IOP Groups

Symbols list

This list was sent to us by Alby Reid of the Education Group, his email address is alby@bleary-id.co.uk. Please also send a copy to the History of Physcis web editor at the address on the contacts page.

Alby is making a list initially restricted to those quantities commonly used in GCSE and A-level teaching and welcomes additions and help in finding out who first suggested these symbols for these physics quantities. There are also some symbols from mathematics used in physics calculations such as i. Items marked (UNKNOWN) are those for which he has no good idea of the origin of the symbol and are therefore ones in which he is particularly interested.

Please note that to see the Greek letters displayed correctly on your screen your Internet browser should conform to HTML level 4

Lowercase Latin font
These may often be written in an italic font.

• a - acceleration
• b
• c - speed of light from 'celeritas'
• d
• e - maths: Napier's constant from 'Euler'
• f - frequency
• g - acceleration due to gravity
• h - Planck's constant from German 'hilfe' meaning 'help'
• i - √ (-1) also used for current
• j - engineering: √(-1) to avoid confusion with current?
• k - Boltzmann's constant (from 'konstant' with subscript B?)
• l - length; litre
• m - mass
• n - refractive index (UNKNOWN)
• o
• p - momentum (UNKNOWN); pressure
• q - charge (is uppercase Q more commonly used?) from French 'quantité'
• r
• s - speed; displacement from latin 'spatium'
• t - time
• u - for atomic mass unit (superseded by Da) from 'unified atomic mass'
• v - velocity
• w
• x - distance
• y
• z

Uppercase Latin font

• A - mass number (UNKNOWN)
• B - magnetic flux density / field strength from 'Biot'; B for bel from 'Bell'.
• C - capacitance
• D
• E - electric field strength
• F - force
• G - gravitational constant
• H - Henry
• I - current from 'intensity'
• J
• K - degrees Kelvin
• L
• M
• N
• O - maths: Big-O notation
• P
• Q - charge (see lowercase q)
• R - ideal gas constant (UNKNOWN); resistance
• S
• T - absolute temperature
• U - internal energy (UNKNOWN)
• V - volume
• W - work (more common as WD?)
• X
• Y
• Z - atomic number (UNKNOWN); impedance (UNKNOWN)

Lowercase Greek font

• α - angular acceleration (lowercase 'a' already used?); alpha particle
• β - beta particle
• γ - gamma ray
• δ - maths: infinitesimal change (UNKNOWN)
• ε - permittivity (UNKNOWN); EMF (lowercase and uppercase 'e' already used)
• ζ
• η - viscosity (UNKNOWN)
• θ - angle (deprecated?) (UNKNOWN)
• ι
• &kappaa;
• λ - wavelength (lowercase 'l' already used?)
• μ - permeability (lowercase 'm' already used?); coefficient of friction (UNKNOWN)
• ν - frequency (deprecated?) (UNKNOWN)
• ξ - eigenvectors (UNKNOWN)
• ο
• π - ratio of circumference of a circle to its radius from Greek for 'perimeter'
• ρ - density (UNKNOWN); resistivity (UNKNOWN)
• σ - Stefan Boltzmann constant (lowercase 's' already used?) from Stefan?
• τ - tau muon; atmospheric opacity (UNKNOWN)
• υ
• φ - work function (lowercase 'f' already used?)
• χ - maths: chi squared test (UNKNOWN)
• ψ - wavefunction (UNKNOWN)
• ω - angular frequency (UNKNOWN)

Uppercase Greek font

• Α -
• Β -
• Γ - Christoffel symbol (UNKNOWN)
• Δ - maths: macroscopic change (UNKNOWN)
• Ε -
• Ζ -
• Η -
• Θ - angle (deprecated?) (UNKNOWN)
• Ι -
• Κ -
• Λ - cosmological constant (UNKNOWN)
• Μ
• Ν
• Ξ
• Ο - maths: Big-O notation (deprecated?)
• Π  - maths: product
• Ρ
• Σ - maths: sum (lowercase 's' already used?)
• Τ
• Υ
• Φ phi
• Χ chi
• Ψ psi
• Ω - ohm to prevent confusion of o with O with 0?

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