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: \( \triangle x Ã \triangle v_x \geq \frac{h}{4\pi m}\)
Those uncomfortable with Heisenberg's system jumped on the wave mechanics side. The conflict between the theories was resolved when SchrÃ¶dinger proved that they were, in fact, identical. In 1926 Heisenberg joined Bohr at the Institute for Theoretical Physics in Copenhagen. This turned out to be one of the most productive periods in Heisenberg's life. In 1927 he was puzzling over the basic quantum properties of electrons.