Length (physics)

Surname

length

${\ displaystyle l, s}$

Size and unit system	unit	dimension
SI	m	L.
cgs	cm	L.
Planck	Planck length	L.
Astronomic	lj , AE , pc	L.

See also: Path length (s), distance (r), height (h), radius (r),
diameter (d), circumference (u), wavelength (λ), u. v. a.

The length is a physical quantity that indicates the extent of physical objects and their distances from one another. The symbol for length is the lower case letter , its SI unit is the meter . A formula symbol is usually used for the length of paths and curves . In the SI system, the length is a basic quantity . ${\ displaystyle l}$ ${\ displaystyle \ mathrm {m}}$ ${\ displaystyle s}$

The length measurement is carried out by comparing the length to be measured with scales of known length. The length of the distances between two points or a scale is considered constant in classical physics. In the special theory of relativity , however, the length depends on the relative state of motion of the respective observer; one speaks of a relativistic length contraction .

etymology

The noun mhd. Lenge , ahd. Lengī , like the adjective lang ( mhd. Lanc , ahd. Lang ), goes back to idg. Longho-s "lang".

Individual evidence

^ The dictionary of origin (= Der Duden in twelve volumes . Volume 7 ). Reprint of the 2nd edition. Dudenverlag, Mannheim 1997 ( p. 403 ). See also Friedrich Kluge : Etymological dictionary of the German language . 7th edition. Trübner, Strasbourg 1910 ( p. 277 ).

[1] The dictionary of origin (= Der Duden in twelve volumes . Volume 7 ). Reprint of the 2nd edition. Dudenverlag, Mannheim 1997 ( p. 403 ). See also Friedrich Kluge : Etymological dictionary of the German language . 7th edition. Trübner, Strasbourg 1910 ( p. 277 ).