However, a terminological difference arises in the expression mean squared error (MSE). The mean squared error of a regression is a number computed from the sum of squares of the computed residuals, and not of the unobservable errors. If that sum of squares is divided by n, the number of observations, the result is the mean of the squared residuals.
Heisenberg Uncertainty Principle. Heisenberg, a German scientist stated the principle of uncertainty which is a consequence of dual nature of matter and waves. The Heisenberg uncertainty principle states that it is impossible to find the position and momentum (velocity) of an electron at the same moment. Mathematical representation of this is as follows: \( \triangle x Ã \triangle v_x \geq \frac{h}{4\pi m}\)
At the same time that the wave properties of matter were discovered, two further discoveries were made by Werner Heisenberg and Max Born that also profoundly influenced (and confused) the future evolution of modern physics and quantum mechanics; Werner Heisenberg developed the uncertainty principle which tells us that we (the observer) can never exactly know both the position and momentum of a particle. As every observation requires an energy exchange (photon) to create the observed 'data', some energy (wave) state of the observed object has to be altered.