical constants

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