# quantum limit

*See also:*

**quantum-limit**

## English[edit]

### Etymology[edit]

The spectroscopic sense is first attested in the 1920s; the measurement sense was coined by Vladimir Braginsky in a 1967 paper, and was originally restricted to the study of gravitational waves.

### Noun[edit]

**quantum limit** (*plural* **quantum limits**)

- (physics) The limit on measurement accuracy at quantum scales due to back-action effects.
- (spectroscopy) The shortest wavelength in an X-ray spectrum.
**1935**, Donald Stover Piston,*The Polarization of X-rays from Thin Targets*[2], page 4:- "The voltage and wave-length at the
**quantum limit**of the spectrum under investigation are denoted by ν_{0}and λ_{0}."

- "The voltage and wave-length at the