Amplituuti

Amplituuti is the Finnish term for amplitude, the quantity that describes the size of an oscillation, wave, or signal. In physics and engineering it typically refers to the maximum extent of displacement from equilibrium in a periodic motion, such as a simple harmonic oscillator. For x(t) = A sin(ωt + φ), A is the amplitude—the maximum displacement. In this sense amplitude measures the strength or intensity of a vibration or wave.

Amplitude also describes the peak value of a waveform in electrical engineering, acoustics, and related fields. The term is distinct from peak-to-peak amplitude (twice the peak value) and root-mean-square (RMS) amplitude, which expresses the effective value for power or heating in many applications.

In quantum mechanics and signal processing, amplitude can be a complex quantity, called a probability amplitude or simply an oscillation envelope; the probability of an outcome is the modulus squared of the amplitude.

Physically, higher amplitude generally implies greater energy or intensity, but energy and power depend on amplitude and other factors such as frequency and the medium.

The concept is ubiquitous across disciplines, with units that reflect the quantity: meters for displacement, volts for electrical signals, pascals for sound pressure, etc.

Origin: amplitude derives from Latin and has been used in wave theory since the 19th century to denote the extent of deformation or oscillation.